• Title/Summary/Keyword: Cool

Search Result 1,541, Processing Time 0.026 seconds

The Effects of Heat Transfer Characteristics of Fibers on the Warm/Cool Touch of Insulating Nonwovens (섬유의 열전달 특성이 보온용 부직포의 접촉온냉감에 미치는 영향)

  • Kim, Hee-Sook
    • Korean Journal of Human Ecology
    • /
    • v.8 no.1
    • /
    • pp.125-134
    • /
    • 1999
  • The purpose of this study was to investigate the effects of heat transfer characteristics of fibers on the Qmax of insulating nonwovens. The effects of fiber type, moisture content, washing cycles on the Qmax were observed. The correlations between Qmax measured by KES-F7 system and subjective warm/cool touch perception test was analyzed. The results obtained were as followed: 1. Heat transfer characteristics of fibers effected on the Qmax of insulating nonwovens. 2. Moisture transport properties of fibers effected considerably on the Qmax of nonwovens and the increasing rate of Qmax by increasing moisture content was much higher at wool than polyester. 3. As a result of subjective perception test, subjective warm/cool touch and wettness of wool nonwoven was increased obviously by increasing moisture content. 4. At the same moisture content, wool nonwoven showed higher subjective cool touch and wetness than polyester. 5. In the physical properties of nonwovens, thickness was the most effective factor on the Qmax of insulating nonwovens.

  • PDF

Analysis Growth Characteristics of the Introduced Species Revegetated on the Highway Cut-slopes (고속도로 비탈면 녹화용 도입초종의 생육특성 분석)

  • 우보명;오구균;김봉년;조영채;전기성
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.26 no.1
    • /
    • pp.12-20
    • /
    • 1998
  • This study was carried out from June 1996 to November 1997 to analyze the growth characteristics of the introduced species revegetated on highway cut-slopes. The number of revegetation measures type surveyed were fourteen such as seed-spraying measures, block-sod pitching measures, and hydro-seeding measures with seed-fertilizer-soil materials. The introduced species for revegetation measures were mostly Festuca arundinancea(cool season grass), Eragrostic curvula(warm season grass), Lolium perenne(cool season grass), Dactylis glomerata(cool season grass), Poa pratensia(cool season grass). The species diversity index of the upper part on highway cut-slopes were greater than that of the middle part and lower part. The growth of introduced species was good on north-facing cut-slope than the others and that was flourish in temperate north forest zone. Also, the introduced species seemed to decrease or disappear, while the ratio of native woody and herb species which were in mature stage seemed to increase.

  • PDF

COCOA: The CO-evolution of cluster COres and the AGNs of central galaxies

  • Baek, Junhyun;Jung, Taehyun;Tremou, Evangelia;Sohn, Bong-Won;Chung, Aeree
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.38 no.2
    • /
    • pp.49.2-49.2
    • /
    • 2013
  • We report preliminary results from a radio study of central galaxies in cool and non-cool core clusters. A cooling flow is expected to rapidly form in the center of galaxy clusters unless additional heating mechanisms such as merging with sub clusters are at work. It has been suggested that cool flows can feed the AGN in the central galaxies, increasing their power. On the other hand, the AGN feedback can also affect the surrounding medium, heating back up the gas in the cluster core region. In this study, we investigate the co-evolution of cool flows and the AGN of galaxies located in the cluster center. For this study, we have selected 13 radio bright central galaxies from clusters with a range of cooling time scale. In this work, we present results of our recent observations using the Korean VLBI Network. We discuss the properties of the sample in radio and other wavelengths.

  • PDF

Analysis of Surface Fibers by Wavelet Transform and Subjective Evaluation of Wool Fabrics (웨이블릿 변환을 이용한 모직물의 표면섬유 분석과 주관적 감각 평가)

  • 김동옥;김은애;유신정
    • Science of Emotion and Sensibility
    • /
    • v.5 no.3
    • /
    • pp.53-59
    • /
    • 2002
  • The surface fibers on the fabric is one of decisive factors which affects human sensory evaluation as well as heat and moisture transfer characteristics. In this study the length and distribution of surface fibers that are extruded from the fabric surface of the wool/wool blend fabrics (14 wool fabrics and 10 wool blend fabrics) and its contribution to subjective sensory evaluation were investigated. In order to quantify the length and distribution of surface fibers, image analysis and wavelet transform technique were introduced. Instant warm-cool feeling of touch, Q$\_$max/, and contact area were also measured and related to the quantified surface fibers. To figure out the effect of surface characteristics on sensory evaluation, human sensory responses to three adjectives which represent surface characteristics and warm-cool feeling of touch were obtained and analyzed. The relationship between the quantified surface fibers assessed by wavelet energy and both warm-cool reeling of touch, Qmax, and human sensory response were discussed.

  • PDF

A Possible Cause for the Cool Homopause of the 8-micron North Polar Hot Spot of Jupiter

  • Kim, Sang-Joon
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.41 no.2
    • /
    • pp.50.1-50.1
    • /
    • 2016
  • We have found cool homopause temperatures (Kim et al. 2016) of 180 - 250 K for the 8-micron North Polar Hot Spot (8NPHS) of Jupiter, which has been observed to be stationary at 180 deg (SysIII) longitude since the early 1980s. The 3-micron spectro-images of Jupiter that we analyzed were obtained with GNIRS, Gemini Near-Infrared Spectrograph at Gemini North on January 13, 2013(UT), and at $8{\mu}m$ on Feburary 6, 2013(UT) with TEXES, the Texas Echelon Cross Echelle Spectrograph at the NASA IRTF. The cool homopause was unexpected, and a possible implication of the relatively cool 8NPHS homopause compared with those of other auroral regions will be presented.

  • PDF

An Empirical Study for the Safe and Effective Operations in Membrane LNG Ships focused on the Tank Cool Down

  • Gim, S.G.;Kim, S.W.
    • 유체기계공업학회:학술대회논문집
    • /
    • 2005.12a
    • /
    • pp.566-572
    • /
    • 2005
  • The most crucial factor in membrane LNG ships to ensure sage operations, is how to effectively control tank pressure at the time of excessive generation of boil off gas (BOG). When the ships carry out tank cool down with her retaining heel prior to arrival at loading port, the vessel encounters the critical situation of excessive BOG and high tank pressure that can lead to high degree of risk. This is to provide one of the best ways to secure safe and effective LNG ship operations focusing on the detailed methods of tank cool down to achieve ATR(Arrival Temperature requirement) without building up high tank pressure and excessive BOG and calculating the appropriate heel quantity to be unutilized for tank cool down and fuel during ballast voyage.

  • PDF

Dynamic Analysis of Cool Thermal Storage Air Conditioning System (빙축열 에어컨의 동적 사이클 해석)

  • Koh, Jae-Yoon;Seo, Tae-Beom
    • Journal of the Korean Solar Energy Society
    • /
    • v.28 no.1
    • /
    • pp.65-74
    • /
    • 2008
  • In this study, dynamic characteristics analysis of AC system is investigated using a cool thermal storage system. A analysing program for cool thermal storage AC system is developed. The performances are studied by several variables and dynamic characteristics. Comparing the result at conventional operation condition with that at the condition using ice storage system, this study showed the effects of the sub cooled degree, superheated degree, efficiency of compressor and evaporating temperature. At the condition using thermal storage system, the thermal storage process was operated during midnight being not needed the cooling of the AC unit through the continuous running of the condenser. The refrigerant was sub-cooled using stored energy after being discharged from the air source condenser during the daytime. The COP was increased owing to the sub-cooling of refrigerant during daytime, thus the power consumption was effectively decreased.

Theoretical Analysis on the Heat and Mass Transfer in a Sorption Cool Pad (흡습 냉각 패드에서의 열 및 물질전달에 관한 연구)

  • 황용신;이대영;박봉철
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.16 no.2
    • /
    • pp.167-174
    • /
    • 2004
  • A sorption cool pad brings cooling effect without any pre-cooling, nor any external energy supply. It uses evaporative cooling effect stimulated by the desiccative sorption. In this paper, heat and mass transfer in the sorption cool pad are investigated theoretically. The evaporative cooling process caused by the desiccant is modeled and analyzed considering the sorption characteristics of the desiccant. Two nondimensional parameters are found to dominate the cooling process: one is related to the psychrometric characteristics and the other is to the sorption capacity of the desiccant. The former decides the time to reach the lowest temperature and the later controls the time duration of the cooling effect being sustained.

Cool Island Intensity in a Large Urban Green in Downtown Daegu: Seasonal Variation and Relationship to Atmospheric Condition (대구 도심에 위치한 대규모 녹지공간의 냉섬 강도: 계절변화와 기상조건에의 관련성)

  • Park, Myong-Hee;Kim, Hae-Dong
    • Journal of Environmental Science International
    • /
    • v.19 no.1
    • /
    • pp.81-87
    • /
    • 2010
  • Cool island intensity urban green space was investigated based in Dalsung Park, that is one of the largest parks in Daegu. Cool island intensity(CII), which is defined as the temperature difference between the green space and its surrounding built-up areas, shows time variations. A through-year measurement(2008-2009) of ground level air temperature revealed seasonal variation and relationship to the atmospheric condition of CII. The temperature variation in the park and the reference downtown Daegu was as same order as CII. The noontime CII is larger in summer than that in winter due to the leaf fall of the park trees. On the other hand, seasonal variation of nighttime CII is not so clear. The nighttime CII was larger under the stable atmosphere.

Occurrence of Brown Blight Caused by Waitea circinata var. zeae on Cool Season Turfgrass in Korea

  • Chang, Taehyun;Lee, Yong Se
    • Mycobiology
    • /
    • v.44 no.4
    • /
    • pp.330-334
    • /
    • 2016
  • In 2010, disease symptoms, including necrotic lesions on stems and leaves with circular yellow-brown or irregular brown color patches, were observed on cool-season turfgrass at golf courses (OHCC) and the Daegu University research farm in Gyeongbuk, Korea. We isolated the causal agent and identified it as Waitea circinata var. zeae by morphological characterization and molecular analysis. To the best of our knowledge, this is the first report of brown patch caused by W. circinata var. zeae on cool-season turfgrass in Korea.