A5008781387- Earthquake Detection and Analysis
- Seismic Waves and Analysis
- Methane Hydrates and Related Phenomena
- Groundwater flow and contamination studies
- Soil and Unsaturated Flow
- Fecal contamination and water quality
- Geophysical and Geoelectrical Methods
- Electrostatics and Colloid Interactions
- Plant nutrient uptake and metabolism
- Soil Geostatistics and Mapping
- Enhanced Oil Recovery Techniques
- Soil Moisture and Remote Sensing
- Landslides and related hazards
- Geophysical Methods and Applications
- Theoretical and Computational Physics
- Soil erosion and sediment transport
- Pickering emulsions and particle stabilization
- Image Processing and 3D Reconstruction
- Urban Stormwater Management Solutions
- Microbial bioremediation and biosurfactants
- Climate change impacts on agriculture
- Soil Mechanics and Vehicle Dynamics
- Irrigation Practices and Water Management
- Potato Plant Research
- Crop Yield and Soil Fertility
Cornell University
2005-2022
Norwegian Institute of Bioeconomy Research
2018-2019
Pennsylvania State University
2013-2016
University of Maryland, College Park
2012-2014
Norwegian University of Life Sciences
2013-2014
City University of New York
2009
The Graduate Center, CUNY
2009
City College of New York
2009
University of Connecticut
2009
The University of Texas at Austin
2008
This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by need for stronger harmonisation research efforts. The procedure involved public consultation through online media, followed two workshops which large number potential science questions were collated, prioritised, and synthesised. In spite diversity participants (230 scientists total), process revealed much about priorities state our science: preference continuity...
Observed phenotypic variation in the lateral root branching density (LRBD) maize (Zea mays) is large (1–41 cm−1 major axis [i.e. brace, crown, seminal, and primary roots]), suggesting that LRBD has varying utility tradeoffs specific environments. Using functional-structural plant model SimRoot, we simulated three-dimensional development of architectures with quantified nitrate phosphorus uptake, competition, whole-plant carbon balances soils availability these nutrients. Sparsely spaced...
Abstract The saturated hydraulic conductivity of soil, K s , is a critical parameter in hydrological models that remains notoriously difficult to predict. In this study, we test the capability model based on percolation theory and path analysis estimate measured 95 undisturbed soil cores collected from contrasting types. One (the pore geometry factor) was derived by fitting, while remaining two parameters diameter, d c effective porosity) were X‐ray computed tomography measurements. gave...
Backgrounds and Aims Crops with reduced requirement for nitrogen (N) fertilizer would have substantial benefits in developed nations, while improving food security developing nations. This study employs the functional structural plant model SimRoot to test hypothesis that variation growth angles of axial roots maize (Zea mays L.) is an important determinant N capture. Methods Six phenotypes contrasting root were modelled 42 d at seven soil nitrate levels from 10 250 kg ha−1 a sand silt loam,...
Colloids have long been known to facilitate the transport of contaminants in soils, but few direct observations made and retention unsaturated porous media. Studies typically limited evaluation column breakthrough curves, resulting differing sometimes conflicting proposed mechanisms. We carried out pore scale visualization studies colloid quartz sand directly observe characterize phenomena. Synthetic hydrophilic (0.8, 2.6, 4.8 microm carboxylated polystyrene latex) relatively hydrophobic...
Mechanistic crop models capable of representing realistic temperature responses key physiological processes are necessary for enhancing our ability to forecast yields and develop adaptive cropping solutions achieving food security in a changing climate. Leaf growth phenology critical components yield that sensitive climate impacts. We developed novel modeling approach incorporates set nonlinear functions augment traditional thermal time methods (e.g., growing degree days) simulating leaf...
Solute transport experiments were conducted in a decimeter scale flow cell packed with sand to study the potential for enhanced mixing of solutes porous media and improved containment injected plumes under multiple pumping-well driven, time-dependent oscillatory respect constant flow. Real-time imaging colorimetric reaction Tiron (1,2-dihydroxybenzene-3,5-disulfonic acid) molybdate was used quantify mixing, whereas fluorescein better examine plume size. Results from small clearly...
We directly observed pore‐scale attachment of fluorescent synthetic polystyrene colloids (1.0 μ m diameter) in a partially saturated sand pack (pore space saturation ranging from 0.7 to 0.9) at four solution ionic strengths (0, 1, 100, 200 mmol NaCl). Sequential confocal laser microscope images were analyzed quantify colloid retention, particularly air‐water meniscus‐solid (AW S) interfaces. concurrently measured effluent concentrations determine overall matrix retention. Ionic strength had...
In recent years, experience has demonstrated that the classical fractal dimensions are not sufficient to describe uniquely interstitial geometry of porous media. At least one additional index or dimension is necessary. Lacunarity, a measure degree which data set translationally invariant, possible candidate. Unfortunately, several approaches exist evaluate it on basis binary images object under study, and unclear what extent lacunarity estimates these methods produce dependent resolution...
The transport of colloid‐contaminant complexes and colloid‐sized pathogens through soil to groundwater is concern. Visualization quantification pore‐scale colloid behavior will enable better description simulation retention mechanisms at individual surfaces, in contrast breakthrough curves which only provide an integrated signal. We tested two procedures for quantifying movement as observed image sequences. After initial testing with static images, three series images synthetic microbead...
The relationship between capillary pressure and saturation in a porous medium often exhibits power-law dependence. physical basis for this relation has been substantiated by assuming that is directly related to the pore radius. When space of fractal structure approach results with an exponent $3\ensuremath{-}{D}_{v}$, where ${D}_{v}$ volume dimension. However, larger values than are realistically allowed result have long known occur. Using thermodynamic formulation equilibrium we show...
Summary Two recent investigations have reported contradictory trends concerning the effect of image resolution on surface fractal dimension soil pores, evaluated via analysis. In one case, dealing with a preferential flow pathway and an ideal fractal, had no influence estimated dimension, whereas in other involving images thin sections, decreased significantly resolution. present paper, we try to determine extent which these conflicting observations may been due different ways was varied. By...
The physics regarding the retention and mobilization of colloids in saturated unsaturated conditions remains poorly understood, partially because inability to measure colloid concentrations situ. In this study, we attached Cd +2 ions clay used synchrotron X rays cause fluoresce. By measuring fluorescence attenuation obtained simultaneous situ water saturations on timescales tens seconds. We technique study transport consisting Na Ca Montmorillonite clays through a preferential flow path...