Enhancing Effluent Water Quality of Sedimentation Basins Using Constructed Wetlands Technology
The Tennessee Valley Authority (TVA) has constructed twelve wetlands to treat acid drainage at reclaimed coal mines and fossil-fueled power plants. These wetlands are designed primarily...
Safety Analysis of Handset Wood Slab Formworks
A reliability index is calculated for flexural strength of a handset wood slab formwork system. Load and resistance models are based on a survey of construction loads and wood test data...
Limit States Design of Wooden Formwork for Concrete Walls
Load and resistance factors are developed for ultimate limit states design of wooden formwork components for concrete walls when the lateral concrete pressures are computed using the ACI...
Development of Standards for Slipform & Jumpform Works
Review of past work indicates substantial effort has been made to publish construction standards and guidelines for slipforms but published material pertaining to jumpforms is scarce....
Kinematics and Trajectory Planning for Robotic Excavation
One of the high volume and repetitive construction operations at the construction site is the excavation of soil. Automation of the excavation work requires a robotic system that is able...
Introduction to Air-Water Mass Transfer
Background is presented to assist individuals in comprehending the terminology, in understanding the need to know the rate of air-water mass transfer, and the historical theories of air-water...
Effect of Gas Flow on Physical Absorption
Air blowing over a liquid surface can greatly increase the rate of physical absorption of a gaseous component. This increase is associated with the initiation of waves and a change in...
Air-Water Transfer: The Role of Partitioning
A review is presented of the role of air-water equilibrium in determining the direction and rate of transfer of chemicals between water bodies and the atmosphere. Because this diffusive...
Formation of Droplets from Bursting Bubbles at an Air-Water Interface
The breakup of an air bubble at a still water surface leads to the formation of two distinct droplet families known respectively as film drops and jet drops. The former are the tiny fragments...
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...
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