• 제목/요약/키워드: Water movement

검색결과 1,111건 처리시간 0.026초

Regional differences in winter activity of hibernating greater horseshoe bats (Rhinolophus ferrumequinum) from Korea

  • Kim, Sun-Sook;Choi, Yu-Seong;Yoo, Jeong-Chil
    • Journal of Ecology and Environment
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    • 제43권1호
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    • pp.1-8
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    • 2019
  • Background: Hibernating bats exhibit ubiquitous winter activity in temperate zones, but there is considerable between- and within-species variety in their intensity and purpose. Bats may fly during winter for sustenance or travel to other hibernacula. This study compared inter-regional variation in the winter activity of the greater horseshoe bat (Rhinolophus ferrumequinum). We predicted that weather and hibernacula-environmental conditions would influence winter activity patterns. Results: Winter activity patterns differed between regions. In the Anseong area, we confirmed movement inside the hibernaculum, but in Hampyeong, we observed movement both inside and between hibernacula. The two regions differ by $4^{\circ}C$ in average winter temperatures. Anseong experiences 22 days during which average daily temperatures exceeded $5^{\circ}C$, whereas Hampyeong experienced 50 such days. During the hibernating period, bat body weight decreased by approximately 17-20% in both regions. Conclusions: Ambient temperatures and winter-roost environments appear to be behind regional differences in hibernating bat activity. As winter temperatures in Korea do not favor insect activity, feeding probability is low for bats. However, bats may need to access water. At Anseong, underground water flows inside the hibernaculum when the reservoir outside is frozen. At Hampyeong, the hibernaculum does not contain a water source, but the reservoir outside does not freeze during winter. In conclusion, water-source location is the most likely explanation for regional variation in the winter activity of hibernating bats.

삼초(三焦)와 영위(營衛)의 상관성(相關性) (The Relation of Three Burning Space And Nutrient & Defensive Qi)

  • 문성식;강정수
    • 혜화의학회지
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    • 제9권1호
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    • pp.105-112
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    • 2000
  • Three burning space concentrating mainly on the text of ${\ll}NeiChing{\gg}$, we got this conclusion by looking at a longitudial perspective of three burning space function, nutrient & defensive qi creation, movement and numbers. 1. Longitudial movement is the law of the universe, by looking at oriental medicine by the thought of heaven and man unity we can tell that longitudial movement concept is used to analyze the physiology of our body. And we can look at our body in a cubic movement suck as top and bottom, left and right, outside and inside, internal and external, upward and downward movement. 2. In Nei Ching the concept of three burning space is seperated in to four different types of three burning space which are three burning space as a fu, three burning space as a water metabolism and excretion organ, and three burning space by its position. 3. nutrient & defensive qi's movement in the channel is the same as the twelve regular channels movement in our body, nutrient qi circulates the yang part twenty five during the day and circulates the ying part twenty five times during the night. Since channel functions corresponds with the sun, moon, and the stars the ups and downs of nutrient & defensive qi's property varies with the difference of the periods. 4. By comparing nutrient & defensive qi's production and property with three burning space's positional property, we can see that three burning space's positional property comes out from the longitudial movement of nutrient & defensive qi.

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Movement of Sand around Revetment under Water Pressure Variation

  • HoWoongShon
    • 지구물리
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    • 제6권4호
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    • pp.221-230
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    • 2003
  • Many hydraulic structures are damaged by under flood flow and storm waves year after year. Many cases of dike and breakwater failure are caused by the suck out of sand from behind the revetment. This type of failure will be in close relation to the dynamic behavior of sand bed around the revetment. In this paper, from this point of view we investigated the basic characteristics of such sand movement by small model tests and tried to explanation the hydro- and soil mechanical mechanism of this phenomenon theoretically.

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흙 살리기운동의 효율적 추진방안 (Directions for the Soil Revitalization Movement in Agriculture)

  • 정진석
    • 농촌지도와개발
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    • 제3권2호
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    • pp.211-218
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    • 1996
  • The soil revitalization movement is the important approach to intensify the agricultural production and sustainable agriculture for the future. The soil have been polluted by abusing chemical fertilizer and inflow foul water from factories and houses during the last three decades. That`s not only farmer`s responsibility but all of us. The cooperative efforts are needed to preserve soil and environment.

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UTLIZIATION OF RADARSAT FOR FORECASTING OIL SLICKT RAJECTORY MOVEMENT

  • Marghany, Maged
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.435-437
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    • 2003
  • This study presents work to utilize RADARSAT SAR image for forecast oil slick trajectory movement. The fractal dimension algorithm used to detect oil slick. The Doppler frequency shift and quasi-linear model was used to simulate a current pattern from RADARSAT image. The Fay’s algorithm of oil slick spreading was developed based on a Doppler frequency shift model. Thus, the study shows that fractal dimension algorithm discriminated the oil slick from the surrounding water features. The quasi-linear model shows that the current pattern can be simulated from single RADARSAT image. The oil slick trajectory model shows that after 48 hrs, the oil slick parcels deposited along the coastal waters.

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TDR(Time Domain Reflectometry)을 이용한 토양함수량의 측정 (Measurement of Soil Water Content by Time Domain Reflectometry)

  • 박재현;윤성용;김상준
    • 한국수자원학회논문집
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    • 제30권6호
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    • pp.587-595
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    • 1997
  • 비포화 흐름에 관하 실험은 토양내 물의 이송특성을 밝히는 매우 중요한 의미를 가지고 있다. 하지만 Tensiometer와 같은 전통적인 측정방법은 비교적 길기 때문에 함수량이 급격하게 변하는 비정상류 비포화흐름을 측정하는데 상당한 어려움이 따른다. 본 연구에서는 TDR을 이용하여 이러한 문제를 해결할 수 있는 함수량 측정방법을 소개하고자 한다. TDR은 구형파를 발생시키는 함수방생기와 반향파를 분석하는 오실로스코프로 구성되어 있다. 토양속에 설치된 탐침을 지나는 구형파는 임피던수가 변하는 지점에서 반향되며 주변토양의 우전율상수 변화에 따라 전파속도가 달라지게 된다. 이 때 토양내 함수량은 함수량에 따른 반향시간특성을 이용하여 추정되어진다. TDR을 이용하는 함수량측정의 검증실험에 의하면 오븐 건조한 함수량에 대한 TDR측정 함수량의 오차율이 3.5% 이내 이었다. 따라서 TDR은 국내토양에 대한 비정상류 상태의 비포화흐름을 측정하는데 매우 훌륭한 실험장치로 판단된다.

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페즈(PES)를 이용한 하천의 토사 이동 시뮬레이션 (Simulation of Sediment Transport in a River System Using Particle Entrainment Simulator)

  • Lee, Young-Soo
    • 상하수도학회지
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    • 제18권1호
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    • pp.5-14
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    • 2004
  • A feasibility of using Particle Entrainment Simulator (PES) to evaluate model variables describing sediment entrainment in a river system was investigated. PES in a laboratory was utilized to simulate the sediment resuspension phenomenon in the river and the subsequent relationship between shear rate and sediment entrainment was developed. The total suspended solids (TSS) data from PES was incorporated into statistical models in an effort to describe behaviors of net particle movement in the river. PES was found to be adequate for simulating particle entrainment phenomenon in a river system. Statistical analysis was used to assess propriety of PES data for predictive purposes. The results showed good relationships between PES results and system variables, such as average stream velocity and net particle movement.

비선형 Boussinesq방정식을 이용한 유로대수층 해석 (Analysis of stream-aquifer using nonlinear Boussinesq equation)

  • 정재성;김민환;방경미
    • 한국환경과학회지
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    • 제11권1호
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    • pp.57-61
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    • 2002
  • To investigate the flow characteristics by the water stage variation between stream-aquifer, the new solution of nonlinear Boussinesq equation was derived and extended using the Boltzmann transformation. The soundness of the analytic solution obtained from this study was examined by the comparison with the linearized analytic solution and the numerical solution by finite difference method. And the movement, velocity, flowrate and volume of flow caused by the stage variation of stream and the existence of regional gradient were estimated. This new analytic solution can express the groundwater movement between stream-aquifer. So, it might be helpful to manage water environment.

물리적인 기반의 토양침식모델 개발 (Physically-based Soil-water Erosion Model - Based on Hairsine and Rose's Concept -)

  • 김성준
    • 한국농공학회지
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    • 제39권4호
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    • pp.82-89
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    • 1997
  • A physically-based soil-water erosion model with simple hydrology and Rose & Hairsine's erosion concept is described, and was implemented in the form of computer program. The model derived from the concept of stream power(Bagnold, 1977) considers settling velocity characteristics of the soil and distinguishes between the processes of entrainment and re-entrainment. It deals separately with rill flow and sheet flow, handles vegetation in terms of soil contact cover, and has the ability to simulate soil movement on nonuniform slopes. The model predicted sediment concentrations reasonably with the results of Mclsaac et al. (1990). It showed a capability to quantitatively predict the movement of soil on uniform and nonuniform slopes. Among the model parameters, soil depositability $({\phi})$ was the most sensitive from the sensitivity analysis.

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수반응 우레탄과 바닥용 경질 폴리우레탄을 이용한 바닥마감재의 성능향상에 관한 실험적 연구 (A study on the improvement for performance of floor finishing materials using poly urethane with water reacting urethane)

  • 강효진;박진상;박종욱;오상근
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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    • pp.653-656
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    • 2006
  • It is necessary for the new material and construction concept to make up for weak point which related to high durability and finish ability to solve exposure limit of exist construction method. This paper is deal with performance test(tier load, anti abrasion, anti impact, permeability, bond test) compositive using for water reacting soft urethane and rigid urethane to improve the exist problem which are crack movement, adhesive on the wet surface, impact and abrasion by tier load. It is getting decreasing demage compare with other exist materials after test by transfer load, movement and impact.

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