The concentration and amounts of NO3-N and TN transported in surface, accelerated subsurface, and subsurface runoff and stream flow draining a 20 ha pasture watershed were measured over a period of 3 yr. A slight decrease and increase of NO3-N and particulate N concentrations, respectively, were obtained with increased flow of the runoff types and stream, due to dilution and increased sediment ...

Features are investigated in eddy current data that are sensitive to corrosion and fatigue cracks in airframe structures while invariant to other NDE noise factors. To investigate subsurface corrosion characterization at the faying surface, a series of eddy current studies were performed using an analytical model for varying total subsurface thickness loss and percentage of the thickness loss o...

LLE Review, Volume 74 131 The cold processing of optical glasses usually involves rough grinding, microgrinding, and polishing. In microgrinding,1,2 the resulting brittle-material-removal rate produces a cracked layer near the glass surface, referred to as subsurface damage (SSD). [Editor’s note: The acronym for subsurface damage (SSD) used in this article should not be confused with its more c...

Twenty-five years ago this month, Thomas Gold published a seminal manuscript suggesting the presence of a "deep, hot biosphere" in the Earth's crust. Since this publication, a considerable amount of attention has been given to the study of deep biospheres, their role in geochemical cycles, and their potential to inform on the origin of life and its potential outside of Earth. Overwhelming evide...

Introduction: Estimates of the global inventory of water on Mars based on a determination of the amount of water required to erode the outflow channels suggest that a quantity equivalent to a global ocean 0.5 to 1 km deep may be stored in the planet’s subsurface [1, 2]. As this inventory post dates the timing of the most efficient processes that may have lead to its removal, the majority of thi...

[1] Current approaches for inverse modeling (IM) to estimate flow and transport properties in subsurface media implicitly assume that uncertainty in the input-output representation of the model arises from uncertainty in the parameter estimates. However, uncertainties in the modeling procedure stem not only from uncertainties in the parameter estimates, but also from measurement errors, from in...

Computer models have been widely used to evaluate the impact of agronomic management on nitrogen (N) dynamics in subsurface drained fields. However, they have not been evaluated as to their ability to capture the variability of nitrate-nitrogen (NO(3)-N) concentration in subsurface drainage at a wide range of N application rates due to possible errors in the simulation of other system component...

Radar remote sensing techniques are becoming more widely applied in dryland regions, because the lower frequency Synthetic Aperture Radar (SAR) systems enable significant penetration into the subsurface under very dry conditions, allowing subsurface characteristics to be interpreted. Field experiments at two contrasting sites in the Libyan Fazzān show ground-penetrating radar (GPR) can be used ...

the starting behavior of a supersonic axisymmetric mixed compression air intake was numerically investigated. the code solves reynolds-averaged navier–stokes equations using an explicit finite volume method in a structured grid by the roe flux difference splitting scheme. further, it uses the baldwin–lomax algebraic model to compute the turbulent viscosity coefficient. the correct method of sur...

electrode arrays allows for the interpretation of the twodimensional distribution of electrical conductivity in the The analytic element method is used to investigate the spatial subsurface. The electrical conductivity distribution can sensitivity of different electrical resistivity tomography (ERT) arrays. By defining the sensitivity of an array to a subsurface location we then be related to t...