Papers by David R Janecky
Geochemistry Geophysics Geosystems, Oct 1, 2006
AGUFM, Dec 1, 2001
ABSTRACT Lattice Boltzmann (LB) techniques are being applied to models of reactive transport proc... more ABSTRACT Lattice Boltzmann (LB) techniques are being applied to models of reactive transport processes in groundwaters with the purpose of modeling small scale (mm) interactions between water and rock in complex solid media. This method was used to create a simple porous media structure in which chemical reactions including sorption, dissolution and precipitation occur. A pre-existing lattice Boltzmann code developed at LANL for physical fluid flow was used as the basis for overlaying chemical exchange controls at each lattice node. Initially, Langmuir sorption isotherms were applied on open channel models varying from 10x4000 to 30x1000 nodes. The resulting breakthrough curves from these chemical slug models are compatible with analytical solutions that apply the isotherm equations on larger scales. The model was then further developed to include multiple solid compositions and dissolution and precipitation reactions to study the small scale spatial and temporal distributions of materials in porous media. Mineral nodes of varying composition which undergo specific chemical reactions can be created in the open channels or among evenly spaced blocks of solid nodes which simulate homogeneous porous media. This model structure is being used to investigate millimeter scale Sr isotopic variations observed in the K-metasomatized Lemitar Tuff from Southern New Mexico. Multiple samples of the adularia will provide an isochron age that may represent the time of K-metasomatism. Physical microsampling of this tuff has demonstrated the secondary adularia has a unique Sr isotopic characteristic (87}Sr/{86Sr near 0.727) relative to the fresh plagioclase and sanidine phenocrysts (0.709). The model is being used to discern between the possibilities of the Sr now present in the altered material originating from the surround matrix or alternatively from an outside source in the altering fluids. An outside source of Sr in the K-metasomatic groundwater would be likely with the failure of the model to recreate the correct Sr characteristic in the altered material while relying on in situ Sr from dissolution and precipitation.
OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), 1989
ABSTRACT We have analyzed trace elements in two types of hydrothermal precipitates using the Los ... more ABSTRACT We have analyzed trace elements in two types of hydrothermal precipitates using the Los Alamos Nuclear Microprobe. Chlorites and epidotes in basalt were analyzed from the Samail Ophiolite of Oman. Sulfide and sulfate minerals were analyzed from samples of active chimney walls from 21/degree/N. East Pacific Rise. These samples are ideal for our study because of the extensive background information available on processes and component characteristics. Initial results indicate significant differences in mobile trace elements between chlorites associated with and those distinctly separate from major stockwork flow zones, consistent with greater water-rock reaction within stockworks. Trace element concentrations across chimney walls also exhibit distinctive patterns which can be correlated with mineral/chemical zonation and possible also with variations in elemental source. 9 refs., 2 figs., 1 tab.
an affirmative action/equal opportunity employer, is operated by the University of California for... more an affirmative action/equal opportunity employer, is operated by the University of California for the U.S. Department of Energy under contract W-7405-ENG-36. By acceptance of this article, the publisher recognizes that the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or to allow others to do so, for U.S. Government purposes. Los Alamos National Laboratory requests that the publisher identify this article as work performed under the auspices of the U.S. Department of Energy. The Los Alamos National Laboratory strongly supports academic freedom and a researcher's right to publish; as an institution, however, the Laboratory does not endorse the viewpoint of a publication or guarantee its technical correctness. Form 836 (1 0/96) DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implid, or assumes any legal liabiiity or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise docs not necessarily constitute or imply its endorsement, recommendation. or favoring by the United States Government or any agency thereof. The views and opinions of authors expnssed herein do not necessarily state or reflect those of the United States Government or any agency thereof. c DISCLAIMER Portions of this document may be illegible electronic image products. Images are produced from the best available original document.
OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), 1992
I. qnfmlml hy IIHI WIIVWUIVd Cnlihwmm h)r W I I !i I)qtmlntml d I IIJWW Ulllk IXOIIti W /40h I~1 ... more I. qnfmlml hy IIHI WIIVWUIVd Cnlihwmm h)r W I I !i I)qtmlntml d I IIJWW Ulllk IXOIIti W /40h I~1 ,30 tl~w9@mm d fhtI nflidn, lfla IJUbhhUl IMqlnlmn Ihl lh U %. 14ww1111M 191itIIlnd mmmmchmwn, lU@~h-MIXIIW Ill t'milhh w MINIXIIIU W IMWIA I(WMu! tttinCBIWMIIIM, IN m (WW d=n hl (h MI, b II S OUVWVWII UWMn 1k I IM AIIInMInWIIWIIII 1141MIIdLWV. Oxalute complexa[ion with duminum(lll) and irrsn(lll) at mmkriitcly CICVMICLI tcmpm!urcs C. Drew Tail, Duvid R. JiLnuctiy, David L. Clark Isotope id Nucltilr Ctwmisiry Division Los Alumos Nuliond l~dxml[w-y Los A]alllos, Nhl 87545 ABSTRACT: '1'o MM lo our lllld~'rs[allding ol"[hcww[llcring ofrt)L"ks inorgdnk rich CllVirolllllL'lllSS ilCll :is.sullmmrlury brines imrJ oil fkkl wakrs, we II;IVC~xiimi[ld k tqwrtilurc (JrqmnrJun[complcxir[ion ofuluminurn w'ilh ox;da[c. Rtin-ran vihration;ll shdics show thnt even t'nc tissociulion consliml for [he Ilighly~l]ilrgd AI(ox)33-uncxrwdwlly inrluiws wilil modcrale lcmpcrulure incrcascs[o 80" C, Tocvirluir[e thcpohm[id illll~orlu[lccoflllcsc A1-oxalirt~spccics in compltx nalurul sysIcHLs, .Ifmrridh; Minfvwk, Flf(idvr md Md!s;
Physics Today, Sep 1, 2006
Journal of Alloys and Compounds, Oct 1, 2007
The Rocky Flats Environmental Technology Site (RFETS) was a U.S. Department of Energy (DOE) envir... more The Rocky Flats Environmental Technology Site (RFETS) was a U.S. Department of Energy (DOE) environmental cleanup site for a previous manufacturing plant that made components for the U.S. nuclear weapons arsenal. The facility was shut down in 1989 to address environmental and safety concerns, and left behind a legacy of contaminated facilities, soils, surface and ground water. In 1995, the
Geophysical monograph, 2009
The purpose of this chapter is to lay out potential geochemical impacts of geologic sequestration... more The purpose of this chapter is to lay out potential geochemical impacts of geologic sequestration. Injection of supercritical carbon dioxide into a brine aquifer shifts rock-dominated reaction systems to fluid-dominated systems controlled by acid-generating reactions and mixed-fluid equilibria. Increased carbonic acid content in the brine reduces the pH of in-situ brine by approximately 1.5 to 4 pH units, depending on brine chemistry, formation lithology, and temperature, to a pH value between 3.5 and 4. Alkalinity is also produced by reaction of carbonic acid with reservoir minerals, but alkalinity of in-situ brine cannot overcome the acidity produced by dissolution of supercritical carbon dioxide fluid. Analysis suggests that displacement of brine as injection proceeds will lead to separation from supercritical carbon dioxide fluid and loss of saturated carbon dioxide, wherein alkalinity can neutralize the acidity, yielding near-neutral to alkaline pH. Silica concentrations and dissolution rates will become enhanced and silica precipitation inhibited in acidic brine. Acidified brine will also react with both reservoir rock and caprock, enriching the brine in metal cations and creating alkalinity. As silica-supersaturated, metal-laden brine migrates into areas without CO 2 , in-situ monitoring can be used to indicate repository performance. Return of silica super-saturated brine to a rockdominated reaction system buffered to neutral pH conditions may enhance precipitation of quartz, chalcedony, or amorphous silica. Reaction kinetics among supercritical carbon dioxide, brine, and rock are comparable to rates in systems containing gaseous carbon dioxide.
Glovebox decontamination and size reduction data developed in the Los Alamos Large Scale Demonstr... more Glovebox decontamination and size reduction data developed in the Los Alamos Large Scale Demonstration and Deployment Project (LSDDP) supports and reinforces the decision that the minimum waste management cost to DOE is on-site disposal of decontaminated large metal objects, as opposed to simple size reduction and disposal as transuranics waste. The LSDDP, in support of the US Department of Energy (DOE), identified and demonstrated technologies to reduce the cost and risk of management of transuranic (TRU) element contaminated large metal objects, i.e., gloveboxes. The Decontamination and Volume Reduction System (DVRS) at Los Alamos National Laboratory (LANL) was designed to process and repackage a crated glovebox line for disposal at the Low Level Waste (LLW) disposal area at LANL. Decontamination and size reduction data was developed by the LSDDP for five decontamination technologies and 4 metal cutting technologies to support the DVRS mission. Cost estimates are developed for a reference glovebox processed at DVRS for disposal under three scenarios; as TRU waste for WIPP, as LLW processed by baseline technologies, and as LLW processed using the demonstrated lowest cost innovative technologies. The results show that the baseline process for glovebox treatment to LLW was more expensive than simple size reduction and shipment to WIPP-for LANL. Application of innovative technologies for decontamination, crate size reduction, glovebox cutting, and improved communications change the conclusion. Application of the innovative technologies makes it more cost effective for LANL to process the glovebox to LLW, separating the TRU contaminants for separate disposal. In addition, the estimate calculates a total cost to DOE, which includes an estimate of the shipping and disposal cost at WIPP. The high costs of preparation for and characterization for WIPP shipment makes it a clear advantage for DOE to treat this particular waste by decontamination to LLW.
Review of Scientific Instruments, Jun 1, 1994
The instrumentation, the luminescence microprobe, and synchronously scanned luminescence spectros... more The instrumentation, the luminescence microprobe, and synchronously scanned luminescence spectroscopy technique described here can be used to classify microliter quantities of oil such as those in fluid inclusions in cements from petroleum reservoirs. It is primarily constructed to obtain synchronously scanned luminescence spectra from microscopic sized samples to characterize the organic classes of compounds that predominate. At present no other technique can so readily analyze a single oil-bearing fluid inclusion. The data collected from the technique are pertinent to evaluating systems and providing quantitative data for solving problems in oil migration and maturation determinations, oil-to-oil and oil-to-source correlations, oil degradation, and episodes and chemistry of cementation.
Computers & Chemical Engineering, Jul 1, 1995
The recent development of the lattice gas automata method and its extension to the lattice Boltzm... more The recent development of the lattice gas automata method and its extension to the lattice Boltzmann method have provided new computational schemes for solving a variety of partial differential equations and modeling chemically reacting systems. The lattice gas method, regarded as the simplest microscopic and kinetic approach which generates meaningful macroscopic dynamics, is fully parallel and can, as a result, be easily programmed on parallel machines. In this paper, we introduce the basic principles of the lattice gas method and the lattice Boltzmann method, their numerical implementations and applications to chemically reacting systems. Comparisons of the lattice Boltzmann method with the lattice gas technique and other traditional numerical schemes, including the finite difference scheme and the pseudo-spectral method, for solving the Navier-Stokes hydrodynamic fluid flows will be discussed. Recent developments of the lattice gas and the lattice Boltzmann method and their applications to pattern formation in chemical reaction-diffusion systems, dynamics will be presented.
Eos, Transactions American Geophysical Union, 1994
American Journal of Science, Oct 1, 1983
Geochimica et Cosmochimica Acta, May 1, 1991
Spectroscopic measurements of palladium(I1) chloride solutions have been performed under ambient ... more Spectroscopic measurements of palladium(I1) chloride solutions have been performed under ambient to elevated temperature conditions with systematic changes in pH and [Cl-]. Spectral signatures from electronic absorption spectra (Uv/Vis) and Raman vibrational spectra were determined, and these were subsequently used to systematically map out species along several paths of the predominance diagram. The species PdClAH20):1$ (x = 2,3, or 4) and Pd(OH)2 were observed, along with a precipitation product formed from > 10 PM [Pd"] solutions under near-neutral conditions. The elemental composition of the precipitation product was examined with a scanning electron micrograph (SEM) and was found to contain chloride as well as palladium. While sub-stoichiometric amounts of available OH-ligand produced UV/ Vis solution spectra likely to be from mixed Pd-Cl-OH species, the pH field of these species would be vanishingly small at low, geologically relevant palladium ion concentrations where [OH-] is no longer the limiting reagent in the transformation. In mildly acidic media, where chloropalladium(I1) species predominate, elevated temperatures (up to 90°C) cause lower charged palladium-chloride species to be favored, consistent with the lowered dielectric constant of water at higher temperatures.
Geochimica et Cosmochimica Acta, Dec 1, 1985
Crystalline basalt, diabase and basalt glass have been reacted with a Na-Ca-K-Cl fluid of seawate... more Crystalline basalt, diabase and basalt glass have been reacted with a Na-Ca-K-Cl fluid of seawater ionic strength at 350-425°C, 375-400 bars pressure and fluid/rock mass ratios of 0.5-1.0, to assess the role of temperature, basalt/diabase chemistry and texture on heavy metal and sulfur mobility during hydrothermal alteration. Alteration of basalt/diabase is characterized by cation fixation and hydrolysis reactions which show
Geological Society, London, Special Publications, 1993
Abstract The geochemical changes associated with the experimental serpentinization of peridotite ... more Abstract The geochemical changes associated with the experimental serpentinization of peridotite are due to reaction with sea water and to the growth of new mineral phases. Since the rare earth elements (REE) and Sr are primarily ensconced in clinopyroxene, it is the unreactive nature of this phase in the presence of sea water that determines the REE content, the 87Sr/86Sr and 143Nd/144Nd ratio of the experimentally produced serpentinites. Serpentinites (after lherzolite and dunite) have chondrite-normalized REE abundance patterns similar to the initial peridotite indicating that the light REE (LREE) are not selectively mobilized by peridotite-sea water interaction at 300°C. However, the serpentinites produced as a result of harzburgite-sea water experiments show an increase in LREE content. Despite the sporadic behaviour of the LREE, the 143Nd/144Nd ratios in experimentally produced serpentinites (after lherzolite and harzburgite) are identical to primary clinopyroxene in the unaltered peridotite. In contrast, a marked change in the strontium isotopic composition of the peridotites occurs during experimental serpentinization due to the growth of hydrous and Ca-rich phases which facilitates the uptake of sea water Sr. Whereas harzburgite and dunite alter to produce serpentinites with high Sr contents and 87Sr/86Sr > 0.709, lherzolites tend to alter to serpentinites with 87Sr/86Sr < 0.709. This behaviour invalidates the use of Rb-Sr data in understanding the origin of oceanic and ophiolitic peridotites, but the relative immobility of the light REE (in clinopyroxene-bearing peridotites) and the low REE content of sea water encourages the careful use of the REE and neodymium isotopes as a petrogenetic indicator for elucidating the origin of serpentinized abyssal peridotites.
Environmental Science & Technology, Nov 6, 1998
... D. Wes Efurd, Wolfgang Runde,* Joe C. Banar ... of the filtrates were made by counting aliquo... more ... D. Wes Efurd, Wolfgang Runde,* Joe C. Banar ... of the filtrates were made by counting aliquots that were stippled onto stainless steel disks, evaporated to dryness under a heat lamp, flamed to dull red, and counted on an α-scintillation counter (Eberline Instrument Corporation ...
Springer eBooks, 1994
Los Alamos NATIONAL LABORATORY LosAlamosNational Laboratory, an affirmative action/equal opportun... more Los Alamos NATIONAL LABORATORY LosAlamosNational Laboratory, an affirmative action/equal opportunity empl(_yer, isoperated bytheUniversity ofCalifornia fortheU.S.Department ofEnergy under contract W-7405-ENG-36. Byacceptance ofthisarticle, thepublisher recognizes thattheU.S.Government retains a nonexclusive, royalty-free licenseto publish orreproduce thepublished formofthiscontribution, ortoallowothers todoso,forU.S.Government purposes. TheLosAlamos National Laboratory requests thatthepublisher identify thisarticleaswork performed undertheauspices oftheU.S.Department ofEnergy.
This report summarizes the results of continuing experiments on the behavior of tracers during fr... more This report summarizes the results of continuing experiments on the behavior of tracers during fracture flow in saturated, welded tuff. These experiments were completed during the past year as part of the Dynamic Transport: Task of geochemical investigations for the Yucca Mountain Project sponsored by the ITS Department of Energy. These experiments are designed to investigate the effects offluid movement in fractures when coupled with matrix diffusion and sorption but isolated from the effects of capillary _uction and two-phase flow characteristic of unsaturated conditions. The experiments reported here are continuations
Uploads
Papers by David R Janecky