event in the time domain. The parametric representation of the seismic events in some cases provided adequate information for accurate event classification, while significantly reducing the minimum size of the neural network. Various networks have achieved classification rates ranging from 88 percent classification of three class problem to 75 percent for the 5 class problem. The results vary dependent on the number of classes and the method of parametric transformations utilized. Multiple tests were performed in order to statistically average the training and classification rates. Test summaries presented and individual test results are given in the appendix.

current oil field monitoring state-of-the-art by providing individual well-level composition data, compared to the multi-well macroscopic information that is currently available. We are seeking a commercialization partner to license the technology or fund us through a Cooperative Research and Development Agreement (CRADA) to a further develop a usable product for commercial purposes.

of information from the same measurement in multiphase fluids including the presence of a significant quantity of gas (˜60% gas volume fraction) in different flow regimes. Besides measuring steady flow, this device is useful for measurements during fast changing flows, such as for a rod-pumped well. Measurements up to about 1000 times a second can reliably be made.

Reduction of toxic Cr(VI) to less toxic Cr(III) is an important process for attenuating Cr(VI) transport in groundwater. This process results in immobilization of chromium as Cr(III) and effectively decreases the overall mobility of the chromium inventory. During both abiotic and biotic reduction of Cr(VI) to Cr(III), a kinetic isotope effect occurs in which the lighter isotope, 52Cr, reacts preferentially, leaving the remaining dissolved Cr(VI) enriched in the heavier isotope, 53Cr. Cr isotopes have proven to be a useful tool for estimating the magnitude of Cr(VI) reduction and for determining where in a hydrologic system reduction is occurring. In this paper, we discuss patterns of reduction in perched-intermediate and regional aquifer systems contaminated with Cr(VI) related to historical use of potassium dichromate as an anticorrosion agent in cooling towers at a power plant at the Los Alamos National Laboratory in northern New Mexico. We utilize Cr isotopes to assess the relative effects of mixing and reduction on measured δ53Cr in groundwater, with an emphasis on where in the system reduction occurs. Chromium isotope measurements provide strong evidence for reduction of Cr(VI) in vadose zone basalts.

Carbonates are one of the most abundant groups of minerals in earth systems and are important in many geological settings and industrial processes. Calcite (CaCO3) thin films produced by atomic layer deposition offer a method to evaluate the surficial properties of carbonates as well as interactions at the carbonate–fluid interface. Using synchrotron X-ray reflectivity and X-ray diffraction, these films are observed to be porous, polycrystalline, and have crystallites oriented with the major (104) calcite cleavage plane parallel to the surface of the z-cut single crystal quartz substrate. An Al2O3 buffer layer, present between quartz and the calcite film, does not affect the as-deposited film, but does influence how the films reorganize in contact with fluid. Without a buffer layer, calcite reorients its crystallites to have populations of (006) and (030) parallel to the substrate, while those with an Al2O3 buffer layer become more amorphous. Amorphous films may represent an analog to amorphous calcium carbonate and provide insights into that material's thermophysical behavior. Due to a higher percentage of pore spaces available for fluid infiltration, films deposited at higher temperature make the calcite thin films more susceptible to amorphization. These films are chemically similar, but structurally dissimilar to bulk natural calcite. Nevertheless, they can be a complementary system to traditional single crystal X-ray surface scattering studies on carbonates, particularly for important but less common minerals, to evaluate mineral–fluid interfacial interactions.

MCNP, RAGE, Mercury, Ares, and Spheral. This document provides a short description of the codes, an overview of the idealized test problems, and discussion of the results for deflection by kinetic impactors and stand-off nuclear explosions.

A series of site investigations and decision-support analyses have been performed related to a chromium plume in the regional aquifer beneath the Los Alamos National Laboratory (LANL). Based on the collected data and site information, alternative conceptual and numerical models representing governing subsurface processes with different complexity and resolution have been developed. The current conceptual model is supported by multiple lines of evidence based on comprehensive analyses of the available data and modeling results. The model is applied for decision-support analyses related to estimation of contaminant-arrival locations and chromium mass flux reaching the regional aquifer, and to optimization of a site monitoring-well network. Plume characterization is a challenging and nonunique problem because multiple models and contamination scenarios are consistent with the site data and conceptual knowledge. To solve this complex problem, an advanced methodology based on model calibration and uncertainty quantification has been developed within the computational framework MADS (http://mads.lanl.gov). This work implements high-performance computing and novel, efficient and robust model analysis techniques for optimization and uncertainty quantification (ABAGUS, Squads, multi-try (multi-start) techniques), which allow for solving problems with large degrees of freedom.

To study the structural behavior of brucite at high temperature, we conducted in situ neutron diffraction experiments of a deuterated brucite powder sample, Mg(OD)2, in the temperature range 313–583 K. The sample was stable up to 553 K, above which it started to decompose into periclase (MgO) and D2O vapor. Rietveld analyses of the obtained data were performed using both single-site and three-site split-atom hydrogen models. Our results show that with increasing temperature, unit-cell parameter c increases at a rate ~7.7 times more rapidly than a. This large anisotropy of thermal expansion is primarily due to rapid increase in the interlayer thickness along the c-axis on heating. The amplitudes of thermal vibration for Mg, O, and D increase linearly with increasing temperature; however, the rate of the increase for the lighter D is much larger. In addition, D vibrates anisotropically with a higher magnitude within the (001) plane, as confirmed by our first-principles phonon calculations. On heating, the interatomic distances between a given D and its associated O and D from the adjacent [MgO6] layer increase, whereas the O–D bond length decreases. This behavior suggests weakened D···O and D···D interlayer interactions but strengthened O–D bonding with increasing temperature.

The diffusion of adsorbed molecules at a solid/fluid interface is a phenomenon of great fundamental interest and technological importance. We use molecular dynamics and kinetic Monte Carlo simulations to investigate the diffusion processes at an aqueous calcite (101̅4) interface under various geologically relevant supercritical conditions [101.3 MPa (1000 atm), 300–800 K]. Between 600 and 700 K, the adsorption configuration changes from an outer- to inner-sphere surface complex, and the desorption free energy barrier, ΔGd, increases greatly. The ratio ΔGd/kBT takes a minimum value at 600 K, making it the temperature with the greatest desorption tendency. Consequently, the temperature dependence of the mean lateral diffusivity of a finite bulk system reverses at 600 K. More interestingly, the system exhibits typical characteristics of bulk fluid-mediated surface diffusion. For example, the mean-squared displacement shows different scaling properties with changes in temperature or bulk thickness. The optimized bulk thickness which maximizes the effective surface diffusivity was also found to vary with temperature.

A new high pressure-temperature (P -T Neutron Reflectometry (NR) cell developed at Los Alamos National Laboratory (LANL) is described that significantly extends the capabilities of solid/fluid interface investigations up to 200MPa ( \(\ensuremath \sim 30000\) psi) and 200 ° C. The cell's simple aluminum construction makes it light and easy to operate while thinned neutron windows allow up to 74% neutron transmission. The wide-open neutron window geometry provides a maximum theoretical \(\ensuremath Q_{{\rm z}}\) range of 0.31Å-1. Accurate T and P controls are integrated on the cell's control panel. Built-in powder wells provide the ability to saturate fluids with reactive solids, producing aqueous species and/or decomposing into gaseous phases. The cell is designed for samples up to 50.8mm in diameter and 10.0mm in thickness. An experiment investigating the high P -T corrosion behavior of aluminum on LANL's Surface ProfilE Analysis Reflectometer (SPEAR) is presented, demonstrating the functioning and capability of the cell. Finally, outlooks on high P -T NR applications and perspectives on future research are discussed.

The diffusion of adsorbed molecules at a solid/fluid interface is a phenomenon of great fundamental interest and technological importance. We use molecular dynamics and kinetic Monte Carlo simulations to investigate the diffusion processes at an aqueous calcite (10 (1) over bar4) interface under various geologically relevant supercritical conditions [101.3 MPa (1000 atm), 300-800 K]. Between 600 and 700 K, the adsorption configuration changes from an outer- to inner-sphere surface complex, and the desorption free energy barrier, Delta G(d), increases greatly. The ratio Delta G(d)/k(B)T takes a minimum value at 600 K, making it the temperature with the greatest desorption tendency. Consequently, the temperature dependence of the mean lateral diffusivity of a finite bulk system reverses at 600 K. More interestingly, the system exhibits typical characteristics of bulk fluid-mediated surface diffusion. For example, the mean-squared displacement shows different scaling properties with changes in temperature or bulk thickness. The optimized bulk thickness which maximizes the effective surface diffusivity was also found to vary with temperature.

The science of signatures focus areas are: (1) Radiological and Nuclear; (2) Chemical and Materials (including explosives); (3) Biological - Signatures of Disease and Health; (4) Energy; (5) Climate; and (6) Space.

A first-of-its-kind study on the shock response of a metal-organic framework (MOF) material to planar impact is reported. MOF Cu-1,3,5-benzenetricarboxylate (Cu-BTC) without and with ferrocene inclusion show anisotropic structural collapse under shock loading. The shock resistance of the Cu-BTC framework is enhanced drastically (by a factor of six) via molecular-level inclusion of ferrocene into the pore structures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

A novel metal-organic replica of α-PbO(2) exhibits high capacity for capture of nerve agent surrogate.

The structure of deuterated jarosite, KFe3(SO4)2(OD)6, was investigated using time-of-flight neutron diffraction up to its dehydroxylation temperature. Rietveld analysis reveals that with increasing temperature, its c dimension expands at a rate ~10 times greater than that for a. This anisotropy of thermal expansion is due to rapid increase in the thickness of the (001) sheet of [Fe(O,OH)6] octahedra and [SO4] tetrahedra with increasing temperature. Fitting of the measured cell volumes yields a coefficient of thermal expansion, α = α0 + α1 T, where α0 = 1.01 × 10−4 K−1 and α1 = −1.15 × 10−7 K−2. On heating, the hydrogen bonds, O1···D–O3, through which the (001) octahedral–tetrahedral sheets are held together, become weakened, as reflected by an increase in the D···O1 distance and a concomitant decrease in the O3–D distance with increasing temperature. On further heating to 575 K, jarosite starts to decompose into nanocrystalline yavapaiite and hematite (as well as water vapor), a direct result of the breaking of the hydrogen bonds that hold the jarosite structure together.