• Journal of the Korean Wood Science and Technology
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• v.42 no.2
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• pp.163-171
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• 2014

Environmental issues about indoor air quality have been increased and focused on volatile organic compounds (VOCs) caused cancer, asthma, and skin disease. Reducing VOCs has been attempted in many different methods such as using environmentally friendly materials and air cleaner or purifier. Charcoal is well known material for absorbing VOCs. Therefore, carbonized board from medium density fiberboard has been developed. We assumed that the source of carbonized boards can be any type of wood-based panels. In this study, carbonized boards were manufactured from oriented strand board (OSB) at 400, 600, 800, and $1000^{\circ}C$. Each carbonized OSB (c-OSB) was evaluated and determined physiomechanical characteristics such as exterior defects, dimensional shrinkage, modulus of elasticity, and bending strength. No external defects were observed on c-OSBs at all carbonizing conditions. As carbonizing temperature increased, less porosity between carbonized wood fibers was observed by SEM analysis. The higher rate of dimensional shrinkage was observed on c-OSB at $1000^{\circ}C$ (66%) than c-OSB at 400, 600, and $800^{\circ}C$ (47%, 58%, and 63%, respectively). The densities of c-OSBs were lower than original OSB, but there was no significant different among the c-OSBs. The bending strength of c-OSB increased 1.58 MPa (c-OSB at $400^{\circ}C$) to 8.03 MPa (c-OSB at $1000^{\circ}C$) as carbonization temperature increased. Carbonization temperature above $800^{\circ}C$ yielded higher bonding strength than that of gypsum board (4.6 MPa). In conclusion, c-OSB may be used in sealing and wall for decorating purpose without additional artwork compare to c-MDF which has smooth surface.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.2
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• pp.151-157
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• 2018

Objectives: This study was conducted in order to evaluate $PM_{10}$ concentrations at eight highway tollgate booths from July to September 2017. Methods: A total of 16 samples were collected from eight toll booths. Each $PM_{10}$ sample was collected using a 37 mm PTFE filter attached to a Personal Environment Monitor. Results: The geometric mean concentrations of $PM_{10}$ in the toll booths was $83.51{\mu}g/m^3$. The mean $PM_{10}$ concentrations measured on freight roadways were much higher than those of measured on general roadways($102.46{\mu}g/m^3$ and $68.05{\mu}g/m^3$, respectively). $PM_{10}$ was revealed to be higher in the morning($105.59{\mu}g/m^3$) than at dawn or in the afternoon($71.26{\mu}g/m^3$ and $61.22{\mu}g/m^3$, respectively). The mean $PM_{10}$ concentration in toll booths ventilated through an air conditioner was higher than that for those using a window or no ventilation. The rate of exceeding the Ministry of Environment Maintenance Limit($200{\mu}g/m^3$) was 6.25%, and the rate of exceeding the Ministry of Labor Recommended Limit($150{\mu}g/m^3$) was 12.5%. Conclusions: In order to protect the health of toll booth workers exposed to airborne dust, it is necessary to check the exposure level from indoor air quality on a regular basis and to manage it appropriately according to the results.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.11 no.1
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• pp.41-48
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• 2004

Purpose: The purpose of this study was to analyze the colony count of airborne microbes contamination every hour in the Neurosurgical Intensive Care Unit (NSICU) in order to identify the relationship of colony count to person-visits. Method: Data were collected during from 11:00 a.m. September 5 to 11:00 a.m. September 6, 2002. This study used blood agar & nutrient agar and handtally counter (USA) for collection of airborne microbes and number of person-visits. Data was analyzed using the SPSSWIN 10.0 with means, Pearson correlation coefficient, and simple regression. Result: The result of this study are as follows. Total colony count of airborne microbes for 24 hours in the NSICU was 4,609. Total number of person-visits to the NSICU was 15,347. The highest scores fur the total colony count in different areas of the NSICU was the rear door, followed by the preparation room, and the front entrance, while the lowest count was in the isolation rooms. There was a statistically significant relationship between colony count and number of person-visits to the NSICU. The most frequently airborne microbes in the NSICU were Micrococcus, CNS, Staphylococcus Micrococcus, Aureus. Conclusion: These findings indicate that the number of person-visits in hospitals influences total colony count of airborne microbes. This study contributes to assessment of biological indoor air quality in hospital and in the development of an NSICU care plan.

• Particle and aerosol research
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• v.13 no.2
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• pp.87-95
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• 2017

Radon ($Rn^{222}$) is a radioactive gas and is found at high concentrations underground. Investigations were done in many years specifically on public transportations such as in the subway stations, concourses and platforms for these are located underground areas. This study correlates the $Rn^{222}$ concentrations with the Particulate Matter (PM) concentration for the gas could be attached or trapped inside these particles. It was done on the opening subway tunnel of Miasageori Station going to Mia Station (Line 4) last August 2016. Based on the result, the $Rn^{222}$ were more influenced on the mass ratio (%) of PM present in the air instead of its mass concentration (${\mu}g/m^3$). As the $PM_{10}$ mass ratio increases ($42.32{\pm}1.03%$) during morning rush-hours, radon starts to increase up to $0.97{\pm}0.03pCi/L$. But during the afternoon $Rn^{222}$ concentrations decreased while the composition were stable at $22.96{\pm}3.0%$, $39.04{\pm}0.6%$ and $38.01{\pm}0.3%$ in $PM_1$, $PM_{2.5}$ and $PM_{10}$ respectively. It was then assumed that it could be the composition of the morning hours of the station were influencing the concentration of the radon.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.607-610
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• 2003

Ozonic use of sterilization and heat treatment of raw material to extend the conservation period of food recently is increased by hard vegetable or microorganism sterilization purpose of fruit. If ozone can create as is easy comparatively because do air or oxygen by raw material and schedule period passes, there is advantage that do not leave the second contaminant because being gotten restored by oxygen. Also, because the effect is big to decolorization beside disinfection effect about microorganism, deodorization, disjointing of venomousness hazardous substance, food save, Indoor air purge, good hand processing, hydrospace agricultural chemicals processing etc. the use extent is wide. This research ran parallel a sterilization experiment of E.coli colitis germs by ozone that manufacture ozonizer that use doped diamond maund electrode (BDD) by boron and searched special quality electrochemistry enemy of the ozonizer and is created. After cultivate E.coli colitis germs during 37C 1 day is LB ship, after do ozonation, was sterilized more than 90% by ozone as result that examine disinfection effect by substance microscope and could confirm excellency of diamond electrode.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.1
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• pp.33-38
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• 2019

This study refers to the deodorization of DDM Environmental Resource Center, which is operating abnormally in the food waste public-resource facilities that are operating nationwide, in accordance with the initial operating conditions. Issues concerning the abnormal deodorization facilities of DDM Environment Resource Center were the deodorization of composting facilities, indoor air quality problems, and overall deodorization of facilities, especially the phenomenon of stopping while operating the RTO and the phenomenon of poor spray in the wet scrubber etc. As an alternative and improvement method for converting such abnormal operation facilities into normal operation facilities, It is proposed to remove the front filter of the upper part of the fermentation tank, and to install scrubbers, air and water separator, and roll filters for dust removal etc.

• Journal of Engineering Education Research
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• v.21 no.3
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• pp.56-65
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• 2018

With rapid advance of technologies including information and communication technologies, jobs are evolving faster than ever. Architectural engineering is no exception in this regard, and the green architectural engineering is emerging fast as a promising new field. In this study, a Delphi study of expert architectural engineers are conducted to find out (1) near future prospects of the field, (2) near future emerging jobs, (3) competencies needed for these jobs, and (4) educational content necessary to build these competencies with regards to the green architectural engineering. Initial Delphi survey consisting of open-ended questions in the above four areas were conducted and came out with 65 items after duplicate removal and semantic refinements. Further refinements via second and third wave of Delphi results into 40 items that the 13 architectural engineering experts may largely agree upon as future prospects with regards to the green architectural engineering. Findings indicate that it is expected that the demand for green architectural engineering and needs for automatic energy control system increase. Also, collaborations with other fields is becoming more and more important in green architectural engineering. The professional work management skills such as knowledge convergence, problem solving, collaboration skills, and creativity linking components from various related areas seem to also be on the increasing need. Near future ready critical skills are found to be the building environment control techniques (thermal, light, sound, and air), the data processing techniques like data mining, energy monitoring, and the control and utilization of environmental analysis software. Experts also agree on new curriculum for green building architecture to be developed with more of converging subjects across disciplines for future ready professional skills and experiences. Major topics to be covered in the near future includes building environment studies, building energy management, energy reduction systems, indoor air quality, global environment and natural phenomena, and machinery and electrical facility. Architectural engineering community should be concerned with building up the competencies identified in this Delphi preparing for fast advancing future.

• Particle and aerosol research
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• v.18 no.4
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• pp.137-145
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• 2022

As many studies on the harmfulness of fine dust have been reported, awareness of its seriousness is spreading. Recently, interest in indoor air quality as well as air pollution is increasing, and research on measures to block fine dust flowing into the room from the outside is being conducted. The clothing company is launching functional clothing to prevent fine dust attached to clothing from entering the room through outdoor activities. However, it is difficult to confirm whether there is actually fine-dust blocking performance, and there is no evaluation standard. In this study, the contamination rate caused by fine dust was quantitatively compared through image processing after contamination of the outer fabric for 4 types of commercially available functional clothing with fine-dust blocking effect. The difference in particle contamination according to the material of the outer fabric was analyzed by comparing the surface resistance, and it was found that the higher the surface resistance of the outer fabric material, the more fine dust was attached. The analysis method of this study is expected to be able to quantitatively compare and evaluate the fine-dust blocking performance of functional clothing.

• Analytical Science and Technology
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• v.22 no.1
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• pp.57-64
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• 2009

A material database has been developed for VOCs and formaldehyde emitted from building materials in this study. New classification system has been made by correlating the classification methods used in Korean Air Cleaning and Environmental Protection Agency. The developed databases include emission rates of TVOC, 5VOC and formaldehyde emitted from each building material. In addition, the databases can be used as an input variable to estimate indoor air quality (IAQ) using computer simulation since they also contain chemical component and general imformation. Box plot was used to do statistical analysis for emission rates of formaldehyde and TVOCs from different types of building materials. Also we confirmed the building materials worsening IAQ by categorizing the emission characteristic of different types of pollutants.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3659-3665
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• 2015

Background: Waterpipe tobacco smoking has becoming popular especially among young people worldwide. Smokers are attracted by its sweeter, smoother smoke, social ambience and the misconception of reduced harm. The objective of this study was to systematically review the effects of waterpipe tobacco policies and practices in reducing its prevalence. Materials and Methods: A systematic review was conducted electronically using the PubMed, OVID, Science Direct, Proquest and Embase databases. All possible studies from 1980 to 2013 were initially screened based on titles and abstracts. The selected articles were subjected to data extraction and quality rating. Results: Three studies met the inclusion criteria and were eligible for this review. Almost all of the waterpipe tobacco products and its accessories did not comply with the regulations on health warning labelling practices as stipulated under Article 11 of WHO FCTC. In addition, the grisly new warning labels for cigarettes introduced by Food and Drug Administration did not affect hookah tobacco smoking generally. Indoor air quality in smoking lounges was found to be poor and some hookah lounges were operated without smoke shop certification. Conclusions: Our findings revealed the availability of minimal information on the practices in controlling waterpipe smoking in reducing its prevalence. The lack of comprehensive legislations or practices in controlling waterpipe smoking warrants further research and policy initiatives to curb this burgeoning global epidemic, especially among the vulnerable younger population.