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A Study of Dyeing Properties of PET Fabrics under Supercritical CO2 Depending on Test Condition: by Temperature, Pressure, Leveling Time (초임계 유체 염색 조건에 따른 PET 섬유의 염색 특성: 온도별, 압력별, 시간별)

  • Choi, Hyunseuk;Park, Shin;Kim, Taeyoung;Song, Taehyun
    • Textile Coloration and Finishing
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    • v.31 no.1
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    • pp.14-24
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    • 2019
  • In this study, dyeability of PET fabric was investigated depending on dyeing temperature, pressure, and leveling time using laboratory scale supercritical $CO_2(scCO_2)$ dyeing machine. Dyeing temperature, pressure, leveling time were varied from 100, 120, $130^{\circ}C$, 150, 200, 250bar, 40, 60, 80, 100min, respectively. It is proved that the higher temperature of $scCO_2$ dyeing process, the higher K/S value and the lower $L^*$ value, which in turn means the lower amount of dyeing molecules remained after process done. Compared 200bar with 250bar of dyeing pressure, $scCO_2$ dyeing fabrics under 250bar appeared to have a lower $L^*$ value, a higher K/S value than those from 200bar, meaning that dyeing color turns to darker with higher dyeing pressure. The experiments showed that the most ideal condition for $scCO_2$ dyeing process is $120^{\circ}C$, 250bar for 60 - 100min of leveling time.

Polarization-independent temperature sensor using cladding layers of the overlay waveguide coupled with a side-polished fiber (측면 연마 광섬유와 결합된 상부 도파로의 클래딩을 이용한 편광 무의존 온도센서)

  • 손경락;김광택;송재원
    • Korean Journal of Optics and Photonics
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    • v.13 no.6
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    • pp.467-472
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    • 2002
  • In this paper, we propose a polarization-insensitive temperature sensor using a thermo-optic effect of the upper and (or) lower cladding of a planar waveguide in contact with a side-polished fiber. A microscope cover glass with thickness of a 170 ${\mu}{\textrm}{m}$ is adopted as an overlay waveguide because this waveguide opposes sudden temperature change and ensures polarization-insensitive responses. The measured polarization-dependence loss is less than 0.3 dB. The temperature can be detected as a result of the shift in coupling wavelength of the sensor. We investigate the shift in coupling wavelength as a function of the temperature variation with respect to the different thermo-optic coefficients of lower and upper claddings. We also show that the temperature sensitivity of the device can be easily controlled by the thermo-optic coefficients of lower and upper claddings of the overlay waveguide.

A study on cooling characteristics of clathrate compound for cold storage applications (저온축열용 포접화합물에 냉각특성에 관한 실험적 연구)

  • 한영옥;김진흥
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.2
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    • pp.205-214
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    • 1999
  • The objective of this paper is to investigate the thermal properties of TMA clathrate compound applicable to cold storage system for building air-conditioning. Especially, the test tube experiments are performed by comparing and analyzing the temperature of phase change, specific heat and subcooling characteristic according to the variation of density, temperature of heat source and charging quantity in TMA clathrate compound. The results are summarized as follows:1) $-15^{\circ}C$ is not proper as the temperature of heat source because the temperature of subcooling is above $8.3^{\circ}C$ 2) temperature of phase change is dropped as the temperature of heat source is lower, 3) the effect of subcooling suppression with about 8$^{\circ}C$ is confirmed when the temperature of heat source is $-10^{\circ}C$ in case of 26, 27, and 30wt%, while the temperature of subcooling is about $0^{\circ}C$ when the temperature of heat source is $-15^{\circ}C$ in case of 25, 26 and 30wt%. Thus, the effect of subcooling suppression is greater as the temperature of heat source is lower. Additionally, the concentrative study is needed on mass concentration causing the phase change without subcooling phenomenon when the temperature of heat source is $-15^{\circ}C$. Thus, it is concluded that TMA clathrate compound has enough thermal properties as the cold storage medium for building air-conditioning.

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Estimating the Air Temperature Cooling Effect of the Cheonggyechun Stream Restoration Project of Seoul, Korea

  • Park Chong-Hwa;Kwon Young-Sang
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • no.2
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    • pp.120-129
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    • 2004
  • Urban stream restoration projects can improve water quality, wildlife habitats, urban landscape, outdoor recreation spaces, and urban microclimate. The objectives of this research were to investigate temperature cooling effect of urban streams by using satellite imagery, to evaluate environmental variables related to stream cooling effect, and to estimate the cooling effect of the Cheonggye stream restoration project of Seoul, Korea. Findings of this research can be summarized as follows. First, a method of estimating temperature distribution around urban streams by using satellite imagery was developed. Scatter plots of distance from stream edges and average temperature obtained through multiple buffering were used for the estimation. Second, urban temperature cooling effect of streams was estimated by comparing background temperature and temperature of each buffer zone. Third, environmental factors affecting stream cooling effect were also identified. Fourth, the temperature cooling effect of the restoration project was estimated based on three scenarios. An estimated cooling effect based on the average cooling effect of existing tributaries showed the most significant effect; $2.0^{\circ}C$ lower than the present level at the edge of the renovated stream. It was estimated that the temperature of the same area would be $1.4^{\circ}C$ cooler than the present level if the cooling effect of the Yangjaechun was used as the bench mark But the effect would be $1.2^{\circ}C$ lower than the present level if environmental variables related to the temperature cooling effect of urban streams were used as the bench mark.

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Improved Resolution of Paper-based Sensor for Proline Detection by Low-temperature Drying of Ninhydrin Solution (닌히드린 용액의 저온 건조에 의한 프롤린 검출을 위한 종이기반 센서의 분해능 개선)

  • Ji-Kwan, Kim;Young-Soo, Choi
    • Journal of Sensor Science and Technology
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    • v.31 no.6
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    • pp.428-432
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    • 2022
  • In this study, we describe the improvement of the resolution of a paper-based sensor by fabricating a high-concentration ninhydrin part using a low-temperature drying method to detect proline with high resolution. In the conventional paper-based sensor for detecting proline, the ninhydrin part is fabricated at room temperature, and in this process, the ninhydrin solution spreads around the ninhydrin part. Therefore, the concentration of the ninhydrin part becomes lower than that of the applied solution, lowering the resolution of the sensor. The proposed paper-based sensor better improved the sensitivity of the sensor compared to the existing sensor by fabricating a high-concentration ninhydrin part through drying the ninhydrin solution using a low-temperature drying method. Owing to the experiment, the intensity of the green color of the paper-based sensor with the integrated ninhydrin part fabricated at 10 ℃ is approximately 20% lower than the paper-based sensor with an integrated ninhydrin part fabricated at room temperature, indicating better sensor resolution. Therefore, the paper-based sensor with an integrated ninhydrin part fabricated at a high concentration could be useful for diagnosing drought.

Developing of Functional Sport Underpants using Infrared Thermal Image Analysis (열적외선 영상분석을 이용한 기능성 스포츠 팬티 개발)

  • Lee, Joong-Sook;Yang, Jeong-Ok;Lee, Bom-Jin
    • Korean Journal of Applied Biomechanics
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    • v.25 no.2
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    • pp.231-240
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    • 2015
  • Objective : This study is for providing data about men's functional sport underpants. It provides the fundamental data of biomechanics by measuring and analyzing the functionality of various underpants using infrared thermal image camera. Method : Then author drew a conclusion based on the final analysis of 965 questionnaire survey results about issues on men's functional sport underpants after discarding invalid questionnaires, as following. Change in body temperature while wearing functional underpants compared to general briefs or boxer pants showed lower temperature by approximately 1~2 degrees Celsius. In the case of general underpants, wearer sweats and feels hotter due to the friction of penis, scrotum and thigh. However functional sport functional underpants improved this issue with ergonomic 3D design by putting penis towards the lower part of the abdomen(below the navel) while putting the scrotum comfortably on the testicles, which enables to make room between the penis, scrotum and thigh of a wearer. Results : This was analyzed to lower the temperature of penis and scrotum. The survey results about the quality of functional underpants showed that 78% of the respondents felt comfortable while driving; 68.5% replied that frictional heat decreased while working out; 78.7% felt less sweat and humidity; 81.7% replied as highly wearable and comfortable; 77.1% replied functional sport underpants were the most comfortable in routine lives or in workout times. Putting all such results together, it is possible to conclude that functional sport is an excellent product. Conclusion : This can be evaluated as an excellent functional sport underpants, towards the penis abdomen (under the navel) in 3D human engineering design, by the scrotum to wearing to be easier to scrotum of pocket, the penis and scrotum and thighs were separated and analyzed with a function that will lower the body temperature of the penis and scrotum.

Thermophysiological Responses and Subjective Sensations when Wearing Clothing with Quickly Water-Absorbent and Dry Properties Under Exercise-Induced Heat Strain (운동에 의한 열 스트레스하에서 흡한속건성 소재 운동복 착용시의 온열생리적 반응 및 주관적 감각)

  • Lee, So-Jin;Park, Shin-Jung
    • Fashion & Textile Research Journal
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    • v.8 no.3
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    • pp.349-356
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    • 2006
  • The purpose of this study was to compare the thermophysiological responses and subjective sensations of clothing materials with different water transfer property investigated in exercising and resting subjects at an ambient temperature of $20^{\circ}C$ and a relative humidity of 40%. Two kinds of clothing ensemble were tested: 100% cotton with highly water-absorbent but slowly dry properties(C) and 100% polyester with quickly water-absorbent and dry properties by four capillary channels(QADP). Seven apparently healthy male participants each undertook two series of experiments comprised 10-min of rest, 20-min of exercise with 70% of $VO_{2max}$ on a treadmill and 20-min of recovery. Mean skin temperature was significantly lower in QADP than in C during exercise and recovery. Clothing microclimate temperature was significantly lower in QADP during exercise and clothing surface temperature was also lower in QADP especially during recovery. Also, clothing surface humidity was significantly higher in QADP after the later half of exercise. The concentration of blood lactic acid tended to decrease to a lower level at recovery 3 minutes when wearing QADP rather than C clothing ensemble. Metabolic energy was marginally significantly less during the second half of exercise in QADP. Body mass loss tended to be greater in C than in QADP. The participants had better scores in thermal sensation, comfortable sensation and wetness in QADP during exercise and recovery. These results show that functional materials with quickly water-absorbent and dry properties can alleviate heat strain and induce more comfortable clothing microclimates and subjective sensations in the exercise-induced hyperthermia.

Study on Air Washer using Underground Water in the Subway Stations (지하철 역사 지하수를 이용한 에어와셔에 관한 연구)

  • Kim, Dong-Gyu;Kim, Hoe-Youl;Chung, Yong-Hyun;Kim, Jong-Ryul;Kum, Jong-Soo
    • Journal of Fisheries and Marine Sciences Education
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    • v.22 no.4
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    • pp.604-610
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    • 2010
  • Busan subway transportation system has been established a key role in the society last 20 years. However many people are suffering from hot and humid environment at subway station and platform due to deteriorated ventilation system as well as insufficient air conditioning system in existing stations and platforms. As a result, these systems require revitalization. There is about 5400tons of low temperature underground water is generated from subway stations every day. By using this method and air washer we are trying to lower the temperature. Air washer is commonly used for removing humidity but in this experiment it will be used as air precooling. This research offers result of experiment using air washer system to lower the temperature in large spaces like subway station. The experiment result has shown when L/G was the same, at condition which water spray temperature at $18^{\circ}C$ resulting inlet and outlet temperature difference larger. Also, in the same water spray temperature conditions, larger L/G condition showed a greater temperature difference. LCC evaluation of both system were shown that air washer system of using underground water will save 53% of the initial cost than refrigeration system, and save 75% of operating cost.

Effects of different stocking density in lairage of fattening pigs in high temperatures

  • Dongcheol Song;Seyeon Chang;Jaewoo An;Sehyun Park;Kyeongho Jeon;Hyuck Kim;Jinho Cho
    • Korean Journal of Agricultural Science
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    • v.50 no.4
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    • pp.861-867
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    • 2023
  • Lairages serve several functions, such as providing post-mortal inspections and providing a reservoir of animals to ensure the slaughter line runs efficiently. High stress lairage conditions can contribute to the accumulation of transport stress in pigs, causing poor pork quality and still stressed pigs at slaughter. The objective of this study was to investigate meat quality, blood profile and behavior changes according to lairage stocking density in in high temperature. Density treatments were as follows: LD, low density (lower than 0.5 m2/100 kg); ND, normal density (0.5 m2/100 kg to 0.83 m2/100 kg); HD, high density (higher than 0.83 m2/100 kg). Air temperature treatment was as follows: HT, high temperature (higher than 24℃). Pigs stocked with LD showed lower pH, WHC (water holding capacity), and higher DL (drip loss) and CL (cooking loss) than those stocked with HD. Pigs stocked with LD showed lower cortisol level than those stocked with HD. Therefore, Pigs exposed to high stock density (lower than 0.5 m2/100 kg) in high air temperature during pre-slaughter caused acute stress and lead to PSE (pale, soft, exudative) pork incidence. Based on obtained results, stocking of too high (lower than 0.5 m2/100 kg) density is generally not good for meat quality and animal welfare at high temperatures.

The Relationship between Clothing Microclimate and Physiological Responses at $15^{\circ}C$ Environment ($15^{\circ}C$ 환경에서 의복기후와 인체생리반응과의 관련성)

  • Park, Joon-Hee;Choi, Jeong-Wha
    • Journal of the Korean Home Economics Association
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    • v.46 no.4
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    • pp.97-105
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    • 2008
  • The objective of this study is to investigate the relationship between clothing microclimate and physiological responses, including subjective sensations, when, in a $15^{\circ}C$ environment, a range of temperatures inside clothing is broadly produced from using various combinations of upper and lower garments. Six male subjects participated in the investigation and the results were as follows. For all types of inside garments, the temperature of the clothing was lower than the skin temperature for the whole body in each case. The mean temperature for inside clothing ($\bar{T}_{cl}$) significantly showed the highest correlation with mean weighted skin temperature (r = 0.816) and was less positively correlated with the temperature of the inside clothing at the chest (r = 0.326) (p < .01). Values for both the energy expenditure and the heart rate were less positively correlated with the clothing microclimate (p < .01). The change of body heat content showed a negative correlation with the surface temperature of the innermost clothing (r = -0.519) and there was a difference between the innermost surface temperature and the outermost surface temperature of the clothing at the chest (r = -0.577). As td increased, the increase of body heat content declined (p < .01). There was a negative correlation between body fat and some of the temperatures inside the clothing (p < .01) and body fat had no significant correlation with the humidity inside the clothing. Subjective sensations were more highly correlated with $\bar{T}_{cl}$ than with the temperature of the inside clothing at the chest and had not significantly correlation with the humidity of the inside clothing. In conclusion, through these results, it can be seen that the temperature inside the clothing was related to various physiological responses and subjective sensations, and that the mean temperature of the inside clothing ($\bar{T}_{cl}$) showed a higher relationship with the temperature of the inside clothing at the abdomen than that at the chest.