• Title/Summary/Keyword: Summer stress

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Growth Characteristics of Creeping bentgrass Cultivars (크리핑 벤트그래스 품종의 생육 특성)

  • 이혜원;정대영;심상렬
    • Asian Journal of Turfgrass Science
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    • v.17 no.2_3
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    • pp.87-97
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    • 2003
  • The growth characteristics of creeping bentgrass seeded in the seaside landfill golf course are as follows. 1. As a result of analysis on the chemical characteristics of soil mixture used for turfgrass ground in this experiment, soil pH was 7.9, which is somewhat higher than the creeping bentgrass reference value of pH 5.5∼6.5; T-N(%) was 0.02, which is proper for the reference value, and trace element too lacked. 2. The cultivar with the fastest water infiltration was Seaside II recorded as 226.2cm/sec, while that with the slowest water infiltration was Pennlinks recorded as 141.1 cm/hr which was too faster than the USGA water infiltration reference value of 15∼30cm/hr. For the surface hardness of turfgrass ground with different cultivars, no statistically significant variation was found between the Penncross grass and the Pennlinks recorded as 18.6mm and 19.1 mm, respectively. The soil penetration was the highest in Pennlinks recorded as 7.6kg/$\textrm{cm}^2$ and lowest in Penn A-1 as 6.1kg/$\textrm{cm}^2$. 3. As a result of evaluation on visual quality at the early stage of growth, Penncross showed the most excellent visual quality compared to the others. However, Penn A-1 showed the most excellent visual quality at a late stage of growth around Sep. 17, 2003, and it was also excellent in the evaluation of visual color. Seaside II showed higher density around the root and the longest root length and was highly resistant to salt compared to others, but the initial sprouting rate was not satisfied, and the visual quality in the summer season was inferior to others. 4. As a result of measurement of the traffic injury, Penncross showed the most tolerant to the traffic stress and Pennlinks showed the most susceptible.

A Study on the Leisure Life Satisfaction of College Students According to the Pattern of Leisure Activities (대학생의 여가활동 유형에 따른 여가생활 만족도)

  • An, Ok-Hee;Choi, Hyun-Sook
    • Journal of Family Resource Management and Policy Review
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    • v.10 no.1
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    • pp.53-66
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    • 2006
  • This study was designed to get basic informations for the purpose of making healthy leisure environment of college students, and which will improve the satisfaction of their school life. Five hundreds of college students in Daegu and Gyeongbuk area were questioned by, our questionnaire during April, 2005. The data of 405 students (165 men, 240 women) Were analyzed by SPSS WIN 12.0 program. The data of 210 were from Daegu and 195 were from Gyeongbuk area, The results are as follows, First, $80\%$ of those questioned spend their leisure time doing some activities and the satisfaction degree was medium... They get the informations about leisure mainly through internet and the purpose of their leisure activities, were, to get rid of stress. Second; It was shown that their main leisure activities were doing internet, meeting friends, and listening music on weekdays, meeting friends, watching movie and doing internet on weekend. The major activities of the students during vocation were meeting friends, doing internet, and watching TV. Third, the students are concern about their leisure life, and they think that leisure life make improve the quality of life. The last, there is a correlation between quite activities such as watching TV, and dynamic activities such as a mountain-climbing leisure life satisfaction on weekdays. On weekend, however, there is a correlation between dynamic activities such as sports and the leisure life satisfaction. Moreover, on summer (winter) break personal activities such as religious activities and the leisure satisfaction.

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Changes in Fish Viral Disease Outbreaks in the Coastal Area of Korea Due to Increasing Water Temperature, an Impact of Climate Change (기후변화에 기인한 연안 수온상승에 따른 연안 어류의 바이러스성 질병 발생 예측)

  • Kim, Wi-Sik;Kim, Seok-Ryel;Park, Myoung-Ae;Lee, Joon-Soo;Avunje, Satheesha;Kim, Do-Hyung;Oh, Myung-Joo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.5
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    • pp.582-588
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    • 2013
  • The impact of global warming on aquatic systems has been a priority research area in the past decade. However, the possibility that increased temperatures will cause shifts in viral disease outbreaks has not been well addressed. In the present study, with increasing water temperature (WT) in the coastal area of Korea, we estimated the possibility of changes in fish viral diseases. From the present time, WT may rise between 0.62 and $1.7^{\circ}C$ by 2050, and the effect on aquaculture could be more adverse than benefitial. Red seabream iridovirus disease (RSIVD) and viral nervous necrosis (VNN) cause high mortality above 22 and $24^{\circ}C$, respectively, and outbreaks could commence earlier and persist for prolonged periods. Nevertheless, the period of occurrence of viral hemorrhagic septicemia (VHS), which outbreaks at a lower WT (< $18^{\circ}C$), could be shorter than the current infectious period. Thermal stress in fish causes reductions in growth and immunocompetence; thus, increases in summer WT can lead to the development of new viral diseases. WT has a strong influence on fish population dynamics; therefore, entry of new viruses and changes in the prevalence of infection can be expected if carrier fishes are introduced or migrate to Korean waters.

The Effects of the Material of Pesticide-Proof Clothing on Human Comfort (농약방제복 소재의 차이가 인체 쾌적성에 미치는 영향)

  • Hwang, Kyoung-Sook;Kim, Kyung-Ran;Lee, Kyung-Suk;Kim, Kyung-Su
    • The Korean Journal of Community Living Science
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    • v.17 no.4
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    • pp.49-56
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    • 2006
  • The purpose of this study was to evaluate the thermal and subjective comfort of various pesticide-proof clothes made from different material. Seven male adults took part in the study, conducted in a climate-chamber controlled with an ambient temperature of $30^{\circ}C$ and a relative humidity of 60%RH. The thermal and subjective responses of subjects wearing pesticide-proof clothing made of Goretex(coating treatment), polyester (water-repellent treatment), non-woven(coating) and nylon(coating) were measured. The main results were summarized as follows: (1) Change of rectal temperature and clothing microclimate were inhibited more effectively in pesticide-proof clothing made of Goretex, polyester and non-woven than nylon materials. (2) Mean skin temperature at the end of the experiment was significantly higher in subjects who wore nylon than non-woven and Goretex, and was lowest in those with pesticide-proof clothing made of polyester. (3) Change of heart rate was significantly lower in subjects with Goretex and polyester clothiing than those with non-woven, and in those with nylon, it was highest. (4) Subjective comfort was greater in subjects with Goretex, polyester and nonwoven clothing than nylon, except for thermal sensation. Thermal sensation was greater in order of polyester, Goretex, non-woven and nylon. Thus, it was concluded that pesticide-proof clothing made of Goretex, polyester and non-woven material could reduce thermal stress during the spraying of pesticides in summer.

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Growth Dynamics of Zostera marina Transplants in the Nakdong Estuary Related to Environmental Changes (낙동강 하구에 이식된 잘피(Zostera marina)의 환경변화에 따른 성장특성)

  • Park, Jung-Im;Lee, Kun-Seop;Son, Min-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.44 no.5
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    • pp.533-542
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    • 2011
  • Numerous seagrass habitat restoration projects have been attempted recently due to the remarkable decline in seagrass coverage. Seagrass transplants tend to adapt to a new environment after experiencing transplanting stress during the early stages of transplantation. Once acclimated, the transplants grow into healthy seagrass beds via vegetative propagation. The establishment and growth dynamics of transplanted seagrasses in bays and coasts are widely reported, but few studies have been conducted on estuaries in Korea. We transplanted Zostera marina in November 2007 and November 2008 in the Nakdong estuary using the staple method, and monitored the survival, adaptation, and growth dynamics of the transplants as well as environmental factors every month for 1 year. Both transplants adapted well to the new environment without initial losses and showed rapid productivity during early summer. However, density of transplants increased 320% in 1 year from the previous year's transplants but that decreased to 59% during the following year. This significant reduction in density in the second year may have been caused by exposure to low salinity (10 psu) for 3 weeks during the unusually long monsoon season. While the survival and growth dynamics of seagrass transplants planted in bays and coasts are mainly controlled by underwater photon flux density and water temperature, salinity was the critical factor for those planted in Nakdong estuary.

Evaluation of Upper Ocean Temperature and Mixed Layer Depth in an Eddy-permitting Global Ocean General Circulation Model (중해상도 전지구 해양대순환 모형의 상층 수온과 혼합층 깊이 모사 성능 평가)

  • Jang, Chan-Joo;Min, Hong-Sik;Kim, Cheol-Ho;Kang, Sok-Kuh;Lie, Heung-Jae
    • Ocean and Polar Research
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    • v.28 no.3
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    • pp.245-258
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    • 2006
  • We investigated seasonal variations of the upper ocean temperature and the mixed layer depth (MLD) in an eddy-permitting global ocean general circulation model (OGCM) to assess the OGCM perfermance. The OGCM is based on the GFDL MOM3 which has a horizontal resolution of 0.5 degree and 30 vertical levels. The OGCM was integrated for 68 years using a monthly-mean climatological wind stress forcing. The model sea surface temperature (SST) and sea surface salinity were restored to the Levitus climatology with a time scale of 30 days. Annual-mean model SST shows a cold bias $(<\;-2^{\circ}C)$ in the summer hemisphere and a warm bias $(>\;1^{\circ}C)$ in the winter hemisphere mainly due to the restoring boundary condition of temperature. The model MLD captures well the observed features in most areas, with a slightly deep bias. However, in the Ross Sea and Weddell Sea, the model shows significantly deeper MLD than the climatology-mainly due to weak salinity stratifications in the model. For amplitude of seasonal variation, the model SST is smaller $(1{\sim}3^{\circ}C)$ than the observation largely due to the restoring surface boundary condition while the model MLD has larger seasonal variation $({\sim}50m)$. It is suggested that for more realistic simulation of the upper ocean structure in the present eddy-permitting ocean model, more refinements in the surface boundary condition for the thermohaline forcing and parameterization for vertical mixing are required, together with the incorporation of a sea-ice model.

Benefit of the Drinking Water Supply System in Office Building by Rainwater Harvesting: A Demo Project in Hanoi, Vietnam

  • Dao, Anh-Dzung;Nguyen, Viet-Anh;Han, Mooyoung
    • Environmental Engineering Research
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    • v.18 no.2
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    • pp.103-108
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    • 2013
  • Vietnam is a developing country with the rate around 5%-6% per year, especially in urban areas. Rapidly developed urban areas lead to stress for infrastructure and the water supply is also stressed. In Hanoi city, total water capacity from the manufactories is around one million cubic meters per day and almost the entire main water source is groundwater but it is not enough to supply all of Hanoi's people, especially in the summer. A demo project is implemented in Hanoi University of Civil Engineering (HUCE) to produce drinking water by using the rainwater and membrane system and supply for people. In this project, rainwater is collected on the rooftop of the lecture building with an area of around $500m^2$ and $100m^3$ volumetric rainwater tanks. Afterwards, the rainwater is treated by the micro-membrane system and supplied to the tap water. Total cost for construction, technology and operation in the first year is around USD 48,558. In the long-term (15 yr) if HUCE invests in the same system, with $20m^3$ volumetric storage tank, it can provide drinking water for 500 staffs in every year. The cost of investment and operation for this system is lower than 30% compared to buying bottled water with the price USD 1.8/bottle. The drinking water parameters after treatment are pH, 7.3-7.75; turbidity, 0.6-0.8 NUT; total dissolved solids, 60-89 mg/L; coliform, 0; heavy metal similar with water quality in the bottle water in Vietnam.

Prevalence of surgical affections with their clinical management in crocodiles (Crocodylus porosus) in Bangladesh

  • Arif, Abu S.M.;Hashim, M.A.;Runa, R.A.;Chowdhury, E.H.;Rahman, Md Siddiqur;Song, Hee-Jong
    • Korean Journal of Veterinary Service
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    • v.33 no.3
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    • pp.313-317
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    • 2010
  • This study was conducted in the saltwater crocodile (Crocodylus porosus) for the occurrence of various surgical affections with their clinical management. During the period of January 2006 to June 2008, a total of 68 adult crocodiles were considered as reference population from the Reptiles Farm Ltd. at Bhaluka, Mymensingh. The occurrence of surgical affections of adult female (88.9%) was significantly (P<0.01) higher than male (11.1%). Prevalence of common surgical affections were wound: 72.2%, fibroma: 11.1% abscess: 5.6%, fracture: 5.6%, tail necrosis: 2.8%, myiasis: 2.8%. Wound was the highest among the affections. Among the identified wounds, biting wound was higher. In summer (57.7%) the occurrence of wound was higher compared to other seasons. In winter season (7.7%) the occurrence of abscess, myiasis, fibroma were higher compared to other seasons. Wounds and fibroma are the major surgical affections in salt water crocodile. The most common site of surgical affection was recorded in crocodile's tail (30.6%). It was suggested that minimal stress, allowing constant and easy access to water, removal of roots of the tree in the basking land of crocodiles pen, basking land of the pen is better filling up by sand, clinical surgical managements are essential for better health and production.

Developing Liquid Cooling Garments to Alleviate Heat Strain of Workers in Summer and Exploring Effective Cooling Temperature and Body Regions (여름철 작업자들의 고체온증 예방을 위한 액체냉각복 개발 및 효과적인 냉각온도와 인체 냉각부위 탐색)

  • Jung, Jae-Yeon;Kang, Juho;Seol, Seonhong;Lee, Joo-Young
    • Fashion & Textile Research Journal
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    • v.22 no.2
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    • pp.250-260
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    • 2020
  • The purpose of the present study was to explore the most effective body region and cooling temperature to alleviate heat strain of workers in hot environments. We developed liquid cooling hood, vest, sleeves and socks and applied the water temperatures of 10, 15, 20, and 25℃ through the liquid cooling garments in a hot and humid environment (33℃ air temperature and 70% RH air humidity). A healthy young male participated in a total of 16 experimental trials (four cooling garments × four cooling temperatures) with the following protocol: 10-min rest, 40-min exercise on a treadmill and 10-min recovery. The results showed that rectal temperature, mean skin temperature, and ratings of perceived exertion during exercise; heart rate and diastolic blood pressure during recovery; and total sweat rate were lower for the vest condition than other garment conditions(p < .05). However, there was no differences in mean skin temperature among the four cooling garments when we compared the values converted by covering area(%BSA). When we classified the results by cooling temperature, there were no consistent differences in thermoregulatory and cardiovascular responses among the four temperatures, but 25℃ water temperature was evaluated as being the most ineffective cooling temperature in terms of subjective responses. In conclusion, the results indicated that wearing cooling vest with < 20℃ cooling temperature can alleviate heat strain of workers in hot and humid environments. If the peripheral body regions are cooled with liquid cooling garments, larger cooling area with lower cooling temperature than 10℃ would be effective to reduce heat strain of workers. Further studies with a vaild number of subjects are required.

Indicative Responses of Rice Plant to Atmospheric Ozone

  • Hur, Jae-Seoun;Kim, Pan-Gi;Yun, Sung-Chul;Park, Eun-Woo
    • The Plant Pathology Journal
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    • v.16 no.3
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    • pp.130-136
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    • 2000
  • Differences in physiological and biochemical responses between sensitive and tolerant rice cultivars to ozone were investigated to develop reliable indications of early ozone damage. Three Korean local rice cultivars -sen-sitive cultivar Dongjin (DJ), moderately tolerant cultivar Hwayeong (HY) and tolerant cultivar Ilmee (IM) were exposed to ozone at the concentrations of 100 nl $\textrm{l}^{-1}$ or 200 nl $\textrm{l}^{-1}$ , 8 h per day for 10 days in a controlled-environment fumigation chamber. The rice cultivars seemed to be endurable to ozone stress at the concentration of 100 nl $\textrm{l}^{-1}$ which is frequently monitored during the growing season in summer. However, severe damage was induced and differential sensitivity was clearly noted among the rice cultivars at the higher ozone concentration. Activation of the glutathion (GR) -ascorbate peroxidase (APX) cycle was likely to be responsible for protection of rice plants against ozone exposure, relating difference in sensitivity of rice cultivars to ozone. Photosynthetic activity appeared to be one of sensitive responses, for which chlorophyll fluorescence and leaf greenness can together provide a very reliable index, a degree of photosynthetic damages by ozone. Formation of malondialdehyde (MDA) was also considered as an indication that can differentiate cultivars sensitivity to ozone. However, the changes in polyamines and total phenolics were not consistent with exposed ozone concentrations and/or ozone sensitivity of the cultivars. The behavior of polyamines and phenolics in the damaged plants at high ozone levels could be interpreted as an indication of ozone injury rather than activation of additional protection mechanisms scavenging active oxygen species formed by ozone. Several responses triggered by ozone could explain the differential sensitivity of the rice cultivars and be used as reliable indications of relative ozone damage to rice plant.

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