• Title/Summary/Keyword: Light Pollution

Search Result 377, Processing Time 0.03 seconds

A Study on Heat Exchange Efficiency of EGR Cooler for Diesel Engine to Meet Euro-5 Emission Regulation (Euro-5 대응 디젤엔진용 EGR 쿨러의 열교환 효율 연구)

  • Lee, Joon;Han, Chang-Suk
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.15 no.3
    • /
    • pp.183-188
    • /
    • 2007
  • Recently, diesel engine has been frequently applied to RV, SUV and light duty truck due to the good fuel economy and high thermal efficiency. $NO_x$ and PM, environmental pollution materials are basically produced in diesel combustion process. The most important target in diesel engine research is the development of system to reduce the emissions of $NO_x$ and PM. Cooled EGR system is an effective method for the reduction of $NO_x$ emission and PM emission from a diesel engine and EGR cooler is the key component of the system. This study investigates the EGR cooler of oval gas tubes compared with the EGR cooler of shell & tubes to verify the heat exchange efficiency of cooler by means of engine dynamometer tests, rig performance tests and numerical analyses.

Development of A Prototype Device to Capture Day/Night Cloud Images based on Whole-Sky Camera Using the Illumination Data (정밀조도정보를 이용한 전천카메라 기반의 주·야간 구름영상촬영용 원형장치 개발)

  • Lee, Jaewon;Park, Inchun;cho, Jungho;Ki, GyunDo;Kim, Young Chul
    • Atmosphere
    • /
    • v.28 no.3
    • /
    • pp.317-324
    • /
    • 2018
  • In this study, we review the ground-based whole-sky camera (WSC), which is developed to continuously capture day and night cloud images using the illumination data from a precision Lightmeter with a high temporal resolution. The WSC is combined with a precision Lightmeter developed in IYA (International Year of Astronomy) for analysis of an artificial light pollution at night and a DSLR camera equipped with a fish-eye lens widely applied in observational astronomy. The WSC is designed to adjust the shutter speed and ISO of the equipped camera according to illumination data in order to stably capture cloud images. And Raspberry Pi is applied to control automatically the related process of taking cloud and sky images every minute under various conditions depending on illumination data from Lightmeter for 24 hours. In addition, it is utilized to post-process and store the cloud images and to upload the data to web page in real time. Finally, we check the technical possibility of the method to observe the cloud distribution (cover, type, height) quantitatively and objectively by the optical system, through analysis of the captured cloud images from the developed device.

Preliminary Study of Energy and GHG Footprint of CFRP Recycling Method using Korea Database

  • Pruitichaiwiboon, Phirada;Lee, Cheul-Kyu;Kim, Young-Ki
    • Proceedings of the KSR Conference
    • /
    • 2009.05a
    • /
    • pp.247-250
    • /
    • 2009
  • Awareness of resource conservation and pollution prevention has been continually increasing. The proven benefits from CFRP's unique combination of light weight and high strength compare to conventional material is well suited for minimizing fuel consumption during vehicle in particular rail operation. Responding the awareness, this work intends to study CFRP's recycling method that is not only technical performance but also environmental view point. According to prior work of technical performance test, this work aims at quantifying the footprint of energy and GHG derived from the two appreciated performance of pyrolysis and acids recycling methods. The streamline LCA is the concept for systematic assessment. The boundary is scoped at the recycling activity, consequently, the data in and out from the specific target activity are obtained under the gate to gate data collection. Its function is recovery carbon fiber. To count and compare function, functional unit is set at 60% of recycling rate. Korea database is mainly source for acquiring the footprint of both. The numerical results presented that the energy footprint of acids and pyrolysis is 164.95 and 1,199.88 MJ-eq., respectively. Meantime, the GHG footprint of is 1,196.22 and 5,916.08 g CO2 eq. for acids and pyrolysis. In summary, the acids recycling method is, in regarding the environmental performance, better than pyrolysis recycling method.

  • PDF

A Study on the Dyeing of Ramie Fabric Treated with Medicinal Plant I . The Natural Dyeing On Ramie Fabric Using Leonuri Herba

  • Seo, Young-nam
    • Plant Resources
    • /
    • v.5 no.1
    • /
    • pp.74-77
    • /
    • 2002
  • This study was performed to investigate the effect of Leonuri Herba extract on the treatment of chromaticity and colorfastness. Leonuri Herba has been used as a Korean medicine for the treatment of woman disease. In the long history of Korea, dyeing has been applied for a means representing the grace of natural and inner esthetic consciousness of man. Vegetable dyes give us such great benefits, diversified color, but no pollution. And ramie fabric has distinctive features such as beautiful brilliance, elegance, and strong durability. So, it is regarded as a special product of Korea traditionally. These studies were carried out to treat with acetate iron, dichloride copper and alum with a mordant to ramie fabric. The ramie fabric was died with Leonuri Herba extract. The results of experiment showed as follows: First, the chromophoric degree was the highest in acetate iron but not distinction in another mordants. Seocond, the light colorfastness was the highest in non treated and dichloride copper, but alum was the lowest. Third, the discoloration was alum and dichloride copper showed first grade in washing colorfastness. Abrasion colorfastness was not significant in this test. According the previous results, Leonuri Herba has an efficiency on woman disease. So it is considered that Leonuri Herba can be applied effectively to a theraphy of climacteric disturbance.

  • PDF

Understanding of Audit Results from Demonstration Companies toward Green Management System Certificate (녹색경영시스템 시범인증기업 심사 자료의 이해)

  • Park, Dong-Joon;Kang, Byung-Hwan;Kim, Ho-Gyun
    • Korean Management Science Review
    • /
    • v.30 no.2
    • /
    • pp.107-116
    • /
    • 2013
  • Climate changes and environmental pollution recently became a matter of global interest. Korean government established low carbon green growth act in the light of international environment regulation and started demonstration certificate project for GMS (Green Management System). We aim to explore audit data resulted from demonstration companies that pursued the GMS certificate. The demonstration companies are consisted of 11 companies that a certification body L gave the certificate. The audit data results were formed by minor nonconformities detected in the field evaluation based on GMS standards, KS I 7001/2 : 2011. We found out significant differences for minor nonconformities between types of industry and between major clauses of Part 1 and Part 2 in GMS standards. We make an effort to figure out the implication of causes of the significant differences. These results are expected to contribute to understand GMS operation situations and are utilized as a reference for energy management, social responsibility, and green gas reduction.

Destruction of Volatile Organic Compounds Using Photocatalyst-Coated Construction Materials (건축자재의 산화티타늄 코팅을 통한 휘발성 유기화합물 분해)

  • Jo Wan-Kuen;Chun Hee-Dong
    • Journal of Environmental Science International
    • /
    • v.14 no.8
    • /
    • pp.785-792
    • /
    • 2005
  • In order to reduce roadside and indoor air pollution for volatile organic compounds VOC), it may be necessary to apply photocatalyst-coated construction materials. This study evaluated the technical feasibility of the application of $TiO_2$ photocatalysis for the removal of VOC present in roadside or indoor air. The photocatalytic removal of five target VOC was investigated: benzene, toluene, ethyl benzene and o,m,p-xylenes. Variables tested for the current study included ultraviolet(UV) light intensity coating materials, relative humidity (RH), and input concentrations. Prior to performing the parameter tests, adsorption of VOC onto the current experiment was surveyed, and no adsorption was observed. Stronger UV intensity provided higher photocatalytic destruction(PCD) efficiency of the target compounds. For higher humidity, higher PCD efficiency was observed. The PCD efficiency depended on coating material. Contrary to certain previous findings, lower PCD efficiencies were observed for the experimental condition of higher input concentrations. The current findings suggested that the four parameters tested in the present study should be considered for the application of photocatalyst-coated construction materials in cleaning VOC of roadside or indoor air.

A Study on Evaluation Method of the Adaptive Cruise Control (ACC 차량의 시험평가 방법에 대한 연구)

  • Kim, Bong Ju;Lee, Seon Bong
    • Journal of Drive and Control
    • /
    • v.14 no.3
    • /
    • pp.8-17
    • /
    • 2017
  • With automobiles sharply increasing in numbers worldwide, we are faced with critical social issues such as traffic accidents, traffic jams, environmental pollution, and economic inefficiency. In response, research on ITS is promoted mainly by regions with advanced automotive industry such as the U.S., Europe, and Japan. While Korea is working on moving forward in the global market through developing and turning to global standards systems related to ASV (Advanced Safety Vehicle), the country is not fully prepared for such projects. The purpose of ACC (Adaptive Cruise Control) is to control a vehicle's longitudinal speed and distance and minimize driver workload. Such a system should be valuable in preventing accidents, as it reduces driver workload in the 21st-century world of telematics created by development of the automobile culture industry. In this light, the thesis presents a method to test and evaluate ACC system and a mathematical method to assess distance. For the proposed test and evaluation, theoretical values are tested with vehicle test and a database is acquired, by using vehicles equipped with an ACC system. Theoretical evaluation criteria for developing ACC system may be used and scenario-specific evaluation methods may find useful application through testing the formula proposed by comparing the database and mathematical method.

Depolarization Ratio Retrievals Using AERONET Sun Photometer Data

  • Lee, Kyung-Hwa;Muller, Detlef;Noh, Young-Min;Shin, Sung-Kyun;Shin, Dong-Ho
    • Journal of the Optical Society of Korea
    • /
    • v.14 no.3
    • /
    • pp.178-184
    • /
    • 2010
  • We present linear particle depolarization ratios (LPDRs) retrieved from measurements with an AERONET Sun photometer at the Gwangju Institute of Science and Technology (GIST), Korea ($35.10^{/circ}N$, $126.53^{\circ}E$) between 19 October and 3 November 2009. The Sun photometer data were classified into three categories according to ${\AA}$ngstr$\ddot{o}$ exponent and size distribution: 1) pure Asian dust (19 October 2009), 2) Asian dust mixed with urban pollution observed in the period from 20-26 October 2009, and 3) clean conditions (3 November). We show that the LPDRs can be used to distinguish among Asian dust, mixed aerosol, and non-Asian dust in the atmosphere. The mean LPDR of the pure Asian dust case is 23 %. Mean LPDRs are 13 % for the mixed case. The lowest mean LPDR is 6 % in the clean case. We compare our results to vertically resolved LPDRs (at 532 nm) measured by a Raman LIDAR system at the same site. In most cases, we find good agreement between LPDRs derived with Sun photometer and measured by LIDAR.

Light Pollution of Street in Residential Area (주거지역의 옥외 가로조명 광공해에 관한 연구)

  • Yi, So-Mi;Kim, Jeong-Tai
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
    • /
    • 2004.05a
    • /
    • pp.9-14
    • /
    • 2004
  • 우리나라의 도시 옥외조명은 1988년 서울올림픽을 전후하여 관심이 확대되었으며, 서울시는 1996년 서울시 경관조명기본방향을 설정하고 숭례문 등 각종 문화재에 옥외조명시설을 설치하기 시작하였다. 최근 옥외조명에 대한 필요성을 인식하고, 설치하고 있는 초기단계에 있어 옥외조명을 계획하는데 반드시 고려해야하는 광공해에 대해서는 아무런 인식 없이 과다한 조명으로 광공해를 유발시키고 있다. 미국과 유럽, 일본 등 선진외국에서는 일찍부터 광공해의 심각성을 인식하고, 이를 방지하기 위해 옥외조명조례의 제정과 가이드라인의 발표로 양호한 조명환경 조성을 위해 노력하고 있다. 이에 본 연구는 광공해가 거주자와 보행자에게 미치는 영향을 고려하여 주거지역의 옥외가로조명의 광공해에 관한 연구를 진행하였다. 외국의 경우 광공해가 발생하는 지역의 조명환경개선사업을 펼쳐 광공해에 따른 악영향을 줄임과 동시에 조명에너지 절약의 효과도 가져왔다. 국내의 경우 전반 확산형(Non-Cutoff) 가로등이 보행자에게는 눈부심을 일으키고, 거주자에게는 프라이버시 침해와 숙면에 방해를 가져오므로 차폐된 조명기구를 사용해 이런 영향을 최소화할 필요가 있다. 따라서 국내의 경우 아직 광공해에 대한 기준이나 가이드라인이 없으므로 이에 대한 대책과 기준안 마련이 시급하다.

  • PDF

ERS SAR observations of the Korean coastal waters

  • Mitnik, Leonid M.;Yoon, Hong-Joo;Dubina, Vyacheslav A.;Kim, Sang-Woo;Kim, Young-Seup
    • Proceedings of the KSRS Conference
    • /
    • 2003.11a
    • /
    • pp.1124-1126
    • /
    • 2003
  • The processes of regional scales in the East Korean coastal waters were investigated by analysis of the Synthetic Aperture Radar (SAR) images taken by the European Research Satellites ERS-1, ERS-2 and Envisat. More than 500 quick look frames taken in 1991-2003 were examined to detect the frames with clearly surface expressions of oceanic phenomena. 26 ERS-1/2 SAR and 11 Envisat wide swath Advanced SAR (ASAR) frames were selected and obtained from the European Space Agency in a form of the precision high-resolution images. The following oceanic phenomena and processes were evident in the radar imagery through the Korean costal waters: fronts, currents, eddies, internal waves, island and ship wakes, oil pollution, etc. They manifested themselves in the field of sea surface roughness, their scale ranged from several tens meters to about 100 km. The most common morphology of these phenomena was a series of contrast dark or light curvilinear lines and bands. The joint analysis of the discussed SAR images with other satellite and in situ data supported and enhanced our interpretation of SAR signatures.

  • PDF