• 제목/요약/키워드: rock wool

검색결과 65건 처리시간 0.022초

제주 송이를 이용한 방울토마토 양액재배에서 양액성분의 변화 (Change of Nutrient Solution Content in Scoria Culture with Cherry Tomato)

  • 장전익;오대민;현해남
    • 한국생물환경조절학회:학술대회논문집
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    • 한국생물환경조절학회 1994년도 가을 심포지움 및 학술논문발표요지
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    • pp.88-91
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    • 1994
  • 실험목적 :제주지방에 화산락인 송이(Scoria)가 수억톤 매장된 것으로 추정된다. 이 제주송이를 배지로 이용한 양액 재배에서 품질과 수량이 perlite, rock wool 등 일반 고형 배지경과 떨어지지 않는 연구 결과는 있으나 작물의 생육 과정에서 제주 송이가 양액 성분변화에 어떤 영향을 미치는지는 아직 발표된 바가 없다. 양액재배용 고형배지로 제주 송이가 안전한 사용을 위한 기초자료를 얻고자 수행했다. (중략)

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건축재료에서 발생되는 석면입자의 특성 연구 (The Characteristics of Dispersed Asbestos Fibers Produced From Building Materials)

  • 유성환
    • 한국대기환경학회지
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    • 제9권3호
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    • pp.191-199
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    • 1993
  • This paper describes the results of a systematic study to determine the characteristics of particle generated from various types of asbestos containing material(ACM) and manmade fiber material(MMFM) during operations of cutting and grinding in laboratory and workplace. Tests were conducted with a specially designed glove box which allowed complete sampling of the generated asbestos fibers. Specificially, air measurements were made during ACM and MMFM installation in building. All personal air samples collected were identified by polarized light microscopy(PLM), X-ray diffraction(XRD) and scanning electron microscope with energy dispersive X-ray analysis(SEM/EDXA). Also, the samples were counted by phase contrast microscope(PCM) in order to compare the results with the permissible exposure standard for workplace. Results indicate that the characterisitcs of fibers found in the roofing sheet, the ceiling and the wall insulation boards were identical to those of asbestos, while the characteristics of fibers found in the ceiling insulation board, the floor tile and the sprayed on insulation products in parking area were identical to those of asbestos, while the characteristics of fibers found in the ceiling insulation board, the floor tile and the sprayed on insulation products in parking area were identical to those of rock wool. The concentrations of airborne fibers from various building materials cut by a grinder for 5 minutes were in the ranges of 0.09 $\sim$ 1.71 fibers/cc(f/cc). The highest concentration(1.71f/cc) was found during grinding the wall insulation board which also contains rock wool. The airborne fiber concentrations generated by installing at workplace were ranged from 0.0009 to 0.029 f/cc. All asbestos fibers from the ceiling insulation board at workplace were less than 20$\mu$m in length and more than 20% of them had the average aspect ratio greater than 20. Therefore, for the purpose of decreasing asbestos and man-made fiber concentrations at the workplace, the ceiling and wall board should use strong binding material to increase the binding force with fiber. Also, the permissible exposure standard for workplace(2.0f/cc) in Korea should be constituted below the maximum avaiable concentration measured at glove box.

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황토를 이용한 친환경 유공 흡음보드의 흡음특성 (Absorption Characteristics of Perforated Environment Friendly Sound Absorbing Board using Hwangto)

  • 김선우;박현구
    • KIEAE Journal
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    • 제11권1호
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    • pp.3-8
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    • 2011
  • Sound absorbing materials used for lightweight panels and interior material are mainly made of fibroid material such as glass wool or rock wool. However these fiber type sound absorbing materials have some problems such that sound absorption could be decreased as time goes by because of durability. In addition, dust scattering from fiber type material can cause another problem in health. In this point of view, this study aims to develop environment friendly sound absorbing material using Hwangto(so called loess or yellow soil), a traditional housing material. Hwangto is natural housing material in Korea and generally known for improving indoor air quality. Hwangto panel is made to construct on the floor, wall and ceiling, and expected that there is not enough absorption. Present study tried to develop environment friendly sound absorbing material that has high sound absorption performance with good environment performance in terms of air quality. Pore rate was designed to maximize the absorption in the specific frequency bands, and two kinds of backing space were applied in order to see the effect of backing space. As a result peak frequency that has maximum absorption is going high as the pore rate is increased. The backing space provides more absorption and makes the peak frequency down to low.

제조시점에 따른 섬유상 흡음재의 물리적 특성 변화 (Changes in Physical Properties of Fibrous Sound Absorption Materials According to the Manufacturing Time)

  • 정영선;김경우
    • 한국소음진동공학회논문집
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    • 제24권7호
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    • pp.562-568
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    • 2014
  • This study aimed to identify changes in the physical properties of artificial mineral-fiber materials used as building insulation that had been installed in the outer walls of buildings for a long time. To achieve this goal, glass fiber and rock wool were collected from outer walls in actual buildings and their acoustic and thermal performances were measured. These were compared with measurements from similar products manufactured recently. The results showed that old, used samples had a lower sound absorption coefficient compared to recently manufactured materials. The old samples also displayed increased compressibility compared to new materials. For example, the compressibility difference for glass wool was 7.32 mm. Old samples had a dynamic stiffness $1.28MN/m^3$ higher than new material samples. The thermal conductivity of both old and new samples increased within creasing temperature. They showed similar results at temperatures between 0 and $20^{\circ}C$.

완충재 종류에 따른 중량바닥충격음 저감특성 평가 (A Study on the Heavy-weight Floor Impact Sound Reduction Evaluation of Characteristics by Resilient Materials)

  • 김경우;양관섭;정진연;임정빈;정갑철
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.1145-1148
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    • 2007
  • Resilient materials are generally used for the floating floors to reduce the floor impact sound. Dynamic stiffness of resilient material, which has the most to do with the floor impact sound reduction. The resilient materials available in Korea include EPS (Styrofoam), recycled urethane types, EVA (Ethylene Vinylacetate) foam rubber, foam PE (Polyethylene), glass fiber & rock wool, recycled tire, foam polypropylene, compressed polyester, and other synthetic materials. In this study, we tested floor impact sound reduction characteristic to a lot of kinds of resilient material. The result of test showed that the amount of the heavy-weight impact sound reduction appeared by being influenced from this dynamic stiffness of resilient material. The dynamic stiffness looked like between other resilient materials, a similar to the amount of the heavy-weight impact sound reduction was shown.

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완충재 종류에 따른 경량바닥충격음 저감특성 평가 (Evaluation of the Light-weight Floor Impact Sound Reduction Characteristics by Types of Resilient Material)

  • 김경우;양관섭;정진연;임정빈;정갑철
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2008년도 춘계학술대회논문집
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    • pp.830-834
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    • 2008
  • Resilient materials are generally used for the floating floors to reduce the floor impact sound. Dynamic stiffness of resilient material, which has the most to do with the floor impact sound reduction. The resilient materials available in Korea include EPS (Styrofoam), recycled urethane types, EVA (Ethylene Vinylacetate) foam rubber, foam PE (Polyethylene), glass fiber & rock wool, recycled tire, foam polypropylene, compressed polyester, and other synthetic materials. In this study, we tested floor impact sound reduction characteristic to a lot of kinds of resilient material. The result of test showed that the amount of the Light-weight impact sound reduction appeared by being influenced from this dynamic stiffness of resilient material. As the decreasing dynamic stiffness of resilient material, the impact sound reduction amount is increased, especially in the low frequency domain.

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양액재배용 석탄회-점토계 배지 개발 (Development of Fly Ash and Clay System Medium for Hydroponic Culture)

  • 강위수;신대용;류근창;김일섭
    • 한국생물환경조절학회:학술대회논문집
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    • 한국생물환경조절학회 1999년도 학술발표논문집
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    • pp.71-74
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    • 1999
  • 농업ㆍ원예분야에서 다공질 재료를 인공배지로 이용하기 위하여는 수분관리의 용이성, 우수한 양분의 유지, 통기성 및 보수성이 요구된다. 이들 성질을 만족시키는 재료로는 점토, 벤토나이트, 질석(vermicutite), 펄라이트(perlite) 및 락-울(rock-wool) 등이 이용된다. 인공배지 재료로 널리 사용되는 펄라이트와 락-울의 원료는 중국 및 호주 등지로부터 수입에 의존하고 있어 양액재배 농가에 커다란 부담이 되며 건습조절이 곤란하여 배지 내 수분함량의 조절이 용이하고 양액사용이 간편한 배지 및 폐기처리시 환경문제를 야기하지 않는 반영구적이며 자연친화형의 배지의 개발이 절실히 요구되고 있다. (중략)

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발포알루미늄의 시공방법에 따른 흡음 특성에 관한 연구 (Sound absorption characteristics of foamed aluminum considering installing on the wall and in the space)

  • 박현구;김항
    • Journal of Advanced Marine Engineering and Technology
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    • 제41권1호
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    • pp.50-55
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    • 2017
  • 발포알루미늄은 친환경 재료로서, 재활용이 가능하며 화재에 안전하여 선박과 해양구조물에 사용되는 흡음재로서 우수한 특성을 가지고 있다. 지금까지 발포알루미늄은 발포율에 따른 흡음성능에 관한 연구가 주로 이루어져 왔다. 발포알루미늄은 기존에 사용되어 왔던 글래스 울, 락 울 등과 같은 섬유질 흡음재와 비교할 때, 강도면에서 우수하기 때문에 다양한 방법으로 시공할 수 있는 장점이 있다. 따라서 본 연구에서는 공간 내에서 발포알루미늄의 다양한 사용 방법을 고려하여 흡음특성에 대한 실험을 실시하였다. 또한 마감재로 페인트 칠에 따른 특성을 포함하여, 양면흡음재로서 사용될 경우 벽면에 수직으로 세워서 시공한 구조와 공중에 매달아 수평으로 시공한 구조에 대한 흡음특성의 변화에 대해 실험적 방법으로 분석하였다.