As starting hypothesis, we argue that the erosion of safe sex practices for people having frequent change of sexual partner might be explained in terms of two mechanisms: instrumental conditioning through “reward” (greater sexual pleasure) following unprotected sex and misperception of the risk to become infected by HIV due to low infectivity of HIV and long delays (long latency and incubation ...

This paper studies rill and gully initiation and propagation on levees, dams, and general earth embankments. It specifically studies where these erosion features occur, and how long a particular embankment can sustain overtopping before breaching and catastrophic failure. This contrasts to previous levee erosion analysis, which has primarily concerned the final effects of erosion, such as soil ...

Suspended sediment resulted from distributed soil erosions facilitates nutrient transportation and influences soil depletion. Phosphorus (P) is one of the major limiting nutrients controlling eutrophication of surface water. Irregular P load pulsed by heavy rainfall may damage the ecological quality of downstream waters. P transport study during rainfall events is important in both predicting a...

This paper gives an overview of the research activities at TEXTOR on impurity production, impurity transport through the plasma, and then deposition. First, laboratory experiments on chemical erosion by hydrogen and oxygen and radiation-enhanced sublimation are described, followed by the main part, which concentrates on the TEXTOR data of impurity release, impurity transport, and redeposition. ...

Improved computer models of erosion have been developed, considering soil hydraulic conductivity. The models deal with erosion of levees, dams and embankments due to overtopping. The simulations trace the formation of rills and gullies, beginning with initial overtopping and continuing to final breaching. Physical models performed at 1-g and high g using a geotechnical centrifuge have been used...

Although hydraulic erosion modeling on a GIS terrain models has been addressed by a body of previous work, it still remains an open problem. In GIS, raster representation and triangular irregular networks (TIN) are the most commonly used surface models, because they are simple and offer implicit topological information. However, these data structures do not allow the simulation of erosion on co...

[1] The controls of forest vegetation, wildfires, and harvest vegetation disturbances on the frequency and magnitude of sediment delivery from a small watershed ( 3.9 km) in the Idaho batholith are investigated through numerical modeling. The model simulates soil development based on continuous bedrock weathering and the divergence of diffusive sediment transport on hillslopes. Soil removal is ...

The present work is concerned with the verification and validation of an implementation of the eigenfracture scheme of Schmidt et al. (SIAM J Multiscale Model Simul 7:1237–1266, 2009) based on material-point erosion, which we refer to as eigenerosion. Eigenerosion is derived from the general eigenfracture scheme by restricting the eigendeformations in a binary sense: they can be either zero, in...

Semiarid landscapes are characterized by vegetated surfaces. Understanding the impact of vegetation on aeolian soil erosion is important for reducing soil erosion or limiting crop damage through abrasion or burial. In the present study, a saltation model fully coupled with a large-eddy simulation airflow model is extended to vegetated landscapes. From this model, the sensitivity of sand erosion...