• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
• /
• pp.253-256
• /
• 2005

This paper is to investigate the mixture proportion, compressive strength and drying. shrinkage of concrete depending on mineral admixtures such as fly ash (FA), blast furnace slag (BS) and cement kiln dust (CKD) under various contents of admixtures. The use of CKD had little effect on strength development at 3 days, while the use of FA and BS lead to similar compressive strength compared with that of control concrete. Concrete with CKD exhibited a reduction of compressive strength at 91 days, meanwhile concrete with FA and BS had a increase compared with that of control concrete. Drying shrinkage of concrete depending on CKD and BS increase compared with that of control concrete about $10\∼20\%$, while the use of FA exhibited reduce compared with that of control concrete about $10\∼15\%$.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
• /
• pp.63-64
• /
• 2019

Due to the rapid deterioration of the domestic atmosphere, people are suffering from inconveniences such as wearing fine dust masks all the time during outdoor activities. In this study, light transmitting concrete, LEFC(Light Emotion Friendly Concrete), using TiO2 photocatalyst was produced. Since the characteristics of LEFC where acrylic rods are inserted require self-consolidating performance, the purpose was to utilize UHPC(Ultra High Performance Concrete) materials to obtain high-flowability. Further, the compressive strength and flexural strength were evaluated to prevent the reduction of epidemiological performance by utilizing UHPC materials. As such, a basic study was carried out to develop LEFC materials using photocatalyst that can purify the air and stimulate human sensibility.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2004년도 추계학술대회
• /
• pp.165-170
• /
• 2004

It used the flow system of the stone polishing machine head and it developed a multi axis whetstone polishing system. With the result, the defect by line contact polishing does not occur in both ends of the stone, and it came to trim smoothly. As the index of the surface roughness decreased to 3.6 times, the polishing effect improved greatly. It decreased greatly the dust and a noise with the wet polishing, and the factors of the duty evasion at production site were solved with the work environment improvement against the polishing process of the stone industry and work intensive reduction.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
• /
• pp.12-13
• /
• 2007

In this paper, we studied the analysis of environmental effects on maximum output power change of crystalline silicon photovoltaic module. During the test period, there was a 5% reduction of maximum output power on an average. And the degree of output power uniformity became better compared to initial value. Using climate data like rain, snow and dust, we tried to find the reasons for maximum power fluctuation. The surface of PV module was monitored using microscope and infrared camera to study temperature distribution. The further analysis is described in the following paper.

• 한국축산시설환경학회지
• /
• 제5권3호
• /
• pp.203-216
• /
• 1999

Recent public concern about air pollution caused by swine production facilities has forced to develop the methods to reduce and control the swine odors. Swine odors were affected the life of pig farm neighborhoods, swine productivity, pig health, diseases, and human right, safety, sanity as negatively. The first approaches of control of swine odors are the change or improve of the classical management systems, which are manure treatment method, manure storage facility, phase feeding, sex-divided feeding, feeder type, liquid-slurry feeding, environment control of swine building and dust control of indoor swine facility. The methods to control odor emission from manure have to include the diet modification as nutritional basis. In recent, research emphasis has focused on manipulating the swine diet to increase the nutrient utilization of the diet to reduce excretion products and reduction of odors. There are lots of feed additives and pit additives introduced as practical basis for reducing odor emissions. The ozone treatment method is candidate as the good system for reducing swine odor. But this system is still too expensive to practice in present.

• 공업화학전망
• /
• 제23권4호
• /
• pp.13-19
• /
• 2020

수년간 고농도 미세먼지 발생으로 인한 실내공기질 관리방안에 관한 논의가 계속되고 있다. 특히, 시민들이 하루에 1.75시간 이상 지하철 및 버스 등의 대중교통 내에서 머물고 있는 것으로 발표되고 있어 환경부에서는 2019년 대중교통에서의 공기질 관리 방안을 강화하는 것으로 발표한 바 있다. 최근 철도차량 등의 대중교통 차량에서 공기질 개선장치가 도입되고 있는 추세이긴 하나, 대부분의 기존 대중교통차량에서는 공기질 개선장치가 적용되어 있지 않고 대기질이 나쁨인 경우 실내 환기가 어려워 이용 시민들의 건강을 해칠 수 있는 상황이다. 이러한 상황에서 강화되는 실내공기질관리법을 만족하기 위해서는 다양한 대중교통 차량에서의 공기질 관리기술을 토대로 신규차량 뿐만 아니라 기존차량에서 적용할 수 있는 실제적인 논의가 필요하다. 본 기고문에서는 대중교통에서의 공기질 현황을 알아보고 효율적인 공기질개선을 위한 미세먼지 및 이산화탄소 저감에 관한 연구동향을 정리하고자 한다.

• 한국정보처리학회:학술대회논문집
• /
• 한국정보처리학회 2020년도 춘계학술발표대회
• /
• pp.5-8
• /
• 2020

매우 작은 크기의 센서들이 산악 등의 험지에 흩뿌려지는 스마트 더스트 환경은 장치들의 컴퓨팅 성능과 리소스가 매우 제한되기 때문에 각 센서들의 위치를 식별하기 매우 힘들다. 또한 초대량의 센서들이 뿌려지는 특성으로 인해 수집, 전송되는 데이터의 크기가 상상하기 힘들 정도로 커질 수 있다. 본 논문에서는 중간 매개 역할을 수행하는 디바이스의 위치와 삼변측량을 이용해 센서들의 위치를 계산하고 계산된 위치를 기반으로 동종의 센서에서 수집된 데이터를 축소, 통합하는 위치 기반 데이터 축소 시스템을 제안한다.

• Safety and Health at Work
• /
• 제15권1호
• /
• pp.114-117
• /
• 2024

A lithium-ion battery is a rechargeable battery that uses the reversible reduction of lithium ions to store energy and is the predominant battery type in many industrial and consumer electronics. The lithium-ion batteries are essential to ensure they operate safely. We conducted an exposure assessment five days after a fire in a battery-testing facility. We assessed some of the potentially hazardous materials after a lithium-ion battery fire.We sampled total suspended particles, hydrogen fluoride, and lithium with real-time monitoring of particulate matter (PM) 1, 2.5, and 10 micrometers (㎛). The area sampling results indicated that primary potential hazardous materials such as dust, hydrogen fluoride, and lithium were below the recommended limits suggested by the Korean Ministry of Labor and the American Conference of Governmental Industrial Hygienists Threshold Limit Values. Based on our assessment, workers were allowed to return to work.

• 한국환경보건학회지
• /
• 제32권1호
• /
• pp.8-18
• /
• 2006

The aim of this study is to evaluate the emission characteristics of mercury, lead, arsenic, and selenium from medium size municipal solid waste incinerators(MSWIs) in Korea. The concentrations of mercury, lead, arsenic, and selenium emitted from medium size MSWI stack were $2.67\;{\mu}g/Sm^3,\;0.38\;mg/Sm^3,\;1.33\;{\mu}g/Sm^3,\;0.28\;{\mu}g/Sm^3$, respectively. The concentration levels of mercury, lead, arsenic in flue gas from medium size MSW incinerator stacks selected were nearly detected under the Korea criteria level. Removal efficiencies of mercury, lead, arsenic, and selenium in waste heat boiler(WHE) and cooling tower(CT) were $90.36\%,\;69.76\%,\;43.04\%,\;40.64\%$, respectively. In general, the removal efficiencies of mercury and lead in WHE were higher than those of arsenic and selenium in WHE. Emission gas temperature reduction from waste heat boiler(WHB) and cooling tower(CT) can control mercury and lead of medium size MSWIs. To evaluate the relationship between mercury, lead, arsenic, selenium of fly ash and those of flue gas, it was carried out to correlation analysis of each metal concentration in the fly ash and in the flue gas from medium size MSWIs. From the correlation analysis, the coefficients of mercury, lead, arsenic, and selenium were 0.61, -0.38, 0.87, 0.28, respectively. The results of correlation analysis revealed that it should be highly positive to the correlation coefficients of mercury and arsenic in the fly ash and those of the flue gas emitted from medium size MSWIs. As it were, the concentrations of mercury and arsenic of flue gas from medium size MSWIs are high unless mercury and arsenic in fly ash are properly controlled in dust collection step in medium size MSWIs. It was also concluded that mercury, lead, arsenic, and selenium from MSWIs stacks could be controlled by waste heat boiler(WHE) and dust collecting step in medium size MSWIs.

• 한국대기환경학회지
• /
• 제32권5호
• /
• pp.526-535
• /
• 2016

Recently, fine dust in atmosphere have been considerably issued as a harmful element for human. Nitrogen oxide ($NO_x$) exhausted from diesel engines and power plants has been disclosed as a main source of secondary production of fine dust. In order to prevent exhausting these nitrogenous compounds into atmosphere, a treatment system with selective catalytic reduction (SCR) catalyst with ammonia as a reductant has been used in various industries. Urea solution has been widely studied to supply ammonia into a SCR catalytic reactor, safely. However, the conversion of urea solution to ammonia has several challenges, especially on a slow conversion velocity. In the present study, a fast urea conversion system including a plasma burner was suggested and designed to evaluate the performances of urea conversion and initial operation time. A designed lab-scale facility has a plasma burner, urea nozzle, mixer, and SCR catalyst which is for hydrolysis of isocyane. Flow rate of methane that is a fuel of the plasma burner was varied to control temperatures in the urea conversion facility. From experimental results, it is found that urea can be converted into ammonia using high temperature condition of above $400^{\circ}C$. In the designed test facility, it is found that ammonia can be produced within 1 min from urea injection and the result shows prospect commercialization of proposed technology in the SCR facilities.