• Title/Summary/Keyword: Outflow rate

Search Result 275, Processing Time 0.024 seconds

A Study on the Estimation of Loss Rate of Dredged Fills (준설토의 유실률 평가에 관한 연구)

  • Kim, Hong-Taek;Kim, Seog-Yeol;Kang, In-Kyu;Park, Jae-Eock
    • Journal of the Korean GEO-environmental Society
    • /
    • v.1 no.1
    • /
    • pp.57-63
    • /
    • 2000
  • Volume change of the dredged soils is composed of loss amount of the soil particles flowing over an outflow weir with water and settlements due to both the self-weight consolidation in reclaimed layer and the desiccation at the surface of reclaimed layer. In order to estimate the amount of soil particles flowing over an outflow weir with water, the breakage theory and the results of hydrometer analyses. To verify a validity of the proposed procedure, evaluated loss ratio is compared with various estimates from the other existing methods.

  • PDF

Impacts of Initial Soil Moisture on Hydrologic Outflow in a Distributed FLO-2D Model (분포형 FLO-2D 수문모형에서 초기토양함수가 유출결과에 미치는 영향)

  • Lee, Khil-Ha
    • Journal of Environmental Science International
    • /
    • v.30 no.8
    • /
    • pp.613-619
    • /
    • 2021
  • Soil water enters the atmosphere via evapotranspiration, where it transforms into atmospheric water vapor and plays important role in the surface-atmosphere energy exchange. Soil conditions have a direct influence on the effective rainfall, and initial soil moisture conditions are important for quantitatively evaluating the effective rainfall in a watershed. To examine the sensitivity of the initial saturation to hydrologic outflow, a two-dimensional distributed FLO-2D hydrologic model was applied to a small watershed. The initial saturation was set to 0.3, 0.5, and 0.7 and the obtained results were compared. The Green-ampt model was chosen to calculate the penetration loss. Depending on the initial soil moisture, the peak flow rate varied by up to 60%, and the total water volume in the watershed by approximately 40%.

Vortex Features in a Half-ducted Axial Fan with Large Bellmouth (Effect of Tip Clearance)

  • Shiomi, Norimasa;Kinoue, Yoichi;Setoguchi, Toshiaki;Kaneko, Kenji
    • International Journal of Fluid Machinery and Systems
    • /
    • v.4 no.3
    • /
    • pp.307-316
    • /
    • 2011
  • In order to clarify the features of tip leakage vortex near blade tip region in a half-ducted axial fan with large bellmouth, the experimental investigation was carried out using a 2-dimensional LDV system. Three sizes of tip clearance (TC) were tested: those sizes were 1mm (0.55% of blade chord length at blade tip), 2mm (1.11% of blade chord length at blade tip) and 4mm (2.22% of blade chord length at blade tip), and those were shown as TC=1mm, TC=2mm and TC=4mm, respectively. Fan characteristic tests and the velocity field measurements were done for each TC. Pressure - flow-rate characteristics and two-dimensional velocity vector maps were shown. The vortex trace and the vortex intensity distribution were also illustrated. As a result, a large difference on the pressure - flow-rate characteristics did not exist for three tip clearance sizes. In case of TC=4mm, the tip leakage vortex was outflow to downstream of rotor was not confirmed at the small and reference flow-rate conditions. Only at the large flow-rate condition, its outflow to downstream of rotor existed. In case of TC=2mm, overall vortex behaviors were almost the same ones in case of TC=4mm. However, the vortex trace inclined toward more tangential direction. In case of TC=1mm, the clear vortex was not observed for all flow-rate conditions.

1.64 ${\mu}m$ features of Jets and Outflows from Young Stellar Objects in the Carina Nebula

  • Shinn, Jong-Ho;Pyo, Tae-Soo;Lee, Jae-Joon;Lee, Ho-Gyu;Kim, Hyun-Jeong;Koo, Bon-Chul;Sung, Hwankyung;Chun, Moo-Young;Lyo, A. Ran;Moon, Dae-Sik;Kyeong, Jaemann;Park, Byeong-Gon;Hur, Hyeonoh;Lee, Yong-Hyun
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.39 no.1
    • /
    • pp.56.2-56.2
    • /
    • 2014
  • We present [Fe II] 1.64 ${\mu}m$ imaging observations for jets and outflows from young stellar objects over the northern part (${\sim}24^{\prime}{\times}45^{\prime}$) of the Carina Nebula, a massive star forming region. The observations were performed with IRIS2 of Anglo-Australian Telescope and the seeing was ~1.5". Eleven jets and outflows features are detected at eight different regions, and are termed as Ionized Fe Objects (IFOs). The [Fe II] features have knotty or elongated shapes, and the detection rate of IFOs against previously identified YSOs is 1.4%. Four IFOs show anti-correlated peak intensities in [Fe II] and $H{\alpha}$, where the ratio I([Fe II])/I($H{\alpha}$) is higher for longish IFOs than for knotty IFOs. We estimate the outflow mass loss rate from the [Fe II] flux using two different methods. The jet-driving objects are identified for three IFOs (IFO-2, -4, and -7). The ratios of the outflow mass loss rate over the disk accretion rate for IFO-4 and -7 are consistent with the previously reported values ($10^{-2}-10^{+1}$), while the ratio is higher for IFO-2. This excess may result from underestimating the disk accretion rate. Other YSO physical parameters show reasonable relations or trends.

  • PDF

Impacts of Contaminated Water Outflow from the Lake Sihwa on the Meiobenthic Animals Living in the Coastal Zones of the Kyonggi Bay (시화호 오염수 방류에 따른 중형저서동물의 군집변동)

  • 김동성;이재학
    • Korean Journal of Environmental Biology
    • /
    • v.18 no.2
    • /
    • pp.279-290
    • /
    • 2000
  • To alleviate the harmful effects from contamination, the Sihwa Lake waters have been regularly fluxed out into the ocean to mix and circulate with the oceanic waters, and then allowed to flow back into the lake. In the present study, eco-environmental impacts by the outflowing contaminated lake waters to the benthic communities of the coastal zones along Kyonggi Bay were examined at three separate areas. A total of 22 groups of meiobenthic animals were commonly found in the subtidal zones of the Bay. All groups of the meiobenthic animals on the 1st and 7th days after the outflow were remarkably reduced in numbers from the selected areas examined, as compared to those observed one day before the outflow. It was also found that the community structure of meiobenthos was changed drastically: At the station near the water gate, for example, where the immediate outflow of the lake water was encountered, the benthic harpacticoids, the group observed to be one of the predominant groups before the outflow, were found to have disappeared completely. For an area that was relatively far away from the water gate, the reduction rate of meiobenthos after the outflow events was slower and more gradual than the nearer sites. An area that is the farthest from the water gate, no reduction in any of the meiobenthos group was observed. The ratio between nematodes/copepods (N/C) was remarkably changed by the outflows at the station near the water gate: One day before the outflow, the ratio was 0.7 while the ratio was 19.0 at the station near the water gate. In contrast, at the stations relatively far from the water gate, the ratio decreased one day after the outflow event, but increasing trends were observed one week later. In the tidal flats, Station 1 exhibited the common observed regional values of the ratio whereas Station 2 showed a very high ratio of 191.3. The results suggested that the contaminated lake water outflows directly effect meiobenthos in a relatively short time period and thus the meiobenthos may be a good indicator animal group for examining the effect of pollution. [Lake Sihwa, contaminat water outflow, meiobenthic animals living]

  • PDF

Arteriovenous Fistula Formation with Prosthetic Graft Using the Vena Comitantes as a Venous Outflow (동반정맥을 정맥유출로 이용한 인조혈관 동정맥루 조성술)

  • Lee, Gun;Lim, Chang-Young;Lee, Hyeon-Jae
    • Journal of Chest Surgery
    • /
    • v.42 no.1
    • /
    • pp.41-45
    • /
    • 2009
  • Background: Arteriovenous fistula formation is not always easy to perform in hemodialysis patients because of poor preservation of veins due to repeated venipuncture and cannulation. We analyzed the patency rate and complications of prosthetic arteriovenous fistulas using the vena comitantes as a venous outflow in the antecubital fossa, which are protected from venipuncture. Material and Method: Between January 2006 and June 2008, 12 patients underwent prosthetic arteriovenous fistula formation using the vena comitantes as a venous outflow. Arterial inflow was via the brachial artery and the graft was placed in a loop fashion. The male-to-female ratio was 7 : 5 and the mean age was $59{\pm}14$ years. Six patients had diabetes mellitus and 10 patients had hypertension. Result: There were no complications, such as a graft infection or bleeding. Five patients showed postoperative stenosis at an average of 3 months. The primary patency rate was 75.0, 65.6, and 52.2% at 3, 6, and 12 months, respectively. All the patients with stenosis were able to continue hemodialysis after intervention therapy. The secondary patency rate was 100% at 12 months. Conclusion: Creation of a prosthetic arteriovenous fistula using uninjured vena comitantes resulted in a good patency rate and this vein may become a substitute for inappropriate superficial veins.

Water Balance in a Paddy Field with Pumping Irrigation System (양수장 용수공급 논 지대의 물수지)

  • 정운태;이근후;이인영
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 1998.10a
    • /
    • pp.1-7
    • /
    • 1998
  • To investigate the water balance in a paddy rice field with the pumping station for irrigation water supply, flow measurements and analysis on various components of water balance were carried out. The investigated area is 103.7 ha, and the irrigation water was supplied for 102 days during the total irrigation period starting from June 1. It was found that the consumption rate was increased as the growing stage was progressed. The variation of evapotranspiration rate was shown same tendency as the consumption rate, while no apparent tendency was found in infiltration rate upon different growing stages. And the ground water input to the area was predominant during the early stage of growing period, while ground water output from the study area was predominant at the end of the growing stage. The range of return flow rate, the ratio of total outflow to total inflow in every decad, was 57.6 to 85.7%. These values are slightly higher than reported values from the other investigation projects.

  • PDF

STUDIES IN FIBRE DIGESTION AND PASSAGE RATE OF LIQUID AND SOLID IN CATTLE AND BUFFALOES

  • Abdullah, N.;Ho, Y.W.;Mahyuddin, M.;Jalaludin, S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.4 no.2
    • /
    • pp.137-141
    • /
    • 1991
  • Rumen liquor characteristics and disappearance rate of dry matter were studied in Kedah-Kelantan cattle and swamp buffaloes fed grass of rice straw-based diet. Cobalt-EDTA and chromium mordented fibres prepared from the faecal material were used to determine the liquid and solid particles movement in both animal species fed with rice straw. Swamp buffaloes showed a more intense rumen fermentation activity than Kedah-Kelantan cattle when both species were fed straw-based diet. The buffaloes also demonstrated faster rates of grass and straw degradation in situ. The fluid outflow rate from the rumen of buffalo ($1.06{\pm}0.19l/h$) was observed to be slower than that of cattle ($1.55{\pm}0.01l/h$). No significant differences between cattle and buffaloes were observed in rumen fluid volume and passage rate of small particles from the rumen.

Application of a geophysical well log technique for determining permeability in borehole

  • Kim Y.;Park J.
    • 한국지구물리탐사학회:학술대회논문집
    • /
    • 2003.11a
    • /
    • pp.432-436
    • /
    • 2003
  • Geophysical well logging techniques which are useful for delineating permeability of geological formation have been reviewed. A new technique for obtaining permeability using conductivity log technique has been discussed. This conductivity logging technique has been tested by monitoring the conductivity change within the model hole using borehole environment water and incoming-outgoing water of different salinity with constant flow rate by maintaining balance between inflow and outflow. Conductivity variation features depended mainly on flow rate, density contrasts due to salinity and temperature contrasts between fluid within the hole and incoming-outgoing fluid. The results of the experiment show uniform change of fluid conductivity within bore hole with time, and a fairly good correlation between the flow rate and the conductivity change rate. This conductivity logging technique is expected to be an efficient tool for determining permeability.

  • PDF

The Role of Adenosine Receptors on Acetylcholine Release in the Rat Hippocampus (흰쥐 해마에서 Acetylcholine 유리에 미치는 Adenosine 수용체의 역할)

  • Choi, Bong-Kyu;Kim, Do-Kyung
    • The Korean Journal of Pharmacology
    • /
    • v.30 no.2
    • /
    • pp.145-152
    • /
    • 1994
  • As it has been reported that the depolarization induced acetylcholine(ACh) release is modulated by activation of presynaptic $A_1-adenosine$ heteroreceptor and various lines of evidence indicate the $A_2-receptor$ is present In hippocampus, this study was undertaken to delineate the role of adenosine receptors on hippocampal ACh release. Slices from the rat hippocampus were equilibrated with $[^3H]-choline$ and the release of the labelled product, $[^3H]-ACh$, which evoked by electrical stimulation(3 Hz, $5\;Vcm^{-1}$, 2 ms, rectangular pulses) was measured, and the influence of various agents on the evoked tritium outflow was Investigated. Adenosine$(0.3{\sim}100\;{\mu}M)$ and CPA$(0.1{\sim}30\;{\mu}M)$ decreased the $[^3H]-ACh$ release in a dose-dependent manner without changing the basal rate of release. DPCPX$(1{\sim}10\;{\mu}M)$, a selective $A_1-receptor$, antagonist, increased the $[^3H]-ACh$ release in a dose related fashion with slight increase of basal tritium release. And the effects of adenosine and CPA were significantly inhibited by $DPCPX(2\;{\mu}M)$ treatment. CPCA, a specific $A_2-agonist$, in concentration ranging from 0.3 to 30 ${\mu}M$, decreased the evoked tritium outflow, and these effects were also abolished by $DPCPX(2\;{\mu}M)$ treatment. But the CPCA effects were not affected by $DMPX(2\;{\mu}M)$, a specific Aa-antagonist, treatment. However, CGS 21680c, a recently introduced potent $A_2-agonist$, in concentration ranging from 0.1 to $10{\mu}M$, did not alter the evoked tritium outflow. These results indicate that the decrement of the evoked ACh release by adenosine is mediated by $A_1-heteroreceptor$, but $A_2-adenosine$ receptor is not involved in ACh release in the rat hippocampus.

  • PDF