• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.56-57
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• 2021

Apartments, an intensive residential type, exist and are supplied in large quantities regardless of the size of the city. The value of an apartment is affected not only by the surrounding infrastructure, but also in terms of maintenance. Defects that occur in apartments come in various forms, and mainly poor finishing accounts for 60% of the defects. Among them, tile defects accounted for a large proportion and were found to be caused by several factors. This paper analyzed the influence of each factor considering the coefficient of thermal expansion affecting tile defects according to the domestic seasonal climate.

• Journal of Korean Society for Atmospheric Environment
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• 제20권E2호
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• pp.53-59
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• 2004

The roadway tunnels in urban areas give rise to problems such as a localized air pollution. Here, we report the results of a case study of an urban roadway tunnel measurement. The size-resolved particle sampling was carried out with a two 2-stage filter pack samplers and an Andersen impactor sampler at the center of Buk-Ak tunnel in November 2001. Particle Induced X-ray Emission (PIXE) was applied to determine the elemental composition of size-resolved particles divided into soluble and insoluble fractions. The Thermal/Optical Reflectance (TOR$^{(R)}$) method was also employed in analyzing of elemental carbon (EC) and organic carbon (OC). Mass concentrations of fine (< 1.2 ${\mu}{\textrm}{m}$) and coarse (> 1.2 ${\mu}{\textrm}{m}$) particles are 165 and 48 $\mu\textrm{g}$ m$^{-3}$ , respectively. Total elemental mass concentration (the sum of insoluble coarse, soluble coarse, insoluble fine, and soluble fine) is found to be 24$\mu\textrm{g}$ m$^{-3}$ and comprises only 11 % of total particle mass concentration. The concentrations of EC, OC, and mass show the clear dependency on particle size with the maximum between 0.1 and 0.43 ${\mu}{\textrm}{m}$ aerodynamic diameters. Total carbon (sum of EC and OC) accounts for approximately 70% of mass concentration.n.

• 한국환경과학회지
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• 제23권8호
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• pp.1409-1418
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• 2014

Foundry has an important economic value in the industry. However, the generation of air pollutants like particulate and odor are serious. Due to the unavoidable usage of molding sand, particulate occurs in almost all the processes. That accounts for the majority of respirable dust in the size less than $10{\mu}m$ As well as particulate, over 22 species of odor-causing gases and VOCs including hydrogen sulfide and ammonia are occurred. Therefore, the development of equipment that can simultaneously remove TVOC and particulate is regarded as an essential research. In this study, the spraying absorbent system was connected with the shear bag filter for the purpose to remove TVOC and particulate simultaneously. Maximization of process efficiency for the affective factors like the powder combination and injection method is conducted. The experiment was performed at the de-molding process of one foundry plant. Through these devices, the removal efficiency of more than 95% for TVOC was achieved with the absorbent that composed by 800 mesh Activated carbon (80%) and 300 mesh zeolite (20%). Also, the durability and economic evaluation were assessed. In the result of Durability assessment, the available recovery to maintain the deodorizing effect at 90% was counted to 350 degree.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.296-302
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• 2004

After the Rio declaration on environment and development in 1992, developed countries are undertaking 'environmentally sustainable transportation (EST)' projects. To meet the needs for EST, current transportation policies in Korea are rapidly reforming and one of its concerns is modernizing and upgrading railway freight system. Planning new railroad construction projects is increasing and subsequent environmental impact assessment (EIA) demands improvements, especially in both the EIA and decision making systems. In this paper, we discuss the present status of EIA for railroad construction projects, especially, by analyzing the EIA documents accumulated for last six years. The EIA for railroad construction projects .accounts for only $4.9\%$ of total project EIAs during 1998-2003. However, the portion is gradually increasing. Major environmental concerns for EIA in railroad construction projects were geomorphological and ecological changes, protection of rare organisms, air pollution, water quality, wast management, noise, etc. We also compared the characteristics of environmental impacts of railroad construction with those of vehicle road construction. The result shows that railroad construction usually requires 3${\~}$4 times longer tunnels and bridges for a given length than vehicle road construction. In addition, the amounts of geomorphological and ecological changes (road-cutting, embankment, devegetation, etc.) in railroad construction were generally less than $40\%$ of those in vehicle road construction. In order to develop environmentally friendly railway systems, monitoring studies for environmental impacts of railroads such as habitat fragmentation and road kills, dispersal of alien plants, tunnelling effects on groundwater and vegetation, and noise impacts are highly required.

• 한국물환경학회지
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• 제28권2호
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• pp.292-299
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• 2012

The objective of this study is to develop a novel method for evaluating forward osmosis (FO) membrane performances using a non-pressurized FO system. Basic membrane performance parameters including water (A) and solute (B) permeability coefficients and unique parameter for FO membrane such as the support layer structural parameter (S) were determined in two FO modes (i.e., active layer faces feed solution (AL-FS) and active layer faces draw solution (AL-DS)). Futhermore, these parameters were compared with those determined in a pressurized reverse osmosis (RO) system. Theoretical water flux was calculated by employing these parameters to a model that accounts for the effects of both internal and external concentration polarization. Water flux from FO experiment was compared to theoretical water fluxes for assessing the reliability of those parameters determined in three different operation modes (i.e., AL-FS FO, AL-DS FO, and RO modes). It is demonstrated that FO membrane performance parameters can be accurately measured in non-pressurized FO mode. Specifically, membrane performance parameters determined in AL-DS FO mode most accurately predict FO water flux. This implies that the evaluation of FO membrane performances should be performed in non-pressurized FO mode, which can prevent membrane compaction and/or defect and more precisely reflect FO operation conditions.

• 한국수소및신에너지학회논문집
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• 제29권1호
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• pp.111-116
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• 2018

The environmental impacts of a 1 kW polymer electrolyte membrane fuel cell (PEMFC) system are quantitatively assessed by performing a Life Cycle Assessment (LCA) study. A PEMFC system produces electricity and heat simultaneously, so an appropriate allocation of associated inputs and outputs is performed between the electricity and heat produced. The environmental impacts of the PEMFC system on the impact categories such as global warming (GW), abiotic depletion (AD), acidification (AC), and eutrophication (EU) are assessed from the life cycle impact assessment. The impact indicator results of the impact assessment on these impact categories are obtained as $3.70E-01kg\;CO_2\;eq./kWh$, 1.86E-03 kg Sb eq./kWh, $4.09E-04kg\;SO_2\;eq./kWh$, and $1.88E-05kg\;PO_4{^{3-}}/kWh$, respectively. For all impact categories studied the most influential stage is the operation stage, which accounts for 98.8%, 98.7%, 70.3%, and 62.3% of the total impact on GW, AD, AC, and EU, respectively. For the impact categories of AD, AC, and EU, most of the environmental impacts during the operation stage is attributed to the production of city gas. However, for the impact category of GW, $CO_2$ emission from the reforming process of city gas is the main reason for the largest contribution of the operation stage to the total impact results.

• 한국환경과학회지
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• 제23권12호
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• pp.2015-2028
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• 2014

We analyzed with HPLC (High Performance Liquid Chromatography) analysis photosynthetic pigments and environmental factors, microscopic observations of the phytoplankton and zooplankton in the seawater every month from February 2009 to November 2010 in Haengam Bay. The level of dissolved inorganic nutrients was the highest between July and September, when freshwater influx was at its peak, whereas chlorophyll a levels were the highest in April and August. Also, phytoplankton pigment concentration increased when dissolved inorganic nutrients are carried into nearshore waters by rainfall runoff. Based on identification of phytoplankton and photosynthetic pigments results, diatoms were mainly dominant while dinoflagellate populations increased at July and August 2009, May 2010. The zooplankton communities are dominated in terms of Noctiluca scintillans. The contribution of Noctiluca scintillans in 2010 accounts for approximately 77.3% of the total zooplankton. Distribution patterns over time of zooplankton in the seasonal distribution of phytoplankton showed a different pattern.

• 한국실내디자인학회논문집
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• 제26권6호
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• pp.53-61
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• 2017

Cityschumers experience the urban with the visual perception while walking an average speed of 4km per hour. At this time, recognition of the color field accounts for more than 70%. Therefore, in this paper the environmental color of urban street is examined by dividing the pedestrian visual field area. In the urban street, the area of the visual field area of the pedestrian is divided into Ground Plane, Roadside, Canopy and Building Wall. In addition, we observe and color survey the environmental color of Exhibition Road, which is the northern side space of South Kensington in London, which adopted the world's first shared space. The color of the visual filed area was dominated as YR, GY, Y, PB. The Ground Pland was dominated by the YR. The reason for this is that the color of the floor has changed due to the shadows of surrounding architecture and facilities. Roadside was dominated in various ways such as GY, BG, PB, B and P. Canopy was mainly composed of PB, GY, etc. It was found that the material color of the lower part of the architecture was reflected. The architecture wall was affected by the reflectance and absorption rate of the transparent material. The first image that comes to mind when thinking about the urban is the street where pedestrians walk, feel and enjoy themselves. Therefore, it is suggested that various policy frameworks for managing and managing urban planning professionals may be different from the perceptions of pedestrians active in mega cities.

• 대기
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• 제31권1호
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• pp.45-60
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• 2021

The synoptic structures and precipitation impact of extratropical cyclones (ETCs) influencing on the three adjacent megacities in East Asia, i.e., Beijing (Beijing ETCs), Seoul (Seoul ETCs) and Tokyo (Tokyo ETCs), are analyzed using ERA-interim reanalysis data from 1979 to 2018. Individual ETC tracks are identified with the automated tracking algorithm applied to 850-hPa relative vorticity field. Among four seasons, ETCs are the most frequent in spring. In this season, Beijing ETCs are mainly generated at the leeside of Altai-Sayan Mountains and primarily develop through interaction between the upper-level trough and lower-level cyclonic circulation. For Seoul ETCs, the leesides of Altai-Sayan Mountains (Seoul-N ETCs) and Tibetan Plateau (Seoul-S ETCs) are main genesis regions and the features of ETCs are different according to the genesis regions. While Seoul-N ETCs mainly develope by the same mechanism of Beijing ETCs, strong diabatic heating due to vapor transport is responsible for the genesis of Seoul-S ETCs. Tokyo ETCs are originated from the leesides of Tibetan Plateau and Kuroshio-Oyashio Extension regions, and strong diabatic heating as well as interaction between upper and lower levels determines the genesis of these ETCs. The precipitation impact resulting from ETCs become strong in the order of Beijing ETCs, Seoul-N ETCs, Seoul-S ETCs, and Tokyo ETCs and accounts for up to 40%, 27%, 52%, and 70% of regional precipitation, respectively.

• 한국환경농학회지
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• 제3권1호
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• pp.63-70
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• 1984

화학적(化學的) 광양측정방법(光量測定方法)을 리용(利用)하여 제주도(濟州島)의 해변(海邊)과 해발(海拔) 1,100m 고지(高地)에서 봄부터 가을사이의 태탕광선중(太湯光線中) 자외선(紫外線) 함양(含量)을 측정(測定)한 결과(結果), 여름과 초가을의 자외선(紫外線) 함풍(含豊)은 봄에 비해서 배(倍) 이상(以上)으로 나타났으며 고지대(高地帶)에서는 더 많은 자외선(紫外線) 함양(含量)이 측정(測定)되었다. 포장조건(圃場條件)에서 UV-B부분(部分)($280{\sim}320nm$) 자외선(紫外線)의 투과률(透過率)이 서로 다른 필름을 피복(被覆)하여 대두(大豆)의 생장발육(生長發育)을 조사(調査)했는데, 광선중(光線中) UV-B의 해작용(害作用)은 인정(認定)되지 않았다. 자외선(紫外線)이 식물(植物)의 광형태형성(光形態形成)에 미치는 효과(效果)를 구명(究明)하기 위하여 미형태형성(米形態形成)에 관여하는 식물(植物)의 광수용체(光受容體) 색소(色素)인 파이토크롬에 UV-B를 쪼이면서 파이토크롬의 변화(變化)를 추적(追跡)하였던바, 분자량(分子量) 124,000인 파이토크롬은 60% Pfr, 분자양(分子量)${\sim}120,000$은 50% Pfr의 광평형(光平衡) 상태(狀態)를 보였다. 광변환중(光變換中) quantum yield는 분자양(分子量) 124,000의 파이토크롬에서는 ${\phi}r=0.016$, ${\phi}fr=0.010$이었으며 분자량(分子量)${\sim}120,000$은 ${\phi}r={\phi}fr=0.012$였다. 포장상웅(圃場狀熊)에서 공시(供試)된 대두(大豆)에 UV-B의 해작용(害作用)이 관찰(觀察)되지 않은 것은, UV-B가 파이토크롬을 변환(變換)시켜 파이토크롬이 관여하는 방어적(防禦的) 형태형성(形態形成) 및 발육(發育)을 촉진(促進)시키기 때문이라고 추론(推論)되었다.