Experiments on Active Structural Control Under Seismic Loads
Two control systems, an active tendon system and an active mass damper system are selected for study for possible real structural implementation. Presented in this paper are simulation...

Tradeoffs Between Active Control and Identification of Structural Systems
This paper explores the tradeoffs between structural identification and structural control in a quantitative manner. Through the intemediary concept of an optimal input, it is shown that...

The CADD Landfill
Designing landfills with CADD, engineers have reduced cut and fill calculations from two weeks to two days. Aerial surveys arrive on magnetic tapes and are loaded into computers by in-house...

Contact Stabilization Process Analysis and Formulation
In this paper, the contact stabilization process is analyzed. In comparison to the conventional activated sludge process, there are a larger number of independent design variables involved...

Importance of Aeration Basin Detention Time in the Activated Sludge Process
Aeration basin detention time is a key design parameter for an activated sludge system at a wastewater treatment plant. The impacts of reducing the aeration time is illustrated by a case...

Control of Nocardia in a Municipal Activated Sludge Facility
The paper reports on a study to determine the cause(s) of the biological imbalance and identify corrective measures. Project activities included: isolation and identification of filamentous...

Optimizing the Activated Sludge Process by Encouraging Futile Cycling
A study was conducted to demonstrate that cell yield in activated sludge processes can be decreased without increasing oxygen consumption by applying operating conditions that encourage...

Gamma Exposure from Rn Progeny in GAC Units
An investigation into the gamma exposure rate generated by granular activated carbon (GAC) water treatment units focused on ten sites that covered a range of source radon (Rn) in water...

Treatment Plant Modifications to Conserve Energy and Improve Performance
Creative funding along with thorough planning and design contributed to the successful energy conservation program at the Willow Lake Wastewater Treatment Plant, Salem, Oregon. By funding...

Comparison of Centrifuge Performance on Oxygen Activated Sludge
This paper compares the performance of centrifuges processing high purity oxygen activated sludge with units processing conventional activated sludge. Comparisons are made both for thickening...

The Influence of Water Tables on Herbicide Losses
Atrazine and metolachlor were applied preemergent on April 22, 1987, to silage corn on high watertable fields which were either subsurface drained (104 mm drain tubes 1 m deep) or surface...

Water Marketing in California
In one of the world's consummate entrepreneurial environments, a commodity as vital as water is so difficult to buy and sell. Why has water marketing become widely used in...

Potential Flow Over a Wavy Bed: A Persistent Error
The standard small-amplitude theory of potential flow over a wavy bed is briefly discussed, together with the three special values of the Froude Number which define four different flow...

Modelling of Sand Bars in Coastal Environments
A mathematical model describes the formation of sand bars by progressive wind-generated waves. The model decomposes into several constituents linked together in a two step morphological...

A Method to Treat Incident Wave Condition in Shallow Water Equation
A method to consider open boundary condition of the shallow water equation to analyze water surface wave and tide is employed in the finite element anaysis. This can be done by considering...

Instability of Bed-Surface Composition Due to Sorting Process in a Stream Composed of Sand and Gravel
Wavy patterns of sorting are often observed in a stream composed of sand and gravel, and they are regarded as instability of bed-surface composition due to selective bed-load transport...

Infiltration of Water to the Ground in a Flood-Control Reservoir with Seepage
As storm water management in urban area with increasing amount of runoff, flood-control reservoir with the bed having large permeability to enrich the groundwater is considered. A dynamical...

Comparison of DAMBRK With DWOPER for Computing Water Surface Elevations at Stream Junctions
The National Weather Service computer programs DWOPER (Operational Dynamic Wave Model) and DAMBRK (Dam-break) are one-dimensional models using an implicit finite difference method of solution...

Improved Numerical Analysis of Steady Water Surface Profiles
As well as HEC-2 and similar models serve the profession, problems exist with their application. In general, inflexibility of use and inaccuracies around transitions between subcritical...

Cellular Automaton Simulation of Viscous Free Surface Fluid Dynamics
It has been demonstrated elsewhere that the simple interaction of a two dimensional field of discrete particles traveling on a regular lattice yields large scale behavior closely approximating...

 

 

 

 

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