• 제목/요약/키워드: warm period

검색결과 423건 처리시간 0.028초

온수지에 의한 관개용수의 수온상승 효과에 관한 연구 (A Study on the Effects of Temperature Rise of Irrigation Water Passed Through the Warm Water Pool.)

  • 연규석;최예환
    • 한국농공학회지
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    • 제19권1호
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    • pp.4323-4337
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    • 1977
  • The study was to estimate the effect of the rise of water temperature in the warm water pool and to make contribution to the establishment of reducing to a damage of cool water as well as to the planning for warm water pool. This observation was performed in Wudu warm water pool located at Wudu-Dong of Chuncheon for two years from 1975 to 1976. The results were showed as follows; 1. The daily variation of water temperature was the least for inset (No.1; 0.6$^{\circ}C$) the second for middle overflow (No2: 3$^{\circ}C$, No.3; 2.3$^{\circ}C$) and another for outflet (No.4; 3.6$^{\circ}C$, No.5; 3.8$^{\circ}C$) And the highest reaching time of water temperature in each block was later about 1 hour than the time at which air temperature happend in the daytime. So, the variation of water temperature was sensitive to the variation of air temperature 2. The monthly variation of water temperature at each measuring point was plotted to be increased with increase in air temperature till August (Mean monthly rising degree; No.1; 1.15$^{\circ}C$, No.2; 1.7$^{\circ}C$, No.3; 1.73$^{\circ}C$, No.4; 2.08$^{\circ}C$, No.5; 2.0$^{\circ}C$), and expressed gradually descended influence upon water temperature after August. 3. The mean temperature of inflow folwed in warm Water pool was 7.5∼12.5$^{\circ}C$, and outflow temperature was described as 13.4∼22.5$^{\circ}C$ to be climbed. And So, the rising interval of water temperature was shown as 6.7∼10.4$^{\circ}C$. 4. The correlation between the rising of water temperature and the weather condition was found out highly significant. As the result, their correlation coefficents of water temperature depending on mean air temperature, ground temperature, wind velocity and relative humidity were to be 0.93, 0.90, - 0.83 and 0.71 respectively. But there was no confrimation of the correlation on the clouds, sunlight time, volume of evaporation, and heat capacity of horizontal place. 5. The water temperature of balance during the period of rice growing in Chuncheon district was shown as table 10, and the mean of whole period was calculated as about 23.7$^{\circ}C$. 6. The observed value of the outflow temperature passed through the warm water pool was higher than that of computed, the mean difference between two value was marked as 1.15$^{\circ}C$ for blockl, 1.18$^{\circ}C$ for block2, and 0.47$^{\circ}C$ for block3, respectivly. Therefore, the ratio on the rising degree between the observed and computed were shown as 53%, 44%, and 18%, mean 38% through each block warm water pool (referring item $\circled9$ of table 11,12, and 13). Accordingly, formula (4) in order to fit for each block warm water pool was transfromed as follow; {{{{ { theta }_{w } - { theta }_{ 0} =[1-exp LEFT { { 1-(1+2 varphi )} over {cp } CDOT { A} over { q} RIGHT } ] TIMES ( { theta }_{w } - { theta }_{ 0}) TIMES C }}}} Here, correction coefficinent was computed 1.38, and being substituted 1.38 for C in preceding formula, the expected water temperature will be calculated to be able to irrigate the rice paddy. As the result, we can apply the coefficient in order to plan and to construct a new warm water pool.

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우리나라 사계절 극한기온현상의 시.공간적 변화 (Spatio-Temporal Changes in Seasonal Extreme Temperature Events in the Republic of Korea)

  • 최광용
    • 대한지리학회지
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    • 제49권4호
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    • pp.489-508
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    • 2014
  • 본 연구에서는 최근 40년 동안(1973~2012) 우리나라 기상청 61개 기상관측소에서 관측한 일최고기온 및 일최저기온 자료를 분석하여 계절별 극한기온현상 변화의 시 공간적 특징을 밝히고자 하였다. 우리나라 평균적으로 봄철에는 온난일의 증가, 여름철에는 한랭야의 감소와 온난야의 증가 현상이 가장 뚜렷하게 나타난다. 가을철에는 여름철과 유사하게 한랭야의 감소와 온난야의 증가, 겨울철에는 한랭야의 감소와 한랭일의 감소 경향이 가장 뚜렷하게 나타난다. 도시화 정도에 상관없이 온난야와 같은 야간 극한기온 현상의 변화는 대부분의 계절 전이 기간에 뚜렷하게 나타나지만, 주간 극한기온현상의 변화는 특정 월에만 나타난다. 대조적으로, 한랭일은 봄철과 여름철에, 온난일은 여름철에, 온난야는 겨울철에 대부분의 관측지점에서 통계적 유의성을 지닌 변화를 살펴볼 수 없다. 온난화에 대한 극한기온현상 변화 민감도는 봄철에 온난일(+6.3일/$^{\circ}C$)과 한랭야(-6.2일/$^{\circ}C$), 여름철에 온난야(+10.4일/$^{\circ}C$)와 온난일(+9.5일/$^{\circ}C$), 가을철에 온난일(+7.7일/$^{\circ}C$), 겨울철에 한랭야(-4.7일/$^{\circ}C$)가 상대적으로 높게 나타났다. 이러한 결과들은 온난화 과정에서 복잡한 기후변화 피드백에 의해 우리나라의 극한기온현상들이 계절마다 주 야간별로 비대칭적인 변화 추세와 민감도를 보이면서 변화하고 있음을 가리킨다.

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가솔린엔진의 연료 미립화 향상을 위한 공급연료 가열에 대한 실험적 연구 (An Experimental Study on the Fuel Heating for Enhancing Fuel Atomization)

  • 윤팔주;박승범;선우명호;천동필
    • 한국자동차공학회논문집
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    • 제9권4호
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    • pp.112-120
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    • 2001
  • Poor fuel vaporization in gasoline engines causes the problem of HC emission during the cold start and warm-up period. This paper presents a strategy to improve fuel atomization during the warm-up phase. In this experiment, the heated fuel-rail system is constructed to investigate the effects of fuel heating on the average size of fuel droplets. The fuel atomization effects are examined by measuring Sauter Mean Diameter (SMD) of the fuel droplets from the three different types (two-hole, pintle, and six-hole) of injectors based upon a returnless heated fuel-rail system. The results show that the six-hole type injector is the most sensitive to fuel heating in terms of SMD among three different types of injectors.

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이중관 배기메니폴드의 HC저감효과 및 열특성에 관한 연구 (A Study on the Reduction of HC and Heat Characteristics of the Dual Pipe Exhaust Manifold)

  • 박경석;허형석
    • 한국자동차공학회논문집
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    • 제9권6호
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    • pp.103-111
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    • 2001
  • During cold-start period, the reduction of exhaust emissions is a challenging task. To decrease harmful gaseous substances such as HC, it is necessary to realize a fast catalyst warm-up. In this study, the performance of dual pipe exhaust system have been carried out through different test mode. From measurement of gas temperature and HC concentration, the following conclusions were derived ; 1) Compared with single pipe, dual pipe exhaust system remarkably increase temperature of exhaust gas going through M.C.C(Main Catalytic Converter). 2) W.C.C.(Warm-up Catalytic Converter) also decreases HC emission. To reduce HC emission, it is helpful to use W.C.C. as well as dual pipe exhaust system. 3) Using finite element method, it is shown that inner parts have much higher distribution of temperature than outer parts.

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한국 남동해안의 용승과 관련된 물리환경 (Physical Envirionment Associated with Upwelling off the Southeast Coast of Korea)

  • 이재철;김대현
    • 한국수산과학회지
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    • 제51권5호
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    • pp.579-589
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    • 2018
  • Data from the two bottom moorings of ADCP (acoustic doppler current profiler), coastal weather station and CTC (conductivity temperature depth) observations for 2001 were analyzed to describe the physical processes associated with upwelling off the southeast coast of Korea. Winds were favorable for upwelling during summer, but were not correlated with currents. Shoaling of isotherms toward the coast due to the baroclinic tilting of the strong East Korean Warm Current (EKWC) provided a favorable background for immediate upwelling-response of surface temperature to southerly winds. This baroclinic effect was supported by a significant inverse coherence between the upper-layer current and bottom temperature near the coast. This upwelling is similar to the Guinea Current upwelling, which is driven by remote forcing (Houghton, 1989). Persistent southward flow was observed below approximately $10^{\circ}C$ isotherm throughout the observation period.

The Effect of the Oceanic Condition on Variations of the Catches of Alaska Pollack in the East Sea (the Japan Sea)

  • HONG Chul-hoon;CHO Kyu-Dae
    • 한국수산과학회지
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    • 제30권6호
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    • pp.997-1004
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    • 1997
  • The effect of the oceanic condition on variations of the catches of Alaska pollack (Theragra chalcogramma) in the East Sea (the Japan Sea) is examined using monthly catches data of this fish and temperature data during 1972 to 1991. Since 1973 the catches of Alaska pollack have gradually increased, showing a peak in 1981, and then rapidly decreased after 1986. A significant negative correlation was found between variations of the catches and the temperature at 50 m depth offshore Mukho. In 1981, the year of the highest catches in the study period, the water mass in the Eastern Korean Coastal Sea of the East Sea was extremely cold, while the year of poor catch, 1979, was much warmer than the annual mean temperature. The results show that the temperature variations around the Eastern Korean Coastal Sea play an important role in the variations of the catches of Alaska pollack, implying that the effect of the Tsushima Warm Current is also very important.

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Three Cases with the Multiple Occurrences of Freezing Rain in One Day in Korea (12 January 2006; 11 January 2008; and 22 February 2009)

  • Park, Chang-Kyun;Byun, Hi-Ryong
    • 대기
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    • 제25권1호
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    • pp.31-49
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    • 2015
  • From the hourly data of 75 Korean weather stations over a 12-year period (2001~2012), this study has chosen three cases (January 12, 2006; January 11, 2008; and February 22, 2009) of multiple freezing rains and investigated the atmospheric circulations that seemed to cause the events. As a result, the receding high pressure type (2006), prevailing high pressure type (2008), and warm front type (2009) are confirmed as synoptic patterns. In all three cases, freezing rain was found in regions with a strong ascending current near the end point of a low-level jet that carried the warm humid air from low latitudes. The strong ascending current resulted from lower-level convergence and upper-level divergence. In 2006 and 2009, the melting process was confirmed. In 2008, the supercooled warm rain process (SWRP) was confirmed. In contrast to existing SWRP theory, it was found that the cool air produced at the middle atmosphere and near the earth's surface led to the formation of freezing rain. The sources of this cool air were supposed to be the evaporative latent heat and the cold advection coming from the northeast. On the other hand, a special case was detected, in which the freezing rain occurred when both the soil surface temperature and surface air temperature were above $0^{\circ}C$. The thickness distributions related to freezing rain in Korea were found to be similar to those in North America. A P-type nomogram was considered for freezing rain forecasting; however, it was not relevant enough to Korea, and few modifications were needed.

동해안의 Cochlodinium polykrikoides 적조 발생에 미치는 해황의 특성 (The Influence of Oceanic Conditions on the Occurrence of Cochlodinium polykrikoides Blooms in the East Sea)

  • 심정민;황재동;정창수;이용화;전경암;권기영
    • 한국환경과학회지
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    • 제19권12호
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    • pp.1385-1395
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    • 2010
  • Harmful dinoflagellate Cochlodinium polykrikoides blooms have been frequently occurred in coastal areas of the East Sea since 1995. We compared the oceanic conditions in years 1995, 2001 and 2003 when the C. polykrikoides bloom was strong, and in years 1998 and 2004 when the C. polykrikoides bloom was not appeared. We studied temporal and spatial variation of upwelling and geostrophic currents on the western channel of Korean Strait, an entrance of the East Sea. The period and occurrence area of C. polykrikoides bloom was depended on variation of upwelling in summer. In the distributions of geostrophic current, southward current was dominant near the coast in August, 1998 and 2000. Whereas northward current was dominant near and off the coast in August, 1995 and 2003 which the C. polykrikoides bloom was strong. When compared dominant phytoplankton of the coastal areas in each year, Kuroshio indicator species Proboscia alata and Chaetoceros affine were dominant, respectively, in 2001 and 2003 at every stations. However, the dominant species was variable at each coastal area in 1998 and 2000. In 2003, the abundance of Sagitta elegans which is known as the cold water indicator was low, but the abundance of S. enflata, warm water indicator, was very high in Gangneung compared to Sokcho. It seemed that the distribution of S. elegans is restricted by strong warm water current. In conclusion, it was estimated that the distribution of C. polykrikoides bloom in the coastal area of the East Sea was closely related with the strength of East Korea Warm Current and upwelling.

영동대설 사례에 대한 MM5 강수량 모의의 통계적 검증 (Statistical Verification of Precipitation Forecasts from MM5 for Heavy Snowfall Events in Yeongdong Region)

  • 이정순;권태영;김덕래
    • 대기
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    • 제16권2호
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    • pp.125-139
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    • 2006
  • Precipitation forecasts from MM5 have been verified for the period 1989-2001 over Yeongdong region to show a tendency of model forecast. We select 57 events which are related with the heavy snowfall in Yeongdong region. They are classified into three precipitation types; mountain type, cold-coastal type, and warm type. The threat score (TS), the probability of detection (POD), and the false-alarm rate (FAR) are computed for categorical verification and the mean squared error (MSE) is also computed for scalar accuracy measures. In the case of POD, warm, mountain, and cold-coastal precipitation type are 0.71, 0.69, and 0.55 in turn, respectively. In aspect of quantitative verification, mountain and cold-coastal type are relatively well matched between forecasts and observations, while for warm type MM5 tends to overestimate precipitation. There are 12 events for the POD below 0.2, mountain, cold-coastal, warm type are 2, 7, 3 events, respectively. Most of their precipitation are distributed over the East Sea nearby Yeongdong region. These events are also shown when there are no or very weak easterlies in the lower troposphere. Even in the case that we use high resolution sea surface temperature (about 18 km) for the boundary condition, there are not much changes in the wind direction to compare that with low resolution sea surface temperature (about 100 km).

입원환자가 지각하는 간호사의 친절에 관한 연구 (A Research on Inpatient Perception of Kindness on Nurse)

  • 강현숙;김일원;김원옥;장광자
    • 기본간호학회지
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    • 제3권2호
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    • pp.259-271
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    • 1996
  • This reserch has been done in order to improve quality of nursing and medical service. In order to improve those qualities the study has been done to know inpatient perception of kindness and meaning of kindness which patients receive from nurse and also what effect inpatient have when they experience kindness from nurse. The subjects were 454 people who admitted in K Hospital. Time period was from October to December 1995. This survey has been done by personal interview with a written questionnaire. Analysis of data has been done by $X^2-test$ and percentage. The results of the research may be summarized as follows. 1. The inpatients perception of kindness on nurse were explanation(26.8%), tolerance(16.3%), warm-heartedness(12.8%), interest(9.5%), ability(8.4%), confidence(6.4%), respect(4.0%), support(2.65%). 2. In order to find out general moaning of kindness, study classified by age, sex, education, job, experience of hospitalization, inpatient ward. As a result of $X^2-test$, no special meaning of kindness was presented in inpatient perception of kindness. 3. Contents kindness which inpatient experienced were, warm-heartedness(23%), understanding(18.1%), interest(17.8%), ability(12.8%), tolerance(5.7%), confidence(2.6%), 4. Over half of subjects(59.1%) answered stability to effect on kindness of Nurse. Next are self-confidence(7.9%), respect(5.3%), confidence(4.6%), warm-heartedness(3.5%), understanding(2.6%). According to above results inpatient feels that meaning of kindness were explanation, tolerance, warm-heartedness. This meaning has no distinctive difference other than consistent meaning. Likewise, inpatient experience about contents of kindness is similar to meaning of kindness. As a result of this research, which show that kindness of nurse gives patient stability, respect and confidence, we would kindness is important for recovery of inpatient. Therefore, this research outcome could be able to help to improve quality of nursing and medical service.

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