We investigated the potential of using a 24-electrode resistivity imaging apparatus for rapid reconnaissance surveys for natural-aggregate accumulation. The surveys were first calibrated at sites with known geometry of sand and gravel layers, which showed that subsurface accumulation of coarse material was accurately resolved with both 2and 4-m electrode spacing. The inverted absolute resistivi...

Incubating salmonid eggs in streambeds are often threatened by deposition of fine sediment within the gravel. To relate sedimentation of spawning gravel beds to sediment transport, infiltration of fine sediment (<2 mm in diameter) into clean gravel beds, bed material size distributions, scour-fill depths, and sediment transport during 10 storm flow events were measured in three streams of north...

Stratification and estimated paleoflow conditions for valley-fill deposits suggest that Ogallala Group streams in western Nebraska were similar to modem streams of south-central Alberta. Ogallala stratification includes medium-scale (0.5 to 2. O m thick) trough crossbedded sand and gravel, tabular indistinctly horizontally bedded and imbricated gravel, and horizontally bedded sand and pebbly sa...

Laboratory scale studies were conducted to investigate the feasibility of Industrial by-products as potential alternative medium to conventional gravel in the drainage layer of leachate collection system as permeable reactive barriers (PRBs) for landfill leachate treatment. Industrial by-products were used to treat effectively the landfill leachate, which is an innovative in-situ remediation te...

this paper presents a model for prediction of the mechanical behavior of sand-gravel mixtures using generalized plasticity and critical state concepts. proposed model is based on the difference between critical state lines of sand and sand-gravel mixture in e-lnp&apos; plane. a generalized plasticity model is considered as the base model for sandy soil. its state parameter, dilation rate and ha...

there are limitations in experimental studies on sand-gravel mixtures due to the small size of testingspecimens. due to this problem, many researchers have worked on prediction of the shear strength of mixture by testingthe sandy fraction of soil alone and developed empirical relationships. most of the previous relationships have beendetermined for low surcharge pressures in which particle brea...

Although environmental enrichment is known to improve laboratory rodent wellbeing and enhance scientific data collection, relatively little is known with regards to the type of enrichment that might be useful for zebrafish (Danio rerio). Therefore, this study explored if zebrafish displayed preferences for a range of enrichments, including substrates, artificial plants, combinations thereof and...

Features extracted from echosounder bottom returns are compared with the ground truth in a North Sea survey area. The ground truth consists of 50 grab samples for which the grain size distribution, and the gravel and shell contents were determined. Echo envelopes are analysed for two single-beam echosounders, operated at frequencies of 66 and 150 kHz. It is shown that a set of six energetic, st...

In recent years, North American prairie vegetation has served as a design model for highly attractive, low-cost and low-maintenance plantings in German urban green spaces. Where mixed-planting techniques, gravel mulch toppings and non-selective maintenance techniques such as mowing are used, prairie plantings are considered to be cost-effective alternative design concepts for public green space...

This studyis part of a collaborativeeffortbetweenMontanaTechand AtlanticRichfield Companyto find solutions for treating metal-contaminated surface runoff from the surrounding city of Butte, Montana. The runoff flows into a storm drai% which transports the suspended and dissolved metals into nearby Silver Bow Creek, a tributary of the Clark Fork River. The study compared percent removal of metrd...