Seasonal O variations in precipitation, soil water, snowmelt, spring flow and stream baseflow were analyzed to characterize seasonal dynamics of groundwater recharge in three central Pennsylvania catchments. The catchments represented three common landscape types: Valley and Ridge-shale (Mahantango Creek), Valley and Ridge-carbonate (Buffalo Run), and Appalachian Plateau-sandstone (Benner Run)....

Soils are three-dimensional (3D) natural bodies conSlStmg of unconsolidated mineral and organic materials that form a continuous blanket over most of the earth's land sUlface. At all scales of measurements, soils are exceedingly complex and variable in bio logical, chemical, physical, mineralogical, and electromagnetic properties. These properties influence the propaga tion velocity, attenuatio...

Development of the new, insensitive, energetic compound, NTO (3-nitro-1,2,4-triazol-5-one), creates need for the data on NTO's fate and transport to predict its behavior in the environment and potential for groundwater contamination. To measure the transport of NTO in soils, we conducted miscible-displacement experiments under steady state and interrupted flow conditions using eight soils havin...

One of the most crucial environmental problems affecting developing countries in arid and semi-arid regions is soil salinity. Its detection using radar imaging systems is one of promising domains of remote sensing research. Detection is based essentially on the relationship between the quantity of existing salts in the soil, the soil moisture content, and the dielectric properties of this mixtu...

stress waves contain useful information about the properties of porous materials; they can be recovered through different non-destructive testing methods such as crosswell, vertical seismic profile, borehole logging as well as sonic tests. in all these methods, it is crucial to assess the effects of frequency on wave attributes including velocity and intrinsic attenuation. the dependency of per...

The reservoir water level in the Three Gorges Reservoir (TGR) of Yangtze River is adjusted between 145 m and 175 throughout year. landslide below bears periodic dynamic seepage pressure on basis original steady-state pressure. In process rising levels particular, effective stress sliding zone soil line reduced, shows an unloading state. order to study creep characteristics landslides a area, di...

introduction: photon attenuation in tissues is the primary physical degrading factor limiting both visual qualitative interpretation and quantitative analysis capabilities of reconstructed single photon emission computed tomography (spect) images. the aim of present study was to investigate the effect of attenuation correction on the detection of activation foci following statistical analysis w...

Sulfate-reducing bacteria (SRB) can affect metal mobility either directly by reductive transformation of metal ions, e.g., uranium, into their insoluble forms or indirectly by formation of metal sulfides. This study evaluated in situ and biostimulated activity of SRB in groundwater-influenced soils from a creek bank contaminated with heavy metals and radionuclides within the former uranium mini...

In this study, the impact of bacterial and fungal processes on (14)C-hexadecane mineralisation was investigated in weathered hydrocarbon contaminated soil. The extent of (14)C-hexadecane mineralisation varied depending on the bioremediation strategy employed. Under enhanced natural attenuation conditions, (14)C-hexadecane mineralisation after 98 days was 8.5 ± 3.7% compared to <1.2% without nit...

objective(s): in spect, the sinogram contains scatter and lack of attenuated counts that degrade the reconstructed image quality and quantity. many techniques for attenuation and scatter correction have been proposed. an acceptable method of correction is to incorporate effects into an iterative statistical reconstruction. here, we propose new maximum likelihood expectation maximization (mlem) ...