• 제목/요약/키워드: dry and wet thermal

검색결과 139건 처리시간 0.024초

Polytrimethylene terephthalate(PTT) 가연사의 수축거동에 관한 연구 (A Study on Shrinkage Properties of Polytrimethylene Terephthalate (PTT) Drawn Textured Yarn)

  • 최재우;장봉식
    • 한국의류산업학회지
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    • 제6권4호
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    • pp.492-496
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    • 2004
  • Shrinkage properties of drawn textured Poly(trimethylene terephthalate, PTT) yarn, which has been developed recently, were investigated to provide fundamental information for the textile industry. Shrinkage ratio characteristics on PTT yarn with six different count were investigated with tension, dry and wet thermal temperature. In non-tension, the shrinkage ratio were increased to increasing temperature at dry and wet thermal treatment, and in tension, the shrinkage ratio were increased to increasing tension at dry and wet thermal treatment.

습·건열 열고정 조건이 스트레치 직물의 역학특성과 의류형성성능에 미치는 영향 (Effect of Wet and Dry Thermal Setting Conditions of Stretch Fabric to Fabric Mechanical Property and Garment Formability)

  • 김현아;김승진
    • 한국의류산업학회지
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    • 제20권1호
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    • pp.83-92
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    • 2018
  • This paper investigated garment formability and fabric mechanical properties of one-way and two-way stretch fabrics according to the thermal treatment methods. One-way and two-way stretch fabrics were woven using 75d and 150d PET/spandex covering yarns and then these were wet thermal treated with four kinds of finishing machines. The fabric mechanical properties of these stretch fabrics specimens were measured and compared with the regular PET fabrics. The stretch ratio of one-way stretch fabric was ranged 12 to 26 percentage, 15 to 45 percentage for 2-way stretch fabrics and 4 to 10 percentage for regular fabrics. Garment formability of stretch fabric was superior than that of regular fabrics, in addition, 2-way stretch fabric was better than one-way. The garment formability of the stretch fabrics treated with CPB and Lava wet thermal machines showed the highest values, and the stretch ratio of these 2-way stretch fabrics was also the highest, which was ranged 20 to 45 percentage. This phenomenon was assumed to be due to high extensibility and bending rigidity with low shear modulus of the 2-way stretch fabric treated with CPB and Lava wet thermal machines. It was shown that the garment formability of stretch fabrics treated without dry thermal treatment was higher than that of dry thermal treated fabrics. It revealed that high stretch fabric was available under the condition of low process tension in the wet and dry thermal treatments of the finishing process, which makes high garment formability.

Thermal behavior of groundwater-saturated Korean buffer under the elevated temperature conditions: In-situ synchrotron X-ray powder diffraction study for the montmorillonite in Korean bentonite

  • Park, Tae-Jin;Seoung, Donghoon
    • Nuclear Engineering and Technology
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    • 제53권5호
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    • pp.1511-1518
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    • 2021
  • In most countries, the thermal criteria for the engineered barrier system (EBS) is set to below 100 ℃ due to the possible illitization in the buffer, which will likely be detrimental to the performance and safety of the repository. On the other hand, if the thermal criteria for the EBS increases, the disposal density and the cost-effectiveness for the high-level radioactive wastes will dramatically increase. Thus, fundamentals on the thermal behavior of the buffer under the elevated temperatures is of crucial importance. Yet, the behaviors at the elevated temperatures of the bentonite under groundwater-saturated conditions have not been reported to-date. Here, we have developed an in-situ synchrotron-based method for the thermal behavior study of the buffer under the elevated temperatures (25-250 ℃), investigated dspacings of the montmorillonite in the Korean bentonite (i.e., Ca-type) at dry and KURT (KAERI Underground Research Tunnel) groundwater-saturated conditions (KJ-ii-dry and KJ-ii-wet), and compared the behaviors with that of MX-80 (i.e., Na-type, MX-80-wet). The hydration states analyzed show tri-, bi-, and mono-hydrated at 25, 120, and 250 ℃, respectively for KJ-ii-wet, whereas tri-, mono-, and de-hydrated at 25, 150, and 250 ℃, respectively for MX-80-wet. The Korean bentonite starts losing the interlayered water at lower temperatures; however, holds them better at higher temperatures as compared with MX-80.

[ $(Th,U)O_2$ ] Pellets: Fabrication and Thermal Properties

  • Kang Ki Won;Yang Jae Ho;Kim Keon Sik;Song Kun Woo;Lee Chan Bock;Jung Youn Ho
    • Nuclear Engineering and Technology
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    • 제35권4호
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    • pp.299-308
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    • 2003
  • Fabrication technique of $(Th,U)O_2$ pellets has been investigated. Powder mixtures of $ThO_2\;and\;UO_2$ were milled in two different ways-dry and wet milling. Milled powder was compacted and sintered to $(Th,U)O_2$ pellets. The wet-milled powder leads to a $(Th,U)O_2$ pellet having a high sintered density and uniform distribution of U and Th, compared to the dry-milled powder. The sintered density of a $(Th,U)O_2$ pellet tends to decrease by increasing the content of $ThO_2$. The thermal conductivity of $ThO_2\;and\;(Th,U)O_2$ pellets was measured by the laser flash method. The thermal conductivity of the $ThO_2$ pellet is higher than that of the $UO_2$ pellet, and the thermal conductivities of $(Th,U)O_2$ pellets containing $65wt\%\;and\;35wt\%\;ThO_2$ pellets are lower than that of the $UO_2$ pellet.

기온 70℃의 복사열 노출 환경에서 건조와 젖은 상태의 소방용 보호장갑 착용 시 쾌적성 평가 (Wear Comfort of Firefighters Protective Gloves in Dry and Wet Conditions at 70℃ Air Temperature with Radiant Heat)

  • 김다미;김도형;이주영
    • 한국생활환경학회지
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    • 제24권1호
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    • pp.95-106
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    • 2017
  • The purpose of this study was to evaluate comfort functions while wearing firefighters' protective gloves in dry and wet conditions at $70^{\circ}C$ air temperature with radiant heat. Four types of firefighting gloves from Korea, Germany, United States, and Japan were evaluated in both dry and wet conditions by eight male firefighters. Firefighters put their hands and forearms wearing gloves into a hands-radiant chamber that maintained at an air temperature of $70{\pm}2^{\circ}C$ ($T_a$) and globe temperature $106^{\circ}C$ ($T_g$). During the exposure, subjects followed a fixed protocol of manual movements and stopped the exposure when they felt being intolerable. Results showed that completion time was extended by 6 min on average when gloves got wet and 15 min for the Japanese gloves was extended when compared to its dry condition (p<.001); microclimate humidity on the palm at the last stage was greater for wet conditions than dry conditions in the all gloves; and skin temperatures on mid-fingertip, palm, and hand were significantly lower for wet conditions than dry conditions especially for Japanese gloves (p<.001). These results indicate that the exposure time without thermal pain to radiant heat could be extended by wetting gloves during the low radiant heat exposure.

습식 및 건식 쌀가루의 유지 종류 및 첨가 비율에 따른 쌀빵 품질 특성 (Effects of the Type and Percentage of a Lipid on the Quality Characteristics of Rice Bread Depending on the Use of Wet and Dry Rice Flour)

  • 김상숙;정혜영
    • 한국식품영양학회지
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    • 제31권4호
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    • pp.511-519
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    • 2018
  • The baking properties of rice bread with different percentages of butter and oil in wet and dry rice flour were investigated. The moisture, damaged starch, mean diameter, pasting properties by amylogram and RVA (Rapid Visco Analyzer), as well as thermal properties by DSC (Differential Scanning Calorimetry) of wet and dry rice flour were analyzed. The specific gravity and color (L, a, b) of the dough, as well as the appearance, color (L, a, b) and texture of the rice bread with different percentages of butter and oil in wet and dry rice flour were also analyzed. As a result, the wet rice flour were composed of a noted higher content in moisture, compared to the dry rice flour (p<0.001). The wet rice flour had lower values of damaged starch, higher values of mean diameter and a higher peak viscosity than was noted in the dry rice flour (p<0.001). The wet rice flour showed a higher degree of hydration and gelatinization than was seen in the dry rice flour (p<0.001). The prevailing principle to utilize the replacement of wet rice flour with oil had a significant effect on the volume, specific volume and hardness of the rice bread (p<0.001). The hardness of the rice bread also showed a decreasing trend as the amount of the added oil was increased into the mixture. These results suggest that the replacement of wet rice flour with 5.8% oil is effective for the production of rice bread.

An Experimental Study of the Airside Performance of Slit Fin-and-Tube Heat Exchangers under Dry and Wet Conditions

  • Chang, Keun-Sun;Long, Phan-Than
    • International Journal of Air-Conditioning and Refrigeration
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    • 제17권1호
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    • pp.7-14
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    • 2009
  • Water condensate accumulated on the surface of a fin-and-tube heat exchanger significantly affects its thermal and hydraulic performances. The purpose of this study is to investigate the effects of condensate retention on the air-side heat transfer performance and flow friction for various flow and geometric conditions. Total of twelve samples of slit and plate fin-and-tube heat exchangers are tested under dry and wet conditions. The thermal fluid measurements are made using a psychrometric calorimeter. Frontal air velocity varies in the range from 0.7 m/s to 1.5 m/s. Using the experimental data, presented are heat transfer coefficients in terms of Colburn j-factors and friction factors, and these data are compared with the existing correlations.

건물 공조용 냉수 코일의 열 설계 (Thermal Design of a Cooling Coil for Building Air Conditioning)

  • 김내현;변호원
    • 한국산학기술학회논문지
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    • 제16권10호
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    • pp.6445-6452
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    • 2015
  • 건물용 공기조화기의 냉수 코일은 작동조건에 따라 건표면, 습표면 또는 부분적인 습표면이 형성된다. 따라서 냉수코일을 적절히 설계하기 위해서는 건표면과 습표면, 그리고 부분적 습표면에 대한 열전달 해석이 필요하다. 본 연구에서는 미소체적에 대한 해석을 통하여 냉수코일의 성능을 계산하는 미소체적 모델을 제시하였다. 해석 모델의 예측치를 냉수코일 실험결과와 비교한 결과 미소 체적 모델은 공기측 전열량을 10.1% 이내에서 예측하고 공기측 압력손실을 11.1%, 현열비도 5.7%내로 예측하였다. 해석 모델을 활용하여 물측 회로의 변화가 냉수코일의 성능에 미치는 영향을 검토하였다.

MOS 소자용 Silicon Carbide의 열산화막 생성 및 특징 (Characteristics and Formation of Thermal Oxidative Film Silicon Carbide for MOS Devices)

  • 오경영;이계홍;이계홍;장성주
    • 한국재료학회지
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    • 제12권5호
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    • pp.327-333
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    • 2002
  • In order to obtain the oxidation layer for SiC MOS, the oxide layers by thermal oxidation process with dry and wet method were deposited and characterized. Deposition temperature for oxidation layer was $1100^{\circ}C$~130$0^{\circ}C$ by $O_2$ and Ar atmosphere. The oxide thickness, surface morphology, and interface characteristic of deposited oxide layers were measurement by ellipsometer, SEM, TEM, AFM, and SIMS. Thickness of oxidation layer was confirmed 50nm and 90nm to with deposition temperature at $1150^{\circ}C$ and $1200{\circ}C$ for dry 4 hours and wet 1 hour, respectively. For the high purity oxidation layer, the necessity of sacrificial oxidation which is etched for the removal of the defeats on the wafer after quickly thermal oxidation was confirmed.

감성소재 PET 사(絲)의 계측방법에 따른 열수축률 변화 (Thermal Shrinkage Variation to the Measuring Method of Sensory PET Filament)

  • 김승진
    • 감성과학
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    • 제10권1호
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    • pp.69-77
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    • 2007
  • 본 연구는 국내 7개 회사와 일본과 타이완 기업에서 만들어진 PET POY 사의 습열과 건축수축률을 연구하였다. 이들 사(絲)의 열적수축률들은 hank방법 (KSK 0215)과 Toray FTA-500 장치를 사용하여 측정되었으며 측정된 데이터는 측정방법에 따라 분석되고 토의되어졌다. 준비된 시료는 PET POY 85d/72f와 120d/35f이며 더구나 250d/48f와 155d/50f PET POY가 일본과 국내사 사이의 습열과 건열수축률의 비교를 위해서 역시 준비되어졌다. 그리고 각 시료들의 습열과 건열수축률들은 원사 케이크 내의 사(絲), 50,000m를 1개의 layer로 각각 나누어 각각의 layer 별로 측정되어졌으며 급내와 급간 열수축률이 측정 분석되었으며 국내와 외국 수입사(絲)에 따른 차이를 hank와 Toray 측정방법에 따라 분석하였다.

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