• Title/Summary/Keyword: cold wind

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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
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    • v.35 no.4
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    • pp.352-361
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    • 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.

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A Case Study on Sea Breeze Circulation and Ozone Concentration due to the Effect of Cold Water in the Southeastern Coastal Area of Korea (한국 남동연안의 냉수대 영향에 의한 해풍순환과 오존농도의 사례연구)

  • Ji, Hyo Eun;Lee, Soon-Hwan;Park, Changhyoun;Lee, Hwa Woon
    • Journal of Environmental Science International
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    • v.23 no.2
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    • pp.261-274
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    • 2014
  • This work investigates the relationship between the sea breeze circulation and ozone concentrations during cold water events in the southeastern coastal area of the Korean Peninsula, where coastal upwelling frequently occur. This analysis was performed based on the classification of two categories, such as cold water and non-cold water events, over the period of 2000-2009. The low air temperature ($0.5^{\circ}C$), low SST ($5^{\circ}C$) and the wind direction(southerly) are the features of the cold water events in the Southeastern coastal area. Moreover, ozone concentrations in the cases of the sea breeze circulation and cold water events were significantly lower (below 30 ppb) than those (70~100 ppb) in the non-clod water events, because of the low air temperature ($10{\sim}20^{\circ}C$) and high wind speed (3~5 m/s) around the southeastern coastal area.

A Study on the Effects of Side Jets to the Longitudinal Aerodynamics of Subsonic Missile (측방 제트가 아음속 유도탄 종방향 공력특성에 미치는 영향 연구)

  • GO, Beom Yong;HUR, Ki Hoon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.3
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    • pp.393-404
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    • 2017
  • Side jet effect on the aerodynamic characteristics of a missile was investigated using experimental and computational methods. A couple of side jets were injected toward outward downstream at mid point of missile body. Cold air jet was used in the wind tunnel test, and cold and hot jet were used in the computation. Wind tunnel test was carried out with jet and without jet, and calculation was performed for three cases ; no jet, cold air jet, and hot mixture gas jet. From the comparison of measured and calculated data for all cases, two points could be deduced. Firstly, side jet made static stability to be unstable by increasing body normal force near the side jet exit and by decreasing tail normal force. Secondly, hot mixture gas had more significant effect on the static stability of a missile-type body than cold air jet.

An Experimental Study on the Application in-situ of Curing Method by Planar Surface Heater for Cold Weather Concreting (전기발열시트 표면가열 양생공법의 현장적용 연구)

  • 김형래;조호규;김찬수;지남용
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2003.05a
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    • pp.19-22
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    • 2003
  • The purpose of this study is to analyze the curing effect of planar surface heater for concreting in cold weather. Some experiments were conducted to evaluate the temperature history of concrete structures cured with heating sheets. Results are as follows ; (1) The temperature of concrete showed continuously rising trend with the heating by planar surface heater under the cold environmental condition of 3~-12$^{\circ}C$. And after about 24 hours the maximum temperature of concrete was reached at 25~3$0^{\circ}C$. (2) The temperature of slab concrete heated by planar surface heater of 130W/$m^2$ was at least $25^{\circ}C$ higher than that of an exterior air, and the curing performance was much more effective than heating by hot wind machine. (3) Through the curing by planar surface heater for 48 hours, the concrete maturity of about 1.5 times to heating by hot wind machine was acquired.

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A study on climate design using cold air flow to reduce air contaminant concentration of underground garage in the apartment complex (냉기류를 이용하여 공동주택단지 내 지하주차장 오염농도를 저감하는 기후 디자인에 관한 연구)

  • Kim, Tae Han;Cho, Kyung Hak;Chroi, Ji Hye;Kim, Seog cheol
    • KIEAE Journal
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    • v.11 no.1
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    • pp.29-38
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    • 2011
  • This study suggested practical application of climate design on apartment complex with the focus on the use of Cold Air Flow and green building design method. The domestic research on the wind path analysis has been associated since the early 21th century in urban planning and site planning, this initiative study aimed to mitigate the urban heat island effect and to promote the sustainable urban development. It is, however, mostly focused on the flow analysis and heat flow in the urban context, due to the poor application of the wind path analysis in actual planning and design. Special attention is paid to the possibilities of identifying and developing the application methods in relation to Cold Air Flow and building design. This study examined these relations and suggested some trenchant approach to a more comprehensive and efficient use of the wind flow analysis in climate design.

Wind Effect on the Distribution of Daily Minimum Temperature Across a Cold Pooling Catchment (냉기호 형성 집수역의 일 최저기온 분포에 미치는 바람효과)

  • Kim, Soo-Ock;Kim, Jin-Hee;Kim, Dae-Jun;Yun, Jin I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.14 no.4
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    • pp.277-282
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    • 2012
  • When wind speed exceeds a certain threshold, daily minimum temperature does not drop as predicted by the geospatial model in a cold pooling catchment. A linear regression equation was derived to explain the warming effect of wind speed on daily minimum temperature by analyzing observations at a low lying location within an enclosed catchment. The equation, Y=2X+0.4 ($R^2$=0.76) where Y stands for the warming ($^{\circ}C$) and X for the mean horizontal wind speed (m/s) at 2m height, was combined to an existing model to predict daily minimum temperature across an enclosed catchment on cold pooling days. The adjusted model was applied to 3 locations submerged in a cold air pool to predict daily minimum temperature on 25 cold pooling days with the input of simulated wind speed at each location. Results showed that bias (mean error) was reduced from -1.33 to -0.37 and estimation error (RMSE) from 1.72 to 1.20, respectively, in comparison with those from the unadjusted model.

Comparison of the Wind Speed from an Atmospheric Pressure Map (Na Wind) and Satellite Scatterometer­observed Wind Speed (NSCAT) over the East (Japan) Sea

  • Park, Kyung-Ae;Kim, Kyung-Ryul;Kim, Kuh;Chung, Jong-Yul;Conillor, Peter-C.
    • Journal of the korean society of oceanography
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    • v.38 no.4
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    • pp.173-184
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    • 2003
  • Major differences between wind speeds from atmospheric pressure maps (Na wind) and near­surface wind speeds derived from satellite scatterometer (NSCAT) observations over the East (Japan) Sea have been examined. The root­mean­square errors of Na wind and NSCAT wind speeds collocated with Japanese Meteorological Agency (JMA) buoy winds are about $3.84\;ms^{-1}\;and\;1.53\;ms^{-1}$, respectively. Time series of NSCAT wind speeds showed a high coherency of 0.92 with the real buoy measurements and contained higher spectral energy at low frequencies (>3 days) than the Na wind. The magnitudes of monthly Na winds are lower than NSCAT winds by up to 45%, particularly in September 1996. The spatial structures between the two are mostly coherent on basin­wide large scales; however, significant differences and energy loss are found on a spatial scale of less than 100 km. This was evidenced by the temporal EOFs (Empirical Orthogonal Functions) of the two wind speed data sets and by their two­dimensional spectra. Since the Na wind was based on the atmospheric pressures on the weather map, it overlooked small­scale features of less than 100 km. The center of the cold­air outbreak through Vladivostok, expressed by the Na wind in January 1997, was shifted towards the North Korean coast when compared with that of the NSCAT wind, whereas NSCAT winds revealed its temporal evolution as well as spatial distribution.

A Study of Literature Review on Tong Bi(痛痺) (통비(痛痺)에 대(對)한 문헌적(文獻的) 고찰(考察))

  • Hong, Soon-Sung;Oh, Min-Suk;Youn, Il-Ji
    • Journal of Haehwa Medicine
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    • v.14 no.1
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    • pp.187-200
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    • 2005
  • 1. The causes of Tong Bi(痛痺) are divided into external cause(wind, cold, dampness) and internal cause(deficiency yang-excess yin, excess cold). but mostly two causes are combined. 2. Chronic Tong Bi can be turn into bone, kidney, zang organs disease and Hak Sul Pung(鶴膝風). 3. The symptoms are severe arthralgia, limit of ROM, localized coldness and edema, white coated tonge fur, wiry and knotted pulse. 4. The principles of medicinal treatment are mainly eliminating the cold and inducing the wind, removing the dampness. 5. The principle of acupucture and moxibustion treatment is mainly eliminating the cold(iron skin treatment, moxibustion, warming acupucture).

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Studies on the Reducing Methods of Cold Wind Damage of Rice Plant by Installation of Wind break Net in the Eastern Coastal Area III. Effect on the Reducing Method of Cold Wind Damage to the Net Meshes of Wind break Net. (동해안 냉조풍지대의 방풍강에 의한 수도의 풍해 경감 연구 III. 방풍강의 강목에 따른 풍해경감 효과)

  • Lee S. P.;Kim S. K.;Lee K. S.;Choi D. U.;Kim C. Y.
    • Proceedings of the Korean Society of Crop Science Conference
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    • 1990.05a
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    • pp.66-67
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    • 1990
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The Oriental and Occidental bibliographic Study of Psoriasis (乾癬에 對한 東.西醫 文獻的 硏究)

  • Kim, Nam-Kwen;Hwang, Chung-yeon;Lim, Gye-sang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.12 no.1
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    • pp.154-178
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    • 1999
  • Psoriasis is the recurrent disease of skin and till now its mechanism, pathogenesis and treatment are not clearly discovered. So, like these papers, we must investigate more safety and effective treatment of psoriasis. And I obtained the following condusions from the Oriental and Occidental bibliographic investigation. 1. In Oriental medicine. Baikbi, Pungsun, Eunselbyong, Songpisun, Baikselpung were the other names of Psoriasis. 2. In Occidental medicine, genetic factors, aggravation and inducible factors, biochemical factors, immunologic factors, disorder of epidermal kinetics, vascular malformation of dermis were cosidered to the pathogenic factors of psoriasis. 3. In Oriental medicine, the pathogenic factors of psoriasis were divided two parts. One is exogenous pathogenic factors which including the blood-heat, blood dryness, blood stasis, deficiency of liver and kidney, inharmony of impulsive and appointed pulsation, deficiency of blood. The other is exogenous pathogenic factors which including the wind-evil, wind-wetness, wind-heat, wind-cold, wetness-heat, cold-wetness, heat-evil. 4. In Occidental medicine, external applicative medicine, internal medicine, ultraviolet therapy, ultraviolet - external applicative medicine compound therapy and etc. were used the therapy of psoriasis. 5. In Oriental medicine, clean away heat and cooling blood, aliment the blood and moisturize, activating blood and expelling blood stasis, harmonize and invigorate the liver and kidney, invigorate the kidney, aliment the blood and moisturize the skin, aliment the blood and expelling the wind, expelling the wind and wetness, clean away heat and expelling wind, expelling the wind and scatter the cold, clean away heat and expelling the wetness, heat up the meridian and scatter the cold, clean away heat and remove the toxin and etc. were used the method of internal therapy of psoriasis. 6. Until Qing dynasty, wind expelling effective prescriptions like Bangpungtongsungsan, Sopungsan. Supungsunkisan and etc. were used and recently Yanghyelgeupungtang, Hwalhyelgeupungtang, Samultanggagam and etc. were used the internal therapy of psoriasis. 7. In the external therapy of psoriasis, Yuhonggo, Pungyugo, Sekryupiyeongo were used the plaster therapy and Folium Rerillae, Camphora, Fructus, Xanthii, Herba Spirodelae compound prescription were used the cleansing therapy, Okgisan, Chiunsan, Galmyogo, Hobunsan, Muisan, Madugo, Jeyugohengin were used the rubbing skin therapy. Rangdok Radix Aconiti, Bijeonilchoalkwang were used the attaching therapy, the extract of Rhizoma Et Radix Veratri was used the spreading pouder therapy. 8. In the acupuncture therapy of psoriasis, the Jelgol, chok Samni(S36), Kansa(P5), Haegye(S41), Wijung(B40) and etc. were used the acupuncture point, and the angle of helix incision threapy that disinfect and cut the angle of helix and plaster the Semen Glycine and Squama Manitis were used.

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