• Title/Summary/Keyword: 수분 전달

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An Experimental Study on the Fry Drying of Low-rank Coal with a High Moisture Content (유중 건조법에 의한 고수분 저품위탄 건조 실험)

  • Moon, Seung-Hyun;Kim, Yong-Woo;Ryu, In-Soo;Lee, Seung-Jae
    • Journal of Energy Engineering
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    • v.18 no.4
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    • pp.213-220
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    • 2009
  • The experimental characteristics for fry drying method was investigated using low-rank coal with a high moisture content. Final temperature, mixing ratio between coal and kerosene, content of coal or kerosene, total weight of the mixture and mixing methods were varied to find out the optimum conditions by measuring moisture of coal. Evaporation of the coal moisture was not completed below $120^{\circ}C$ of final temperature. The amount of moisture was not significantly different over $130^{\circ}C$. Coal moisture was easily evaporated by increasing coal content, which showed that the moisture evaporation could be significantly enhanced by the remove of evaporated moisture from kerosene rather than by heat transfer to the coal. High total weight of the mixture resulted in lowering moisture content of coal with long evaporation time. On the other hand, low total weight was difficult to reduce the moisture below a certain level, but could reduce evaporation time. Thus, it can concluded that kerosene content should be lowered to the extent maintaining the mobility of the mixture in order to enhance evaporation. It was also observed that evacuation and mixing by using nitrogen could improve drying of coal.

Specimens and method for evaluating the moisturizing ability of lip makeup products (립메이크업 제품의 보습능 평가용 시편과 측정법)

  • Sung, Jee Eun;Jung, Jung Hui;Ryu, Hee-Wook
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.4
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    • pp.727-736
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    • 2017
  • In this study, the method of evaluation of moisturizing ability of cosmetics using specimens was studied as an alternative method of clinical tests. Cosmetic spreadability, surface drying, and moisture loss rate of four specimens (Japanese cake (Maru mochi), Garaetteok, wheat flour, and agar) were evaluated. Also, the water loss rate of the specimens and the transepidermal waterloss were analyzed for 10 kinds of lip make-up products (5 kinds of lipstick, 3 kinds of lip balm, 2 kinds of lip gloss). The moisture loss rate (moisture evaporation sensitivity) of the agar specimen was highest in the order of agar> Garaetteok> Japanese cake> wheat flour. Agar specimens are the most suitable in terms of spreadability, surface crack, and raw material supply. Containers for the preparation of agar specimens are suitable for plastic materials with low heat transfer, which can produce convex, smooth surface specimens. In the evaluation of moisturizing ability of lip makeup products, there was a strong correlation between the water loss rate and the transepidermal waterloss rate measured with agar specimens. These results show that the proposed method can be used as one of the useful alternative test methods.

An evaluation of the comfort and pattern design for cover fabric of train seats. (철도 차량 시트 커버직물의 패턴 디자인과 쾌적성 평가)

  • 이현자;박세진;박길순;이현영
    • Proceedings of the KSR Conference
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    • 2000.11a
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    • pp.183-189
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    • 2000
  • 시트 커버 직물은 철도차량 내부 인테리어와 실내를 구성하며, 시각적으로 커버 직물의 디자인 요소 중 패턴과 쾌적한 커버지가 철도차량에 대한 전체적인 이미지를 형성하게 된다. 본 연구는 한국인의 감성에 따른 시트 패던 디자인과 쾌적한 시트 커버 직물의 요건을 제시하고자 한다. 디자인 분석체계는 패턴 디자인의 최소단위를 Pattern Primitive(PP), 최소 반복 단위를 Repealed Pattern Unit(RPU)로 개념화하여 분류하여 파악한다. 또한 쾌적하고 안락한 시트를 위해서 착석 상태에서의 열수분 전달특성과 직물의 발수도, 일광견뢰도, 마찰견뢰도, Q-max, 공기투과도, 마찰대전압 등 물리적 특성을 비교한다.

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내열성 방염직물의 역학 특성과 수분전달 특성

  • 정유미;안승국
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.10a
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    • pp.426-429
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    • 1998
  • 의복의 여러 가지 기능 중 하나는 인간을 열이나 추운 환경으로부터 보호하는 것이다. 이러한 의복 중 방염직물(flame-resistant fabrics)은 산업적으로 열과 접촉하거나 위험한 환경에서 작업하는 작업자들을 열로부터 보호하는 중요한 역할을 하고 있다. 내열성 방염직물로 만들어진 작업복이 요구되어 지는 작업환경은 제철소에서와 같이 연속적으로 위험성이 있는 곳과 비행기 사고나 건물화재와 같은 잠재 위험성이 있는 곳 등이다[1]. (중략)

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Convective Heat Transfer Characteristics on a Plate Cooled by Rectangular Water Jets (사각수분류에 의한 평판상에서의 대류열전달 특성)

  • Kim, Uen-Young;Jeon, Sung-Taek;Park, Jong-Suen;Lee, Doug-Bong
    • Solar Energy
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    • v.15 no.1
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    • pp.53-71
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    • 1995
  • Experiments have been conducted on a planar, free surface jet of water to investigate the effects of aspect ratios(AR=6.67, 15, 26.67), average nozzle velocity($V_0=3.3m/s{\sim}78m/s$) and nozzle-to-plate spacings($Z/W=6{\sim}40$) on the characteristics of heat transfer, when 3 rectangular waterjets impinging on a flat plate which has the uniform heat flux. the scondary peaks which produced by circular jets also produced by rectangular water jets. The position of the scondary peaks depends upon the aspect ratio of nozzle. The heat transfer coefficient was subjected to the influence of aspect ratio. The heat transfer correlations and best position of nozzles which produced maximum heat transfer coefficient at stagnation point are provided.

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Characteristics of Microwave-Assisted Drying of Plant Cells of Taxus chinensis for Moisture Removal (수분 제거를 위한 식물세포 Taxus chinensis의 마이크로웨이브를 이용한 건조 특성)

  • Nam, Hyeon-Woo;Kim, Jin-Hyun
    • Applied Chemistry for Engineering
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    • v.31 no.2
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    • pp.208-214
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    • 2020
  • In this study, the characteristics and mechanism of microwave-assisted drying were investigated to improve the efficiency of the storage and extraction of biomass through the removal of moisture from plant cell Taxus chinensis. The efficiency of microwave-assisted drying increased with increasing microwave power. When the experimental data were fitted to typical drying kinetic models, the page and modified Page models were the most appropriate. The microwave-assisted drying was determined to be a spontaneous endothermic process, and randomness increased during the drying process. The effective diffusion coefficient (3.445 × 10-9~7.163 × 10-7 ㎡/s) and mass transfer coefficient (3.1529 × 10-5~1.2895 × 10-2 m/s) increased with increasing microwave power. The small Biot number (0.3890~0.7198) indicated that the mass transfer process was externally controlled.

Osmoregulatory Physiology in Ixodidae Ticks: An Alternative Target for Management of Tick (진드기의 수분조절 생리와 진드기 방제전략)

  • Maldonado-Ruiz, L. Paulina;Kim, Donghun;Park, Yoonseong
    • Korean journal of applied entomology
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    • v.61 no.1
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    • pp.91-100
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    • 2022
  • Ticks are the arthropod vector capable of transmitting diverse pathogens, which include bacteria, viruses, protozoan and fungi. Ticks are able to survive under stressful environmental conditions. One of evolutionary outcomes of these obligatory hematophagous arthropods is the survival for extended periods of time without a blood meal during off-host periods. Water conservation biology and heat tolerance have allowed ticks to thrive even under high temperatures and low relative humidity, thus they have become highly successful arthropods as they are distributed globally. Tick osmoregulatory physiology is a complex mechanism, which involves multiple osmoregulatory organs (salivary glands, Malpighian tubules, hindgut and synganglion) for the acquisition and excretion of water and ions. Blood feeding and water vapor uptake have been early reported as the primary passages for ixodid tick to acquire water. Recently, we have learned that ticks can actively drink environmental water allowing hydration. The acquired water can be traced to the salivary glands (type I acini) and the midgut diverticula. This opens new avenues for tick management through the delivery of toxic agents into their drinking water, in addition to an alternative strategy for the study of tick physiology. Here we address the osmoregulatory physiology in the ixodid ticks as a potential target physiological mechanism for tick control. We discuss the implications of water drinking behavior for tick control through the delivery of toxic agents and discuss the dermal excretion physiology as an additional pathway to induce tick dehydration and tick death.

The appearance change and heat·moisture transfer properties of knitted fabric by yarn shrinkage (원사의 수축에 따른 다공성 편성물의 형태변화와 열·수분 전달특성)

  • Sang, Jeong-Seon;Park, Juhyun;Lee, Mee-Sik;Oh, Kyung Wha
    • The Research Journal of the Costume Culture
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    • v.25 no.6
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    • pp.880-892
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    • 2017
  • In this study, the appearance change and the heat moisture transfer properties of knitted fabric by yarn shrinkage were examined to obtain useful data on the development of thermo-sensitive functional materials. Eleven types of knitted fabric were knitted using highly bulky acrylic-blended yarn. After shrinking the specimens using dry heat treatment, the appearance change and thickness were measured. An HEC simulator was adopted for measuring the heat moisture transfer properties of specimens by yarn shrinkage. When holes were arranged vertically in the mesh structure, the specimens with 2,500 and 5,000 holes showed high percent change of hole area, appearance, and thickness. When holes were diagonally arranged in the mesh structure, the percent change of hole area in the specimen with 1,250 holes was larger than the one with 2,500 holes. However, the dimensional stability of the specimen with 2,500 holes was better because of its smaller appearance and thickness change. In the tuck structure, the percent change of hole area in the specimen with 625 and 416 holes was relatively large compared with the appearance and thickness change. Furthermore, the hole size in the tuck structure was smaller than that in the mesh structure but the percent change of hole area was larger. Therefore, it was proved that the tuck structure is more suitable than the mesh structure for developing thermo-sensitive functional materials. Heat moisture transfer property test verified that the change of hole area by yarn shrinkage enabled obtaining the thermal effect due to the distinct temperature difference in the inner layer.

Fire Resistance Performance of High Strength Concrete with 4 Deformation Factors (4변형 인자에 의한 고강도콘크리트의 내화성능 평가)

  • Lee, Tae Gyu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.5
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    • pp.112-120
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    • 2012
  • A numerical model considering the internal vaporization and the creep effect, in the form of a analytical program, for tracing the behavior of high strength concrete(HSC) members exposed to fire is presented. The two stages, i.e., spalling procedure and fire resistance time, associated with the thermal, moisture flow, creep and structural analysis, for the prediction of fire resistance behavior are explained. The use of the analytical program for tracing the response of HSC member from the initial pre-loading stage to collapse, due to fire, is demonstrated. Moisture evaporates, when concrete is exposed to fire, not only at concrete surface but also at inside the concrete to adjust the equilibrium and transfer properties of moisture. Finite element method is employed to facilitate the moisture diffusion analysis for any position of member, so that the prediction method of the moisture distribution inside the concrete members at fire is developed. The validity of the numerical model used in this program is established by comparing the predictions from this program with results from others fire resistance tests. The analytical program can be used to predict the fire resistance of HSC members for any value of the significant parameters, such as load, sectional dimensions, member length, and concrete strength.