• Title/Summary/Keyword: Cold-water damage

Search Result 88, Processing Time 0.024 seconds

A Quantification Method for the Cold Pool Effect on Nocturnal Temperature in a Closed Catchment (폐쇄집수역의 냉기호 모의를 통한 일 최저기온 분포 추정)

  • Kim, Soo-Ock;Yun, Jin-I.
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.13 no.4
    • /
    • pp.176-184
    • /
    • 2011
  • Cold air on sloping surfaces flows down to the valley bottom in mountainous terrain at calm and clear nights. Based on the assumption that the cold air flow may be the same as the water flow, current models estimate temperature drop by regarding the cold air accumulation at a given location as the water-like free drainage. At a closed catchment whose outlet is blocked by man-made obstacles such as banks and roads, however, the water-like free drainage assumption is no longer valid because the cold air accumulates from the bottom first. We developed an empirical model to estimate quantitatively the effect of cold pool on nocturnal temperature in a closed catchment. In our model, a closed catchment is treated like a "vessel", and a digital elevation model (DEM) was used to calculate the maximum capacity of the cold pool formed in a closed catchment. We introduce a topographical variable named "shape factor", which is the ratio of the cold air accumulation potential across the whole catchment area to the maximum capacity of the cold pool to describe the relative size of temperature drop at a wider range of catchment shapes. The shape factor is then used to simulate the density profile of cold pool formed in a given catchment based on a hypsometric equation. The cold lake module was incorporated with the existing model (i.e., Chung et al., 2006), generating a new model and predicting distribution of minimum temperature over closed catchments. We applied this model to Akyang valley (i.e., a typical closed catchment of 53 $km^2$ area) in the southern skirt of Mt. Jiri National Park where 12 automated weather stations (AWS) are operational. The performance of the model was evaluated based on the feasibility of delineating the temperature pattern accurately at cold pool forming at night. Overall, the model's ability of simulating the spatial pattern of lower temperature were improved especially at the valley bottom, showing a similar pattern of the estimated temperature with that of thermal images obtained across the valley at dawn (0520 to 0600 local standard time) of 17 May 2011. Error in temperature estimation, calculated with the root mean square error using the 10 low-lying AWSs, was substantially decreased from $1.30^{\circ}C$ with the existing model to $0.71^{\circ}C$ with the new model. These results suggest the feasibility of the new method in predicting the site-specific freeze and frost warning at a closed catchment.

Studies on the Reducing Methods of Cold Wind Damage of Rice Plant by Installation of Windbreak Net in the Eastern Coastal Area (동해안 냉조풍지대의 방풍망에 의한 수도의 풍해경감방법)

  • 이승필;이광석;최대웅;손삼곤;김칠용
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.32 no.2
    • /
    • pp.163-172
    • /
    • 1987
  • Results obtained from this study conducted to find the effect of wind-break net on reducing cold wind damage in the eastern coastal cold wind damaged area are summarized as follows. The rice critical safe heading date was up to Aug. 10 in the eastern coastal area, which the frequency of gale Aug. 10 to Sep. 10 is high. The frequencies of westries and cold wind from sea were 25%, respectively, in this area. The effects of wind-break net on reducing wind verocity were 26.9, 34,6% with raising air temperature of 0.4-0.7$^{\circ}C$ and water temperature of 0.3-0.5$^{\circ}C$. The effect of wind-break net was up to 10 time's distance of wind-break net's height from wind-break net. The installation of wind-break inhanced to rice growth, so showed the heading date earlier by 2-5days and increased culm length, no.of panicles per hill and no. of spiklets per panicle. The yield decrease in this area was due to sterilization, poor ripening and light 1,000 grain weight. The yields showed 20-28% increase by installation of wind-break net. The effect of wind-break net was most in the installation plot with wind-break net against cold wind from sea and westries installed in the panicle formation stage.

  • PDF

Causes of Cold Damage of Rice Plant and Its Control 1. Effects of Temperature on the Growth and Absorption of Mineral Nutrients (수도냉해의 발생기구와 그의 대책에 관한 연구 제1보 수도의 생장과 무기양분흡수에 미치는 온도의 영향)

  • 임형빈
    • Journal of Plant Biology
    • /
    • v.17 no.4
    • /
    • pp.31-37
    • /
    • 1974
  • Seedlings of Nongbaek representing strong cold tolerant variety of rice plant, Jinheung of medium variety and Tongil of weak variety were used respectively for the present study. These seedlings were water cultured in phytotron which maintained at the daytime and night temperature of 30-$25^{\circ}C$, 20-2$0^{\circ}C$, 20-15$^{\circ}C$ and 15-1$0^{\circ}C$. The growth rate of plant height, tillering rate, increase in dry weight and absorption pattern of important mineral nutrients at their early growth stage under each temperature conditions were observed. Generally, it appeared that Nongbaek was more active in the growth of plant height than Jinheung, and Jinheung was more active than Tongil under low temperature condition. The tillering rate of these three varieties was equally rapid while it was decreased in the order of weak cold tolerant variety, such as Tongil, Jinheung and Nongbaek as the temperature declined gradually. The dry weigh tincreasing curve showed almost the same pattern in the varieties at the treatment of each temperature. Under low temperature conditions, Nongbaek showed higher absorption rate of N per dry weight and higher absorption amount of per plant body, Jinheung followed and Tongil was the lowest. The absorption amount of P2O5 increased in the top part compared with the roots as temperature rose and decreased as temperature declined. There seemed to be no difference of absorption among the varieties which have different cold tolerance each other. Under low temperature the absorption rate of K per dry weight was high, as a whole, especially Nongbaek was markedly higher than the other two. The absorption rate of Ca, Mg and Fe was also equally high in all varieties under low temperature and Nongbaek showed a more absorptive tendency in the absorption amount under low temperature.

  • PDF

A Study on the Condensation Prevention of Bulk Carrier (화물선의 결로 방지에 대한 연구)

  • Oh, Sae-Gin;Kim, Won-Ouk;Kim, Seung-Hwan;Lee, Seung-Geun;Kim, Jong-Su
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.17 no.4
    • /
    • pp.429-434
    • /
    • 2011
  • Bulk cargo loaded into ship can be damaged by various kinds reasons. This paper aims to analyze about cargo damage of coil carrier ship due to condensation. Condensation is the formation of liquid drops of water from water vapor. Condensation consists of small drops of water which form when warm water vapour or steam touches a cold surface such as a window. In general, condensation have occurred by temperature difference at large building and ship's tank. It is phenomenon that can occur often to oceangoing vessel moving temperature difference places in similar time. This paper proposes a new method using dehumidification device and fan heater to prevent bulk cargo damage of coil carrier ship from condensation.

Cultural Practices for Reducing Cold Wind Damage of Rice Plant in Eastern Coastal Area of Korea (동해안지대 도작의 냉조풍피해와 피해경감대책)

  • 이승필;김칠용
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.36 no.5
    • /
    • pp.407-428
    • /
    • 1991
  • The eastern coastal area having variability of climate is located within Taebaek mountain range and the east coast of Korea. It is therefore ease to cause the wind damages in paddy field during rice growing season. The wind damages to rice plant in this area were mainly caused by the Fohn wind (dry and hot wind) blowing over the Taebaek mountain range and the cold humid wind from the coast. The dry wind cause such as the white head, broken leaves, cut-leaves, dried leaves, shattering of grain, glume discolouration and lodging, On the other hand the cold humid wind derived from Ootsuku air mass in summer cause such symptom as the poor rice growth, degeneration of rachis brenches and poor ripening. To minimize the wind damages and utilize as a preparatory data for wind injury of rice in future, several experiments such as the selection of wind resistant variety to wind damage, determination of optimum transplanting date, improvement of fertilizer application methods, improvement of soils and effect of wind break net were carried out for 8 years from 1982 to 1989 in the eastern coastal area. The results obtained are summarized as follows. 1. According to available statisical data from Korean meteorological services (1954-1989) it is apperent that cold humid winds frequently cause damage to rice fields from August 10th to September 10th, it is therefore advisable to plan rice cultivation in such a way that the heading date should not be later than August 10th. 2. During the rice production season, two winds cause severe damage to the rice fields in eastern coastal area of Korea. One is the Fohn winds blowing over the Taebaek mountain range and the other is the cold humid wind form the coast. The frequency of occurrence of each wind was 25%. 3. To avoid damage caused by typhoon winds three different varieties of rice were planted at various areas. 4. In the eastern coastal area of Korea, the optimum ripening temperature for rice was about 22.2$^{\circ}C$ and the optimum heading date wad August 10th. The optimum transplanting time for the earily maturity variety was June 10th., medium maturity variety was May 20th and that of late maturity was May 10th by means of growing days degree (GDD) from transplanting date to heading date. 5.38% of this coastal area is sandy loamy soil while 28% is high humus soil. These soil types are very poor for rice cultivation. In this coastal area, the water table is high, the drainage is poor and the water temperature is low. The low water temperature makes it difficult for urea to dissolve, as a result rice growth was delayed, and the rice plant became sterile. But over application of urea resulted in blast disease in rice plants. It is therefore advise that Ammonium sulphate is used in this area instead of urea. 6. The low temperature of the soil inhibits activities of microorganism for phosphorus utilization so the rice plant could not easily absorb the phosphorus in the soil. Therefore phosphorus should be applied in splits from transplanting to panicle initiation rather than based application. 7. Wind damage was severe in the sandy loamy soil as compared to clay soils. With the application of silicate. compost and soil from mointain area. the sand loamy soil was improved for rice grain colour and ripening. 8. The use of wind break nets created a mocro-climate such as increased air. soil and water temperature as well as the reduction of wind velocity by 30%. This hastened rice growth, reduced white head and glume discolouration. improved rice quality and increased yield. 9. Two meter high wind break net was used around the rice experimental fields and the top of it. The material was polyethylene sheets. The optimum spacing was 0.5Cm x 0.5Cm. and that of setting up the wind break net was before panicle initiation. With this set up, the field was avoided off th cold humid wind and the Fohn. The yield in the treatment was 20% higher than the control. 10. After typhoon, paddy field was irrigated deeply and water was sprayed to reduce white head, glume discolouration, so rice yield was increased because of increasing ripening ratio and 1, 000 grain weight.

  • PDF

Effect of Different Wind-break Net on Reducing Damage of Cold Sea Wind (수도 풍해경감을 위한 방풍강 강목의 효과)

  • 이승필;김상경;이광석;최대웅;김칠용
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.35 no.4
    • /
    • pp.352-361
    • /
    • 1990
  • The reducing effect of wind injury was investigated using several wind-break nets in Youngdeok province where cold-wind damage is often occurred during rice growing season. The white-head damage of rice have been often occurred by typhoon during the period between August 15 to September 10 in the cold wind area of the eastern coastal during the last 11 years (1979-1989). This may suggest that the critical period for heading will be by August 15 in the regions. High evaporation coefficient, more than 250 due to typhoon passage over the regions resulted high injury of white head. Generally, the wind injury have been caused by warm and dry westerlies through Fohn apperance in Taebaeg mountains and by cool-humid wind which blows from coast to inland. The frequency of occurrence of the two types of typhoons were 25, 20%, respectively during rice cultivation. The instalation of wind-break net significantly reduced the wind blowing speed, depending on the net mesher with the higher effect in dence net. The distances between the net and cropping area also affect the wind speed: 23% reduction at 1m distance. 34% at 10m and 28% at 20m, respectively. The reducing effect was also observed even at 10 times height of the wind-break net. The instalation of wind-break net gave several effects on climate factor, showing that temperature increased by 0.8$^{\circ}C$(maximum), 0.7$^{\circ}C$(minimum), 0.6$^{\circ}C$(average) : water temperatures increased by 0.5$^{\circ}C$(maximum), 0.6$^{\circ}C$(minimum), 0.5$^{\circ}C$(average) : soil temperature increased 0.4$^{\circ}C$. The earlier heading and increasing growth rate, use of light, culm length, panicle number per hill, spikelet number per panicle, fertility and 1,000 grain weight were observed in the fields with the wind-break nets resulting in 10-15% increase in rice yield using 0.5${\times}$0.5cm nets. The increasing seedlings per hill gave higher grain yield by 13% in the cold wind damage regions of eastern coastals. and the wind-break was more significant in the field without the wind-break net. Wind injury of rice plant in the cold wind regions of eastern coastals in korea could be reduced by selection of tolerant varieties to wind injury, adjustment of transplanting time, and establishment of wind-break nets.

  • PDF

Analysis of Temperature Change of Tunnel Lining with Heating Element (발열체가 적용된 터널 라이닝 내부 및 배면의 온도변화 분석)

  • Jin, Hyunwoo;Kim, Teasik;Hwang, Youngcheol
    • Journal of the Korean GEO-environmental Society
    • /
    • v.18 no.1
    • /
    • pp.5-12
    • /
    • 2017
  • The damage of the tunnel lining on the cold regions can be represented by cracks and leaks caused by freezing of ground water. However, domestically, the relevant construction guidelines are not provided so far. Thus, in this research, the mechanical behavior and thermal conductivity of designated tunnel area are measured using instrumentation system installed in the lining concrete inside tunnels in order to analysis their behavior with regard to temperature variations. Previous research mainly focused on the effect of temperature on the tunnel lining based on the air and initial ground temperature at urban regions. Thus, this study analyzes effects of air temperature and initial ground temperature of designated tunnel area at the cold regions. The temperature of the groundwater at the backfill of the tunnel lining are analyzed to evaluate the heating element. Numerical analyses are performed to evaluate the heating element with regard to the various initial ground temperatures.

Characteristics of High Water Temperature Occurrence in Coastal and Inland Bays of Korea during the Summers of 2018-2021 (2018년~2021년 여름철 우리나라 연안 고수온 현상)

  • Lee, Joon-Soo;Kwon, Mi-Ok;Ahn, Ji-Suk;Park, Myung-Hee;Song, Ji-Yeong;Han, In-Seong;Jung, Rae Hong
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.28 no.5
    • /
    • pp.753-763
    • /
    • 2022
  • In coastal and inland bays, where most of Korea's aquaculture is located, massive aquaculture damage occurs every year due to frequent anomalous high water temperatures. The interannual fluctuations of water temperature in July over the past four years (2018-2021) were the second largest since 1990 (after the period of 1994-1997) due to anomalous high temperatures, rainy seasons, and typhoons. Through analysis of heat flux and heat balance in areas of concern for high water temperatures (i.e., Cheonsu Bay, Gamak Bay, Guryongpo), the occurrence of high water temperatures in Cheonsu Bay and Gamak Bay in the summer seasons was confirmed to derive mainly from heat inflow through the sea surface from the air. Based on estimations of the average ocean heat transport rate in July for the four-year period of 2018-2021, Cheonsu Bay and Gamak Bay accounted for 13.5% and 62.3% outflow of the net heat flux, respectively. However, the ocean heat transport rate in Guryongpo Hajeong differed significantly from -174.5% to 132.5% of the net heat flux by year depending on the occurrence of cold water mass.

A Study on the Application of Non-glutinous rice in Shanghanlun (『상한론(傷寒論)』의 갱미(粳米) 입약법(入藥法)에 대한 고찰)

  • Ahn, Jin-hee
    • Journal of Korean Medical classics
    • /
    • v.32 no.2
    • /
    • pp.71-92
    • /
    • 2019
  • Objectives : To examine various ways non-glutinous rice has been applied in different formulas of "Shanghanlun" and the relationship between non-glutinous rice and the formulas' effects. Methods : First, texts that included non-glutinous rice were selected from the "Shanghanlun". Then, they were categorized according to the application of non-glutinous rice, followed by analysis of its relationship with each formula. Results : Most formulas that used non-glutinous rice in raw form when decocting with other ingredients included Shigao. Non-glutinous rice alleviates coldness of Shigao as in the case with Taohuatang where it stops diarrhea. Non-glutinous rice used in Wumeiwan warms the center and boosts Qi and helps the medicinal ingredients to bind when made into pellets. In Guizhitang and Lizhongwan, non-glutinous rice assists Stomach Qi. In Shizaotang, porridge is taken after diarrhea to help quick recovery. To prevent damage of Zheng Qi, Baisan can be mixed with rice water for administration. The level of cathartic effect can be managed through giving cold or hot porridge to the patient according to his/her response to the medicine. Mazirenwan, Mulizexiesan, Banxiasan, Sinisan, Wulingsan are mixed in rice water for administration. It makes it easier to swallow than when mixed with plain water. The application of rice flour is either internal or external. In Zhufutang, where rice flour is parched, it harmonizes the center and stops diarrhea. In Daqinglongtang when there is too much perspiration, warm powder is sprinkled on the skin to stop sweating. Clear porridge in Jiuziyisifang and rice flour in Shechuangzisan were exclusive to "Jinguiyaolue", while Baisan and rice water mixture could only be found in "Shanghanlun". Conclusions : The excavation and research on various ways non-glutinous rice was applied in treatment holds certain meaning in contemporary practice of Korean Medicine where treatment leans heavily on medicinal treatment rather than food, and all ingredients are boiled together in large quantities for most decoctions.

A Literature Study on the External Treatment of a Burn (火傷의 外治法에 對한 文獻的 考察 (外用藥을 중심으로))

  • Yu, Mi-Kyoung;Jeong, Dong-hwan;Sim, Sang-hee;Park, Su-Yeon;Kim, Jong-han;Choi, Jung-hwa
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
    • /
    • v.16 no.3
    • /
    • pp.38-67
    • /
    • 2003
  • The burn is acute skin injury caused by fire, hot water. steam. hot oil, sour and salty. It is occurred frequently in the daily life as well as oriental therapy like moxibustion therapy, physical therapy. Nevertheless, medical treatment of the burn is almost dependent on western cure. So we chose the oriental medicine textbooks and the oriental medicine journals that were dealing with the drugs, processing the drugs. peculiar treatment put first external cure. The results were as follows; 1. The burn is acute skin injury caused by fire, hot water, steam, hot oil, sour and salty. 2. The burn cause blisters, irritability and restlessness, nausea, dryness of mouth, constipation, in case of serious, coma, dyspnea and death. The early stage of the burn, blisters form by skin damage and they burst into skin ulceration from which pus issues, the latter term, the wound form scab and healed up. 3. In a light case, medical treatment of the burn was used external treatment by medicine for externalism use, in a serious case, it was used both as an internal remedy and medicine for outward application. Also in the early stage, it was careful of using the cold and cool medicine, as the process of healing, it was used alleviating pain, detoxicating, moistening the skin, growing muscle and skin, convergence, evacuating pus, regeneration of the tissue, strengthen the spleen and nourishing the stomach. 4. The external treatment medication is Herba Ephedrae Oil(麻油), Radix ET Rhizoma Rhei(大黃), Glauberitum(寒水石), Water(水), Pig OiI(猪油), Pig Fat(猪脂), Radix Angelicae Gigantis(當歸), Rhizoma Coptidis(黃連), Cortex Phellodindri(黃栢). The White of an Egg(鷄子淸), Raw Honey(生蜜), Honey(蜜), Wine(酒), Etc. It is mostly the cold and cool medications. 5. Soft extracted and powered dosage form in external treatment is much used. The soft extracted form(32times used) are mostly Chung Ryang paste(淸凉膏) and Fructus Papaveris paste(罌粟膏). The powered form(30times used) are mostly Bingsang Powder(氷霜散), Bosaenggugo Powder(保生救苦散), Sahwang Powder(四黃散). The others is much a various powder adding solvent. 6. If varicella stage, erosion after varicella stage, oozing stage and extreme pain stage, the powder adding solvent is much used. If little oozing stage. ulcering stage, scabing stage and a chronic stage, Soft extracted dosage form is much used. 7. The most many(26.65%) used method is that apply each medication power mixed water(水), wine(酒), honey(蜜) in a wounded part.

  • PDF