The Influence of water flow rate on Pumping Rate in Mytilus Edulis using a Refined Direct Measurement Apparatus

1976 ◽  
Vol 56 (2) ◽  
pp. 311-319 ◽  
Author(s):  
D. I. Hildreth
Keyword(s):  
Water Flow ◽  
Direct Measurement ◽  
Water Flow Rate ◽  
Mantle Cavity ◽  
Water Current ◽  
Ciliary Activity ◽  
Pumping Rate ◽  
Influence Of Water ◽  
Food Particles ◽  
Flow Through

INTRODUCTIONWork on pumping and filtration rates of bivalve molluscs was initially concerned with the physiological concept of pumping water through the mantle cavity. Comprehensive reviews are given by Winter (1970) and Ali (1971). The methods are of two kinds; direct, in which the flow of exhaled water itself is measured, and indirect, in which the rate of clearance of food particles is used to calculate water flow through the gills.There is a disadvantage in the indirect method when used to calculate volumes of water pumped because it involves the assumption that a fixed percentage (often 100% with large particles) of the particulate matter passing through the gill system is retained. Pumping rate is thus estimated as a function of the particle collecting properties of the latero-frontal cirri, whereas the water current is produced by the lateral cilia. Although the structure of the latero-frontal cirri is now well documented (Moore, 1971), their efficiency in particle retention can alter under certain conditions (Dral, 1967). There is need, therefore, for direct measurement of the quantity of water pumped. Recent advances in the understanding of branchial innervation and the control of lateral ciliary activity also reinforce this point (Aiello, 1960, 1962, 1970; Paparo, 1972, 1973).The constant level chamber for direct measurement of pumping rate was devised by Galtsoff (1926), to ensure that separation of the exhalant water current from the bivalve was not interfered with by pressure differences produced by the process of separation. The apparatus has been used in various forms by Galtsoff (1926, 1928, 1946), Nelson (1935, 1936), Collier & Ray (1948), Loosanoff & Engle (1947), Loosanoff & Nomejko (1946) and more recently by Drinnan (1964) and Davids (1964).

Experimental Characterization of Two-Phase Flow Through Valves Applied to Liquid-Assisted Gas-Lift

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Renato P. Coutinho ◽  
Paulo J. Waltrich ◽  
Wesley C. Williams ◽  
Parviz Mehdizadeh ◽  
Stuart Scott ◽  
...  
Keyword(s):  
Water Flow ◽  
Two Phase Flow ◽  
Numerical Study ◽  
Water Flow Rate ◽  
Phase Flow ◽  
Experimental Characterization ◽  
Two Phase ◽  
Flow Through ◽  
Gas Lift

Abstract Liquid-assisted gas-lift (LAGL) is a recently developed concept to unload wells using a gas–liquid fluid mixture. The success deployment of the LAGL technology is related to the behavior of two-phase flow through gas-lift valves. For this reason, this work presents an experimental and numerical study on two-phase flow through orifice gas-lift valves used in liquid-assisted gas-lift unloading. To the knowledge of the authors, there is no investigation in the literature on experimental characterization of two-phase flow through gas-lift valves. Experimental data are presented for methane-water flow through gas-lift valves with different orifice port sizes: 12.7 and 17.5 mm. The experiments were performed for pressures ranging from 1.00 to 9.00 MPa, gas flow rates from 0 to 4.71 m3/h, and water flow rate from 0 to 0.68 m3/min. The experimental results are compared to numerical models published in the literature for two-phase flow through restrictions and to commercial multiphase flow simulators. It is observed that some models developed for two-phase flow through restrictions could successfully characterize two-phase flow thorough gas-lift valves with errors lower than 10%. However, it is first necessary to experimentally determine the discharge coefficient (CD) for each gas-lift valve. The commercial flow simulators showed a similar performance as the models available in the literature.

Optimization and Application of NTC Thick Film Segmented Thermistors

2013 ◽  
Vol 543 ◽  
pp. 491-494 ◽  
Author(s):  
Maria Vesna Nikolic ◽  
Obrad.S. Aleksic ◽  
Branka M. Radojcic ◽  
Miloljub D. Lukovic ◽  
Nenad Nikolic ◽  
...  
Keyword(s):  
Thick Film ◽  
Water Flow ◽  
Water Flow Rate ◽  
Input Voltage ◽  
Glass Frit ◽  
Water Current ◽  
Thermal Sensor ◽  
Layer By Layer ◽  
Reduced Dimensions ◽  
Water Mains

NTC thermistor paste for printing thermal sensors on alumina was formed of very fine Ni0.5Cu0.2Zn1.0Mn1.3O4 thermistor powder obtained by a combined mechanical activation/thermal treatment process, organic vehicle and glass frit. Sheet resistivity was measured using an R-test matrix and it was much lower than the value determined for pure nickel manganite thermistors. The thermistor exponential coefficient was calculated from the R[ diagram measured in the temperature range-30 to +120°C in a climatic chamber. Thick film segmented thermistors with reduced dimensions (optimized construction) were printed sequentially layer by layer, dried and fired at 850°C/10 min in air. Electrodes were printed of PdAg conductive and solderable paste. The samples obtained were characterized by electrical and thermal measurements. The obtained NTC segmented thermistors with reduced dimensions were applied in a thermal sensor for water flow in the water mains. It contained a cold thermistor for measuring input water temperature and a self-heating thermistor for measuring the dependence of water current on water flow rate at a set input voltage power. Initial measurements show that the thermal sensor system requires a low input voltage power making it much easier and safer for operation.

Influence of Water Speed on Tadpoles of Ranidella signifera and R. riparia (Anura:Leptodactylidae)

1980 ◽  
Vol 28 (1) ◽  
pp. 79 ◽  
Author(s):  
FJ Odendaal ◽  
CM Bull
Keyword(s):  
Water Flow ◽  
South Australia ◽  
Breeding Habitat ◽  
Water Current ◽  
Similar Species ◽  
Flinders Ranges ◽  
Species Overlap ◽  
Influence Of Water ◽  
The Difference ◽  
Water Speed

Ranidella riparia is restricted to the Flinders Ranges of South Australia. and has a distribution largely allopatric to that of the morphologically similar species, R. signifera. The distributions of these two species overlap in the lower Flinders Ranges. In an experimental water flow, tadpoles of R. riparia were less often moved by the water current than those of R. signifera, and the difference increased with increasing water speed. In the Flinders Ranges most of the breeding habitat for frogs is in fast flowing creeks. The likelihood that tadpoles of R. signifera would be swept away in these creeks may be a factor restricting its distribution in this area.

scholarly journals Flow Measurements Using a Sluice Gate; Analysis of Applicability

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 819
Author(s):  
Elżbieta Kubrak ◽  
Janusz Kubrak ◽  
Adam Kiczko ◽  
Michał Kubrak
Keyword(s):  
Water Flow ◽  
Cross Section ◽  
Discharge Capacity ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Sluice Gate ◽  
Flow Measurements ◽  
Discharge Coefficients ◽  
Flow Through ◽  
Submerged Conditions

This study analyzes the possibilities of using an irrigation sluice gate in submerged conditions to measure water flow rate. Hydraulic experiments on sluice gate discharge capacity were performed on a model made on a 1:2 scale. Measurements were taken for the submerged flow of the sluice gate. Nomograms and relationships for discharge coefficients of the analyzed sluice gate were developed. The possibility of using the existing nomogram for discharge capacity of the submerged sluice gate to determine the discharge capacity of the modeled gate was also investigated. The effect of narrowing of the sluice gate cross-section resulting from different mounting techniques on its capacity was explained. The analyses confirmed the possibility of using the formulas for the submerged sluice gate to estimate the flow through the irrigation sluice gate.

Self-aggregation Phenomenon and Stable Flow Conditions in a Two-Phase Flow Through a Minichannel

2015 ◽  
Vol 70 (10) ◽  
pp. 843-849 ◽  
Author(s):  
Grzegorz Górski ◽  
Grzegorz Litak ◽  
Romuald Mosdorf ◽  
Andrzej Rysak
Keyword(s):  
Water Flow ◽  
Light Transmission ◽  
Water Flow Rate ◽  
Air Bubbles ◽  
Two Phase ◽  
Quantification Analysis ◽  
Flow Through ◽  
Stable Flow ◽  
Self Aggregation ◽  
Aggregation Phenomenon

AbstractBy increasing a water flow rate of the two-phase (air–water) flow through a minichannel, both the partitioning of air slugs into air bubbles of different sizes and small air bubbles aggregation into larger air bubbles were identified. These phenomena were studied in detail by using the corresponding sequences of light transmission time series recorded with a laser-phototransistor sensor. To distinguish any instabilities in air slugs along with their break-ups and aggregations, the recurrence plots and recurrence quantification analysis were applied.

scholarly journals Evidence for One-way Valves in the Water-flow System of Sponges

1978 ◽  
Vol 76 (1) ◽  
pp. 137-148
Author(s):  
STEVEN VOGEL
Keyword(s):  
Direct Evidence ◽  
Flow System ◽  
Water Source ◽  
Water Current ◽  
Positive Pressure ◽  
Pumping Rate ◽  
Flow Through ◽  
Hollow Cylinders ◽  
Ambient Currents ◽  
A Current

A water current over a marine sponge can increase flow through the sponge; even a current below the active pumping rate is effective. To investigate the structural correlates of such flow induction, two series of models were tested in a flow tank. These models were hollow cylinders with either wall perforations serving as ostia or an apical orifice as osculum. They were connected to an external reservoir which acted as a water source with the osculum exposed to flow, or as a sink where ostia were exposed. The reservoir could be raised or lowered to simulate active pumping. The models differed from intact sponges in showing much lower flow induction in general and no induction with ambient currents much below the active pumping rate. The magnitude of flow induction could be raised to near normal by the addition of one-way valves in the model ostia. These valves prevented backflow out of the ostia lateral and downstream to the current while permitting the positive pressure on the upstream ostia to augment flow. To be effective at low ambient currents, the valves had to be isolated from the active pump; if the valves were located in the ‘dermis’, the ‘subdermal space’ provided the requisite isolation. Direct evidence for functional valves was obtained by cannulating freshly collected Haliclona viridis and observing that water could be more easily drawn out of an osculum than forced into it.

scholarly journals The Ventilation Cycle in Octopus

1985 ◽  
Vol 116 (1) ◽  
pp. 375-383
Author(s):  
M. J. WELLS ◽  
P. J. SMITH
Keyword(s):  
Water Flow ◽  
Cycle Time ◽  
Mantle Cavity ◽  
Pressure Differential ◽  
Pressure Measurements ◽  
Flow Through

Pressure measurements made at various points inside the mantle show that the ventilatory stream of the resting animal is driven by very small (often less than 0.5 cmH2O) pressure differences. Inspiration occupies less than onethird of the total cycle time, while flow across the gills is evidently continuous, since there is always a pressure differential between the prebranchial and postbranchial parts of the mantle cavity. The fact that branchial heartbeats do not correlate with ventilatory movements is further evidence that water flow through to the gills is both steady and continuous.

Influence of water flow rate in mold on hooks and inclusions at the subsurface of ultra low carbon Al-killed continuous casting slabs

2019 ◽  
Vol 116 (2) ◽  
pp. 215 ◽  
Author(s):  
Lifeng Zhang ◽  
Xubin Zhang ◽  
Ying Ren ◽  
Wen Yang
Keyword(s):  
Numerical Simulation ◽  
Continuous Casting ◽  
Water Flow ◽  
Flow Rate ◽  
Shell Thickness ◽  
Water Flow Rate ◽  
Low Carbon ◽  
Hook Depth ◽  
Influence Of Water

The influence of water flow rate on the surface cleanliness of slabs was investigated through the hook reveal and inclusion detection. The numerical simulation was performed to calculate the shell thickness with different water flow rate. With the decrease of the water flow rate from 99 to 88 L/s, the hook depth reduced at most of positions, and the number of > 5 μm inclusions decreased. The contour was calculated to provide guidance for adjustment of the water flow rate.

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