Using a Lagrangian approach, the authors have previously shown that the kinetics of concentration variance and dilution of passive solutes in heterogeneous aquifers depend on the ratio between twoand one-particle covariances. Extending this approach, it is here demonstrated that, for point injections, the two-particle covariance coincides with the variance of the centroid location. Then, based ...

[1] Time-lapse geophysical tomography can provide valuable qualitative insights into hydrologic transport phenomena associated with aquifer dynamics, tracer experiments, and engineered remediation. Increasingly, tomograms are used to infer the spatial and/or temporal moments of solute plumes; these moments provide quantitative information about transport processes (e.g., advection, dispersion, ...

Highly aqueously dispersible (soluble) TiO2 nanoparticles are usually synthesized by a solution-based sol-gel (solvolysis/condensation) process, and no direct precipitation of titania has been reported. This paper proposes a new approach to synthesize stable TiO2 nanoparticles by a non-solvolytic method - direct liquid phase precipitation at room temperature. Ligand-capped TiO2 nanoparticles ar...

Recently, Schlickeiser and Miller have calculated anew the acceleration rate of cosmic rays by fast magnetosonic plasma waves in a small-beta plasma, using a linear dispersion relation. They found that the transit-time damping of fast mode waves provides the dominant contribution to the stochastic acceleration rate of cosmic ray particles, both, in pure fast mode wave turbulence as well as in a...

[1] Bromide breakthrough curves from push-pull tests were obtained at two wells before, during, and after citrate injections to assess how citrate-induced colloid mobilization affected physical aquifer transport properties. Tailing and incomplete bromide recoveries (67–95%) could not be fit with a conservative advection/dispersion model, and the results of batch tests using aquifer solids impli...

DNA recovery using solid-phase extraction is a fundamental technique in molecular biology and biotechnology. Our research group developed a novel DNA recovery method using amine-modified magnetic nanoparticles (MNPs) as a solid support. The use of MNPs simplifies the DNA recovery processes and permits their use in automated systems. In this study, we prepared polyamidoamine-modified superparama...

In this study, we develop a saturation-dependent treatment of dispersion in porous media using concepts from critical path analysis, cluster statistics of percolation, and fractal scaling of percolation clusters. We calculate spatial solute distributions as a function of time and calculate arrival time distributions as a function of system size. Our previous results correctly predict the range ...

Introduction Conclusions References Tables Figures ◭ ◮ ◭ ◮ Back Close Full Screen / Esc Papers published in Hydrology and Earth System Sciences Discussions are under open-access review for the journal Hydrology and Earth System Sciences Abstract Introduction Conclusions References Tables Figures ◭ ◮ ◭ ◮ Back Close Full Screen / Esc Abstract We present here numerical modeling of infiltration ins...

The coupled ̄ow-mass transport inverse problem is formulated using the maximum likelihood estimation concept. An evolutionary computational algorithm, the genetic algorithm, is applied to search for a global or near-global solution. The resulting inverse model allows for ̄ow and transport parameter estimation, based on inversion of spatial and temporal distributions of head and concentration meas...

Abstract In quantum spin systems, lower energy state for a nuclear in an external field is ( $$+1/2$$ + 1 / 2 ) while the higher $$-1/2$$ - ). A continuum analog to discrete model led nonlinear Schrodinger equation (NLS...