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...
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)...
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...
New Experimental Results on the Parameters Influencing Air-Sea Gas Exchange
Gas exchange experiments from large linear and circular facilities are presented which provide some more insight into the influence of waves on the gas exchange process. The experimental...
Parameterization of Air-Ocean Gas Transfer
A renewal-type model, based on the physics of a molecular sublayer, allows the derivation of parameters to describe air-ocean gas transfer and the temperature difference across the cold...
Oxygen Transfer in Full Lift Hypolimnetic Aeration Systems
A series of experiments were conducted to examine the effect of diffuser depth, diffuser orifice diameter and separator box surface area on oxygen transfer (mg/L), daily oxygen load (kg...
Field Tests on a Bubbleless Membrane Aerator
A novel bubbleless hollow fiber membrane aerator has been developed and tested for the oxygenation of water. In this process pure oxygen is maintained on the inside of a bundle of sealed,...
Experiment on the Efficiency of an Aspirator-Blower Type Aerator
An aspirator-blower type aerator was designed and tested successfully for small lake application. The experiment showed that significant amount of air flow can be generated by the aspirator...
Theoretical Investigation of Oxygenating Bubble Plumes
Rehabilitation of lakes by oxygenation with air or oxygen plumes has been proven to be biologically feasible. Oxygenating plumes are released from areal sources and the gases are absorbed...
The Use of a Deep Shaft for the Waste Water Treatment Plant of Orgamol SA
The first version of a new deep aeration system has been built for Orgamol SA, a chemical plant in the Rhone valley, Switzerland. Construction, operation and oxygen transfer mode of the...
Oxygen Mass Transfer to Flowing Ground Water Using Oxygen Microbubbles
Mass balance and transfer of oxygen has been studied from oxygen microbubbles to low dissolved oxygen ground water passing through variously configured pilot scale vertical slice test...
Steady Turbulent Gas Desorption in Surface Condenser Tubes
A one-dimensional steady two-phase separated flow model in conjunction with the energy and mass transfer equations and an associated turbulent mass transfer coefficient model are utilized...
Designing Better Hollow Fibre Contactors
In this paper we calculate optimum hollow fibre module designs for gas absorption by maximizing the mass transferred per unit cost. Two costs are considered; the membrane cost and the...
Avoiding Defective Specifications
Despite everyone's best efforts, the design intent as portrayed in the contract documents is rarely crystal clear. As a result, the owner and the project team often find themselves...
Jointless Redecking
If you're redecking a bridge, why not eliminate a major cause of its corrosion at the same time? Why not remove the expansion joints? The Department of Public Works in Steuben...
Update: Bridge Scour
Nearly 500 bridges have failed because of hydraulic conditions�primarily scour�since 1950, but the collapse of the Route 90 bridge over Schoharie Creek in April 1987 focused national attention...
Rehabbing the U.S.
When it comes to protecting its $1.4 trillion investment in public-works infrastructure, the U.S. has been like a homeowner who puts off fixing a leak until the ceiling lands on his head....
Foundation Studies in a Fault Zone and a Steep Valley Slope
This paper presents two case histories which illustrate unique problems in defining the character of rock for support of structures. The first case study concerns a conventional building...
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