Distribution of Rubidium, Strontium, and Zirconium in Tuff From Two Deep Coreholes at Yucca Mountain, Nevada
Variations in concentrations of trace elements Rb, Sr, and Zr within the sequence of high-silica tuff and dacitic lava beneath Yucca Mountain reflect both primary composition and secondary...
Strontium Isotopes in Carbonate Deposits at Crater Flat, Nevada
Strontium isotope studies of carbonates from soils, veins, eolian dust and Paleozoic basement sampled near Crater Flat, southwest of Yucca Mountain, provide evidence for the origins of...
Active Control of Structures with Soil-Structure Interaction
The objective of this paper is investigate the effect of soil flexibility on the performance of the active control system for seismic-excited buildings. By using the critical-mode control...
Time-Delayed Control of Nondispersive Continuous Systems
This paper deals with the noncollocated, time-delayed active point control of continuous systems. It considers systems of finite spatial extent which can be modelled by the undamped wave...
Optimal Control Configuration for Active Control of Structural Vibrations
An active tendon control mechanism is used to control the vibrations of a bridge-like structure. A single control force controls three modes of vibrations. Special attention is paid to...
Input-Output Discrete-Time Control of Structures
This paper outlines an approach for active control of structures based on the identification of a linear difference equation to describe the control loop and the design of a discrete-time...
Combined Nitrogen and Phosphorus Removal in a Cyclic Activated Sludge System Without Anoxic Mixing Sequences
A simplified methodology for combined phosphorus and nitrogen removal through reactor configuration, cyclic sequencing and the control of aeration intensity in variable volume activated...
Separation of Organics from the Aqueous Phase Using Polymeric Resins
The adsorption of tetrachloroethene (PCE) onto several polymeric materials is reported and compared to activated carbon F-400. In addition, the bisolute adsorption of chloroform and trichloroethene...
Development of a Sorbent for Removal of Nonionic Pollutants from Water
Sorption of anionic surfactants onto mineral oxides and, and the subsequent partitioning of non-ionic organic substance into the organic phase of these synthetic sorbents was studied....
Anoxic-Aerobic Activated Sludge Treatment
An activated sludge system was operated at a relatively low SRT of 1-2 days at the City of Phoenix to meet secondary treatment requirements. Operating MLSS concentrations were 400-600...
Aerobic Denitrification in Activated Sludge
Definitive proof of the phenomenon of concurrent biological nitrification-denitrification in activated sludge is presented. The mechanism appears to be an inhibition of oxygen respiration...
Degradation of 1-Naphthylamine by Activated Sludge Using Bioaugmentation
This paper presents the results of ongoing research using a novel bioaugmentation scheme for activated sludge (AS) treatment of trace levels of a hazardous compound (1-Naphthylamine, 1NA)....
The Effects of Hazardous Organic Pollutants on the Performance of Activated Sludge Systems
The effects of phthalate esters (diethyl phthalate and dimethyl phthalate) and phenols (2,4-dinitrophenol, 2,4-dimethylphenol and 4-nitrophenol) on the performance of a laboratory-scale...
Evaluation and Rehabilitation of Clogged Drains at Concrete Gravity Dams
Studies have shown that properly spaced drains of adequate depth provide the principal means of relief from uplift pressures beneath concrete gravity dams. Drains often become encrusted...
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...
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...
Carbon Dioxide Pressure in Surface Waters of Canadian Lakes
Direct measurements of the partial pressure (pCO2) of carbon dioxide were made in lakes of three study areas: ELA (the Experimental Lakes Area) and...
Oceanic CO2 Uptake and Future Atmospheric CO2 Concentrations
The global pattern of water column inventories of bomb-produced 14C suggests that an upwelling of bomb 14C-free...
Active Control of Structures Under Stochastic Base Excitation with a Predominant Frequency
Active control of structures under stochastic base excitation is investigated. The synthesis of an active control system discussed in the study is based on the use of stochastic control...
Mode Truncation Effects on Flexible Space Structures
This paper deals with the problem of active vibration control of flexible space structures. The main difficulty associated with this problem is that the structure has infinite vibration...
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