local site conditions have a strong effect on ground response during earthquakes. two important soil parameters that control the amplification effects of seismic motions by a soil column are the soil hysteretic damping ratio and shear wave velocity. this paper presents the results of in situ damping ratio measurements performed using continuous surface wave attenuation data at a site in semnan ...

One of the beneficial roles of riparian buffers is the capacity to attenuate groundwater nitrate before it can discharge to streams. Denitrification is one of the most important processes that permanently removes nitrate from groundwater; it requires anoxic conditions, a carbon source, and a suitable residence time as the reaction is microbially mediated. As denitrification rates are highly dep...

Bioremediation of diesel oil in soil can occur by natural attenuation, or treated by biostimulation or bioaugmentation. In this study we evaluated all three technologies on the degradation of total petroleum hydrocarbons (TPH) in soil. In addition, the number of diesel-degrading microorganisms present and microbial activity as indexed by the dehydrogenase assay were monitored. Soils contaminate...

Were evaluated natural attenuation, biostimulation and bioaugmentation on the degradation of total petroleum hydrocarbons (TPH) in soils contaminated with diesel oil. Bioaugmentation showed the greatest degradation in the light (C12 C23) fractions (72.7%) and heavy (C23 C40) fractions of TPH (75.2%) and natural attenuation was more effective than biostimulation. The greatest dehydrogenase activ...

required. These basic properties of the soil can then be evaluated to assess the acoustic imaging tradeoffs for The potential application of this work is the detection and imaging detecting and characterizing buried artifacts. The acousof buried objects using acoustic methodology. To image buried artifacts, it is vital to know speed and attenuation of sound in the particular tic attenuation coe...

A quantitative understanding of soil water content or soil water status is of great importance to many applications, such as landslide monitoring, rockfill dam health monitoring, precision agriculture, etc. In this paper, a feasibility study was conducted to monitor the soil water content in real time using permanent embedded piezoceramic-based transducers called smart aggregates (SAs). An acti...

Accurate soil moisture content measurements are vital to precision irrigation management. Remote sensing using the microwave spectrum (such as GPS signals) has been used for measuring large area soil moisture contents. In our previous work, we estimated surface soil moisture contents for bare soil using a GPS Delay Mapping Receiver (DMR) developed by NASA. However, the effect of vegetation was ...

Soil porosity (ϕ) is of a great deal for environmental studies due to the fact that water infiltrates and suffers redistribution in the soil pore space. Many physical and biochemical processes related to environmental quality occur in the soil porous system. Representative determinations of ϕ are necessary due to the importance of this physical property in several fields of natural sciences. In...

Long-term studies to observe natural attenuation have been described for many field locations. Often the attenuation can only be inferred to be biodegradation, based on, for instance, the presence of cis-dichloroethylene (DCE) where only trichloroethylene (TCE) was a known contaminant. Because in several instances we had observed such transitions in the presence of plants, an unplanted control ...

In order to effectively control vibration related problems, the development of a reliable vibration monitoring system and the proper assessment of attenuation characteristics of various vibrations are essential. Various ground vibrations caused by train loading, blasting, friction pile driving and hydraulic hammer compaction were measured using 3D geophones inside of the borehole as well as on ...