• Title/Summary/Keyword: dry and wet thermal

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

  • Choi, Jae-Woo;Jang, Bong-Sik
    • Fashion & Textile Research Journal
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    • v.6 no.4
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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.

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

  • Kim, Hyun-Ah;Kim, Seung-Jin
    • Fashion & Textile Research Journal
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    • v.20 no.1
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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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    • v.53 no.5
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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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    • v.35 no.4
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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.

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

  • Kim, Dami;Kim, Dohyung;Lee, Joo-Young
    • Journal of Korean Living Environment System
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    • v.24 no.1
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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.

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 (습식 및 건식 쌀가루의 유지 종류 및 첨가 비율에 따른 쌀빵 품질 특성)

  • Kim, Sang Sook;Chung, Hae Young
    • The Korean Journal of Food And Nutrition
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    • v.31 no.4
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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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    • v.17 no.1
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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.

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

  • Kim, Nae-Hyun;Byun, Ho-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6445-6452
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    • 2015
  • The surface of the cooling coil becomes dry, wet or partially wet depending on the operating condition. Thus, a proper design of the cooling coil should include a heat transfer analysis on dry, wet or partially wet surfaces. In this study, an elementary model, which analyzes the cooling on an elementaty basis, is proposed. Comparison of the predictions of the model with experimental data of the cooling coil revealed that heat transfer rates were predicted within 10.1%, airside pressure drop within 11.1% and sensible heat ratio within 5.7%. The model was used to investigate the effect of water circuitory on cooling coil performance.

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

  • O, Gyeong-Yeong;Lee, Gye-Hong;Lee, Gye-Hong;Jang, Seong-Ju
    • Korean Journal of Materials Research
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    • v.12 no.5
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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.

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

  • Kim, Seung-Jin
    • Science of Emotion and Sensibility
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    • v.10 no.1
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    • pp.69-77
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    • 2007
  • This study surveys wet and dry thermal shrinkages of PET POY manufactured by domestic seven companies and foreign companies in Japan and Taiwan. These thermal shrinkages were measured by hank method (KSK 0215) and foray FTA-500 apparatus, and these measured data were analysed and discussed with measuring methods. The specimens prepared were PET POY 85d/72f and 120d/36f, furthermore, 250d/48f and 155d/50f PET POY were also prepared for comparison of wet and dry thermal shrinkages between Japan and domestic PET POY. And the wet and dry thermal shrinkages of each specimens were measured according to the each layer divided by 50,000m of the cake, and between and within thermal shrinkages were analysed and discussed with the domestic and foreign PET POY and measuring methods such as hank ant Toray methods.

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