The mechanical behavior of soils has been traditionally described using continuum-mechanics-based models. These are empirical relations based on laboratory tests of soil specimens. The investigation of the soils at the grain scale using discrete element models has become possible in recent years. These models have provided valuable understanding of many micromechanical aspects of soil deformati...

We collected urban soil samples impacted by polycyclic aromatic hydrocarbons (PAHs) from a sorbent-based remediation field trial to address concerns about unwanted side-effects of 2% powdered (PAC) or granular (GAC) activated carbon amendment on soil microbiology and pollutant biodegradation. After three years, total microbial cell counts and respiration rates were highest in the GAC amended so...

The application of urea fertilizer has always been associated with heavy N losses therefore, improving its efficiency is critical to minimize economic and environmental losses associated with its application. One possible approach to improve the nitrogen losses from the surface applied urea is to coat it with sulfur, urease inhibitor (agrotain) and other biodegradable materials. A pot experimen...

The potential for non-point-source pollution of surface waters from agricultural lands continues to be a concern. Our objective was to determine the effect of surface residue management and fertilizer application timing in regards to soil moisture conditions on nutrient losses in runoff. Studies were conducted using a rainfall simulator that applied 125 mm h-1 for 3 h to an Austin (Udorthentic ...

A model-based control for fast autonomous four-wheel mobile robots on soft soils is developed. This control strategy takes into account slip and skid effects to extend the mobility over planar granular soils. Each wheel is independently actuated by an electric motor. The overall objective is to follow a path roughly at relatively high speed. Some results obtained in dynamic simulation are prese...

With the development of society and economy, land subsidence in soft soil areas has become a prominent geological disaster our country’s coastal area. Land characteristics irreversibility, wide influence range, long aging, etc., these are closely related to soil, such as physical mechanical parameters, microstructure characteristics, etc. The Nansha District Guangzhou was taken study area this ...