• Title/Summary/Keyword: Carpet

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Prediction of Cascade Performance of Circular-Arc Blades with CFD

  • Suzuki, Masami;Setoguchi, Toshiaki;Kaneko, Kenji
    • International Journal of Fluid Machinery and Systems
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    • v.4 no.4
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    • pp.360-366
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    • 2011
  • Thin circular-arc blade is often used as a guide vane, a deflecting vane, or a rotating blade of low pressure axial-flow turbomachine because of its easy manufacture. Ordinary design of the blade elements of these machines is done by use of the carpet diagrams for a cascade of circular-arc blades. However, the application of the carpet diagrams is limited to relatively low cambered blade operating under optimum inlet flow conditions. In order to extend the applicable range, additional design data is necessary. Computational fluid dynamics (CFD) is a promising method to get these data. In this paper, two-dimensonal cascade performances of circular-arc blade are widely analyzed with CFD. The results have been compared with the results of experiment and potential theory, and useful information has been obtained. Turning angle and total pressure loss coefficients are satisfactorily predicted for lowly cambered blade. For high camber angle of $67^{\circ}$, the CFD results agree with experiment for the angle of attack less than that for shockless inlet condition.

A Study on Types of Design Composition and Characteristics of Patterns Expressed in Persian Carpets (페르시아 카페트에 표현된 디자인 구도 및 패턴특징에 관한 연구)

  • 김희선
    • Journal of the Korea Fashion and Costume Design Association
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    • v.5 no.1
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    • pp.25-32
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    • 2003
  • The purpose of this study is to categorize the types of design composition and analyse the characteristics of patterns expressed in persian carpets. For this study, 188 works of Persian carpets were selected out in the book "Carpet & Rug" and contents in the internet sites of www. carpetwordwide.net/, www.jafarnet.com/. The types of design composition expressed in Persian carpets were classified into the following categories. 1) Medallion design composition 2) Mihrab design composition 3) All over design composition 4) Vase design composition 5) Garden design composition 6) Moharamat design composition 7) Painting design composition 8) Tree of Life design composition 9) Plant Pattern design composition 10) Mosaic pattern design composition. Patterns expressed in Persian carpets were Mosk pattern, Tree of life pattern, Lotus pattern being related to their religion and Hunting picture patterns related to their real life. In particular, various patterns of beautiful flowers, plants, trees, animals such as birds, insects and stream, beauriful landscapes were expressed in Persian carpets.

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Antimicrobial Peptides (AMPs): Peptide Structure and Mode of Action

  • Park, Yoon-Kyung;Hahm, Kyung-Soo
    • BMB Reports
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    • v.38 no.5
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    • pp.507-516
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    • 2005
  • Antimicrobial peptides (AMPs) have been isolated and characterized from tissues and organisms representing virtually every kingdom and phylum. Their amino acid composition, amphipathicity, cationic charge, and size allow them to attach to and insert into membrane bilayers to form pores by 'barrel-stave', 'carpet' or 'toroidal-pore' mechanisms. Although these models are helpful for defining mechanisms of AMP activity, their relevance to resolving how peptides damage and kill microorganisms still needs to be clarified. Moreover, many AMPs employ sophisticated and dynamic mechanisms of action to carry out their likely roles in antimicrobial host defense. Recently, it has been speculated that transmembrane pore formation is not the only mechanism of microbial killing by AMPs. In fact, several observations suggest that translocated AMPs can alter cytoplasmic membrane septum formation, reduce cell-wall, nucleic acid, and protein synthesis, and inhibit enzymatic activity. In this review, we present the structures of several AMPs as well as models of how AMPs induce pore formation. AMPs have received special attention as a possible alternative way to combat antibiotic-resistant bacterial strains. It may be possible to design synthetic AMPs with enhanced activity for microbial cells, especially those with antibiotic resistance, as well as synergistic effects with conventional antibiotic agents that lack cytotoxic or hemolytic activity.

A Study on Fire Characteristics of Solid Combustible Materials Based on Real Scale Fire Test (실규모 실험에 의한 고체가연물의 화재특성 연구)

  • Kim, Sung-Chan
    • Fire Science and Engineering
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    • v.25 no.5
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    • pp.62-68
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    • 2011
  • A series of fire tests involving realistic solid combustible materials was conducted to quantify the heat release rate and investigate the fire growth characteristics during the initial fire growth stage. For these tests, single/double wood cribs, urethane cushion having polypropylene covers and wood crib on nylon carpet with urethane carpet padding were used as a fuel source. The fire growth coefficient of the solid combustible materials was quantified and the fire growth characteristics were compared with the $t^2$ fire scenario. The mean effective heat of combustion was evaluated by the total mass loss of fuel and total energy release concept and examined the effect of the ventilation and fire condition. The present study provides the practical information on the fire growth characteristics of solid combustible material to design to a set of fire scenarios for the fire risk analysis.

Central Asian Carpets, Assyrian Stone Thresholds, and Greco-Roman Mosaics - Cultural Exchange and Integration on the Silk Road

  • He, ZHANG
    • Acta Via Serica
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    • v.7 no.2
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    • pp.1-38
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    • 2022
  • Many knotted carpets from western China and Central Asia from 700 BCE to 700 CE demonstrate strong resemblances to the Assyrian-Persian stone reliefs and Hellenistic-Romanmosaics. Egypt reveals the earliest samples in plain linen fiber and carpets with colorful designs in the mural paintings. The Egyptian wall decoration in faience shows the motifs of waterlily in two variations in the design, both of which appear in the Assyrian floor thresholds designs. The same waterlily or four-petal design in the Egyptian and Assyrian stonework also appear in the Pazyryk knotted carpet in the same manner. The Assyrian thresholds show a composition with a central area and borders in a square or rectangular overall design, which again parallels the Pazyryk carpet. The ideas of composition and motifs commonly seen in the Hellenistic and Roman mosaics appear in the carpets of Central Asia and western China. The similarities between the stone mosaic works and carpets demonstrate clearly that the remote places and peoples in ancient times learned from, and exchanged with, each other the ideas and artistic styles, and integrated to create some local artistic traditions, thanks to the roles the easy-to-carry textiles played throughout the Silk Road. The carpets played their roles: as practical material for daily use, and as carrier of cultural information through their designs.

Trial Manufacture and Disinfection Evaluation of Anoxic Chamber System for Museum Insects (저산소 농도 살충 챔버 시스템 시제작 및 박물관 해충 살충 성능 평가)

  • Oh, Joonsuk;Choi, Jungeun;Lee, Jangmook
    • Journal of Conservation Science
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    • v.28 no.4
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    • pp.377-385
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    • 2012
  • Anoxic treatments using argon and nitrogen gas in controlled atmospheres have been used as a alternative to methyl bromide for insect disinfection in museums. Anoxic chamber system was manufactured and installed at The National Folk Museum of Korea for the first time in Korea. The internal capacity of anoxic chamber is 0.5m3 in which is able to use argon, nitrogen and carbon dioxide gas. This system is equipped with oxygen concentration, temperature and ralative humidity control devices and automatically controlled oxygen concentration from 0.01 to 20%, temperature from 10 to $50^{\circ}C$ and relative humidity 30 to 80%. To control the oxygen concentration, anoxic chamber system is adopted semi-dynamic method which supplies mixture of humidified gas and dry gas whenever oxygen concentration in chamber becomes higher than setting value. It has kept regularly oxygen concentration, temperature and relative humidity for 20 days using argon gas. To evaluate the disinfection of cigarette beetle larvae and adults and varied carpet beetle larvae, the anoxic chamber system maintained 0.01% of oxygen concentration, $25^{\circ}C$ in temperature and 50% in relative humidity for 30 days. Cigarette beetle larvae were killed in 7 days and adults in 3~5 days. And varied carpet beetle larvae were killed in 3 days. It reaches the conclusion form the evaluation this anoxic chamber system can be used to develop anoxic treatment as an alternative of methyl bromide for insect disinfection of infested cultural properties in museums.

전도성 Noise가 위치제어 시스템에 미치는 영향 고찰

  • Lee, Seong-Jae;Yun, Ju-Hyeong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.288-288
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    • 2009
  • Most of Static electricity forms part of our daily experience broadly. Most people have noticed from time to time electric shocks when closing of their car or after walking across a carpet, operating shredder in winter and touching a metal handle. This electrostatic discharge nuisance is normally a minor inconvenience, but in some cases static electricity can cause more serious problems. Static electricity can also be harnessed to good effect in Position Control System.

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An experimental study on the emission of volatile organic compounds(VOCs) from carpet (카페트에서 방출되는 VOCs에 관한 실험적 연구)

  • 신동민;김창녕;천만영
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.04a
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    • pp.177-178
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    • 2002
  • 최근 국내의 생활 문화가 점차 서구화되어 가면서 카페트를 사용하는 장소가 증가하고 있으며, 실내 소음 방지, 보온, 분위기 조성 등을 위한 목적으로 카페트의 사용범위는 점차 넓어지고 있다. 하지만 이러한 카페트는 실내 VOCs 방출원 중의 하나로 보고되고 있으며, 여기서 방출된 VOCs는 실내 공기질(Indoor Air Quality: 이하 IAQ라 칭함)저하를 유발하는 요소 중의 하나이다. (중략)

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Mass trasnfer model for VOCs emission from carpet (카페트에서 방출되는 휘발성 유기화합물의 물질전달 모델)

  • 신동민;김창녕
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.11a
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    • pp.214-215
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    • 2002
  • 실내공기 질 저하 요인중의 하나인 카페트에서 방출되는 휘발성 유기화합물(이하VOCs)이 실험적으로 측정되어, 카페트의 VOCs 방출과정이 모델링 되었다. 실험으로 측정된 데이터는 실험 범위 내에서만 유효한 값을 가지며, 세부적이며 국소적인 값은 파악되기가 어렵다. 따라서 이러한 실험의 한계가 극복되는 동시에 실험결과가 수학적으로 응용되기 위해서는 물리적 현상에 기반을 둔 모델링이 요구된다. (중략)

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A Study on the Flow Coefficient of Compartment Fire (건물화재시 개구부의 흐름계수에 관한 연구)

  • 허만성
    • Fire Science and Engineering
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    • v.10 no.4
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    • pp.19-27
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    • 1996
  • The objective of this research is to study on the upper layer temperature, interface height and flow regime in case of several furniture fires such as trashcan, chair, carpet, sofa, mattress and wardrobe as a fire starter in a residential room by performing the experimental studies. The upper layer temperature and the Interface height were relatively well agreed with the experimental results when the flow coefficient at the opening was 0.65-0.8 for the rectangular trashcan, 0.65-0.9 for the circular trashcan and chair, and 0.7-0.9 for the carpet, sofa, mattress and wardrobe. The interface heights for the seven furniture fires were around 1[m] maintaining steady state. However, at the time of the maximum temperature, the interface height was lowered to 0.25[m]-0.75[m] from the floor. The flow regime at the opening was filling and buoyant for the distributed fire, and for the concentrated fire it was filling and then quickly changed to flow, and the flow period was long. The descending speed of the interface height was proportioned to the inflammability of the furniture and the contact surface area with air. The time required to come down around 1[m] was within 1-3 minutes.

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