• Fashion & Textile Research Journal
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• v.2 no.5
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• pp.416-422
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• 2000

In this study, to find out the physiological reaction of the human body and the sensation of comfort when people are wearing sportswear which is made of waterproof breathable fabrics under general environmental conditions (temperature : $20{\pm}1^{\circ}C$, humidity : $60{\pm}5%RH$, air current : 0.1 m/sec) and rainy environmental conditions (temperature : $20{\pm}1^{\circ}C$, humidity : $60{\pm}5%RH$, air current : 0.1 m/sec, rainfall : 250 1/hr), we made an experiment with sportswear in an artificial climate chamber and studied the thermal physiological response and subjective sensation. Mean skin temperature of the subjects was low and had a big range of fluctuation in rainy environmental conditions of two condition. Temperature started to increase at the beginning of the exercise, reached the maximum at the 2nd level of the exercise and then started to decline. Rectal temperature showed a slighter increase and bigger range of fluctuation in general conditions than in rainy conditions. Except clothing micro climate in rainy conditions, temperature and humidity and their range of fluctuation around back were higher than those around chest. Humidity was high and had wide range of fluctuation in general conditions. Heart rate was 4.4 beats/min higher in general conditions. In subjective test on rainy conditions, the feeling of discomfort increased due to the raindrops fallen on the skin. Unlike that in general conditions, cold sensation increased and humidity sensation reached to the peak after the exercise. In wearing sportswear made of shape memory breathable waterproof fabric, controlling function over a small amount of heat and water was distinctive while it turned out to be not so comfortable over a large amount of heat and water. Through this, the limitation of shape memory breathable waterproof fabric was recognised.

• Hwankyungkyoyuk
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• v.12 no.1
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• pp.391-409
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• 1999

From the students' point of view, this study was carried out to find out barriers to environmental conservation practice of secondary school students. According to the questionare and interview with secondary school students on barriers to environmental conservation practice at home, school, society and fellow-relation conditions and in personal psychology, the following findings were resulted. The major barriers to environmental conservation practice are (1) not doing environmental conservation practice of parents, friends and neighborhood, (2) having no interest in environment and environmental problems, (3) dirty and laboriousness of environmental conservation practice, (4) lack of environmental equipments, (5) the shortage of chance and time for environmental conversation practice, (6) lack of the inducement for environmental conservaton from school, (7) little effects of individual environmental practice, (8) a busy life, (9) shortage of the voluntary courage to practice for environmental conservation, (10) lack of compensation on the environmental conservation practice, (11) anti-environmental behavior among friends, (12) urging on edcation of parents. Those barriers related with home, school, society and fellow-relation anti-environmental conditions hold back environmental conservation practice of secondary school students. Those barriers are divided into three closely correlated tipes, (1) unpleasant traits of environmental conservation practice such as cleaning, recycling were linked with personal psychology, (2) lack of the social interest and practice for environmental conservation were linked with personal psychology, (3) the social atmosphere to urge on education was linked with students' busy life and the shortage of chance and time for environmental conversation practice. According to the results, attractive environmental education programs, home environmental education, cooperative environmental conservation programs, and inducements for environmental conservation are reguired of secondary school students to promote environmental conservation practice.

• Corrosion Science and Technology
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• v.16 no.1
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• pp.8-14
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• 2017

The corrosion behavior of a ferritic/martensitic steel T91 exposed to an aqueous solution containing chloride and sulfate ions is investigated depending on the stimulated all-volatile treatment (AVT) and under oxygenated treatment (OT) conditions. The corrosion of T91 steel under OT condition is severe, while the corrosion under AVT condition is not. The co-existence of chloride and sulfate ions has antagonistic effect on the corrosion of T91 steel in both AVT and OT conditions. Unlike to corrosion resistance in the aqueous solution, OT pretreatment provides T91 steel lower oxidation-resistance than VAT pretreatment. From scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis, the lower corrosion resistance in the aqueous solution by VAT conditions possibly is due to the formation of pits. In addition, the lower oxidation resistance of T91 steel pretreated by OT conditions is explained as follows: the cracks formed during the immersion under OT conditions accelerated peeling-off rate of the oxide film.

• Environmental Engineering Research
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• v.17 no.3
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• pp.139-144
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• 2012

In this study, the effects of starvation on floc characteristics when treating saline wastewater using a sequencing batch reactor (SBR) were investigated. The effectiveness over 5 days of starvation for aerobic and non-aerobic strategies for maintaining the physical characteristics of floc-forming sludge and the recovery period needed to regain the initial pollutant removal efficiency were investigated. Experiment results revealed that the sludge volume index (SVI) increased and the floc size and fractal dimension decreased after starvation under both aerobic and non-aerobic conditions. Sludge settleability deteriorated faster under aerobic conditions compared to non-aerobic conditions. Under non-aerobic conditions, the SBR required less time to return to its initial pollutant removal efficiency and settleability. Floc size, fractal dimension, and SVI were observed to be fairly correlated with each other. The results demonstrated that it was better to maintain the sludge under non-aerobic rather than aerobic starvation, because it adapted to, resisted starvation and had a quicker re-start afterward.

• Journal of the Korean GEO-environmental Society
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• v.17 no.12
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• pp.65-72
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• 2016

There are numerous factors that affect stress distribution in a buried pipe, such as the shape, size, and stiffness of the pipe, its burial depth, and the stiffness of the surrounding soil. In addition, the pipe can benefit from the soil arching effect to some extent, through which the overburden and surcharge pressure at the crown can be carried by the adjacent soil. As a result, the buried pipe needs to support only a portion of the load that is not transferred to the adjacent soil. This paper presents numerical efforts to investigate the stress distribution in the buried concrete pipe under various environmental conditions. To that end, a nonlinear elasto-plastic model for backfill materials was implemented into finite element software by a user-defined subroutine (user material, or UMAT) to more precisely analyze the soil behavior surrounding a buried concrete pipe subjected to surface loading. In addition, three different backfill materials with a native soil were selected to examine the material-specific stress distribution in pipe. The environmental conditions considering in this study the loading effect and void effects were investigated using finite element method. The simulation results provide information on how the pressures are redistributed, and how the buried concrete pipe behaves under various environmental conditions.

• Journal of Environmental Science International
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• v.12 no.11
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• pp.1137-1144
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• 2003

To provide evidence that the changes in oceanic environmental conditions are useful indices for predicting stock structure and distribution of the Pacific saury (Cololabis saira), the body length compositions and catch per unit fishing effort were examined in relation to the sea surface temperature(SST) anomalies in the Tsushima Warm Current(TWC) region. The size of the fish became larger(smaller) than the average in the same size category during the season of higher SST(lower SST) as opposed to the normal SST. The year-to-year changes in body size caused by the changes in the environmental conditions led the stock to be homogeneous during the period of high stock level from the late 1950s to early 1970s and in the 1990s. The changes in body size manifested by higher(lower) occurrence rates of larger (smaller) sized groups in relation to temperature anomalies suggest that the changes in the environmental conditions affect the distribution and the structure of the stock in the TWC region. Therefore, if the SST anomaly derived from satellite data is large enough in the early spring months(Mar. or Apr.), it is possible to predict whether or not sea temperature will be favorable for large sized groups of saury at normal or slightly earlier time of commencement of the fishery in spring(Apr.∼June).

• Journal of Environmental Impact Assessment
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• v.19 no.6
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• pp.563-571
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• 2010

In carrying out the prior review on environmental conditions for basic plan of public waters reclamation, the important item is review on conditions of location on prearranged reclaimed land. In this study, environmental assessment which needs careful consideration in the first stage of selecting location is presented by analyzing environmental impact assessment on public waters reclamation projects for about 10 years. The assessment index for alternative comparison is divided into two parts according to importance level. What is most important in alternative comparison is the comparison on direct influence due to reclamation. In other words, it figures out damaged extent of natural shoreline as well as intertidal and infralittoral zones. Comparing influence extent due to reclamation through the 1st comparison on this is regarded as to be important. In case there is no significant difference by alternatives through the 1st assessment, the 2nd assessment should be carried out. In the 2nd assessment indexes are damaged quantity of benthic organism, change in seawater current, erosion, accumulation and exchangeable rate of seawater. The plan for selecting optimal location which minimizes environmental influence in establishing public waters reclamation plan is demonstrated through model cases. For this, 3 districts which have similar environment and scale are selected, and then comparison on location alternative is made through environmental assessment index. In addition, the comparison on 3 arrangement alternatives are conducted, targeting certain areas. It is thought that carrying out comparison review on respective areas in the same cities and counties, not merely comparing arrangement plan by selecting 1 targeting area in advance, is the most appropriate. Besides, selection of arrangement plan considering environment, which minimizes damage of natural shoreline and influence due to change of seawater current is required in alternative comparison on arrangement plan as well. In case of the prior review on environmental conditions though alternative comparison method presented in this study is carried out, it is safely said that the influence on ocean environment due to public waters reclamation can be minimized.

• Journal of Environmental Science International
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• v.21 no.9
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• pp.1043-1051
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• 2012

Coagulation, flocculation, and dissolved air flotation (DAF) experiments were performed with humic acid to evaluate the influence of operational conditions on removal efficiencies. We investigated coagulation, flocculation, and flotation conditions of humic acid removal using a laboratory-scale DAF system. This paper deals with coagulant type (aluminum sulfate and PSO-M) and the most relevant operational conditions (velocity gradients for coagulation and flocculation, retention time and recycle ratio and flotation time). Results showed that optimal conditions for removing humic acid, yielding CHA removal efficiencies of approximately 85 %, are a recycle ratio of 40 %, coagulant dosages of 0.15 - 0.20 gAl/gHA as aluminum sulfate and 0.03 - 0.12 gAl/gHA as PSO-M, coagulation($400s^{-1}$ and 60s), flocculation($60s^{-1}$ and 900s or more), and flotation(490 kPa or more and at least 10 min).

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.148-156
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• 2014

The objective of this study is to compare NOx emissions from light duty diesel vehicles measured from on-road tests that conducted under various driving routes and seasonal conditions. We measured real-driving NOx emissions using PEMS, portable emissions measurement system, under the urban, rural and motorway road traffic conditions. On-road tests were repeated at summer, fall and winter season. The accumulated driving distance is more than 1,200 km per each vehicle. Route average NOx emission factors were compared among nine route-season combinations. The emission characteristics of each combinations were investigated using time series mass emission rates and vehicle operation-based emission rates and activities, which is based on U.S. EPA's MOVES model. Most concerned route-season combination is "urban road condition at summer", which shows two to eleven times higher NOx emissions than other combinations. The emission rates and activities under low speed operating conditions should be managed in order to reduce urban-summer NOx. From a NOx control strategy perspective, the exhaust gas recirculation, EGR, is observed to be properly operated under wide range of vehicle driving conditions in Euro-5 vehicles, even if the air conditioner turns on. In high power demanding conditions, the effect of overspeeding could be more critical than that of air conditioner activation.

• Journal of Korean Society on Water Environment
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• v.28 no.3
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• pp.426-435
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• 2012

The variation of stream flow is the one of the most important factors which influence on that of water quality in the unit watershed. The target water quality goal is established and permissible load is allotted in the base of the standard flow condition along with its water quality for the management of Total Maximum Daily Loads (TMDLs). A standard flow selected could cause problems in the load allotment if it was not properly arranged. This study reviewed the acquisition of water quality data, the self-variation and the retainability in water quality on the specific flow conditions. This study also proposed the median and the adjusted average flow condition out of general flow conditions as alternative standard flow conditions. It is considered that the alternatives can make the water quality data easily acquired and the water quality representativeness more enhanced on the standard flow conditions.