The Effect of Surface Films on Concentration Fluctuations Close to a Gas/Liquid Interface
Modeling of gas/liquid mass transport requires knowledge concerning the behavior of near-surface concentration fluctuations at clean and film-covered gas/liquid interfaces. Previous measurements...
Hydrodynamics and Mass Transfer on a Moving Drop of Water
The fluid dynamics and mass transfer associated with moving water drops are examined. In the first part, numerical solution of the transient hydrodynamics around and inside a drop falling...
Hydrodynamics and Mass Transfer in a Jet-Agitated Vessel
Experiments of carbon dioxide absorption in water have been carried out in a turbulent vessel presenting a zero mean shear stress value at the gas-liquid interface. Liquid-phase turbulence...
Effect of Temperature on Gas Transfer at Low Surface Renewal Rates
In order to investigate the dependence of gas transfer coefficients on temperature under conditions of low surface renewal rates, laboratory experiments were conducted using simultaneous...
Turbulent Water Aeration: Analytical Approach and Experimental Data
Analytical studies based on the statistical theory of turbulence were carried out in order to identify some relevant parameters which may be associated with the reaeration rate coefficient...
Turbulent Velocity and Gas Concentration Measurements in the Near-Surface Layer
An experiment was undertaken to study the mechanism of interfacial mass transfer. Near-surface liquid turbulence and oxygen concentration fluctuations have been measured in a grid-stirred...
Isotropic Fractionation During Air-Water Transfer of Oxygen and Nitrogen
We present empirical results that show the kinetic fractionation during gas exchange is 0.9972 ? .0002 for oxygen and 0.9987 ? .0001 for nitrogen. These values are larger than the solubility...
A Fluorescence Technique to Measure Concentration Gradients near an Interface
A new fluorescence technique which measures the concentration profile in a mass transfer boundary layer is described. It uses a tracer whose fluorescent intensity is inversely proportional...
Regional Estimates of Gas Transfer Using an Airborne System
The aircraft-based eddy correlation technique was recently used to obtain regional observations of transfer processes of sensible and latent heat as well as carbon dioxide over wetlands...
From Mean Fluxes to a Detailed Experimental Investigation of the Gas Transfer Process
Three new experimental techniques are discussed which allow a much more detailed investigation of the gas transfer process than any previous techniques. Using heat as a proxy tracer for...
Methane Tracer Technique for Gas Transfer at Hydraulic Structures
Using a simple headspace gas chromatographic technique, gas transfer at several hydraulic structures were investigated. Naturally occurring methane was used as a tracer gas to measure...
Measurement of Reaeration Coefficient with the Soluble Solids Probe
The results of analytical and experimental studies are presented, showing that the proposed method for indirect determination of gas transfer coefficients at gas-liquid interfaces, based...
Dissolved Oxygen and Woody Debris: Detecting Sensitive Forest Streams
Early watershed studies showed that timber harvesting and yarding could depress dissolved oxygen in nearby streams when fresh slash entered streams and streamside shade was reduced. State...
Rainfall-Reaeration Effects
The effect of rainfall intensity on reaeration has not been adequately reported in the literature. It is clear that rainfall causes surface turbulence and increases reaeration, and a significant...
Epilimnetic Dissolved Oxygen Content and Surface Water Pump Performance
Surface water pumps have been operated and monitored at TVA's Douglas Dam since 1987. The purpose of these pumps is to improve the dissolved oxygen (DO) content of the hydropower...
Gas Transfer at Hydraulic Structures
The objective of this paper is to identify and briefly summarize the state-of-the-art in measuring and describing gas transfer at hydraulic structures. Basic theory of mass transfer at...
Oxygen Transfer in Turbulent Shear Flows
Oxygen transfer equation for the air-water two-phase aeration region of turbulent shear flow in a vertical pipe is derived. Dimensionless variables significant in characterizing the transfer...
Technology Development for Auto-Venting Turbines
Experimentation with venting air into the hydroturbines at Norris Dam has convinced the Tennessee Valley Authority (TVA) that this is a viable method for increasing dissolved oxygen (DO)...
A Simple Empirical Model of Aeration at Navigation Dams
In a study of aeration at 28 dams in the upper Ohio River basin, site-specific least-squares linear regression models were used to describe the dissolved oxygen deficit below each dam...
Oxygen Transfer at Spillways
A relationship for oxygen transfer efficiency, E, at spillways and gated spillways with a hydraulic jump or plunge pool, has been developed from conceptual considerations and fit to measurements...
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