The Dilemma of Measuring Small Pressure Changes in a Settling Tube
A compact settling tube was developed to determine fall-velocity and particle-size frequency distributions and specific gravities of sand-range sediment samples by means of direct measurements...

Fluid Mud Problems in Lakes, Reservoirs and Detention Ponds
An experimental study of wind induced surfacing of fluid mud bottoms in shallow water has been conducted. The experiments involved a channel placed within a wind tunnel, where a two-layered,...

Hurricane Hugo One Year Later
Hurricane Hugo, which made landfall on September 21, 1989, was the first serious storm to cross the South Carolina coast in over 30 years. During this period, the coastal areas had grown...

Landfill Park: From Eyesore to Asset
By reclaiming a 50 acre landfill as a recreational area, Cambridge, Mass. increased its open space by 20%. The park includes three softball and three soccer fields, one multisport field,...

Properties of Small-Scale Waves in Sheared Gas-Liquid Flows
Small wind-generated waves are examined theoretically and experimentally in a small laboratory flow system, at conditions close to neutral stability in an attempt to better characterize...

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...

Gas Transfer Velocities and Radar Backscatter from the Water Surface
Gas transfer velocities of sulfur hexafluoride, methane, and nitrous oxide were determined in two different wind-wave tanks and related to friction velocity and radar backscatter from...

Volatilization of PCBs From the Great Lakes
The potential volatilization of polychlorobiphenyls (PCBs) and other semi-volatile organic chemicals (SOCs) from Lake Superior and Green Bay, Lake Michigan, is being investigated. The...

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...

Gas Transfer Velocities on Lakes Measured with Sulfur Hexafluoride
Gas transfer velocities have been determined on five lakes ranging in size from 0.13 km2 to 450 km2 using...

Structure of the Drift Current Observed Below Capillary-Gravity Waves
Measurements by laser-Doppler velocimeter were performed in a wind-wave tank to investigate the structure of the water surface boundary layer under capillary-gravity wind waves in the...

Turbulence Level Below the Waves and Its Relation to Absorption
A review of recent experimental studies carried out on gas transfer at water surfaces in various situations shows that the absorption coefficient is better related to the turbulence level...

The Enhancement of Air-Sea Gas Exchange by Oceanic Whitecapping
The hypothesis that oceanic whitecaps and the accompanying buoyant bubble plumes greatly enhance the air-sea transfer coefficient of gases subject to liquid phase control has recently...

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...

In-Situ Calibration of USGS Piezometer Installations
Among the few potentially liquefiable sites around the world that have been permanently instrumented with pore-pressure transducers and accelerometers, only the Wildlife Site in the Imperial...

The Structural Curtain
Curtain walls are not standard off-the-shelf items. For major projects, they are almost always custom-designed. Typically, curtain walls are on the critical path of project and often account...

Ultimate Air Rights
The new 1 million sq ft office tower at 450 Lexington Ave. rises from available space between commuter railroad tracks, through the center of a renovated four-story post office and up...

A Study of Liquefaction Countermeasures for Manholes Under the Pavement
The gravel drain method has proven to be an effective countermeasure for underground structures in liquefying ground. However, due to the road pavement, there is no draining passage through...

Seismic Risk Assessments of Small Earth Dams
A procedure has been developed which attempts to assess the risk of damage or failure of small earth dams and embankments when subjected to seismic input motions. The procedure is based...

 

 

 

 

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