• Journal of Environmental Science International
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• v.30 no.7
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• pp.547-555
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• 2021

To compare the vitality among cool-season turfgrasses under summer weather conditions and to obtain information to improve the management of turfgrasses in golf courses and sports fields., the chlorophyll fluorescence of three cool-season turfgrasses commonly planted on golf courses in the Jeju area was measured. The turfgrasses were perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), and creeping bentgrass (Agrostis palustris Huds.). In perennial ryegrass and Kentucky bluegrass, the chlorophyll index was low in early summer and high in late summer. In creeping bentgrass, it remained low throughout the study. Fo tended to be low in the early summer and high in late summer in the three turfgrasses. However, the difference in F_o between late summer and early summer was markedly higher in perennial ryegrass than in Kentucky bluegrass or creeping bentgrass. F_m tended to be low in early summer and high in late summer, without obvious differences among the three turfgrasses. F_v/F_m, a measure of photochemical efficiency, was also low in early summer and high in late summer in the three turfgrasses. However, F_v/F_m in late summer was mostly higher in Kentucky bluegrass and creeping bentgrass than in perennial ryegrass, indicating that the former are more resistant to the high temperature and humidity of late summer. Furthermore, Kentucky bluegrass had a high chlorophyll index in late summer and would be most resistant to the harsh conditions of late summer.

• International Journal of Human Ecology
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• v.8 no.1
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• pp.27-37
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• 2007

The purpose of this study is to investigate the preference of the hand and the sensibility image of underwear textiles according to seasons. According to a recent survey of 109 college students, using a 7 scale evaluation to the preference of the hand and the sensibility image among 13 summer and 10 winter underwear textiles. The data was analyzed through mean, SD, factor analysis, t-test, Person correlation analysis and regression analysis using SPSS Win 11.0. The summer underwear textiles were classified according to six tactile factors: stiffness/surface unevenness, weight, elasticity, moistness, extension, and warm-cool and 3 sensibility image factors: elegant individual, modern, and sporty-casual. The winter textiles were classified according to six tactile factors: stiffness/surface unevenness, elasticity, warm-cool, drapability, moistness and flexibility and divided into 2 sensibility images: modern elegant and sporty-casual. Factors expressing hand and sensibility image according to season showed significant difference. In the summer, weight, in the winter, drapability and flexibility showed significant difference at the hand factor evaluation. The hand factors: weight, warm-cool and modern sensibility image factors effect the preference of summer underwear textile, also the hand factors-elasticity, stiffness/surface unevenness and the sensibility image factor-easy-sport-casual-effect the preference of winter textiles. Therefore, the thin, light, and cool textiles which are also gorgeous and sporty-casual are preferred for summer underwear textiles while soft, simple and comfortable textiles are preferred for winter textiles.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.4
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• pp.203-208
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• 1991

This experiment was carried out to compare the effects of summer temperature and nitrogen application on carbohydrates and fiber contents in orchardrass stubble grown in the cool summer year, 1980 and in the hot summer year, 1984. For this study, the contents of carbohydrates, neutral detergent fiber (NDF), acid detergent fiber(ADF) and hemicellulose in orchardgrass stubble were investigated. 1. Total water soluble carbohydrates(TSC) in orchardrass stubble were accumulated during the period of cool season and were declined when the weather was hot and dry. The reserve level of those were decreased when a new leaf emerged after the start of plant growth and then were increased as the plant was in full flourish. 2. The reserve of carbohydrate content in orchardgrass stubble was about twice times higher in cool summer year than that in hot summer year, and the reserve rate of carbohydrates showed to be fast in cool summer year. When the nitrogen fertilizer applied, the content of TSC in orchardgrass stubble more lowered but not significantly different(p<0.05). 3. The contents of NDF, ADF and hemicellulose in orchardgrass stubble in cool summer year were not significantly different from those in hot summer year. These contents showed also no significant difference among different levels of nitrogen applications. 4. The relationship of carbohydrate, NDF, ADF and hemicelluose contents according to the levels of nitrogen applications were negatively correlated in cool summer year. But there was no consistency in hot summer year.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1136-1145
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• 1996

This study was to develop the most effective cooling system which is needed to cool greenhouse during summer night to get early blooming of strawberries. Various cooling systems were designed and constructed to utilize the cool air and water from tan abandoned coal mine. Cooling systems built for this study were an evaporative cooling system with pad, cooling system using a small or large radiator , and duct cooling system using cool are drawn from coal mine. These systems were individual tested to investigate their effects on cooling greenhouse during summer night. Also, a combined cooling system was tested with operating an evaporative cooling system, small radiator, and duct cooling system simultaneously. The results in this study showed that individual cooling systems such as evaporative cooling system, small radiator, and cooling duct had about the same effect on cooling greenhouse. The combined system had little better cooling effect than that of individual cooling syst m except the large radiator . The most effective system for cooling of greenhouse was obtained with using a large a large radiator as the heat exchanger. With operating a large radiator, temperature inside the greenhouse was dropped to about 15-16$^{\circ}C$ while outside temperature was 23-24$^{\circ}C$ during summer night.

• 베이커리
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• no.6 s.443
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• pp.106-111
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• 2005

• Journal of the speleological society of Korea
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• no.8
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• pp.55-64
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• 1998

Many of the familiar roadside signs advertising caves open to the public carry the phrase, “Come underground and cool off”. This is reasonable advice, for during the heat of summer the temperature of these caves is indeed pleasantly cool. If the principal tourist season were in the winter instead of the summer, however, the signs would probably read, “Come underground and warm up”, for in winter these same caves are far warmer than the surface. Cave temperatures are nearly constant throughout the year.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.2
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• pp.77-84
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• 2001

This study was carried out to investigate the utilizing of cool-season turfgrass in areas, excluding greens, of Korean golf courses. Data collected from 120 golf courses were subjected to frequency and T-test analysis using SPSSWIN. The results obtained were as follows: 1) seventy eight golf curses were utilizing cool-season turfgrass in areas except of the greens. At thirty five golf courses (46.0%) of them, the area utilized appeared tee, green collar, green approach etc. (tee>green collar>green approach). At 37 golf courses(48.7%), a mix of Kentucky Bluegrass and Perennial Ryegrass was utilized and the ratio of the mix was 70:30(v/v). At 57 golf courses(76.0%), seed sowing was utilized. 2) In Korean golf courses, the cognition of utilizing cool-season turfgrass depended on the existence of the practice. The cognition of the experienced was more´ affirmative´ than that of the inexperienced. 3) In the experienced, the preference was determined by turfgrass quality and good appearance and recuperative rate of cool-season turfgrass. In the inexperienced, the preference was determined by turfgrass quality god appearance. 4) The experienced recommended the mix of Kentucky bluegrass and Perennial Ryegrass. 5) It seems that the golf courses having used cool-season turfgrass have difficulties in the maintenance in summer while the golf courses without using cool-season turfgrass have difficulties in the maintenance in summer and the selection of turfgrass variety.

• Journal of Environmental Science International
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• v.31 no.4
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• pp.311-318
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• 2022

In this study, we analyzed the relationships between weather factors and photosystem II activity (F_v/F_m), as a measure of photochemical efficiency, in three cool-season turfgrasses commonly planted on golf courses in Jeju, South Korea: perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), and creeping bentgrass (Agrostis palustris Huds.). In all three turfgrasses, F_v/F_m was higher during late summer than during early summer. However, in late summer, F_v/F_m was significantly lower in perennial ryegrass than in the other two species. In early summer, F_v/F_m in perennial ryegrass and Kentucky bluegrass was positively correlated with mean low temperature and extreme minimum temperature, whereas, in late summer, this parameter in Kentucky bluegrass and creeping bentgrass was positively correlated with relative humidity, and in creeping bentgrass was negatively correlated with mean high temperature, mean low temperature, and extreme maximum temperature. These results indicate that raising low temperatures is favorable for perennial ryegrass and Kentucky bluegrass in early summer, whereas, in late summer, the lowering of high temperatures proves to be beneficial for creeping bentgrass, and raising relative humidity is conducive to the growth of Kentucky bluegrass and creeping bentgrass. These findings will contribute to improving the selection and management of turfgrasses on golf courses and sports fields.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.3
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• pp.169-174
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• 2002

When the long - lasting stationary fronts were pushed northward by the Pacific Highs in late July, mostly clear skies with intermittent showers were a typical weather of August in Korea. However, torrential rains and flash floods are now a seasonal event of August in recent years. Some meteorologists suspect this unusual phenomenon might be connected with the global change and are concerned about the possibility of change in summer climatic pattern in Korea. August of year 2002 must be remembered to be one of the record breaking months with respect to the rainfall events. In this paper, we analyzed the weather and crop data nationwide for August in 2002, and suggest a few countermeasures necessary to overcome the wet and cool summer impacts on agricultural sector.

• Fashion & Textile Research Journal
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• v.16 no.2
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• pp.326-332
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• 2014

To develop cool touch feeling fabrics for summer clothing material, it was manufactured several compositions of woven fabrics, having rayon multi-filament yarn (non-twisted) as warp and various kinds of yarn, such as viscose rayon multi-filament yarn (twisted), tencel$^{(R)}$ spun yarn, PET high absorbance quick dry filament yarn, and PET based rayon-like yarn, as weft. After preparing the fabrics, basic properties of the fabrics were investigated, such as air-permeability, tensile strength, absorption rate, drying rate, etc. Also, surface warm / cool sensations of the woven fabrics were assessed by Qmax Warm / Cool Touch Tester. It was observed that the fabrics composed of viscose rayon multi-filament yarn (warp) and PET high absorbance quick dry filament yarn (weft) showed excellent surface cool touch sensation-the highest Qmax value. This is because the fabric having flat shaped PET high absorbance quick dry filament shows the largest contact area with Qmax measuring plate. And, the fabric also showed superior high absorbance and quick dry property as expected. In addition, we treated phase change material (PCM) on the surface of the fabric composed of viscose rayon multi-filament yarn (warp) and PET high absorbance quick dry filament yarn(weft) to improve the cool touch feeling. However, the surface cool touch feeling was impaired by resin treated with PCM during the finishing process.