• Title/Summary/Keyword: Cool

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Recognition of teachers and students' for operating BizCool in Industrial High School (공업고 BizCool 운영에 대한 담당 교사와 학생의 인식)

  • Shin, Yun-Chul;Eun, Tae-Uk;Lee, Yong-Jin;Kim, Jin-Soo
    • 대한공업교육학회지
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    • v.32 no.2
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    • pp.104-131
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    • 2007
  • The purpose of this study is to research and analyze recognition of teachers and students about operating BizCool in technical high school. These results were obtained by questioning teachers and students of high school which operated BizCool. Above of all, On the Teachers' recognition about BizCool. First, the most effective programs in BizCool are the entrepreneurial club activities, and these activites fostering an entrepreneurial mind as the primary benefits of operating BizCool. Second, to activate BizCool they want to employ staff whose responsibility is to organize BizCool because of the demand and pressure involved, and Bizcool entrepreneurial club should be connected with related enterprises. The development and spread of standard managing models is necessary. Third, Students also have to be able to learn essential knowledge about management, increasing their will to rely on themselves, and getting actual chances to conduct business. Finally, On the Students' recognition about BizCool. First, The contents and level of Bizcool, the availability of BizCool material, the fostering and learning of entrepreneurship are relatively easy and they show much interest in systematic entrepreneurial education. Second, the data show that BizCool is helpful for students to create an entrepreneurial mind and increase confidence about conducting business. Third, about school activities. Entrepreneurial club activities did not help to improve students' grades, to develop good habits or to make friends.

Analysis of the thermal performances of air-earth direct heat exchanger (공기 지중간 직접열교환시스템의 열성능 해석)

  • Kim, W.K.;An, J.S.;Choi, Y.D.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.9 no.2
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    • pp.112-121
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    • 1997
  • This study is focused on the development and selection of optimal cool tube system to maximize its thermal performance. Cool tube is devised to reduce the heating and cooling load of building by preheating or refreshing of intake air. Finite volume method was adopted to solve the conduction problem between the cool tube and earth. We examine the cool tube system for two operating periods, a short term(12 hours) and a long term(3 months). The results of short term operations reveal that condensation significantly influences and raises the exit air temperature. For long term operations, optimum conditions of cool tube system are obtained with variations of flow-rate, depth, length and diameter of cool tube.

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Effect of Heat Stress on Minerals Concentration in Blood and Colostrum of Heifers Around Parturition

  • Toharmat, T.;Kume, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.10 no.3
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    • pp.298-303
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    • 1997
  • Sixteen holstein heifers were employed to study the effect of thermal stress on rectal temperature and mineral status of heifers around parturition during hot and cool weather. During the hot weather, rectal temperatures of the heifers measured at 08:30 and 15:30 h from 7 d prepartum to parturition were higher than those during the cool weather. Blood hematocrit and hemoglobin were not significantly different between the hot and cool weather, but at 2 and 1 wk prepartum, those during the hot weather were higher. Plasma Ca, inorganic P and Fe of the heifers during the hot weather were higher than those during the cool weather, but plasma Mg and Zn and serum alkaline phosphatase during the hot weather were lower. Colostral protein and Mg of heifers at parturition during the hot weather were lower than those during the cool weather, but colostral Ca, P, Fe and Zn were not affected by the weather.

Analysis on the thermal performances of air-earth direct heat exchanger in one year (공기 지중간 직접열교환시스템의 연중 열성능 해석)

  • Kim, W.K.;An, J.S.;Choi, Y.D.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.9 no.4
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    • pp.517-526
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    • 1997
  • This study is focused on the development and selection of the optimal cool tube system to maximize its thermal performance. Cool tube is devised to reduce the heating and cooling load of building by preheating or refreshing of intake air with buried pipes. Finite volume method is adopted to solve the conduction problem between the cool tube and earth. We examine the cool tube system for two operating periods, a short term(12 hours) and a long term(3 months). The results of short term operations reveal that condensation significantly influences and raises the exit air temperature. For long term operations, optimum conditions of cool tube system are obtained with variations of flow-rate, depth, length and diameter of cool tube.

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Effects of the initial charging pressure of gas on the cool-down characteristics of the Joule-Thomson cryocooler (초기충전압력이 쥴톰슨냉동기의 강온에 미치는 영향)

  • Hong, Yong-Ju;Park, Seong-Je;Choi, Young-Don
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2160-2164
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    • 2008
  • Miniature Joule-Thomson cryocoolers have been widely used for rapid cooling of infrared detectors, probes of cryosurgery, thermal cameras, missile homing head and guidance system, due to their special features of simple configuration, compact structure and rapid cool-down characteristics. The cool-down time, the temperature at the cold end, the running time and the gas consumption are the important indicators of the performance of the J-T cryocooler. In this study, the initial cool-down stages of the J-T cryocooler were investigated by numerical simulations. The results show the effects of the initial charging pressures of gas on the cool-down time and the temperature at the cold end and the gas consumptions.

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Effects of Warm-up and Cool-down Exercises for Preventing Delayed Onset Muscle Soreness on Pain and Muscle Activation (지연성근육통 예방을 위한 준비운동과 정리운동이 통증과 근활성도에 미치는 효과)

  • Oh, Duck-Won
    • Physical Therapy Korea
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    • v.20 no.1
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    • pp.28-35
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    • 2013
  • The purpose of this study was to determine the effects of warm-up and cool-down exercises on pain and muscle activation of delayed onset muscle soreness after intense exercise. Delayed onset muscle soreness was caused by the eccentric exercise in the elbow flexor muscle of the non-dominant upper limb. Forty-four subjects volunteered to participate in this study and were randomly assigned to one of the following groups: warm-up and cool-down group, only warm-up group, only cool-down group, or control group with no intervention. The level of perceived pain using the visual analogue scale and electromyographic activation change in maximal voluntary isometric contraction were measured 4 times at the following times: 10 min, 24 hr, 48 hr, and 72 hr after the exercise. The results revealed the main effect between the groups and interaction effect between the group and measurement session (p<.05). The warm-up and cool-down group showed most favorable results with respect to reduced perceived pain level and increased muscle strength in most measurement sessions, and the only warm-up group showed significantly more decreased pain level than the control group at 24 hr and 48 hr and more increased muscle activation than the cool-down group at 48 hr (p<.05). However, there were no significant differences in pain level and muscle activation between the only cool-down group and control group at all measurement sessions (p>.05). The findings suggest that the warm-up exercise performed before an intense exercise had beneficial effects on the symptoms of delayed onset muscle soreness, whereas cool-down exercise performed after the intense exercise did not.

A Study on the Growth Characteristics of Native Plants by Seeding Amounts of Cool-season Turfgrasses on the Disturbed Slope (훼손비탈면의 한지형 잔디 파종량에 따른 자생식물의 생육특성에 관한 연구)

  • Kim, Jae-Hwan;Shim, Sang-Ryul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.5
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    • pp.1-12
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    • 2009
  • This research was initiated to investigate the revegetation characteristics under the seeding amount treatments of cool-season turfgrasses on the disturbed slope. 4 different seeding amounts of cool-season turfgrasses (0.0 $g/m^2$, 1.5 $g/m^2$, 3.0 $g/m^2$, 6.0 $g/m^2$) with the same seeding amounts of native woody (Rhus chinensis, Albizzia julibrissin) and herbaceous plants (Lotus corniculatus var. japonicus, Dianthus sinensis, Aster yomena) were treated with 3 replications on the experimental disturbed slope. Data such as soil hardness (mm), moisture content (%), surface coverage rate (%), the number of each germinating plant and plant height were analyzed. There were no statistic differences observed in the soil hardness and the soil moisture content while a significant difference was observed in the surface coverage rates. The surface coverage rates were higher in 3.0 $g/m^2$ and 6.0 $g/m^2$ plots compared to the rest two plots of cool-season turfgrasses. However, the emergence of native woody and herbaceous plants was relatively low in 3.0 $g/m^2$ and 6.0 $g/m^2$ plots of high seeding amounts of cool-season turfgrasses. This result indicated that high seeding amounts of cool-season turfgrasses could decrease the emergence of native woody and herbaceous plants. We concluded that 1.5 g~3.0 $g/m^2$ seeding amounts of cool-season turfgrasses was optimum level for the balanced emergence of cool-season turfgrasses, native woody and herbaceous plants in the viewpoint of the ecological disturbed slope revegetation.

Flooding Tolerance of Cool-Season Turfgrass for the Revegetation of Waterside Slopes (수변 비탈면 녹화를 위한 한지형잔디의 내침수성 연구)

  • Shim, Sang-Ryul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.2
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    • pp.45-52
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    • 2015
  • Cool-season turfgrass is a rapidly increasing of usage for the revegetation of waterside slopes in dams, lakes and rivers. The purpose of this research is to identify the flooding tolerance of cool-season turfgrass with respect to the flooding periods of 0(control), 2, 4 and 6 days, respectively. The surface coverage ratio, turfgrass injury and soil moisture content were measured to assess the flooding tolerance of cool-season turfgrass. The increase in the flooding periods with 4 and 6 days resulted in the lower surface coverage ratio for cool-season turfgrass while no significant difference was found in the 2 days flooding when compared to 0 day (the control plot) flooding plot. In case of the turfgrass injury and the soil moisture content, however, the higher values were found with the increase of flooding periods in 2, 4 to 6 days. We observed that the higher the turfgrass injury and soil moisture content increased, the lower the surface covrage ratio decreased. In these regards, we also observed that the tolerance of cool season turfgrass were high in the 2 days flooding condition, medium in the 4 days flooding condition and low in the 6 days flooding condition. The flooding tolerance of cool-season turfgrass was gradually weakened in over 2 days flooding periods due to $O_2$ deficiency in the anaerobic soil condition. Therefore, we could suggest cool-season turfgrass within 2 days flooding periods for the revegetation of waterside slopes in dams, lakes and rivers.

A Study on the Development of Dance Sportswear with Cool-touch Function (냉감 기능성 댄스스포츠 웨어 개발에 관한 연구)

  • Jun, Mi-Hwa;Jang, Jeong-Ah;Koo, Young-Seok
    • Fashion & Textile Research Journal
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    • v.22 no.1
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    • pp.66-75
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    • 2020
  • This study helps develop cool-touch functional dance sportswear. We suggest a draft design for dance sportswear that chooses appropriate cool-touch functional materials based on an investigation of the changes of body surface temperature before and after exercise, the physical properties of cool-touch materials on the market, and the preference for cooling tools. The results are as follows. First, cool-touch functional sportswear products on the market utilize materials such as PCM, Delta fabric, high gauge fabric, and ice chips as well as incorporate functions such as UV block and eyelets for enhanced breathability. Polyester and polyurethane fibers are mainly used for cool-touch functional sportswear. Second, the neck area showed the highest surface temperatures (32.7℃ and 32.1℃) before and after exercise. Body surface temperatures measured after exercise were also lower than temperatures measured before exercise when wearing dance sportswear. Third, as for the physical properties of cool-touch materials, material 1 showed amaximum drying speed (130 min), material 3 the best moisture absorption speed (122 × 132 min), and material 4 the best thermal conductivity (0.013 7 w/m·K). Fourth, a draft design for a cool-touch functional dance sportswear was suggested, including a neckband made of removable soft PVC material on the neck area and applying material 4 in F1, B4, S2 and lower arm areas and material 1 in the armpit area. Deodorant tape was also attached to the armpit area for added comfort and antibacterial deodorant effect.

Development of IR Reflective Cool Pigment and Paint (차열도료용 Cool Pigment 및 Paint 개발)

  • Kwon, Myon-Joo;Do, Young-Woong;Ha, Jin-Wook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.8
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    • pp.3800-3805
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    • 2012
  • Infrared(IR) reflective black cool pigment and paint which is used for interior/exterior materials(IR reflectance >30%) to prevent heat island effect and to increase energy efficiency were studied. Cool pigment was synthesized using mixture of $Fe_2O_3$ and $Cr_2O_3$ with calcination from 900 to $1,200^{\circ}C$. Cool paint was prepared by formulation of cool pigment, acrylic resins, and other additives. Results showed that optimum color fixation of pigment obtained by mole ratio of Fe to Cr was 0.9 with calcination temperature at $1,000^{\circ}C$. The cool paint formulated by 20% pigment and 1.5% dispersive additive with $125{\mu}m$ thickness of coated layer showed optimum IR reflectance. Temperature difference on surface between cool paint and ordinary paint(STD) was $36.5^{\circ}C$ and IR reflectance(TSR) was 39.3% at wavelength from 700 to 2,500nm. And color change was not detected during 500hrs weathering test.