Monitoring and Quantifying Rate-Limited Mass Transfer Using Geoelectrical Measurements
Non-Fickian solute-transport behavior has been observed at research and aquifer remediationsites in diverse geologic settings. Anomalous behavior such as concentration rebound, long breakthrough...
Power Shift
Engineers designing a Manhattan skyscraper with offices in the lower floors and residences in the upper found that they had to employ several unusual methods to accommodate client needs....
Dam within a Dam
A routine inspection of the Rock Run Dam, an 84-year-old Ambursen-type structure in Chester County, Pennsylvania, revealed major stress cracks and water stains on the inside face of the...
Weighing Anchors
Modern anchorage systems offer design engineers and contractors unprecedented choice in load transfer mechanisms. Some anchors are highly specialized, while others are appropriate for...
Optimization of the Aquifer Remediation Costs and Design with Pulsed Pumping
(No paper) Pump-and-treat is a common technique for the remediation of contaminated aquifers. However, slow kinetic mass transfer at sites contaminated with organic compounds may reduce...
Casting Hot and Cold
Contractors and engineers battled the Minnesota winter to build a concrete segmental bridge with form travelers. Superstructure segments were poured in temperatures as low as -19F, using...
Design-Build & Co.: A Brave New World
There are many inherent risks in overseas work. These are made greater by current project delivery methods, such as design/build operate transfer, and build own operate transfer. The author...
Optimal Geometric Shape of a Surface Aeration Tank
This paper presents the results of a laboratory investigation on three cross-sectional shapes?square, rectangular and circular of surface aeration tanks, without any baffles, to find out...
Predicting Transport of Organics through Soil Columns using Distributed Mass-Transfer Rates
A numerical model to describe contaminant transport through soil columns, including distributed mass-transfer, is developed. Both a gamma distribution and a lognormal distribution are...
Simulation of Dissolved Oxygen in Sacramento-San Joaquin Delta
A one-dimensional model has been developed to simulate water quality in a complex multi-channel estuarine system. The model utilizes a Lagrangian reference frame for transport computations....
Automatic, Remote, Multiplexed Geotechnical Measurements with Time Domain Reflectometry (TDR)
Time Domain Reflectometry (TDR) has been employed successfully in geotechnical applications such as monitoring of rock mass deformation in a variety of geometries; however, required operation...
An Object-Oriented Approach to PC Finite-Element Solutions
A methodology for developing a finite-element program with a variety of applications within civil engineering is presented. Application include simple structural analysis, groundwater...
Deformations About Excavations in Highly Stressed Rock
The central business district of Sydney, New South Wales (NSW), is dominated by the Hawkesbury Sandstone, a Triassic sedimentary formation. Measurements have confirmed the existence of...
A Coupled Mass Transfer and Surface Complexation Model for Uranium (VI) Removal from Wastewaters
A remediation technique has been developed for removing uranium (VI) from complex contaminated groundwater using flake chitin as a biosorbent in batch and continuous flow configurations....
Computer simulation of pulsed pumping for remediation under mass transfer limited conditions
The article presents the computer simulation of choosing the right time periods for interruption and pumping in the pulsed pumping process. It will calculate a set of criteria under mass...
Modeling of Biofiltration of Natural Organic Matter in Drinking Water Treatment
A multi-substrate model of the biofiltration of natural organic matter in drinking water was developed and successfully applied. This model assumes that biofiltration is a two-step process...
Quantification of the Mechanisms Controlling the Removal Rate of Volatile Contaminants by Air Sparging
Air sparging is a technology for removing dissolved and volatile phase chemicals (VOCs) from the saturated zone. It is used in conjunction with soil vapor extraction (SVE) and sometimes...
Effect of Roughness and Thickness of Biofilms on External Mass Transfer Resistance
The effect of roughness and thickness of biofilms on the dissolved oxygen (DO) concentration boundary layer thickness (DO CBLT) and the external mass transfer process in a biofilm system...
Development of a Model for the ABF/AS Process
A modelling approach has been established for the activated biofiltration/activated sludge (ABF/AS) process. This approach indicates that ABF/AS systems can be considered as a variation...
Modeling Full-Scale Diffused Aeration Systems
The purpose of this research was to show the direct relationship of the oxygen mass transfer coefficient (KLaT)...
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