• Title/Summary/Keyword: Covering material

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Estimation of Heat Insulation and Light Transmission Performance According to Covering Methods of Plastic Greenhouses (플라스틱온실의 피복방식에 따른 보온 및 광투과 성능 평가)

  • Lee, Hyun-Woo;Kim, Young-Shik;Sim, Sang-Youn;Lee, Jong-Won;Diop, Souleymane
    • Journal of Bio-Environment Control
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    • v.22 no.3
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    • pp.270-278
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    • 2013
  • The objective of the present study is to provide data needed to decide covering method to be able to increase the thermal insulation and light transmittance efficiency of commercial greenhouse. The thermal insulation effect, PPF transmittance and quantity of condensation water were estimated in experimental tomato greenhouses covered with three types of coverings of single layer, air inflated and conventional double layers covering. The overall heat flow of air inflated double layers greenhouse was similar to that of conventional double layers greenhouse, but the temperature between covering material and thermal screen in air inflated double layers greenhouse was lower than that in conventional double layers greenhouse at the same outside temperature condition due to air leakage through the gap of roof vent. The overall heat transfer coefficients acquired by experiment that was performed in single layer and conventional double layers greenhouses were close to those obtained from model experiment. Even though the PPF transmittance of air inflated double layers greenhouse was lower than that of single layer greenhouse, which was greater than that of conventional double layers greenhouse. The quantity of condensation water on covering surface of single layer greenhouse was greater than that of air inflated double layers greenhouse due to lower covering surface temperature.

Effect of Covering Method of Ventilating Non-Woven Fabric and $\textrm{GA}_3$ Treatment on the Growth and Yield of Leaf Lettuce during Low Temperature Season (통기성 부직포의 피복방법 및 $\textrm{GA}_3$ 처리가 저온기에 잎상추의 생육 및 수량에 미치는 영향)

  • 최영환;손병구;강점순;안종길
    • Journal of Bio-Environment Control
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    • v.12 no.2
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    • pp.72-76
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    • 2003
  • This study was conducted to estimate stimulation of plant growth of green and red leafy lettuces (Lactuca sutiva L. cv. Chungchima and Jugchima) at affected by covering method and time with protected film materials containing concentrated PO film and GA$_3$ foliar spray. Plants were covered with ‘Pasraido’ material from October 26 to November 31 (direct 1), from November 5 to November 31 (direct 2), or with a tunnel, or direct 2+ tunnel. Mean air temperature and relative humidity under the covering were higher in direct and tunnel, direct and non-covering, in that order. The fresh weight and dry weight of red and green lettuces increased in direct and tunnel followed by direct 1, direct 2, tunnel and the control. GA$_3$ treatment promoted the growth in all covering methods, but decreased the chlorophyll contents. Fresh weight and dry weight were higher in red lettuce than in green lettuce in the control.

Effect of covering materials on seedling quality of rice (못자리 피복재가 벼의 묘소질에 미치는 영향)

  • Song, Suk-Yeon;Kim, Tae-Heon;Sohn, Jae-Keun
    • Current Research on Agriculture and Life Sciences
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    • v.28
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    • pp.47-52
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    • 2010
  • This study was carried out to investigate the availability of covering material used for raising seedlings in the rice nursery bed. The pre-germinated seeds of a rice cultivar 'Chilbo' were sown into seedling tray ($60{\times}30{\times}2.5cm$) on 20th April and 3rd May 2010. Polypropylene spunbonded fabric (PSF) and lagging were used for covering materials in rice nursery bed. The growth characteristics of seedlings were evaluated at 8, 15 and 25 days after sowing (DAS) in the nursery beds covered with PSF and lagging, respectively. The plant height of 8-day old seedlings grown in lagging nursery bed was longer by 2cm than those in PSF nursery bed when the seeds were sown on 20th April, but seedling quality grown in lagging nursery bed was poor compared with that in PSF nursery bed. The growth characteristics of 15-day old seedlings were similar to that of 8-day old seedlings. The plant height of 8, 15 and 25-day old seedlings grown in lagging nursery was longer than those in PSF nursery when the seeds were sown on 3rd May. The seedling quality grown in PSF nursery was better than that in lagging nursery. The seedlings grown in PSF nursery have more leaves and better seedling quality compared with that of lagging nursery. The seedling quality was remarkably decreased with the increase of nursery period in lagging bed but seedlings quality were recovered at 5 days after hardening treatment by removing the lagging.

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A Study on the Design Expression of Architectural Material Matter as Epidermal Concept (표피로서 건축 재료의 디자인 표현에 관한 연구)

  • Kim, So-Hee
    • Korean Institute of Interior Design Journal
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    • no.34
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    • pp.29-36
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    • 2002
  • Skin Architecture', which has been an important topic of architectural discourse in the recent past, is playing an even greater role in the design expression of architectural materials nowadays. The purpose of this study is to define the epidermal conception about material matter and to discover the various modes of visual effect in the use of architectural materials.Epidermal thought is expressed in different forms, ranging from a simple covering made up of materials of all kinds , removable or technological wrappings. Analyzing the recent experiments from the works of Bernard chumi, Herzog & de Meuron, Peter Zumthor, Gigon & Guyer , it can be argued that the skin is a good emotional approach in the design expression of architectural material matter as epidermal concept since the 1980's.

A Bibliographical Study on the Kim Ch$\v{o}$olni's W$\v{o}$njong Kongsin Nock$\v{o}$n (금천리(金天理) 원종공신록권(原從功臣錄券)의 서지적(書誌的) 고찰(考察))

  • Chon, Hye-Bong
    • Journal of the Korean BIBLIA Society for library and Information Science
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    • v.6 no.1
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    • pp.111-131
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    • 1984
  • The W$\v{o}$njong Kongsin Nock$\v{o}$n (原從功臣錄券) is a kind of the official document to granting a privilege and stipend which was awarded in 1395 to Kim Ch$\v{o}$lni (金天理). devoted his master who was latter set on a throne of the first King Taejo of Yi dynasty. In the present study are concretely verified that the Nock$\v{o}$n is bibliographically invaluable archives of early Yi dynasty in the viewpoint of the followings: 1) Unique material of biographies covering those meritorious retainers to deserving the foundation of Yi dynasty. 2) Worthy material of history including the meritorious examples on the founding of a new Kingdom which were omitted in the true record of the Yi dynasty. 3) Priceless material of philology written in the Korean ancient languages to use the letter of Yi-du (吏讀).

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Effect of the Covering Method of Simple Ventilating Cover Material on Growth and Development, Yield, Quality in the Leaf Lettuce during Low Temperature (통기성 간이피복재의 피복방법이 저온기에 잎상추의 생육, 수량 및 품질에 미치는 영향)

  • 안종길;빈기효홍;최영환;손병구;강점순
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2001.11a
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    • pp.96-101
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    • 2001
  • 동계의 노지 및 무가온 시설재배시에 상추와 시금치 등의 엽채류 재배는 생육이 거의 정지되는 온도에서 재배되고 있다. 이와 같은 저온기의 불량환경조건을 개선하기 위하어 저온성 엽채류에 직접 피복할 수 있는 통기성 피복자재가 개발되어 생육촉진이나 품질향상을 위한 연구가 지속되어 왔으나 피복방법의 개선에 관한 연구는 아직도 미흡한 실정이다. (중략)

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A Study on the Short-Circuit Characteristics of Vinyl Cords Damaged by External Flame (외부화염에 의해 소손된 비닐 코드의 단락 특성에 관한 연구)

  • Choi Chung-Seog;Kim Hyang-Kon;Shong Kil-Mok
    • Fire Science and Engineering
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    • v.18 no.4
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    • pp.72-77
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    • 2004
  • In this paper, we studied on the short-circuit process, surface structure, and component variation of vinyl cords. In the results of high speed imaging system (HSIS) analysis, as soon as wire covering was damaged by heat, the conductor of wire came in contact with the other conduct of wire, and the short-circuit occurred. Stereomicroscope and SEM analysis indicated that the source part of wire showed V-type form. The molten beads of load part were bigger than those of source part. In the results of EDX analysis, Cu and O were detected in the source part, whereas covering material (Cl, Ca), Cu and O were detected in the load part. The results will help us to find out the cause of electrical fire.

Vibration control laws via shunted piezoelectric transducers: A review

  • Qureshi, Ehtesham Mustafa;Shen, Xing;Chen, JinJin
    • International Journal of Aeronautical and Space Sciences
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    • v.15 no.1
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    • pp.1-19
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    • 2014
  • Attaching a piezoelectric transducer to a vibrating structure, and shunting it with an electric circuit, gives rise to different passive, semi-passive, and semi-active control techniques. This paper attempts to review the research related to structural vibration control, via passive, semi-passive, and semi-active control methods. First, the existing electromechanical modeling is reviewed, along with the modeling methods. These range from lumped parameters, to distributed parameters modeling of piezostructural systems shunted by electrical networks. Vibration control laws are then discussed, covering passive, semi-passive, and semi-active control techniques, which are classified according to whether external power is supplied to the piezoelectric transducers, or not. Emphasis is placed on recent articles covering semi-passive and semi-active control techniques, based upon switched shunt circuits. This review provides the necessary background material for researchers interested in the growing field of vibration damping and control, via shunted piezostructural systems.

Reduction of Floor Impact Noise and Impact Force for PVC Floor Covering and Floor Mat (PVC 바닥 마감재와 바닥 매트의 바닥충격음 및 충격력 저감)

  • Mun, Dae-Ho;Song, Guk-Gon;Lee, Cheol-Seung;Park, Hong-Gun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.7
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    • pp.501-508
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    • 2014
  • Floor finishing materials such as floor coverings and floor mats can reduce floor impact noise easily. When an impact was applied to the floor, its finishing material is deformed and the impact force that was applied to the concrete slab is changed. The softer finishing materials were, the more impact force decreased. An experimental study was performed using 14 PVC floor coverings and 16 floor mats to capture the characteristics of impact force and impact noise in the residential buildings. The test results show that the impact force spectrum and the floor impact noise spectrum have a linear relationship in the case of a bare concrete slab, and the characteristics of impact force reduction are the same as those of floor impact noise reduction.