National Library of Energy BETA

Sample records for half-sample stratum pair402

  1. --No Title--

    U.S. Energy Information Administration (EIA) Indexed Site

    File02: (file02cb83.csv) BLDGID2 Building ID STR402 Half-sample stratum PAIR402 Half-sample pair number SQFTC2 Square footage SQFTC17. BCWM2C Principal activity BCWOM25....

  2. Water permeation through stratum corneum lipid bilayers from atomistic simulations

    E-Print Network [OSTI]

    Chinmay Das; Peter D. Olmsted; Massimo G. Noro


    Stratum corneum, the outermost layer of skin, consists of keratin filled rigid non-viable corneocyte cells surrounded by multilayers of lipids. The lipid layer is responsible for the barrier properties of the skin. We calculate the excess chemical potential and diffusivity of water as a function of depth in lipid bilayers with compositions representative of the stratum corneum using atomistic molecular dynamics simulations. The maximum in the excess free energy of water inside the lipid bilayers is found to be twice that of water in phospholipid bilayers at the same temperature. Permeability, which decreases exponentially with the free energy barrier, is reduced by several orders of magnitude as compared to with phospholipid bilayers. The average time it takes for a water molecule to cross the bilayer is calculated by solving the Smoluchowski equation in presence of the free energy barrier. For a bilayer composed of a 2:2:1 molar ratio of ceramide NS 24:0, cholesterol and free fatty acid 24:0 at 300K, we estimate the permeability P=3.7e-9 cm/s and the average crossing time \\tau_{av}=0.69 ms. The permeability is about 30 times smaller than existing experimental results on mammalian skin sections.

  3. Stratum Approaches to Temporal DBMS Implementation Kristian Torp Christian S. Jensen

    E-Print Network [OSTI]

    Snodgrass, Richard T.

    Stratum Approaches to Temporal DBMS Implementation Kristian Torp Christian S. Jensen Department temporal DBMSs have assumed that a temporal DBMS must be built from scratch, employing an integrated a temporal DBMS as a stratum on top of an existing non-temporal DBMS, rendering implementation more feasible

  4. Developmental plasticity of cutaneous water loss and lipid composition in stratum corneum of desert

    E-Print Network [OSTI]

    Williams, Jos. B.

    Developmental plasticity of cutaneous water loss and lipid composition in stratum corneum of desert and cerebrosides in the SC compared with mesic spar- rows. In this study, we investigated developmental plasticity modifications of the lipid composition of the SC. The expression of plasticity in CWL seems to be a response

  5. A study of bias in variance estimation with one unit per stratum 

    E-Print Network [OSTI]

    Kieffer, Grace Kloor


    . estimate of Y is L h=l h h th where y is the sample mean in the 'h stratum, The variance of h the estimate is given by where L 2 h S2 Var Y= ZN (1- ? ) h h=l h Nh N E (yh -"h) S 2 i=1 N -1 h If the strata allocations, n , are ail at least two... in their bias formula results when the strata are paired and the A. , are equal in pairs so that n1 (2, 7 In this case the variance estimate becomes I, /2 g=l (2. 8) Seth L8 ] gives the above estimate and. its bias I, /2 B = E (Nh'Yh'-Nh2Yh2 1. 1...

  6. The effect of stratum thickness ratio on crossflow in a stratified petroleum reservoir 

    E-Print Network [OSTI]

    Kereluk, Michael Joseph


    and vi s c ous f or c e s. The mechanism with which this investigation deals is that of viscous crossflow, In a lineas system viscous crossflow results from the difference between the horizontal viscous pressure gradients ahead of and behind a front...


    E-Print Network [OSTI]

    Williams, Jos. B.

    estrato co´rneo, la capa ma´s externa de la epidermis, esta´ formado por ce´lulas aplanadas embebidas en

  8. Gaguk Zakaria received his Stratum One (Bachelor of Science) degree in Electrical Engineering in 1985 from Bandung Institute of Technology, Bandung, Indonesia, and his

    E-Print Network [OSTI]

    Beex, A. A. "Louis"

    Engineering in 1985 from Bandung Institute of Technology, Bandung, Indonesia, and his Master of Science degree

  9. Accretion, Sediment Deposition and Suspended Sediment Dynamics in Mugu Lagoon, a Southern California Coastal Estuary

    E-Print Network [OSTI]

    Rosencranz, Jordan Alexander


    creek and marsh stratum on sediment deposition. Error barsBorgnis. 2009. Dynamics of sediment accumulation in Pond A21Vegetation on Suspended Sediment, Yangtze Delta. Journal of

  10. Supplementary materials for this article are available online. Please click the JCGS link at

    E-Print Network [OSTI]

    Craiu, V. Radu

    global posi- tioning system (GPS) collars generates a data stratum composed of m = 2 visited locations to longitudinal data composed of clusters of matched case-control strata. The estimation of model parameters by maximum like- lihood is especially difficult when the number of cases per stratum is greater than one

  11. Dynamic characterization of hydrophobic and hydrophilic solutes in oleic-acid enhanced transdermal delivery using two-photon fluorescence microscopy

    SciTech Connect (OSTI)

    Tseng, Te-Yu; Yang, Chiu-Sheng; Chen, Yang-Fang [Department of Physics, National Taiwan University, Taipei, Taiwan (China); Tsai, Tsung-Hua [Department of Dermatology, Far Eastern Memorial Hospital, New Taipei City, Taiwan (China); Dong, Chen-Yuan, E-mail: [Department of Physics, National Taiwan University, Taipei, Taiwan (China); Center for Quantum Science and Engineering, National Taiwan University, Taipei, Taiwan (China); Center for Optoelectronic Biomedicine, National Taiwan University, Taipei, Taiwan (China)


    In this letter, we propose an efficient methodology of investigating dynamic properties of sulforhodamine B and rhodamine B hexyl ester molecules transporting across ex-vivo human stratum corneum with and without oleic acid enhancement. Three-dimensional, time-lapse fluorescence images of the stratum corneum can be obtained using two-photon fluorescence microscopy. Furthermore, temporal quantifications of transport enhancements in diffusion parameters can be achieved with the use of Fick's second law. Dynamic characterization of solutes transporting across the stratum corneum is an effective method for understanding transient phenomena in transdermal delivery of probe molecules, leading to improved delivery strategies of molecular species for therapeutic purposes.

  12. Method for in situ heating of hydrocarbonaceous formations

    DOE Patents [OSTI]

    Little, William E. (Morgantown, WV); McLendon, Thomas R. (Laramie, WY)


    A method for extracting valuable constituents from underground hydrocarbonaceous deposits such as heavy crude tar sands and oil shale is disclosed. Initially, a stratum containing a rich deposit is hydraulically fractured to form a horizontally extending fracture plane. A conducting liquid and proppant is then injected into the fracture plane to form a conducting plane. Electrical excitations are then introduced into the stratum adjacent the conducting plate to retort the rich stratum along the conducting plane. The valuable constituents from the stratum adjacent the conducting plate are then recovered. Subsequently, the remainder of the deposit is also combustion retorted to further recover valuable constituents from the deposit. Various R.F. heating systems are also disclosed for use in the present invention.

  13. Mechanistic investigation of skin barrier perturbation induced by surfactants in the presence of humectants

    E-Print Network [OSTI]

    Ghosh, Saswata


    The stratum corneum (SC) of the skin functions as a barrier between the body and the environment. Surfactants such as Sodium Dodecyl Sulfate (SDS) are used in skin cleansers and in skin-care formulations because of their ...

  14. Population Reference Bureau Kenneth W. Wachter

    E-Print Network [OSTI]

    Wachter, Kenneth W.

    -Recapture Estimates 2. Logistic Regression for Stratum Rates 3. Synthetic Estimation for Small Areas KWW ­ p. 14/2 #12,000 households · American Community Survey: Reverse Record Check KWW ­ p. 20/2 #12;References Bell, Robert and M

  15. Abstract--We examined the diel ver-tical distribution, concentration, and

    E-Print Network [OSTI]

    than during the day, and there was evidence of larval diel vertical migration. Depth stratum. The 74 depth-stratified samples yielded 1571 fish larvae from 20 taxa, representing 11 families, and 128 increased from the surface to 50 m, then decreased with depth. Larval concentrations were higher at night

  16. Copyright 2009 by ASME1 INTRODUCTION

    E-Print Network [OSTI]

    Aguilar, Guillermo

    . Cryopneumatic (CPx) is a new technology under development which combines the quick freezing of stratum cornuem-Aldrich Co. (St. Luis, MO). Porcine skin samples with intact SC were obtained from a local meat processor for 60 min. (a) (b) Figure 1. Experimental setup to freeze and stretch porcine skin: (a) R134a spurt; (b

  17. Author's personal copy The distribution and behaviour of Patiriella mortenseni and P. regularis in

    E-Print Network [OSTI]

    Russell, Michael P.

    (Low Salinity Layer = LSL) on top of marine (34) water. The relative depth of the LSL varies both the near-freshwater stratum on the surface from the marine waters below. This low salinity layer (LSL to organisms found in shallow water. A series of transects in Doubtful Sound and the more northern Milford

  18. Response of Wetland Soils to Flow Alterations in the Sabine River below Toledo Bend Dam for the Texas Instream Flows Program. 

    E-Print Network [OSTI]

    Nally, Deseri 1975-


    sites were identified below the dam using high radar LIDAR digital elevation modeling. Soils were collected from each stratum to a depth of 50 cm using a stratified random approach. Distinct patterns were observed in regards to the pH, redox, Ferrous...

  19. Drainage in a model stratified porous medium This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    capillary pressure must build up in the non- wetting fluid at the pore entrance; this pressure is given by P is typically much larger than the viscous pressure associated with flow into a pore. Consequently, the flow by balancing the stratum-scale viscous pressure driving the flow with the capillary pressure required to invade


    E-Print Network [OSTI]

    Riley, Shawn J.

    . The only exception to this was that the Committee wished to sample the city of Detroit as a stratum, Wayne [excluding Detroit]) 7. Detroit City #12;iv REGION Number of Cases Margin of Sampling Error Upper.9% Southwest 108 + 9.5% Southeast 271 + 6.0% Detroit 120 + 9.0% Statewide Total 1,001 + 3.1% As a result


    E-Print Network [OSTI]

    thin surface stratum of the sea is.warmed by direct solar radiation. Further transference of the heat by the sun's rays, and cooling by the radiation of heat from the water to the air in autumn and winter. Added to all of which the temperature at any given depth, date, and local- ity depends to a large degree


    E-Print Network [OSTI]

    Niileksela, Christopher Robert


    --achievement relations. A three-stratum model of cognitive abilities based on Cattell-Horn-Carroll (CHC) theory was used in the analysis. Results showed that the factor structure and factor loadings of the CHC model were invariant among groups, and SLD group membership...


    E-Print Network [OSTI]

    Pawlik, Joseph

    MARINE ECOLOGY PROGRESS SERIES Mar Ecol Prog Ser Vol. 224: 103­114, 2001 Published December 19 process: solitary larvae first colonize a suitable but previously uninhabited sub- stratum; gregarious the conditions under which larvae of a gregarious species colonize new habitats. We first confirmed

  4. ORIGINAL PAPER Response properties of visual neurons in the turtle nucleus isthmi

    E-Print Network [OSTI]

    Wessel, Ralf

    response properties, together with the modulatory role of the Ipc in tectal visual processing, suggest Isthmi pars parvocellularis PBN Parabigeminal nucleus RGC Retinal ganglion cell SFGS Stratum fibrosum et. 2007; Caudill et al. 2010) that influences visual processing by direct modula- tion of tectal circuits


    SciTech Connect (OSTI)

    Shine, G.


    The SRR sampling campaign to obtain residual solids material from the Savannah River Site (SRS) Tank Farm Tank 12 primary vessel resulted in obtaining appreciable material in all 6 planned source samples from the mound strata but only in 5 of the 6 planned source samples from the floor stratum. Consequently, the design of the compositing scheme presented in the Tank 12 Sampling and Analysis Plan, Pavletich (2014a), must be revised. Analytical Development of SRNL statistically evaluated the sampling uncertainty associated with using various compositing arrays and splitting one or more samples for compositing. The variance of the simple mean of composite sample concentrations is a reasonable standard to investigate the impact of the following sampling options. Composite Sample Design Option (a). Assign only 1 source sample from the floor stratum and 1 source sample from each of the mound strata to each of the composite samples. Each source sample contributes material to only 1 composite sample. Two source samples from the floor stratum would not be used. Composite Sample Design Option (b). Assign 2 source samples from the floor stratum and 1 source sample from each of the mound strata to each composite sample. This infers that one source sample from the floor must be used twice, with 2 composite samples sharing material from this particular source sample. All five source samples from the floor would be used. Composite Sample Design Option (c). Assign 3 source samples from the floor stratum and 1 source sample from each of the mound strata to each composite sample. This infers that several of the source samples from the floor stratum must be assigned to more than one composite sample. All 5 source samples from the floor would be used. Using fewer than 12 source samples will increase the sampling variability over that of the Basic Composite Sample Design, Pavletich (2013). Considering the impact to the variance of the simple mean of the composite sample concentrations, the recommendation is to construct each sample composite using four or five source samples. Although the variance using 5 source samples per composite sample (Composite Sample Design Option (c)) was slightly less than the variance using 4 source samples per composite sample (Composite Sample Design Option (b)), there is no practical difference between those variances. This does not consider that the measurement error variance, which is the same for all composite sample design options considered in this report, will further dilute any differences. Composite Sample Design Option (a) had the largest variance for the mean concentration in the three composite samples and should be avoided. These results are consistent with Pavletich (2014b) which utilizes a low elevation and a high elevation mound source sample and two floor source samples for each composite sample. Utilizing the four source samples per composite design, Pavletich (2014b) utilizes aliquots of Floor Sample 4 for two composite samples.

  6. An Archaeological Survey for the Chatfield Water Supply Corporation Water System Improvements Project in Navarro County Texas 

    E-Print Network [OSTI]

    Moore, William


    testing of site 41NV670 was performed to determine the research potential of this unique site which consisted of a bison bone bed approximately 15 feet below the surface of a relict flood plain and within a heavy clay mantle. This investigation... was performed using shovel testing, excavation of two 1 x 1 meter test units, one backhoe trench, surface inspection of creek exposures, and an evaluation by a geomorphologist. Site 41NV670 consists of a stratum of bison bone identified as modern bison (Bison...

  7. Instrumental Variable Analysis with a Nonlinear Exposure–Outcome Relationship

    E-Print Network [OSTI]

    Burgess, Stephen; Davies, Neil M.; Thompson, Simon G.


    this merely reflects reverse causation (sick people lose weight) or confounding (underweight individuals dif- fer in other risk factors from those of average weight) or whether there is a causal effect of low BMi on increased mortality.3 in a randomized... as the sample size increases. either stratum- specific or sliding window estimates can equally be estimated with a binary outcome by using a log-linear or logistic analy- sis model to estimate a relative risk or odds ratio parameter. a localized average causal...

  8. A dry electrophysiology electrode using CNT arrays

    E-Print Network [OSTI]

    Ruffini, G; Farres, E; Grau, C; Marco-Pallares, J; Mendoza, Eric; Ray, C; Silva, R; Dunne, Stephen; Farres, Esteve; Grau, Carles; Marco-Pallares, Josep; Mendoza, Ernest; Ray, Chris; Ruffini, Giulio; Silva, Ravi


    We describe the concept of a dry electrode sensor for biopotential measurement applications (ENOBIO) designed to eliminate the noise and inconvenience associated to the use of electrolytic gel. ENOBIO uses nanotechnology to remove gel-related noise, as well as maintaining a good contact impedance to minimise interference noise. The contact surface of the electrode will be covered with an array/forest of carbon nanotubes and will also be tested with an Ag/AgCl coating to provide ionic-electronic transduction. The nanotubes are to penetrate the outer layers of the skin, the Stratum Corneum, improving electrical contact. We discuss requirements, skin properties, nanotube penetration and transduction, noise sources, prototype design logic and biocompatibility. A future paper will report test results.

  9. Detailed Studies of Hydrocarbon Radicals: C2H Dissociation

    SciTech Connect (OSTI)

    Wittig, Curt


    A novel experimental technique was examined whose goal was the ejection of radical species into the gas phase from a platform (film) of cold non-reactive material. The underlying principle was one of photo-initiated heat release in a stratum that lies below a layer of CO2 or a layer of amorphous solid water (ASW) and CO2. A molecular precursor to the radical species of interest is deposited near or on the film's surface, where it can be photo-dissociated. It proved unfeasible to avoid the rampant formation of fissures, as opposed to large "flakes." This led to many interesting results, but resulted in our aborting the scheme as a means of launching cold C2H radical into the gas phase. A journal article resulted that is germane to astrophysics but not combustion chemistry.

  10. Fuel injector system

    DOE Patents [OSTI]

    Hsu, Bertrand D. (Erie, PA); Leonard, Gary L. (Schenctady, NY)


    A fuel injection system particularly adapted for injecting coal slurry fuels at high pressures includes an accumulator-type fuel injector which utilizes high-pressure pilot fuel as a purging fluid to prevent hard particles in the fuel from impeding the opening and closing movement of a needle valve, and as a hydraulic medium to hold the needle valve in its closed position. A fluid passage in the injector delivers an appropriately small amount of the ignition-aiding pilot fuel to an appropriate region of a chamber in the injector's nozzle so that at the beginning of each injection interval the first stratum of fuel to be discharged consists essentially of pilot fuel and thereafter mostly slurry fuel is injected.

  11. Statistical Analysis of Tank 5 Floor Sample Results

    SciTech Connect (OSTI)

    Shine, E. P.


    Sampling has been completed for the characterization of the residual material on the floor of Tank 5 in the F-Area Tank Farm at the Savannah River Site (SRS), near Aiken, SC. The sampling was performed by Savannah River Remediation (SRR) LLC using a stratified random sampling plan with volume-proportional compositing. The plan consisted of partitioning the residual material on the floor of Tank 5 into three non-overlapping strata: two strata enclosed accumulations, and a third stratum consisted of a thin layer of material outside the regions of the two accumulations. Each of three composite samples was constructed from five primary sample locations of residual material on the floor of Tank 5. Three of the primary samples were obtained from the stratum containing the thin layer of material, and one primary sample was obtained from each of the two strata containing an accumulation. This report documents the statistical analyses of the analytical results for the composite samples. The objective of the analysis is to determine the mean concentrations and upper 95% confidence (UCL95) bounds for the mean concentrations for a set of analytes in the tank residuals. The statistical procedures employed in the analyses were consistent with the Environmental Protection Agency (EPA) technical guidance by Singh and others [2010]. Savannah River National Laboratory (SRNL) measured the sample bulk density, nonvolatile beta, gross alpha, and the radionuclide1, elemental, and chemical concentrations three times for each of the composite samples. The analyte concentration data were partitioned into three separate groups for further analysis: analytes with every measurement above their minimum detectable concentrations (MDCs), analytes with no measurements above their MDCs, and analytes with a mixture of some measurement results above and below their MDCs. The means, standard deviations, and UCL95s were computed for the analytes in the two groups that had at least some measurements above their MDCs. The identification of distributions and the selection of UCL95 procedures generally followed the protocol in Singh, Armbya, and Singh [2010]. When all of an analyte's measurements lie below their MDCs, only a summary of the MDCs can be provided. The measurement results reported by SRNL are listed, and the results of this analysis are reported. The data were generally found to follow a normal distribution, and to be homogenous across composite samples.

  12. Portable measurement system for soil resistivity and application to Quaternary clayey sediment

    SciTech Connect (OSTI)

    Nakagawa, Koichi; Morii, Takeo


    A simple device to measure electrical resistivity has been developed for field and laboratory use. The measurement system comprises a probe unit, current wave generator, amplified, A/D converter, data acquisition unit with RS-232C interface and notebook personal computer. The system is applicable to soils and soft rocks as long as the probe needles can pierce into them. Frequency range of the measurement system extends from 100 Hz to 10 MHz. The total error of the system is less than 5%. In situ measurements of the resistivity and shear resistance by means of pocket-sized penetrometer were applied to Pleistocene clayey beds. Some laboratory tests were also conducted to examine the interpretation of the in situ resistivity. Marine and non-marine clayey sediments are different in their resistivities of the stratum by in situ test and the clay suspension sampled from the strata. Physical and mechanical properties were compared with the resistivity and general relationships among them were explored to clarify the characteristics of inter-particle bonding. Some possible mechanism regarding the peculiar weathering of clayey sediment or mudstone beds is discussed from the viewpoint of physico-chemical process, which is conspicuous especially near the ground surface.

  13. The landscape of G-structures in eight-manifold compactifications of M-theory

    E-Print Network [OSTI]

    Babalic, Elena Mirela


    We consider spaces of "virtual" constrained generalized Killing spinors, i.e. spaces of Majorana spinors which correspond to "off-shell" $s$-extended supersymmetry in compactifications of eleven-dimensional supergravity based on eight-manifolds $M$. Such spaces naturally induce two stratifications of $M$, called the chirality and stabilizer stratification. For the case $s=2$, we describe the former using the canonical Whitney stratification of a three-dimensional semi-algebraic set ${\\cal R}$. We also show that the stabilizer stratification coincides with the rank stratification of a cosmooth generalized distribution ${\\cal D}_0$ and describe it explicitly using the Whitney stratification of a four-dimensional semi-algebraic set $\\mathfrak{P}$. The stabilizer groups along the strata are isomorphic with $\\mathrm{SU}(2)$, $\\mathrm{SU}(3)$, $\\mathrm{G}_2$ or $\\mathrm{SU}(4)$, where $\\mathrm{SU(2)}$ corresponds to the open stratum, which is generically non-empty. We also determine the rank stratification of a lar...

  14. The landscape of G-structures in eight-manifold compactifications of M-theory

    E-Print Network [OSTI]

    Elena Mirela Babalic; Calin Iuliu Lazaroiu


    We consider spaces of "virtual" constrained generalized Killing spinors, i.e. spaces of Majorana spinors which correspond to "off-shell" $s$-extended supersymmetry in compactifications of eleven-dimensional supergravity based on eight-manifolds $M$. Such spaces naturally induce two stratifications of $M$, called the chirality and stabilizer stratification. For the case $s=2$, we describe the former using the canonical Whitney stratification of a three-dimensional semi-algebraic set ${\\cal R}$. We also show that the stabilizer stratification coincides with the rank stratification of a cosmooth generalized distribution ${\\cal D}_0$ and describe it explicitly using the Whitney stratification of a four-dimensional semi-algebraic set $\\mathfrak{P}$. The stabilizer groups along the strata are isomorphic with $\\mathrm{SU}(2)$, $\\mathrm{SU}(3)$, $\\mathrm{G}_2$ or $\\mathrm{SU}(4)$, where $\\mathrm{SU(2)}$ corresponds to the open stratum, which is generically non-empty. We also determine the rank stratification of a larger generalized distribution ${\\cal D}$ which turns out to be integrable in the case of compactifications down to $\\mathrm{AdS}_3$.

  15. Sampling Plan for Assaying Plates Containing Depleted or Normal Uranium

    SciTech Connect (OSTI)

    Ivan R. Thomas


    This paper describes the rationale behind the proposed method for selecting a 'representative' sample of uranium metal plates, portions of which will be destructively assayed at the Y-12 Security Complex. The total inventory of plates is segregated into two populations, one for Material Type 10 (depleted uranium (DU)) and one for Material Type 81 (normal [or natural] uranium (NU)). The plates within each population are further stratified by common dimensions. A spreadsheet gives the collective mass of uranium element (and isotope for DU) and the piece count of all plates within each stratum. These data are summarized in Table 1. All plates are 100% uranium metal, and all but approximately 60% of the NU plates have Kel-F{reg_sign} coating. The book inventory gives an overall U-235 isotopic percentage of 0.22% for the DU plates, ranging from 0.19% to 0.22%. The U-235 ratio of the NU plates is assumed to be 0.71%. As shown in Table 1, the vast majority of the plates are comprised of depleted uranium, so most of the plates will be sampled from the DU population.

  16. Response of South American ecosystems to precipitation variability

    SciTech Connect (OSTI)

    Ganguly, Auroop R [ORNL; Erickson III, David J [ORNL; Bras, Rafael L [ORNL


    The Ecosystem Demography Model 2 is a dynamic ecosystem model and land surface energy balance model. ED2 discretizes landscapes of particular terrain and meteorology into fractional areas of unique disturbance history. Each fraction, defined by a shared vertical soil column and canopy air space, contains a stratum of plant groups unique in functional type, size and number density. The result is a vertically distributed representation of energy transfer and plant dynamics (mortality, productivity, recruitment, disturbance, resource competition, etc) that successfully approximates the behaviour of individual-based vegetation models. In previous exercises simulating Amazonian land surface dynamics with ED2, it was observed that when using grid averaged precipitation as an external forcing the resulting water balance typically over-estimated leaf interception and leaf evaporation while under estimating through-fall and transpiration. To investigate this result, two scenario were conducted in which land surface biophysics and ecosystem demography over the Northern portion of South America are simulated over {approx}200 years: (1) ED2 is forced with grid averaged values taken from the ERA40 reanalysis meteorological dataset; (2) ED2 is forced with ERA40 reanalysis, but with its precipitation re-sampled to reflect statistical qualities of point precipitation found at rain gauge stations in the region. The findings in this study suggest that the equilibrium moisture states and vegetation demography are co-dependent and show sensitivity to temporal variability in precipitation. These sensitivities will need to be accounted for in future projections of coupled climate-ecosystem changes in South America.

  17. Temporary Cementitious Sealers in Enhanced Geothermal Systems

    SciTech Connect (OSTI)

    Sugama T.; Pyatina, T.; Butcher, T.; Brothers, L.; Bour, D.


    Unlike conventional hydrothennal geothermal technology that utilizes hot water as the energy conversion resources tapped from natural hydrothermal reservoir located at {approx}10 km below the ground surface, Enhanced Geothermal System (EGS) must create a hydrothermal reservoir in a hot rock stratum at temperatures {ge}200 C, present in {approx}5 km deep underground by employing hydraulic fracturing. This is the process of initiating and propagating a fracture as well as opening pre-existing fractures in a rock layer. In this operation, a considerable attention is paid to the pre-existing fractures and pressure-generated ones made in the underground foundation during drilling and logging. These fractures in terms of lost circulation zones often cause the wastage of a substantial amount of the circulated water-based drilling fluid or mud. Thus, such lost circulation zones must be plugged by sealing materials, so that the drilling operation can resume and continue. Next, one important consideration is the fact that the sealers must be disintegrated by highly pressured water to reopen the plugged fractures and to promote the propagation of reopened fractures. In response to this need, the objective of this phase I project in FYs 2009-2011 was to develop temporary cementitious fracture sealing materials possessing self-degradable properties generating when {ge} 200 C-heated scalers came in contact with water. At BNL, we formulated two types of non-Portland cementitious systems using inexpensive industrial by-products with pozzolanic properties, such as granulated blast-furnace slag from the steel industries, and fly ashes from coal-combustion power plants. These byproducts were activated by sodium silicate to initiate their pozzolanic reactions, and to create a cemetitious structure. One developed system was sodium silicate alkali-activated slag/Class C fly ash (AASC); the other was sodium silicate alkali-activated slag/Class F fly ash (AASF) as the binder of temper-try sealers. Two specific additives without sodium silicate as alkaline additive were developed in this project: One additive was the sodium carboxymethyl cellulose (CMC) as self-degradation promoting additive; the other was the hard-burned magnesium oxide (MgO) made from calcinating at 1,000-1,500 C as an expansive additive. The AASC and AASF cementitious sealers made by incorporating an appropriate amount of these additives met the following six criteria: 1) One dry mix component product; 2) plastic viscosity, 20 to 70 cp at 300 rpm; 3) maintenance of pumpability for at least 1 hour at 85 C; 4) compressive strength >2000 psi; 5) self-degradable by injection with water at a certain pressure; and 6) expandable and swelling properties; {ge}0.5% of total volume of the sealer.