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Sample records for non-steady state multi-phase

  1. Non-steady-state aerosol filtration in nanostructured fibrous media.

    PubMed

    Przekop, Rafal; Gradoń, Leon

    2011-06-28

    The filtration of aerosol particles using composites of nano- and microsized fibrous structures is a promising method for the effective separation of nanoparticles from gases. A multi-scale physical system describing the flow pattern and particle deposition at a non-steady-state condition requires an advanced method of modelling. The combination of lattice Boltzmann and Brownian dynamics was used for analysis of the particle deposition pattern in a fibrous system. The dendritic structures of deposits for neutral and charged fibres and particles are present. The efficiency of deposition, deposit morphology, porosity and fractal dimension were calculated for a selected operational condition of the process.

  2. The Budyko functions under non-steady-state conditions

    NASA Astrophysics Data System (ADS)

    Moussa, Roger; Lhomme, Jean-Paul

    2016-12-01

    The Budyko functions relate the evaporation ratio E / P (E is evaporation and P precipitation) to the aridity index Φ = Ep / P (Ep is potential evaporation) and are valid on long timescales under steady-state conditions. A new physically based formulation (noted as Moussa-Lhomme, ML) is proposed to extend the Budyko framework under non-steady-state conditions taking into account the change in terrestrial water storage ΔS. The variation in storage amount ΔS is taken as negative when withdrawn from the area at stake and used for evaporation and positive otherwise, when removed from the precipitation and stored in the area. The ML formulation introduces a dimensionless parameter HE = -ΔS / Ep and can be applied with any Budyko function. It represents a generic framework, easy to use at various time steps (year, season or month), with the only data required being Ep, P and ΔS. For the particular case where the Fu-Zhang equation is used, the ML formulation with ΔS ≤ 0 is similar to the analytical solution of Greve et al. (2016) in the standard Budyko space (Ep / P, E / P), a simple relationship existing between their respective parameters. The ML formulation is extended to the space [Ep / (P - ΔS), E / (P - ΔS)] and compared to the formulations of Chen et al. (2013) and Du et al. (2016). The ML (or Greve et al., 2016) feasible domain has a similar upper limit to that of Chen et al. (2013) and Du et al. (2016), but its lower boundary is different. Moreover, the domain of variation of Ep / (P - ΔS) differs: for ΔS ≤ 0, it is bounded by an upper limit 1 / HE in the ML formulation, while it is only bounded by a lower limit in Chen et al.'s (2013) and Du et al.'s (2016) formulations. The ML formulation can also be conducted using the dimensionless parameter HP = -ΔS / P instead of HE, which yields another form of the equations.

  3. Dynamic evolution of initial instability during non-steady-state growth.

    PubMed

    Dong, Zhibo; Zheng, Wenjian; Wei, Yanhong; Song, Kuijing

    2014-06-01

    Dynamic evolution of initial instability is investigated by an analytic model obtained by modifying the theory of Warren and Langer [Phys. Rev. E 47, 2702 (1993)] and the quantitative phase-field model in directional solidification under transient conditions for realistic parameters of a dilute alloy. The evolutions of tip velocity and concentration in the liquid side of the interface predicted by the analytic model agree very well with that from the phase-field simulation in the linear growth stage of the non-steady-state growth, indicating that the model could be used as a convenient method to study the initial instability during non-steady-state growth. The influences of non-steady-state conditions which include the increasing rate of pulling speed and temperature gradient at the onset of initial instability are investigated, and we find that, the initial instability seems to depend strongly on the non-steady-state conditions and the non-steady-state history, and thus, it should be primarily considered in the study of the transient growth.

  4. Quantifying biases in non-steady state chamber measurements of soil-atmosphere gas exchange

    USDA-ARS?s Scientific Manuscript database

    Limitations of non-steady state (NSS) chamber methods for determining soil-to-atmosphere trace gas exchange rates have been recognized for several decades. Of these limitations, the so-called “chamber effect” is one of the most challenging to overcome. The chamber effect can be defined as the inhere...

  5. Theoretical comparison of advanced methods for calculating nitrous oxide fluxes using non-steady state chambers

    USDA-ARS?s Scientific Manuscript database

    Several flux-calculation (FC) schemes are available for determining soil-to-atmosphere emissions of nitrous oxide (N2O) and other trace gases using data from non-steady-state flux chambers. Recently developed methods claim to provide more accuracy in estimating the true pre-deployment flux (f0) comp...

  6. Mechanism of Non-Steady State Dissolution of Goethite in the Presence of Siderophores

    NASA Astrophysics Data System (ADS)

    Reichard, P. U.; Kretzschmar, R.; Kraemer, S. M.

    2003-12-01

    Iron is an essential micronutrient for almost all known organisms. Bacteria, fungi, and graminaceous plants are capable of exuding siderophores as part of an iron acquisition strategy. The production of these strong iron chelating ligands is induced by iron limited conditions. Grasses under iron stress, for example, exude phytosiderophores into the rhizosphere in a special diurnal rhythm (Roemheld and Marschner 1986). A few hours after sunrise the exudation starts, culminates around noon and is shut down again until about 4 hours after noon. The phytosiderophores diffuse into the rhizosphere (Marschner et al. 1986) and are passively back transported to the plants by advective flow induced by high transpiration around noon. Despite a fairly short residence time of the phytosiderophores in the rhizosphere, it is a very effective strategy for iron acquisition. To investigate the effect of such pulse inputs of siderophores on iron acquisition, we studied the dissolution mechanism of goethite (alpha-FeOOH), a mineral phase common in soils, under non-steady state conditions. In consideration of the chemical complexity of the rhizosphere, we also investigated the effect of other organic ligands commonly found in the rhizosphere (e. g. oxalate) on the dissolution kinetics. The dissolution experiments were conducted in batch reactors with a constant goethite solids concentration of 2.5 g/l, an ionic strength of 0.01 M, a pH of 6 and 100 microM oxalate. To induce non-steady state conditions, 3 mM phytosiderophores were added to a batch after the goethite-oxalate suspension reacted for a certain time period. Before the siderophore was added to the goethite-oxalate suspension, no dissolution of iron was observed. But, with the addition of the siderophore, a high rate was observed for the iron mobilization under these non-steady state conditions that subsequently was followed by a slow steady state dissolution rate. The results of these non-steady state experiments are very

  7. A Series RCL Circuit Theory for Analyzing Non-Steady-State Water Uptake of Maize Plants

    NASA Astrophysics Data System (ADS)

    Zhuang, Jie; Yu, Gui-Rui; Nakayama, Keiichi

    2014-10-01

    Understanding water uptake and transport through the soil-plant continuum is vital for ecosystem management and agricultural water use. Plant water uptake under natural conditions is a non-steady transient flow controlled by root distribution, plant configuration, soil hydraulics, and climatic conditions. Despite significant progress in model development, a mechanistic description of transient water uptake has not been developed or remains incomplete. Here, based on advanced electrical network theory (RLC circuit theory), we developed a non-steady state biophysical model to mechanistically analyze the fluctuations of uptake rates in response to water stress. We found that the non-steady-state model captures the nature of instantaneity and hysteresis of plant water uptake due to the considerations of water storage in plant xylem and coarse roots (capacitance effect), hydraulic architecture of leaf system (inductance effect), and soil-root contact (fuse effect). The model provides insights into the important role of plant configuration and hydraulic heterogeneity in helping plants survive an adverse environment. Our tests against field data suggest that the non-steady-state model has great potential for being used to interpret the smart water strategy of plants, which is intrinsically determined by stem size, leaf size/thickness and distribution, root system architecture, and the ratio of fine-to-coarse root lengths.

  8. A Series RCL Circuit Theory for Analyzing Non-Steady-State Water Uptake of Maize Plants

    PubMed Central

    Zhuang, Jie; Yu, Gui-Rui; Nakayama, Keiichi

    2014-01-01

    Understanding water uptake and transport through the soil-plant continuum is vital for ecosystem management and agricultural water use. Plant water uptake under natural conditions is a non-steady transient flow controlled by root distribution, plant configuration, soil hydraulics, and climatic conditions. Despite significant progress in model development, a mechanistic description of transient water uptake has not been developed or remains incomplete. Here, based on advanced electrical network theory (RLC circuit theory), we developed a non-steady state biophysical model to mechanistically analyze the fluctuations of uptake rates in response to water stress. We found that the non-steady-state model captures the nature of instantaneity and hysteresis of plant water uptake due to the considerations of water storage in plant xylem and coarse roots (capacitance effect), hydraulic architecture of leaf system (inductance effect), and soil-root contact (fuse effect). The model provides insights into the important role of plant configuration and hydraulic heterogeneity in helping plants survive an adverse environment. Our tests against field data suggest that the non-steady-state model has great potential for being used to interpret the smart water strategy of plants, which is intrinsically determined by stem size, leaf size/thickness and distribution, root system architecture, and the ratio of fine-to-coarse root lengths. PMID:25335512

  9. A series RCL circuit theory for analyzing non-steady-state water uptake of maize plants.

    PubMed

    Zhuang, Jie; Yu, Gui-Rui; Nakayama, Keiichi

    2014-10-22

    Understanding water uptake and transport through the soil-plant continuum is vital for ecosystem management and agricultural water use. Plant water uptake under natural conditions is a non-steady transient flow controlled by root distribution, plant configuration, soil hydraulics, and climatic conditions. Despite significant progress in model development, a mechanistic description of transient water uptake has not been developed or remains incomplete. Here, based on advanced electrical network theory (RLC circuit theory), we developed a non-steady state biophysical model to mechanistically analyze the fluctuations of uptake rates in response to water stress. We found that the non-steady-state model captures the nature of instantaneity and hysteresis of plant water uptake due to the considerations of water storage in plant xylem and coarse roots (capacitance effect), hydraulic architecture of leaf system (inductance effect), and soil-root contact (fuse effect). The model provides insights into the important role of plant configuration and hydraulic heterogeneity in helping plants survive an adverse environment. Our tests against field data suggest that the non-steady-state model has great potential for being used to interpret the smart water strategy of plants, which is intrinsically determined by stem size, leaf size/thickness and distribution, root system architecture, and the ratio of fine-to-coarse root lengths.

  10. Steady-state and non-steady state operation of counter-current chromatography devices.

    PubMed

    Kostanyan, Artak E; Ignatova, Svetlana N; Sutherland, Ian A; Hewitson, Peter; Zakhodjaeva, Yulya A; Erastov, Andrey A

    2013-11-01

    Different variants of separation processes based on steady-state (continuous sample loading) and non-steady state (batch) operating modes of CCC columns have been analyzed and compared. The analysis is carried out on the basis of the modified equilibrium cell model, which takes into account both mechanisms of band broadening - interphase mass transfer and axial mixing. A full theoretical treatment of the intermittent counter-current chromatography with short sample loading time is performed. Analytical expressions are presented allowing the simulation of the intermittent counter-current chromatography separations for various experimental conditions. Chromatographic and extraction separations have been compared and advantages and disadvantages of the two methods have been evaluated. Further technical development of the CCC machines to implement counter-current extraction separations is considered.

  11. Steady- and non-steady-state carbonate-silicate controls on atmospheric CO2

    USGS Publications Warehouse

    Sundquist, E.T.

    1991-01-01

    Two contrasting hypotheses have recently been proposed for the past long-term relation between atmospheric CO2 and the carbonate-silicate geochemical cycle. One approach (Berner, 1990) suggests that CO2 levels have varied in a manner that has maintained chemical weathering and carbonate sedimentation at a steady state with respect to tectonically controlled decarbonation reactions. A second approach (Raymo et al., 1988), applied specificlly to the late Cenozoic, suggests a decrease in CO2 caused by an uplift-induced increase in chemical weathering, without regard to the rate of decarbonation. According to the steady-state (first) hypothesis, increased weathering and carbonate sedimentation are generally associated with increasing atmospheric CO2, whereas the uplift (second) hypothesis implies decreasing CO2 under the same conditions. An ocean-atmosphere-sediment model has been used to assess the response of atmospheric CO2 and carbonate sedimentation to global perturbations in chemical weathering and decarbonation reactions. Although this assessment is theoretical and cannot yet be related to the geologic record, the model simulations compare steady-state and non-steady-state carbonate-silicate cycle response. The e-fold response time of the 'CO2-weathering' feedback mechanism is between 300 and 400 ka. The response of carbonate sedimentation is much more rapid. These response times provide a measure of the strength of steady-state assumptions, and imply that certain systematic relations are sustained throughout steady-state and non-steady-state scenarios for the carbonate-silicate cycle. The simulations suggest that feedbacks can maintain the system near a steady state, but that non-steady-state effects may contribute to long-term trends. The steady-state and uplift hypotheses are not necessarily incompatible over time scales of a few million years. ?? 1991.

  12. Multi-Phase Extraction: State-of-the-Practice

    EPA Pesticide Factsheets

    This report describes the state-of-the-practice for multi-phase extraction (MPE) of contaminated soil and groundwater, focusing primarily on the application and use of MPE at sites with halogenated volatile organic compounds (VOCs).

  13. Non-steady-state operation of polymer/TiO2 photovoltaic devices

    NASA Astrophysics Data System (ADS)

    Kirov, Kiril R.; Burlakov, Victor M.; Xie, Zhibin; Henry, Bernard M.; Carey, Michelle J.; Grovenor, Christopher R. M.; Burn, Paul L.; Assender, Hazel E.; Briggs, G. Andrew D.

    2004-11-01

    We present data on the initial period of operation of Gilch-route MEH-PPV/TiO2 composite solar cells (CSCs) which show that during this period the CSCs operate in a non-steady state regime. The behavior is complex and may include a gradual rise of the open circuit voltage (Voc) and of the short-circuit current density (Jsc) with time, a passage through a maximum of either or both parameters, and even a sign reversal. The mechanisms most probably contributing to the transient processes are: i) diffusion driven redistribution of charges resulting in the build up of a quasi steady state charge density profile across the device; ii) photo-doping resulting in a relatively slow increase of the average charge carrier concentration and consequently of the conductivity of the device. The latter is responsible for a strong decrease in Voc, and is evidenced by the significant increase in dark current after device illumination.

  14. Temporal full-colour tuning through non-steady-state upconversion.

    PubMed

    Deng, Renren; Qin, Fei; Chen, Runfeng; Huang, Wei; Hong, Minghui; Liu, Xiaogang

    2015-03-01

    Developing light-harvesting materials with tunable emission colours has always been at the forefront of colour display technologies. The variation in materials composition, phase and structure can provide a useful tool for producing a wide range of emission colours, but controlling the colour gamut in a material with a fixed composition remains a daunting challenge. Here, we demonstrate a convenient, versatile approach to dynamically fine-tuning emission in the full colour range from a new class of core-shell upconversion nanocrystals by adjusting the pulse width of infrared laser beams. Our mechanistic investigations suggest that the unprecedented colour tunability from these nanocrystals is governed by a non-steady-state upconversion process. These findings provide keen insights into controlling energy transfer in out-of-equilibrium optical processes, while offering the possibility for the construction of true three-dimensional, full-colour display systems with high spatial resolution and locally addressable colour gamut.

  15. Non-steady-state subduction and trench-parallel flow induced by overriding plate structure

    NASA Astrophysics Data System (ADS)

    Rodríguez-González, Juan; Billen, Magali I.; Negredo, Ana M.

    2014-09-01

    The direction of plate tectonic motion and the direction of mantle flow, as inferred from observations of seismic anisotropy measurements, show a good global correlation far from subduction zones. However, this correlation is poor near subduction zones, where below the slab seismic anisotropy is aligned parallel to the trench and above the slab has a complex pattern, which has not been fully explained. Here we present time-dependent three-dimensional (3D) fully-dynamic simulations of subduction to study the effect of overriding plate structure on the evolution of slab geometry and induced mantle flow. We find that along-strike variation in thermal thickness of the overriding plate causes increased hydrodynamic suction and shallower slab dip beneath the colder portion of the overriding plate; the variation in slab geometry drives strong trench-parallel flow beneath the slab and a complex flow pattern above the slab. This new mechanism for driving trench-parallel flow provides a good explanation for seismic anisotropy observations from the Middle and South America subduction zones, where both slab dip and overriding plate thermal state are strongly variable and correlated, and thus may be an important mechanism in other subduction zones. The location and strength of trench-parallel flow vary with the time-dependent evolution of the slab, suggesting that the global variability in seismic anisotropy observations in subduction zones is in part due to the non-steady-state behavior of these systems.

  16. Precise non-steady-state characterization of solid active materials with no preliminary mechanistic assumptions

    DOE PAGES

    Constales, Denis; Yablonsky, Gregory S.; Wang, Lucun; ...

    2017-04-25

    This paper presents a straightforward and user-friendly procedure for extracting a reactivity characterization of catalytic reactions on solid materials under non-steady-state conditions, particularly in temporal analysis of products (TAP) experiments. The kinetic parameters derived by this procedure can help with the development of detailed mechanistic understanding. The procedure consists of the following two major steps: 1) Three “Laplace reactivities” are first determined based on the moments of the exit flow pulse response data; 2) Depending on a select kinetic model, kinetic constants of elementary reaction steps can then be expressed as a function of reactivities and determined accordingly. In particular,more » we distinguish two calculation methods based on the availability and reliability of reactant and product data. The theoretical results are illustrated using a reverse example with given parameters as well as an experimental example of CO oxidation over a supported Au/SiO2 catalyst. The procedure presented here provides an efficient tool for kinetic characterization of many complex chemical reactions.« less

  17. Early non-steady-state population pharmacokinetics of oral cyclosporine in renal transplant recipients.

    PubMed

    Baek, Hyunjeong; Han, Seunghoon; Yim, Dong-Seok; Kim, Sung Joo; Lee, Soo-Youn; Jang, Hye Ryoun; Lee, Jung Eun; Kim, Dae Joong; Kim, Yoon-Goo; Oh, Ha Young; Huh, Wooseong

    2014-01-01

    This study aimed to evaluate the change in the pharmacokinetics (PK) of cyclosporine in the non-steady-state period in the first week after renal transplantation; the factors influencing this change, including genetic variability; and the time point concentration that correlated best with drug exposure. Data were obtained from 69 patients, and PK studies were conducted on postoperative days (PODs) 2, 3, and 7. Samples were taken pre-dose and at 1, 2, 3, 4, 6, 8, and 12 hours after drug administration. MDR1, CYP3A4, and CYP3A5 were genotyped. A population PK analysis and correlational analysis between the concentration at each time point and the area under the time-concentration curve were performed. A two-compartment model with first-order absorption was chosen. The rate and extent of drug absorption showed a significant increase on POD3, followed by a slight decrease on POD7. Until POD3, 8 hours post-dose was the single time point concentration that correlated best with drug exposure and 3 hours was the best time point on POD7. In both analyses, the MDR1 genotype showed potential as a factor influencing PK change. We conclude that oral administration of cyclosporine and dose adjustment based on a single concentration measurement might result in unexpected drug exposure during this early posttransplantation period.

  18. Non-steady-state modelling of faecal coliform removal in deep tertiary lagoons.

    PubMed

    Xu, P; Brissaud, F; Fazio, A

    2002-07-01

    In Noirmoutier, a French island off the Atlantic coast, secondary effluents flow into a series of four lagoons, 1.4-2.8 m deep, and are reused for agricultural irrigation. The excess water is disposed of to the sea. The aim of this study was to provide a model capable of predicting the microbiological quality of the water pumped for irrigation or discharged to the sea. Meteorological variables, flow rates, physical-chemical characteristics and faecal coliform (FC) contents were monitored for a year and a half. The hydraulic pattern of each lagoon was assumed to be that of completely mixed reactor because of the calculated dispersion numbers and the wind mixing effect. Coliform decay was assumed to follow first order kinetics in each lagoon. Die-off coefficients were calculated in each lagoon using a non-steady-state model. The main bacterial removal mechanism was shown to be solar irradiation. Empirical equations were established to calculate die-off coefficients as a function of received solar energy and temperature. FC die-off rates were higher in the first lagoon and then decreased successively in those following. FC numbers in the different lagoons were predicted with reasonable accuracy in spite of high variation in inlet water quality. The model will facilitate the prediction of water quality under various climatic conditions and different water reuse scenarios and will help to optimise reclamation and storage facilities.

  19. Non-steady state diagenesis of organic and inorganic sulfur in lake sediments

    NASA Astrophysics Data System (ADS)

    Couture, Raoul-Marie; Fischer, Rachele; Van Cappellen, Philippe; Gobeil, Charles

    2016-12-01

    Sulfur controls the fate of many geochemical elements in lake sediments, including iron, phosphorus and environmentally important trace elements. We measured the speciation of pore-water and sediment-bound sulfur (aqueous sulfate and sulfides, elemental sulfur, iron monosulfide, pyrite, organic sulfur) and supporting geochemical variables (carbon, oxygen, iron) in the sediments of a perennially oxygenated and a seasonally anoxic basin of an oligotrophic lake in Québec, using a combination of pore-water analyses, sequential extractions and X-ray absorption near edge structure. A non-steady state early diagenetic model was developed and calibrated against this extensive dataset to help unravel the pathways and quantify the rates of S transformations. Results suggest that the main source of S to the sediments is the settling of organic ester-sulfate (R-O-SO3-H). Hydrolysis of these compounds provides an additional source of sulfate for anaerobic microbial oxidation of sedimentary organic matter, releasing sulfide to the pore-water. Reduced solid-bound S species accumulate as thiols (R-SH) and iron sulfides in the perennially oxygenated and seasonally anoxic basin, respectively. The model-estimated rate constant for R-SH formation is lower than previously estimated for this particular lacustrine site, but similar to that proposed for marine shelf sediments. The solid sediment S profiles, however, carry the imprint of the time-dependent sulfate input to the lake. Iron sulfide enrichments formed during past decades of elevated atmospheric SO4 deposition are presently dissolving. In the sediments of the perennially oxygenated basin this reaction hampers the build-up of Fe(III) (oxy)hydroxide near the sediment-water interface.

  20. Beneficial Effects of Cooling during Constant Power Non-steady State Cycling.

    PubMed

    Homestead, Eric P; Ryan, Benjamin J; Goodrich, Jesse A; Byrnes, William C

    2017-02-01

    This study compared the effects of cooling on the energetic and associated physiological and perceptual responses to constant power, non-steady state cycling. Twelve males cycled at their lactate threshold power for 60 min or until exhaustion under 3 conditions: wearing a cooling vest and sleeves (COOL), a synthetic shirt embedded with an active particle technology claimed to facilitate evaporative heat loss (EVAP), and a standard synthetic shirt (CON). When adjusted for time, the increase in gastrointestinal temperature from baseline was reduced during COOL and EVAP compared to CON (1.44±0.45 and 1.52±0.43 vs. 1.66±0.45°C, p<0.05). Sweat rate was reduced during COOL compared to EVAP and CON (1 312±331 vs. 1 525±393 and 1 550±548 mL·h(-1), p<0.01). Gross efficiency decreased over time across conditions (p<0.01), but COOL attenuated this decrease by 22% compared to CON (p<0.05). The rating of perceived exertion was reduced during COOL and EVAP compared to CON (p<0.01). In conclusion, cooling using a vest and sleeves or wearing an active particle technology shirt reduced the rise in gastrointestinal temperature and rating of perceived exertion compared to a standard synthetic shirt. Cooling using a vest and sleeves also reduced the decrease in gross efficiency and sweat rate compared to wearing the standard synthetic shirt. © Georg Thieme Verlag KG Stuttgart · New York.

  1. The non-steady state growth of pearlite outside the Hultgren extrapolation

    SciTech Connect

    Martin-Aranda, Maria; Rementeria, Rosalia; Hackenberg, Robert Errol; Urones-Garrote, Esteban; Tsai, Shao Pu; Yang, Jen Ren; Capdevila, Carlos

    2016-12-14

    Here, the goal of this paper is to analyse the effect of adding Al on the non-steady pearlite growth occurring in a Fe–C–Mn system. The results are discussed in terms of the partitioning of elements across the austenite/ferrite and austenite/cementite interfaces, and the modification of the pearlite driving force related to the change in carbon activity in austenite.

  2. The Non-Steady State Growth of Pearlite outside the Hultgren Extrapolation

    PubMed Central

    Martin-Aranda, Maria; Rementeria, Rosalia; Hackenberg, Robert; Urones-Garrote, Esteban; Tsai, Shao Pu; Yang, Jen Ren; Capdevila, Carlos

    2016-01-01

    The goal of this paper is to analyse the effect of adding Al on the non-steady pearlite growth occurring in a Fe–C–Mn system. The results are discussed in terms of the partitioning of elements across the austenite/ferrite and austenite/cementite interfaces, and the modification of the pearlite driving force related to the change in carbon activity in austenite. PMID:28774131

  3. Oxygen isotope signatures of transpired water vapor: the role of isotopic non-steady-state transpiration under natural conditions.

    PubMed

    Dubbert, Maren; Cuntz, Matthias; Piayda, Arndt; Werner, Christiane

    2014-09-01

    The oxygen isotope signature of water is a powerful tracer of water movement from plants to the global scale. However, little is known about the short-term variability of oxygen isotopes leaving the ecosystem via transpiration, as high-frequency measurements are lacking. A laser spectrometer was coupled to a gas-exchange chamber directly estimating branch-level fluxes in order to evaluate the short-term variability of the isotopic composition of transpiration (δE ) and to investigate the role of isotopic non-steady-state transpiration under natural conditions in cork-oak trees (Quercus suber) during distinct Mediterranean seasons. The measured δ(18) O of transpiration (δE ) deviated from isotopic steady state throughout most of the day even when leaf water at the evaporating sites was near isotopic steady state. High agreement was found between estimated and modeled δE values assuming non-steady-state enrichment of leaf water. Isoforcing, that is, the influence of the transpirational δ(18) O flux on atmospheric values, deviated from steady-state calculations but daily means were similar between steady state and non-steady state. However, strong daytime isoforcing on the atmosphere implies that short-term variations in δE are likely to have consequences for large-scale applications, for example, partitioning of ecosystem fluxes or satellite-based applications.

  4. Non-steady State Soil Organic Carbon Storage in Undisturbed Watersheds Due to Diffusive Sediment Transport

    NASA Astrophysics Data System (ADS)

    Yoo, K.; Amundson, R.; Heimsath, A. M.; Dietrich, W. E.

    2003-12-01

    Most soil C models assume that plant C inputs are matched by C loss through heterotrophic respiration. While these models are applicable for level terrain, on soil mantled uplands in hilly to mountainous regions, persistent soil mass transport represents a potentially large, but unstudied, flux of soil C. In this research we quantify the soil C erosional fluxes and non-steady state soil C storage within two undisturbed grass-covered hillslopes in Coastal California: Tennessee Valley (TV) (coastal Marin County) and Black Diamond (BD) (interior Contra Costa County). At both sites, previous geomorphic studies have quantified both the sediment transport processes (TV= gopher driven sediment transport; BD= abiotic soil shrink/swell) and their rates. Hillslope patterns of soil C storage were examined in relation to slope position with a hillslope sediment transport model. The average C erosion rates from convex slopes are between 1.4 and 2.7 g C m -2 yr-1 at TV and approximately 8 g C m-2 yr-1 at BD. The C erosional flux is locally as high as 14% of above ground net primary productivity (NPP) at TV and 8% at BD. The convex slopes are net C sinks because NPP likely exceeds respiration by a value equaling the size of C erosion. Eroded soils ultimately accumulate in depositional settings which have residence times on the order of 13kyrs at TV and 5.3kyrs at BD. At TV hollow, 15-24 kg C m-2 of soil C has accumulated at a long-term rate of 1.6-1.9 g C m-2 yr-1 . The present rates of C accumulation were calculated to be 0.3 g C m-2 yr-1 at TV and 0.6 g C m-2 yr-1 at BD. During the hollow infilling, the depositional C inputs have been greater than C accumulation rates, meaning that much of the incoming eroded C is ultimately oxidized to CO2. At both sites, a fraction of the eroded C is exported from the watershed (C of 0.1-0.5 g C m-2 yr-1 at TV and 2 g C m-2 yr-1 at BD). When all hillslope components are integrated, these watersheds are continuous atmospheric C sinks at rates

  5. Comparing Steady State to Time Interval and Non-Steady State Measurements of Resting Metabolic Rate.

    PubMed

    Irving, Chelsea Jayne; Eggett, Dennis L; Fullmer, Susan

    2017-02-01

    The 2 most common methods to determine resting metabolic rate (RMR) with indirect calorimetry are steady state (SS) and time intervals. Studies have suggested SS more accurately reflects RMR, but further research is needed. Our objective was to compare the bias, precision, and accuracy of SS to time intervals and non-SS measurements in a healthy adult population. Seventy-seven participants were measured for 45 minutes using a Quark RMR. Inclusion criteria included healthy participants aged 18-65 years. Pregnant and lactating women were excluded. Paired t tests compared differences between measures. Bland-Altman plots were used to determine precision. Bias occurred if there was a significant difference between the means. Accuracy was determined by counting the number of absolute differences between SS compared with non-SS and time intervals that were <75 calories. Of 77 participants, 84% achieved SS, and 95% achieved SS by minute 30. Most differences between SS and time intervals were statistically but not practically significant. Bland-Altman plots showed SS measurements were generally lower than any time interval, suggesting SS is more indicative of RMR. Non-SS was significantly more biased ( P = .0005), less precise (spread of limits of agreement was 269 calories), and less accurate (65%) than SS. We conclude that non-SS is not equivalent to SS. We also conclude that using 5-minute SS is more indicative of RMR than any time interval that was tested in healthy populations. If SS cannot be achieved, we recommend repeating the measurement.

  6. Non-steady-state photoelectromotive force effect under linear and periodical phase modulation: application to detection of Doppler frequency shift.

    PubMed

    Mansurova, S; Zarate, P Moreno; Rodriguez, P; Stepanov, S; Köber, S; Meerholz, K

    2012-02-01

    Non-steady-state photoelectromotive force effect in the presence of periodical and linear phase shift was investigated both theoretically and experimentally. It was shown that superposition of oscillating and linear movements of the interference pattern leads to the appearance of the sharp peak in the frequency dependence of the photoelectromotive force output current when the frequency of periodical modulation matches the frequency of the linear phase shift. We demonstrated experimentally that this effect can be used for determination of a Doppler frequency shift between signal and reference beam.

  7. An arbitrary lagrangian-eulerian finite element approach to non-steady state fluid flows. Application to mould filling

    SciTech Connect

    Gaston, L.; Glut, B.; Bellet, M.; Chenot, J.L.

    1995-12-31

    This paper presents a two-dimensional lagrangian-eulerian finite element approach of non-steady state Navier-Stokes fluid flows with free surfaces, like those occurring during the mould filling stage in casting processes. The proposed model is based on a mixed velocity-pressure finite element formulation, including an augmented Lagrangian technique and an iterative solver of Uzawa type. Mesh updating is carried out through an arbitrary lagrangian-eulerian method in order to describe properly the free surface evolution. Heat transfer through the fluid flow is solved by a convection-diffusion splitting technique. The efficiency of the method is illustrated on an example of gravity casting.

  8. The Completion of Non-Steady-State Queue Model on The Queue System in Dr. Yap Eye Hospital Yogyakarta

    NASA Astrophysics Data System (ADS)

    Helmi Manggala Putri, Arum; Subekti, Retno; Binatari, Nikenasih

    2017-06-01

    Dr Yap Eye Hospital Yogyakarta is one of the most popular reference eye hospitals in Yogyakarta. There are so many patients coming from other cities and many of them are BPJS (Badan Penyelenggara Jaminan Sosial, Social Security Administrative Bodies) patients. Therefore, it causes numerous BPJS patients were in long queue at counter C of the registration section so that it needs to be analysed using queue system. Queue system analysis aims to give queue model overview and determine its effectiveness measure. The data collecting technique used in this research are by interview and observation. After getting the arrival data and the service data of BPJS patients per 5 minutes, the next steps are investigating steady-state condition, examining the Poisson distribution, determining queue models, and counting the effectiveness measure. Based on the result of data observation on Tuesday, February 16th, 2016, it shows that the queue system at counter C has (M/M/1):(GD/∞/∞) queue model. The analysis result in counter C shows that the queue system is a non-steady-state condition. Three ways to cope a non-steady-state problem on queue system are proposed in this research such as bounding the capacity of queue system, adding the servers, and doing Monte Carlo simulation. The queue system in counter C will reach steady-state if the capacity of patients is not more than 52 BPJS patients or adding one more server. By using Monte Carlo simulation, it shows that the effectiveness measure of the average waiting time for BPJS patients in counter C is 36 minutes 65 seconds. In addition, the average queue length of BPJS patients is 11 patients.

  9. Solvent selection for cyclohexane-cyclohexene-benzene separation by extractive distillation using non-steady-state gas chromatography

    SciTech Connect

    Vega, A.; Diez, F.; Esteban, R.; Coca, J.

    1997-03-01

    The infinite-dilution activity coefficients of cyclohexane, cyclohexene, and benzene in N,N-dimethylformamide, N-methylpyrrolidone, N,N-dimethylacetamide, phenyl acetate, and dimethyl malonate have been determined at temperatures ranging from 40 to 80 C, by non-steady-state gas chromatography. From these data, the limiting selectivity-solvency properties for cyclohexane-benzene, cyclohexene-benzene, and cyclohexane-cyclohexene, in the presence of the aforementioned solvents, are studied, and the solvents tested are considered for the cyclohexane-cyclohexene-benzene separation by extractive distillation. According to the results, N,N-dimethylacetamide seems to be an adequate solvent for the cyclohexane-benzene and cyclohexene-benzene separations. The separation of cyclohexane-cyclohexene is the most difficult, in spite of the difference of boiling points, much higher than for cyclohexane-benzene.

  10. Estimating equations for biomarker based exposure estimation under non-steady-state conditions.

    PubMed

    Bartell, Scott M; Johnson, Wesley O

    2011-06-13

    Unrealistic steady-state assumptions are often used to estimate toxicant exposure rates from biomarkers. A biomarker may instead be modeled as a weighted sum of historical time-varying exposures. Estimating equations are derived for a zero-inflated gamma distribution for daily exposures with a known exposure frequency. Simulation studies suggest that the estimating equations can provide accurate estimates of exposure magnitude at any reasonable sample size, and reasonable estimates of the exposure variance at larger sample sizes.

  11. Non-steady-state transport of superthermal electrons in the plasmasphere

    NASA Technical Reports Server (NTRS)

    Khazanov, George V.; Liemohn, Michael W.; Gombosi, Tamas I.; Nagy, Andrew F.

    1993-01-01

    Numerical solutions to the time-dependent kinetic equation, which describes the transport of superthermal electrons in the splasmasphere between the two conjugate ionospheres, are presented. The model calculates the distribution function as a function of time, field-aligned distance, energy, and pitch-angle. The processes of refilling, depleting, and establishing steady-state conditions of superthermal electrons in the plasmasphere are discussed.

  12. Collisional evolution - an analytical study for the non steady-state mass distribution.

    NASA Astrophysics Data System (ADS)

    Vieira Martins, R.

    1999-05-01

    To study the collisional evolution of asteroidal groups one can use an analytical solution for the self-similar collision cascades. This solution is suitable to study the steady-state mass distribution of the collisional fragmentation. However, out of the steady-state conditions, this solution is not satisfactory for some values of the collisional parameters. In fact, for some values for the exponent of the mass distribution power law of an asteroidal group and its relation to the exponent of the function which describes "how rocks break" the author arrives at singular points for the equation which describes the collisional evolution. These singularities appear since some approximations are usually made in the laborious evaluation of many integrals that appear in the analytical calculations. They concern the cutoff for the smallest and the largest bodies. These singularities set some restrictions to the study of the analytical solution for the collisional equation. To overcome these singularities the author performed an algebraic computation considering the smallest and the largest bodies and he obtained the analytical expressions for the integrals that describe the collisional evolution without restriction on the parameters. However, the new distribution is more sensitive to the values of the collisional parameters. In particular the steady-state solution for the differential mass distribution has exponents slightly different from 11/6 for the usual parameters in the asteroid belt. The sensitivity of this distribution with respect to the parameters is analyzed for the usual values in the asteroidal groups. With an expression for the mass distribution without singularities, one can evaluate also its time evolution. The author arrives at an analytical expression given by a power series of terms constituted by a small parameter multiplied by the mass to an exponent, which depends on the initial power law distribution. This expression is a formal solution for the

  13. Seasonal variations in ectotherm growth rates: Quantifying growth as an intermittent non steady state compensatory process

    USGS Publications Warehouse

    Guarini, J.-M.; Chauvaud, Laurent; Cloern, J.E.; Clavier, J.; Coston-Guarini, J.; Patry, Y.

    2011-01-01

    Generally, growth rates of living organisms are considered to be at steady state, varying only under environmental forcing factors. For example, these rates may be described as a function of light for plants or organic food resources for animals and these could be regulated (or not) by temperature or other conditions. But, what are the consequences for an individual's growth (and also for the population growth) if growth rate variations are themselves dynamic and not steady state? For organisms presenting phases of dormancy or long periods of stress, this is a crucial question. A dynamic perspective for quantifying short-term growth was explored using the daily growth record of the scallop Pecten maximus (L.). This species is a good biological model for ectotherm growth because the shell records growth striae daily. Independently, a generic mathematical function representing the dynamics of mean daily growth rate (MDGR) was implemented to simulate a diverse set of growth patterns. Once the function was calibrated with the striae patterns, the growth rate dynamics appeared as a forced damped oscillation during the growth period having a basic periodicity during two transitory phases (mean duration 43. days) and appearing at both growth start and growth end. This phase is most likely due to the internal dynamics of energy transfer within the organism rather than to external forcing factors. After growth restart, the transitory regime represents successive phases of over-growth and regulation. This pattern corresponds to a typical representation of compensatory growth, which from an evolutionary perspective can be interpreted as an adaptive strategy to coping with a fluctuating environment. ?? 2011 Elsevier B.V.

  14. Non-steady state carbonate recycling and implications for the evolution of atmospheric P CO 2

    NASA Astrophysics Data System (ADS)

    Edmond, John M.; Huh, Youngsook

    2003-11-01

    Most treatments of the Phanerozoic evolution of the carbon dioxide content of the atmosphere (P CO 2) assume a steady state closed system. Release of CO 2 by mantle degassing and by biogenic precipitation of carbonates and their metamorphism in subduction zones balances the consumption by continental aluminosilicate weathering. Small perturbations in this balance bring about changes in P CO 2, but given the small size of the atmospheric CO 2 reservoir relative to the rate of fixation by weathering, mechanisms that maintain this apparently precarious balance dominate current thinking. At present, the Atlantic and Indian oceans are major depocenters of CaCO 3, but subduction of ocean floor and the deposits on it is minimal in these basins. The locus of metamorphic regeneration of CO 2 is restricted to the trenches off Central America. This is due to global asymmetries in the age of crust being subducted, in the distribution of oceanic carbonate productivity, and in the carbonate compensation depth, coupled with the poor preservation of old carbonate sediments. There is no causal relationship between the metamorphic release and weathering uptake of CO 2 and subsequent deposition of carbonate on timescales shorter than a complete cycle of opening and closure of a basin. We hypothesize that the low present-day P CO 2 is maintained by a time lag between: (1) mantle outgassing and metamorphic regeneration related to orogenic events in the geologic past, and (2) consumption driven by recent mountain building in the Tethyan zone and in the Western Americas. If this is true, then at the present 'kinetic minimum' both the terrestrial biosphere and the weathering rates are CO 2 limited. Atmospheric P CO 2 levels are controlled by weathering reactions only at this limit. In epochs of tectonic stability, outgassed CO 2 can accumulate in the atmosphere to very high concentrations with no obvious limit. Thus, as in the past, the current ice age will persist for tens of millions of

  15. Finite element and physical simulations of non-steady state metal flow and temperature distribution in twin roll strip casting

    SciTech Connect

    Shiomi, Masanori; Mori, Kenichiro; Osakada, Kozo

    1995-12-31

    Non-steady-state metal flow and temperature distribution in twin roll strip casting are simulated by the finite element method. In the present simulation, the viscoplastic finite element method is combined with that for heat conduction to calculate the metal flow and the temperature distribution during the casting process. The solid, mushy and liquid phases are assumed to be viscoplastic materials with individual flow stresses. In the temperature analysis, the latent heat due to solidification of the molten metal is taken into account by using the temperature recovery method. Since the metal flow and temperature distribution do not often attain to steady states, they are simulated by the stepwise calculation. To examine the accuracy of the calculated results, physical simulation of plane-strain twin roll strip casting is carried out by use of paraffin wax as a model material. The calculated profiles of the solid region agree qualitatively well with the experimental ones. Twin roll strip casting processes for stainless steel are also simulated. An optimum roll speed for obtaining a strip without a liquid zone under a minimum rolling load is obtained from the results of the simulation.

  16. Evaluation of CETP activity in vivo under non-steady-state conditions: influence of anacetrapib on HDL-TG flux.

    PubMed

    McLaren, David G; Previs, Stephen F; Phair, Robert D; Stout, Steven J; Xie, Dan; Chen, Ying; Salituro, Gino M; Xu, Suoyu S; Castro-Perez, Jose M; Opiteck, Gregory J; Akinsanya, Karen O; Cleary, Michele A; Dansky, Hayes M; Johns, Douglas G; Roddy, Thomas P

    2016-03-01

    Studies in lipoprotein kinetics almost exclusively rely on steady-state approaches to modeling. Herein, we have used a non-steady-state experimental design to examine the role of cholesteryl ester transfer protein (CETP) in mediating HDL-TG flux in vivo in rhesus macaques, and therefore, we developed an alternative strategy to model the data. Two isotopomers ([(2)H11] and [(13)C18]) of oleic acid were administered (orally and intravenously, respectively) to serve as precursors for labeling TGs in apoB-containing lipoproteins. The flux of a specific TG (52:2) from these donor lipoproteins to HDL was used as the measure of CETP activity; calculations are also presented to estimate total HDL-TG flux. Based on our data, we estimate that the peak total postprandial TG flux to HDL via CETP is ∼ 13 mg · h(-1) · kg(-1) and show that this transfer was inhibited by 97% following anacetrapib treatment. Collectively, these data demonstrate that HDL TG flux can be used as a measure of CETP activity in vivo. The fact that the donor lipoproteins can be labeled in situ using well-established stable isotope tracer techniques suggests ways to measure this activity for native lipoproteins in free-living subjects under any physiological conditions. Copyright © 2016 by the American Society for Biochemistry and Molecular Biology, Inc.

  17. Non-steady-state photo-EMF in nanostructured GaN and polypyrrole within porous matrices

    NASA Astrophysics Data System (ADS)

    Bryushinin, M.; Golubev, V.; Kumzerov, Y.; Kurdyukov, D.; Sokolov, I.

    2009-06-01

    We report an experimental investigation of the non-steady-state photoelectromotive force in nanostructured GaN within porous glass and polypyrrole within chrysotile asbestos. The samples are illuminated by an oscillating interference pattern created by two coherent light beams and the alternating current is detected as a response of the material. Dependences of the signal amplitude versus temporal and spatial frequencies, light intensity, and temperature are studied for two wavelengths λ=442 and 532 nm. The conductivity of the GaN composite is measured: σ=(1.1-1.6)×10-10 Ω-1 cm-1 ( λ=442 nm, I 0=0.045-0.19 W/cm2, T=293 K) and σ=(3.5-4.6)×10-10 Ω-1 cm-1 ( λ=532 nm, I 0=2.3 W/cm2, T=249-388 K). The diffusion length of photocarriers in polypyrrole nanowires is also estimated: L D=0.18 μm.

  18. Oxygen isotope signatures of transpired water vapor - the role of isotopic non-steady-state transpiration of Mediterranean cork-oaks (Quercus suber L.)under natural conditions

    NASA Astrophysics Data System (ADS)

    Dubbert, Maren; Piayda, Arndt; Cuntz, Matthias; Werner, Christiane

    2014-05-01

    Oxygen isotope signatures of transpired water vapor (δT) are a powerful tracer of water movement from plants to the global scale, but little is known on short-term variability of δT as direct high-frequency measurements are lacking. A laser spectrometer was coupled to a gas-exchange chamber directly estimating branch-level fluxes and δT to evaluate a modeling approach and investigate the role of isotopic non-steady-state transpiration under natural conditions in distinct seasons in cork-oaks (Quercus suber L.). The isotope signature of transpiration (δT) always deviated from steady-state predictions (ΔT) throughout most of the day even when leaf water at the evaporating sites is near isotopic steady-state. Thus, ΔT is further amplified compared to deviations of leaf water isotopes from steady-state, specifically in dry conditions. High agreement was found for direct estimates and modeled ΔT assuming non-steady-state conditions of leaf-water at the evaporating sites. Strong isoforcing on the atmosphere of transpiration in isotopic non-steady-state imply that short-term variations in δT have likely consequences for large-scale applications, e.g. partitioning of ecosystem evapotranspiration or carbon fluxes using C18O16O, or satellite-based applications.

  19. A non-steady-state condition in sediments at the gas hydrate stability boundary off West Spitsbergen: Evidence for gas hydrate dissociation or just dynamic methane transport

    NASA Astrophysics Data System (ADS)

    Treude, Tina; Krause, Stefan; Bertics, Victoria; Steinle, Lea; Niemann, Helge; Liebetrau, Volker; Feseker, Tomas; Burwicz, Ewa; Krastel, Sebastian; Berndt, Christian

    2015-04-01

    In 2008, a large area with several hundred methane plumes was discovered along the West Spitsbergen continental margin at water depths between 150 and 400 m (Westbrook et al. 2009). Many of the observed plumes were located at the boundary of gas hydrate stability (~400 m water depth). It was speculated that the methane escape at this depth was correlated with gas hydrate destabilization caused by recent increases in water temperatures recorded in this region. In a later study, geochemical analyses of authigenic carbonates and modeling of heat flow data combined with seasonal changes in water temperature demonstrated that the methane seeps were active already prior to industrial warming but that the gas hydrate system nevertheless reacts very sensitive to even seasonal temperature changes (Berndt et al. 2014). Here, we report about a methane seep site at the gas hydrate stability boundary (394 m water depth) that features unusual geochemical profiles indicative for non-steady state conditions. Sediment was recovered with a gravity corer (core length 210 cm) and samples were analyzed to study porewater geochemistry, methane concentration, authigenic carbonates, and microbial activity. Porewater profiles revealed two zones of sulfate-methane transition at 50 and 200 cm sediment depth. The twin zones were confirmed by a double peaking in sulfide, total alkalinity, anaerobic oxidation of methane, and sulfate reduction. d18O values sharply increased from around -2.8 ‰ between 0 and 126 cm to -1.2 ‰ below 126 cm sediment depth. While U/Th isotope measurements of authigenic seep carbonates that were collected from different depths of the core illustrated that methane seepage must be occurring at this site since at least 3000 years, the biogeochemical profiles suggest that methane flux must have been altered recently. By applying a multi-phase reaction-transport model using known initial parameters from the study site (e.g. water depth, temperature profile, salinity

  20. The role of C and Mn at the austenite/pearlite reaction front during non-steady-state pearlite growth in a Fe-C-Mn steel

    DOE PAGES

    Aranda, M. M.; Rementeria, R.; Poplawsky, Jonathan D.; ...

    2015-04-18

    The role of C and Mn during the growth of pearlite under non-steady state conditions is analyzed by comparing the phase compositions of austenite, ferrite and cementite (γ+α+θ) through the use of transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and atom probe tomography (APT) measurements across the austenite/pearlite interface. Furthermore, a local Mn enrichment and C depletion at the austenite/pearlite interface has been measured, which causes a change in the driving force with time during divergent pearlite growth.

  1. Application of a non-steady-state orbit-following Monte-Carlo code to neutron modeling in the MAST spherical tokamak

    NASA Astrophysics Data System (ADS)

    Tani, K.; Shinohara, K.; Oikawa, T.; Tsutsui, H.; McClements, K. G.; Akers, R. J.; Liu, Y. Q.; Suzuki, M.; Ide, S.; Kusama, Y.; Tsuji-Iio, S.

    2016-11-01

    As part of the verification and validation of a newly developed non-steady-state orbit-following Monte-Carlo code, application studies of time dependent neutron rates have been made for a specific shot in the Mega Amp Spherical Tokamak (MAST) using 3D fields representing vacuum resonant magnetic perturbations (RMPs) and toroidal field (TF) ripples. The time evolution of density, temperature and rotation rate in the application of the code to MAST are taken directly from experiment. The calculation results approximately agree with the experimental data. It is also found that a full orbit-following scheme is essential to reproduce the neutron rates in MAST.

  2. The role of C and Mn at the austenite/pearlite reaction front during non-steady-state pearlite growth in a Fe-C-Mn steel

    SciTech Connect

    Aranda, M. M.; Rementeria, R.; Poplawsky, Jonathan D.; Urones-Garrote, E.; Capdevila, Carlos

    2015-04-18

    The role of C and Mn during the growth of pearlite under non-steady state conditions is analyzed by comparing the phase compositions of austenite, ferrite and cementite (γ+α+θ) through the use of transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and atom probe tomography (APT) measurements across the austenite/pearlite interface. Furthermore, a local Mn enrichment and C depletion at the austenite/pearlite interface has been measured, which causes a change in the driving force with time during divergent pearlite growth.

  3. Non-steady-state, non-uniform transpiration rate and leaf anatomy effects on the progressive stable isotope enrichment of leaf water along monocot leaves.

    PubMed

    Ogée, J; Cuntz, M; Peylin, P; Bariac, T

    2007-04-01

    This study focuses on the spatial patterns of transpiration-driven water isotope enrichment (Delta(lw)) along monocot leaves. It has been suggested that these spatial patterns are the result of competing effects of advection and (back-)diffusion of water isotopes along leaf veins and in the mesophyll, but also reflect leaf geometry (e.g. leaf length, interveinal distance) and non-uniform gas-exchange parameters. We therefore developed a two-dimensional model of isotopic leaf water enrichment that incorporates new features, compared with previous models, such as radial diffusion in the xylem, longitudinal diffusion in the mesophyll, non-uniform gas-exchange parameters and non-steady-state effects. The model reproduces well all published measurements of Delta(lw) along monocot leaf blades, except at the leaf tip and given the uncertainties on measurements and model parameters. We show that the longitudinal diffusion in the mesophyll cannot explain the observed reduction in the isotope gradient at the leaf tip. Our results also suggest that the observed differences in Delta(lw) between C(3) and C(4) plants reflect more differences in mesophyll tortuosity rather than in leaf length or interveinal distance. Mesophyll tortuosity is by far the most sensitive parameter and different values are required for different experiments on the same plant species. Finally, using new measurements of non-steady-state, spatially varying leaf water enrichment we show that spatial patterns are in steady state around midday only, just as observed for bulk leaf water enrichment, but can be easily upscaled to the whole leaf level, regardless of their degree of heterogeneity along the leaf.

  4. Steady state or non-steady state? Identifying driving mechanisms of oxygen isotope signatures of leaf transpiration in functionally distinct plant species

    NASA Astrophysics Data System (ADS)

    Dubbert, Maren; Kübert, Angelika; Cuntz, Matthias; Werner, Christiane

    2015-04-01

    observed plant functional types. However, in accordance with our findings in the lab, species specific differences in the leaf water turn over time, significantly influenced the amount of time plants transpired at non-steady state during the day (Dubbert et al., 2013, 2014). Our results emphasize the significance of considering isotopic non-steady state of transpiration and specifically to account for the specific differences of plant species resulting from distinct physiological traits of their leaves when applying isoflux models in ecosystem studies. Dubbert, M; Cuntz, M; Piayda, A; Maguas, C; Werner, C: Partitioning evapotranspiration - Testing the Craig and Gordon model with field measurements of oxygen isotope ratios of evaporative fluxes. J Hydrol (2013) Dubbert, M; Piayda, A; Cuntz, M; Correia, AC; Costa e Silva, F; Pereira, JS; Werner, C: Stable oxygen isotope and flux partitioning demonstrates understory of an oak savanna contributes up to half of ecosystem carbon and water exchange, Frontiers in Plant Science (2014a)

  5. A dynamic, non-steady state approach for paritioning of soil evaporation and plant water use at landscape scales

    NASA Astrophysics Data System (ADS)

    Caylor, K. K.; Wayland, H.; Scanlon, T. M.

    2015-12-01

    Seperate characterization of plant water use and soil evaporation are critical to understanding ecohydrological dynamics of dryland ecosystems and for efficiently managing water in dryland agriculture. The application of stable isotopes as a tracer of these individual fluxes has been constrained by obtaining robust measurements of the isotopic composition of plant water use (δT) that may be scaled up to the ecosystem level. Of particular concern is the fact that the isotopic composition of plant transpiration is usually assumed to be equal to the isotopic composition of xylem water; the so-called steady-state assumption. However, our results and the findings of other published studies strongly suggest that steady state conditions are unrealistic for vegetation in dynamic natural environments. This talk focuses on the development of a simple framework for using relationships between plant transpiration and δT to partition ET at the landscape level. Our method uses a newly-derived empirical relationship between leaf conductance and isotopic fractionation during transpiration to solve a system of equations that can provide solutions to the fraction of total ET composed of bare soil evaporation and transpiration. We apply our method to a time series of evapotranspiration fluxes and near-surface water vapor isotopic composition at a field station in central Kenya and compare the results with partitioning obtained from both steady-state approaches and non-isotopic approaches for partitioning.

  6. Non-steady state mass action dynamics without rate constants: dynamics of coupled reactions using chemical potentials

    NASA Astrophysics Data System (ADS)

    Cannon, William R.; Baker, Scott E.

    2017-10-01

    Comprehensive and predictive simulation of coupled reaction networks has long been a goal of biology and other fields. Currently, metabolic network models that utilize enzyme mass action kinetics have predictive power but are limited in scope and application by the fact that the determination of enzyme rate constants is laborious and low throughput. We present a statistical thermodynamic formulation of the law of mass action for coupled reactions at both steady states and non-stationary states. The formulation uses chemical potentials instead of rate constants. When used to model deterministic systems, the method corresponds to a rescaling of the time dependent reactions in such a way that steady states can be reached on the same time scale but with significantly fewer computational steps. The relationships between reaction affinities, free energy changes and generalized detailed balance are central to the discussion. The significance for applications in systems biology are discussed as is the concept and assumption of maximum entropy production rate as a biological principle that links thermodynamics to natural selection.

  7. Non-steady state mass action dynamics without rate constants: dynamics of coupled reactions using chemical potentials.

    PubMed

    Cannon, William R; Baker, Scott E

    2017-08-16

    Comprehensive and predictive simulation of coupled reaction networks has long been a goal of biology and other fields. Currently, metabolic network models that utilize enzyme mass action kinetics have predictive power but are limited in scope and application by the fact that the determination of enzyme rate constants is laborious and low throughput. We present a statistical thermodynamic formulation of the law of mass action for coupled reactions at both steady states and non-stationary states. The formulation uses chemical potentials instead of rate constants. When used to model deterministic systems, the method corresponds to a rescaling of the time dependent reactions in such a way that steady states can be reached on the same time scale but with significantly fewer computational steps. The relationships between reaction affinities, free energy changes and generalized detailed balance are central to the discussion. The significance for applications in systems biology are discussed as is the concept and assumption of maximum entropy production rate as a biological principle that links thermodynamics to natural selection.

  8. Investigation of a 10 MHz, non-steady state cavity for pulse energy enhancement of ultrafast fiber lasers

    NASA Astrophysics Data System (ADS)

    Breitkopf, Sven; Wunderlich, Stefano; Eidam, Tino; Shestaev, Evgeny; Gottschall, Thomas; Carstens, Henning; Holzberger, Simon; Pupeza, Ioachim; Limpert, Jens; Tünnermann, Andreas

    2016-03-01

    Here, we present a passive 30-m long enhancement cavity that supports a steady-state enhancement of 198, which is the highest enhancement that has ever been reached in such a long cavity. Furthermore, we demonstrate the extraction of a short burst with a total energy of 53.6 μJ employing an acousto-optic modulator (AOM) as a switching device. The cavity was seeded with pulses of 1.49 μJ energy at 10 MHz repetition rate. The individual output coupled pulses showed an energy enhancement of up to 8.5 while the whole burst contained the entire energy of 36 input pulses. In the last section theoretical considerations for the single pulse extraction are presented and briefly discussed.

  9. A Potentially Non-Steady State Pinedale Glacial Maximum, as Indicated by Half Moon Lake Glacial Valley, Wyoming

    NASA Astrophysics Data System (ADS)

    Vacco, D.; Alley, R. B.; Pollard, D.

    2008-12-01

    The greatest extent of glacial ice during MIS2 (Wisconsinan) in the western US may record a short-lived (sub- millennial) cold event rather than an extended Last Glacial Maximum, based on modeling experiments simulating the Pinedale moraines of Half Moon Lake and adjacent valleys near Pinedale, Wyoming. In some locations including the Half Moon Lake valley, Bull Lake (MIS6) moraines lie well down-valley (2 km) of Pinedale moraines, whereas nearby the moraines are much more closely nested (e.g., Fremont Lake valley, 0.5 km). In a simple flow-line glacier model of Half Moon Lake valley, the subglacial topography (steep upper reaches feeding a nearly flat and locally overdeepened region down-glacier) introduces strong hysteresis behavior with abrupt transitions. We have been unable to find any steady conditions that would grow a steady-state glacier ending at the Pinedale moraines. Instead, the ice preferentially terminates either well up-valley, inside modern Half Moon Lake, or advances to the Bull Lake terminal moraines. In the model, advance of the glacier terminus past Half Moon Lake thickens the ice up-valley of the lake, raising more of the glacier into the accumulation zone and causing further advance. If we specify a warming event as the ice reaches the Pinedale moraines, a steady state Pinedale terminus is possible for a narrow range of parameters; smaller warming allows continuing advance, and larger warming triggers retreat. The modeled time-scale for advance from Half Moon Lake to the Pinedale moraines is typically some centuries for climatic perturbations tested, suggesting the hypothesis that the Pinedale maximum at this site records a short-lived event perhaps linked to the Dansgaard-Oeschger or Heinrich oscillations of the North Atlantic. Simulations for the adjacent Fremont Lake valley, in which the Bull Lake terminated up-valley of any prominent flattening of the valley floor, show more-nearly linear dependence of terminus position on snowline

  10. Non-steady state simulation of BOM removal in drinking water biofilters: applications and full-scale validation.

    PubMed

    Hozalski, R M; Bouwer, E J

    2001-01-01

    A biofilter model called "BIOFILT" was used to simulate the removal of biodegradable organic matter (BOM) in full-scale biofilters subjected to a wide range of operating conditions. Parameters that were varied included BOM composition, water temperature (3.0-22.5 degrees C), and biomass removal during backwashing (0-100%). Results from biofilter simulations suggest a strong dependence of BOM removal on BOM composition. BOM with a greater diffusivity or with faster degradation kinetics was removed to a greater extent and also contributed to shorter biofilter start-up times. In addition, in simulations involving mixtures of BOM (i.e. readily degradable and slowly degradable components), the presence of readily degradable substrate significantly enhanced the removal of slowly degradable material primarily due to the ability to maintain greater biomass levels in the biofilters. Declines in pseudo-steady state BOM removal were observed as temperature was decreased from 22.5 to 3 degrees C and the magnitude of the change was significantly affected by BOM composition. However, significant removals of BOM are possible at low temperatures (3-6 degrees C). Concerning the impact of backwashing on biofilter performance, BOM removal was not affected by backwash resulting in biomass removals of 60% or less. This suggests that periodic backwashing should not significantly impact biofilter performance as observed biomass removals from full-scale biofilters were negligible. In general, the simulation results were in good qualitative and quantitative agreement with experimental results obtained from full-scale biofilters.

  11. Contributions of evaporation, isotopic non-steady state transpiration and atmospheric mixing on the delta18O of water vapour in Pacific Northwest coniferous forests.

    PubMed

    Lai, Chun-Ta; Ehleringer, James R; Bond, Barbara J; Paw U, Kyaw Tha

    2006-01-01

    Changes in the 2H and 18O of atmospheric water vapour provide information for integrating aspects of gas exchange within forest canopies. In this study, we show that diurnal fluctuations in the oxygen isotope ratio (delta 18O) as high as 4% per hundred were observed for water vapour (delta (18)Ovp) above and within an old-growth coniferous forest in the Pacific Northwest region of the United States. Values of delta 18Ovp decreased in the morning, reached a minimum at midday, and recovered to early-morning values in the late afternoon, creating a nearly symmetrical diurnal pattern for two consecutive summer days. A mass balance budget was derived and assessed for the 18O of canopy water vapour over a 2-d period by considering the 18O-isoflux of canopy transpiration, soil evaporation and the air entering the canopy column. The budget was used to address two questions: (1) do delta 18O values of canopy water vapour reflect the biospheric influence, or are such signals swamped by atmospheric mixing? and (2) what mechanisms drive temporal variations of delta 18Ovp? Model calculations show that the entry of air into the canopy column resulted in an isotopically depleted 18O-isoflux in the morning of day 1, causing values of delta 18Ovp, to decrease. An isotopically enriched 18O-isoflux resulting from transpiration then offset this decreased delta 18Ovp later during the day. Contributions of 18O-isoflux from soil evaporation were relatively small on day 1 but were more significant on day 2, despite the small H2(16)O fluxes. From measurements of leaf water volume and sapflux, we determined the turnover time of leaf water in the needles of Douglas-fir trees as approximately 11 h at midday. Such an extended turnover time suggests that transpiration may not have occurred at the commonly assumed isotopic steady state. We tested a non-steady state model for predicting delta 18O of leaf water. Our model calculations show that assuming isotopic steady state increased isoflux of

  12. iRhom2 regulates CSF1R cell surface expression and non-steady state myelopoiesis in mice.

    PubMed

    Qing, Xiaoping; Rogers, Lindsay; Mortha, Arthur; Lavin, Yonit; Redecha, Patricia; Issuree, Priya D; Maretzky, Thorsten; Merad, Miriam; McIlwain, David; Mak, Tak W; Overall, Christopher M; Blobel, Carl P; Salmon, Jane E

    2016-12-01

    CSF1R (colony stimulating factor 1 receptor) is the main receptor for CSF1 and has crucial roles in regulating myelopoeisis. CSF1R can be proteolytically released from the cell surface by ADAM17 (A disintegrin and metalloprotease 17). Here, we identified CSF1R as a major substrate of ADAM17 in an unbiased degradomics screen. We explored the impact of CSF1R shedding by ADAM17 and its upstream regulator, inactive rhomboid protein 2 (iRhom2, gene name Rhbdf2), on homeostatic development of mouse myeloid cells. In iRhom2-/- mice, we found constitutive accumulation of membrane-bound CSF1R on myeloid cells at steady state, although cell numbers of these populations were not altered. However, in the context of mixed bone marrow (BM) chimera, under competitive pressure, iRhom2-/- BM progenitor-derived monocytes, tissue macrophages and lung DCs showed a repopulation advantage over those derived from wild-type (WT) BM progenitors, suggesting enhanced CSF1R signaling in the absence of iRhom2. In vitro experiments indicate that iRhom2-/- Lin(-) SCA-1(+) c-Kit(+) (LSKs) cells, but not granulocyte-macrophage progenitors (GMPs), had faster growth rates than WT cells in response to CSF1. Our results shed light on an important role of iRhom2/ADAM17 pathway in regulation of CSF1R shedding and repopulation of monocytes, macrophages and DCs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. A First-Principles Multi-phase Equation of State of Carbon under Extreme Conditions

    SciTech Connect

    Correa, A A; Benedict, X L; Young, D A; Schwegler, E; Bonev, S A

    2008-02-01

    We describe the construction of a multi-phase equation of state for carbon at extreme pressures based on ab initio electronic structure calculations of two solid phases (diamond and BC8) and the liquid. Solid-phase free energies are built from knowledge of the cold curves and phonon calculations, together with direct ab initio molecular dynamics calculations of the equation of state, which are used to extract anharmonic corrections to the phonon free energy. The liquid free energy is constructed based on results from molecular dynamics calculations and constraints determined from previously calculated melting curves, assuming a simple solid-like free energy model. The resulting equation of state is extended to extreme densities and temperatures with a Thomas Fermi-based free energy model. Comparisons to available experimental results are discussed.

  14. Evaluation of CETP activity in vivo under non-steady-state conditions: influence of anacetrapib on HDL-TG flux[S

    PubMed Central

    McLaren, David G.; Previs, Stephen F.; Phair, Robert D.; Stout, Steven J.; Xie, Dan; Chen, Ying; Salituro, Gino M.; Xu, Suoyu S.; Castro-Perez, Jose M.; Opiteck, Gregory J.; Akinsanya, Karen O.; Cleary, Michele A.; Dansky, Hayes M.; Johns, Douglas G.; Roddy, Thomas P.

    2016-01-01

    Studies in lipoprotein kinetics almost exclusively rely on steady-state approaches to modeling. Herein, we have used a non-steady-state experimental design to examine the role of cholesteryl ester transfer protein (CETP) in mediating HDL-TG flux in vivo in rhesus macaques, and therefore, we developed an alternative strategy to model the data. Two isotopomers ([2H11] and [13C18]) of oleic acid were administered (orally and intravenously, respectively) to serve as precursors for labeling TGs in apoB-containing lipoproteins. The flux of a specific TG (52:2) from these donor lipoproteins to HDL was used as the measure of CETP activity; calculations are also presented to estimate total HDL-TG flux. Based on our data, we estimate that the peak total postprandial TG flux to HDL via CETP is ∼13 mg·h−1·kg−1 and show that this transfer was inhibited by 97% following anacetrapib treatment. Collectively, these data demonstrate that HDL TG flux can be used as a measure of CETP activity in vivo. The fact that the donor lipoproteins can be labeled in situ using well-established stable isotope tracer techniques suggests ways to measure this activity for native lipoproteins in free-living subjects under any physiological conditions. PMID:26658238

  15. Non-steady-state measurement of in vivo radioligand binding with positron emission tomography: specificity analysis and comparison with in vitro binding

    SciTech Connect

    Perlmutter, J.S.; Moerlein, S.M.; Hwang, D.R.; Todd, R.D. )

    1991-05-01

    We previously have developed a non-steady-state method for in vivo measurement of radioligand-receptor binding in brain using positron emission tomography (PET) and {sup 18}F-spiperone ({sup 18}F-SP). This method has proven to be highly sensitive to the detection of decreases in the apparent number of available specific binding sites. The purposes of this investigation are to demonstrate the specificity of this PET assay and compare findings to in vitro binding assays. Three to six studies were performed in each of five male baboons. Each animal was pretreated with either ketanserin (serotonergic (S2)), eticlopride (dopaminergic (D2)), or unlabeled SP to compete with {sup 18}F-SP for specific binding sites. Sequential PET scans and arterial-blood samples were collected for 3 hr after intravenous injection of {sup 18}F-SP. Data were analyzed with a three-compartment model that considered the accumulation of radiolabeled metabolites in arterial blood. Five baboons were killed, and radioligand-receptor binding in vitro was measured by homogenate techniques. There was no detectable in vitro or in vivo specific binding of SP in cerebellum. The specific binding of SP in striatal tissue in vitro was approximately 74% to D2 sites and 26% to S2 sites, whereas ketanserin displaced all specific binding in frontal cortex. In close agreement, specific binding measured in vivo with PET revealed that 68% of apparent striatal binding could be blocked by pretreatment with eticlopride, and 34% by ketanserin.

  16. Modeling non-steady state radioisotope transport in the vadose zone - A case study using uranium isotopes at Peña Blanca, Mexico

    NASA Astrophysics Data System (ADS)

    Ku, T. L.; Luo, S.; Goldstein, S. J.; Murrell, M. T.; Chu, W. L.; Dobson, P. F.

    2009-10-01

    Current models using U- and Th-series disequilibria to study radioisotope transport in groundwater systems mostly consider a steady-state situation. These models have limited applicability to the vadose zone (UZ) where the concentration and migratory behavior of radioisotopes in fluid are often transitory. We present here, as a first attempt of its kind, a model simulating the non-steady state, intermittent fluid transport in vadose layers. It provides quantitative constraints on in-situ migration of dissolved and colloidal radioisotopes in terms of retardation factor and rock-water interaction (or water transit) time. For uranium, the simulation predicts that intermittent flushing in the UZ leads to a linear relationship between reciprocal U concentration and 234U/ 238U ratio in percolating waters, with the intercept and slope bearing information on the rates of dissolution and α-recoil of U isotopes, respectively. The general validity of the model appears to be borne out by the measurement of uranium isotopes in UZ waters collected at various times over a period during 1995-2006 from a site in the Peña Blanca mining district, Mexico, where the Nopal I uranium deposit is located. Enhanced 234U/ 238U ratios in vadose-zone waters resulting from lengthened non-flushing time as prescribed by the model provide an interpretative basis for using 234U/ 238U in cave calcites to reconstruct the regional changes in hydrology and climate. We also provide a theoretical account of the model's potential applications using radium isotopes.

  17. Modeling non-steady state radioisotope transport in the vadose zone--A case study using uranium isotopes at Pena Blanca, Mexico

    SciTech Connect

    Ku, T. L.; Luo, S.; Goldstein, S. J.; Murrell, M. T.; Chu, W. L.; Dobson, P. F.

    2009-06-01

    Current models using U- and Th-series disequilibria to study radioisotope transport in groundwater systems mostly consider a steady-state situation. These models have limited applicability to the vadose zone (UZ) where the concentration and migratory behavior of radioisotopes in fluid are often transitory. We present here, as a first attempt of its kind, a model simulating the non-steady state, intermittent fluid transport in vadose layers. It provides quantitative constraints on in-situ migration of dissolved and colloidal radioisotopes in terms of retardation factor and rock-water interaction (or water transit) time. For uranium, the simulation predicts that intermittent flushing in the UZ leads to a linear relationship between reciprocal U concentration and {sup 234}U/{sup 238}U ratio in percolating waters, with the intercept and slope bearing information on the rates of dissolution and {alpha}-recoil of U isotopes, respectively. The general validity of the model appears to be borne out by the measurement of uranium isotopes in UZ waters collected at various times over a period during 1995-2006 from a site in the Pena Blanca mining district, Mexico, where the Nopal I uranium deposit is located. Enhanced {sup 234}U/{sup 238}U ratios in vadose-zone waters resulting from lengthened non-flushing time as prescribed by the model provide an interpretative basis for using {sup 234}U/{sup 238}U in cave calcites to reconstruct the regional changes in hydrology and climate. We also provide a theoretical account of the model's potential applications using radium isotopes.

  18. Shock Equation of State of Multi-Phase Epoxy-Based Composite (Al-MnO2-Epoxy)

    DTIC Science & Technology

    2010-10-01

    There are several studies in the literature regarding the equation of state of alumina-epoxy composites. Although these single component systems...paper presents the shock equation of state results on a multi-phase composite Al-MnO2-epoxy. Equation of state experiments were conducted using three...The experimental equation of state data is compared to volume averaged and mesoscale mixture models.

  19. Rubisco activase is a key regulator of non-steady-state photosynthesis at any leaf temperature and, to a lesser extent, of steady-state photosynthesis at high temperature.

    PubMed

    Yamori, Wataru; Masumoto, Chisato; Fukayama, Hiroshi; Makino, Amane

    2012-09-01

    The role of Rubisco activase in steady-state and non-steady-state photosynthesis was analyzed in wild-type (Oryza sativa) and transgenic rice that expressed different amounts of Rubisco activase. Below 25°C, the Rubisco activation state and steady-state photosynthesis were only affected when Rubisco activase was reduced by more than 70%. However, at 40°C, smaller reductions in Rubisco activase content were linked to a reduced Rubisco activation state and steady-state photosynthesis. As a result, overexpression of maize Rubisco activase in rice did not lead to an increase of the Rubisco activation state, nor to an increase in photosynthetic rate below 25°C, but had a small stimulatory effect at 40°C. On the other hand, the rate at which photosynthesis approached the steady state following an increase in light intensity was rapid in Rubisco activase-overexpressing plants, intermediate in the wild-type, and slowest in antisense plants at any leaf temperature. In Rubisco activase-overexpressing plants, Rubisco activation state at low light was maintained at higher levels than in the wild-type. Thus, rapid regulation by Rubisco activase following an increase in light intensity and/or maintenance of a high Rubisco activation state at low light would result in a rapid increase in Rubisco activation state and photosynthetic rate following an increase in light intensity. It is concluded that Rubisco activase plays an important role in the regulation of non-steady-state photosynthesis at any leaf temperature and, to a lesser extent, of steady-state photosynthesis at high temperature.

  20. Magnetization Transfer Imaging of Rat Brain under Non-steady-state Conditions. Contrast Prediction Using a Binary Spin-Bath Model and a Super-Lorentzian Lineshape

    NASA Astrophysics Data System (ADS)

    Quesson, Bruno; Thiaudière, Eric; Delalande, Christophe; Chateil, Jean-Francois; Moonen, Chrit T. W.; Canioni, Paul

    1998-02-01

    Magnetization transfer contrast imaging using turbo spin echo and continuous wave off-resonance irradiation was carried out on rat brainin vivoat 4.7 T. By systematically varying the off-resonance irradiation power and the offset-frequency, the signal intensities obtained under steady-state for both transverse and longitudinal magnetization were successfully analyzed with a simple binary spin-bath model taking into account a free water compartment and a pool of protons with restricted motions bearing a super-Lorentzian lineshape. Due to important RF power deposition, such experimental conditions are not practical for routine imaging on humans. An extension of the model was derived to describe the system for shorter off-resonance pulse duration, i.e., when the longitudinal magnetization of the free protons has not reached a steady-state. Data sets obtained for three regions of interest, namely thecorpus callosum,the basal ganglia, and the temporal lobe, were correctly interpreted for off-resonance pulse durations varying from 0.3 to 3 s. The parameter sets obtained from the calculations made it possible to predict the contrast between the different regions as a function of the pulse power, the offset frequency, and pulse duration. Such an approach could be extended to contrast prediction for human brain at 1.5 T.

  1. Non-steady-state exhumation of the Higher Himalaya, N.W. India: insights from a combined isotopic and sedimentological approach.

    NASA Astrophysics Data System (ADS)

    Najman, Y.; Pringle, M.; Bickle, M.; Garzanti, E.; Burbank, D.; Ando, S.; Brozovic, N.

    2003-04-01

    Quantitative constraints to the exhumation of an orogen can be gained from the sediment record of the mountain belt's erosion. Our approach uses the determination of lag times, defined as the difference between a detrital mineral's isotopic age, which it starts to acquire at depth in the source region, and its host sediment depositional age. We use Ar-Ar ages of High-Himalayan derived detrital micas from a 20--5 Ma magnetostratigraphically dated section in the foreland basin of NW India to constrain exhumation of the Higher Himalaya. This work includes our previously published dataset and interpretations for the 20--13 Ma part of the sediment section (White et al., EPSL 2002), and new data for the 12--5 Ma sediment record. The data show zero lag times, indicative of rapid exhumation of the High Himalaya, between 20--17 Ma. After this time the lag times increase and there is no further evidence of rapid exhumation. Continued denudation to higher metamorphic levels is indicated by progressive appearance of index minerals in the sediment succession; first garnet (Najman &Garzanti 2000), followed by staurolite at 20 Ma, kyanite by 12 Ma and sillimanite at ca. 8 Ma. Calculation of exhumation rates from lag times can be determined using a thermal model which allows for advective modification of the geotherm. An exhumation rate of up to 5 mm/yr is calculated from the rapidly exhuming micas, slowing to <1mm/yr for the more slowly exhuming micas. This transition at 17 Ma corresponds to the first time that thrusting propagates into the footwall of the MCT, indicating the onset of a period of frontal accretion in the orogen. Exhumational steady state in an orogen, as defined by Willett &Brandon (Geology 2002), can be recognised in the sediment record as periods when lag times remain constant through time (Bernet et al., Geology 2001). Our data show that lag times do not remain constant upsection. Therefore, there is no evidence that the High Himalaya was in exhumational

  2. A multi-phase Equation of State diagnostic applied to the study of shock loaded tin

    NASA Astrophysics Data System (ADS)

    Shenton-Taylor, Caroline; Glauser, Antony; Ota, Thomas; Price, Ed

    2011-06-01

    The accurate detection of shock driven material phase transitions demands a multiple diagnostic capable of simultaneously measuring temperature, emissivity, pressure and velocity. By combining optical pyrometry with reflectivity based emissivity diagnostics we report shock loaded tin temperatures from 820 K to 1780 K with associated probable errors down to +/- 12.8 K. In addition simultaneous Class 4 laser heterodyne velocimetry recorded the tin surface velocity as viewed through a LiF anvil. Constraining the tin pressure with lithium fluoride generated microsecond experiment time durations; thermal diffusion models identified the tin/glue/LiF layer as advantageous for temperature measurement. Across a range of pressures, the emissivity corrected temperature data were found to be well aligned with a single tin Equation of State model. AWE Crown Owned Copyright (2011).

  3. Part-2: Analytical Expressions of Concentrations of Glucose, Oxygen, and Gluconic Acid in a Composite Membrane for Closed-Loop Insulin Delivery for the Non-steady State Conditions.

    PubMed

    Mehala, N; Rajendran, L; Meena, V

    2017-02-01

    A mathematical model developed by Abdekhodaie and Wu (J Membr Sci 335:21-31, 2009), which describes a dynamic process involving an enzymatic reaction and diffusion of reactants and product inside glucose-sensitive composite membrane has been discussed. This theoretical model depicts a system of non-linear non-steady state reaction diffusion equations. These equations have been solved using new approach of homotopy perturbation method and analytical solutions pertaining to the concentrations of glucose, oxygen, and gluconic acid are derived. These analytical results are compared with the numerical results, and limiting case results for steady state conditions and a good agreement is observed. The influence of various kinetic parameters involved in the model has been presented graphically. Theoretical evaluation of the kinetic parameters like the maximal reaction velocity (V max) and Michaelis-Menten constants for glucose and oxygen (K g and K ox) is also reported. This predicted model is very much useful for designing the glucose-responsive composite membranes for closed-loop insulin delivery.

  4. Refined non-steady-state gas-liquid chromatography for accurate determination of limiting activity coefficients of volatile organic compounds in water: application to C(1)-C(5) alkanols.

    PubMed

    Dohnal, Vladimír; Ondo, Daniel

    2005-12-02

    This work presents a new refined method of non-steady-state gas-liquid chromatography (NSGLC) suitable for determination of limiting activity coefficients of VOCs in water. The modifications done to the original NSGLC theory address its elements (as the solvent elution rate from the column) as well as other new aspects. The experimental procedure is modified accordingly, taking advantage of current technical innovations. The refined method is used systematically to determine limiting activity coefficients (Henry's law constants, limiting relative volatilities) of isomeric C(1)-C(5) alkanols in water at 328.15K. Applied to retention data measured in this work the refined NSGLC theory gives values 15-20% higher than those from the original approach. The values obtained by the refined NSGLC method agree very well (typically within 3%) with the most reliable literature data determined by other experimental techniques, this result verifying thus the correct performance of the refined method and demonstrating an improved accuracy of the new results.

  5. Non-steady Reconnection in Global Simulations of Magnetosphere Dynamics

    NASA Technical Reports Server (NTRS)

    Kuznetsova, M. M.; Hesse, M.; Sibeck, D.; Rastaetter, L.; Toth, G.; Ridley, A.

    2008-01-01

    To analyze the non-steady magnetic reconnection during quasi-steady solar wind driving we employed high resolution global MHD model BATSRUS with non-MHD corrections in diffusion regions around the reconnection sites. To clarify the role of small-scale non-MHD effects on the global magnetospheric dynamic we performed simulations with different models of dissipation. We found that magnetopause surface is not in steady state even during extended periods of steady solar wind conditions. The so-called tilted reconnection lines become unstable due to formation of pressure bubbles, strong core field flux tubes, vortices, and traveling magnetic field cavities. Non-steady dayside reconnection results in formation of flux tubes with bended axis magnetically connecting magnetic field cavities generated at flanks and strong core segments formed near the subsolar region. We found that the rate of magnetic flux loading to the tail lobes is not very sensitive to the dissipation mechanism and details of the dayside reconnection. On the other hand the magnetotail reconnection rate, the speed of the reconnection site retreat and the global magnetotail dynamics strongly depend on the model of dissipation. THEMIS and Cluster observations are consistent with signatures predicted by simulations.

  6. Non-steady wind turbine response to daytime atmospheric turbulence

    NASA Astrophysics Data System (ADS)

    Nandi, Tarak N.; Herrig, Andreas; Brasseur, James G.

    2017-03-01

    Relevant to drivetrain bearing fatigue failures, we analyse non-steady wind turbine responses from interactions between energy-dominant daytime atmospheric turbulence eddies and the rotating blades of a GE 1.5 MW wind turbine using a unique dataset from a GE field experiment and computer simulation. Time-resolved local velocity data were collected at the leading and trailing edges of an instrumented blade together with generator power, revolutions per minute, pitch and yaw. Wind velocity and temperature were measured upwind on a meteorological tower. The stability state and other atmospheric conditions during the field experiment were replicated with a large-eddy simulation in which was embedded a GE 1.5 MW wind turbine rotor modelled with an advanced actuator line method. Both datasets identify three important response time scales: advective passage of energy-dominant eddies (≈25-50 s), blade rotation (once per revolution (1P), ≈3 s) and sub-1P scale (<1 s) response to internal eddy structure. Large-amplitude short-time ramp-like and oscillatory load fluctuations result in response to temporal changes in velocity vector inclination in the aerofoil plane, modulated by eddy passage at longer time scales. Generator power responds strongly to large-eddy wind modulations. We show that internal dynamics of the blade boundary layer near the trailing edge is temporally modulated by the non-steady external flow that was measured at the leading edge, as well as blade-generated turbulence motions. This article is part of the themed issue 'Wind energy in complex terrains'.

  7. Non-steady wind turbine response to daytime atmospheric turbulence.

    PubMed

    Nandi, Tarak N; Herrig, Andreas; Brasseur, James G

    2017-04-13

    Relevant to drivetrain bearing fatigue failures, we analyse non-steady wind turbine responses from interactions between energy-dominant daytime atmospheric turbulence eddies and the rotating blades of a GE 1.5 MW wind turbine using a unique dataset from a GE field experiment and computer simulation. Time-resolved local velocity data were collected at the leading and trailing edges of an instrumented blade together with generator power, revolutions per minute, pitch and yaw. Wind velocity and temperature were measured upwind on a meteorological tower. The stability state and other atmospheric conditions during the field experiment were replicated with a large-eddy simulation in which was embedded a GE 1.5 MW wind turbine rotor modelled with an advanced actuator line method. Both datasets identify three important response time scales: advective passage of energy-dominant eddies (≈25-50 s), blade rotation (once per revolution (1P), ≈3 s) and sub-1P scale (<1 s) response to internal eddy structure. Large-amplitude short-time ramp-like and oscillatory load fluctuations result in response to temporal changes in velocity vector inclination in the aerofoil plane, modulated by eddy passage at longer time scales. Generator power responds strongly to large-eddy wind modulations. We show that internal dynamics of the blade boundary layer near the trailing edge is temporally modulated by the non-steady external flow that was measured at the leading edge, as well as blade-generated turbulence motions.This article is part of the themed issue 'Wind energy in complex terrains'.

  8. Implementation of a complex multi-phase equation of state for cerium and its correlation with experiment

    SciTech Connect

    Cherne, Frank J; Jensen, Brian J; Elkin, Vyacheslav M

    2009-01-01

    The complexity of cerium combined with its interesting material properties makes it a desirable material to examine dynamically. Characteristics such as the softening of the material before the phase change, low pressure solid-solid phase change, predicted low pressure melt boundary, and the solid-solid critical point add complexity to the construction of its equation of state. Currently, we are incorporating a feedback loop between a theoretical understanding of the material and an experimental understanding. Using a model equation of state for cerium we compare calculated wave profiles with experimental wave profiles for a number of front surface impact (cerium impacting a plated window) experiments. Using the calculated release isentrope we predict the temperature of the observed rarefaction shock. These experiments showed that the release state occurs at different magnitudes, thus allowing us to infer where dynamic {gamma} - {alpha} phase boundary is.

  9. Promoting state health department evidence-based cancer and chronic disease prevention: a multi-phase dissemination study with a cluster randomized trial component

    PubMed Central

    2013-01-01

    Background Cancer and other chronic diseases reduce quality and length of life and productivity, and represent a significant financial burden to society. Evidence-based public health approaches to prevent cancer and other chronic diseases have been identified in recent decades and have the potential for high impact. Yet, barriers to implement prevention approaches persist as a result of multiple factors including lack of organizational support, limited resources, competing emerging priorities and crises, and limited skill among the public health workforce. The purpose of this study is to learn how best to promote the adoption of evidence based public health practice related to chronic disease prevention. Methods/design This paper describes the methods for a multi-phase dissemination study with a cluster randomized trial component that will evaluate the dissemination of public health knowledge about evidence-based prevention of cancer and other chronic diseases. Phase one involves development of measures of practitioner views on and organizational supports for evidence-based public health and data collection using a national online survey involving state health department chronic disease practitioners. In phase two, a cluster randomized trial design will be conducted to test receptivity and usefulness of dissemination strategies directed toward state health department chronic disease practitioners to enhance capacity and organizational support for evidence-based chronic disease prevention. Twelve state health department chronic disease units will be randomly selected and assigned to intervention or control. State health department staff and the university-based study team will jointly identify, refine, and select dissemination strategies within intervention units. Intervention (dissemination) strategies may include multi-day in-person training workshops, electronic information exchange modalities, and remote technical assistance. Evaluation methods include pre

  10. Process tomography applied to multi-phase flow measurement

    NASA Astrophysics Data System (ADS)

    Dyakowski, T.

    1996-03-01

    This paper presents the state of the art in measuring multi-phase flows by using tomographic techniques. The results presented show a wide range of industrial applications of process tomography from the nuclear and chemical to the food industry. This is illustrated by examples of the application of various tomographic sensors to the measurement of geometric or kinematic parameters of multi-phase flows. An application of process tomography for the validation of computational fluid dynamic models and the possibility of constructing a flowmeter for multi-phase flow are addressed.

  11. A transient kinetic study of the mechanism of the NO/C{sub 3}H{sub 6}/O{sub 2} reaction over Pt-SiO{sub 2} catalysts. Part 1: Non-steady-state transient switching experiments

    SciTech Connect

    Burch, R.; Sullivan, J.A.

    1999-03-10

    The mechanism of the reduction of NO by C{sub 3}H{sub 6} under lean-burn conditions on a Pt catalyst has been investigated using transient techniques. Switches of O{sub 2} and C{sub 3}H{sub 6} into and out of a stream of C{sub 3}H{sub 6}/NO/O{sub 2} over a 1% Pt-SiO{sub 2} catalyst were performed at temperatures above and below that at which maximum NO{sub x} conversion is seen, i.e., 220 and 250 C. The transient reaction studies show that at low temperatures the Pt is reduced and covered with carbonaceous material while at high temperatures it is oxidized and covered with O{sub ads} species. Rapid changes in the surface oxidation state of the Pt are observed after the removal or reintroduction of the O{sub 2} and C{sub 3}H{sub 6} reactants at all temperatures. The results of each individual switch are discussed in terms of a mechanism for NO{sub x} reduction and alkene oxidation over Pt-based catalysts in the lean-No{sub x} process. The conclusions are found to be consistent with the previous model for the NO{sub x} reduction model. It is proposed that at low temperatures the NO reacts by decomposition on reduced Pt sites, whereas at high temperatures it reacts with O{sub ads} on oxidized Pt to form NO{sub 2}.

  12. Meteorites, Continents, Heat, and Non-Steady State Geodynamics

    NASA Astrophysics Data System (ADS)

    White, W. M.; Morgan, J. P.

    2011-12-01

    Previous geochemical estimates of terrestrial radiogenic heat production were based on the assumption that refractory lithophile elements, such as the REE, U, and Th, are present in the Earth in chondritic relative proportions (the 'modified chondritic Earth' model, e.g., McDonough & Sun, Chem. Geol., 120: 223, 1995). However, 142Nd/144Nd ratios in modern terrestrial materials are 10 and 18 ppm higher than in enstatite and ordinary chondrites, respectively. One explanation is that the Sm/Nd ratio in the Earth, or at least the observable part of it, is 3 to 6% higher than chondritic, implying the Earth is non-chondritic, even for refractory lithophile elements. The most likely explanation is that a low Sm/Nd igneous protocrust formed as the Earth accreted and was lost through collisional erosion. A protocrust 3 to 6% enriched in Nd relative to Sm would have been even more strongly enriched in the more highly incompatible elements K, U, and Th. Calculations based on a model of protocrust formation and collisional erosion (O'Neill, & Palme, Phil. Trans. R. Soc. A366: 4205, 2008) that satisfy both Sm-Nd and Lu-Hf isotopic constraints imply U and Th concentrations in the bulk silicate Earth (BSE) that are 20 to 40% lower than in the 'modified chondritic Earth' model. Assuming a K/U = 13800 for the BSE, the K concentration is 10 to 30% lower than previously believed. This corresponds to a terrestrial heat production of 3.0 to 3.9 pW/kg or 11.9 to 15.8 TW. At the high end, these estimates are in excellent agreement with those of Lyubetskaya & Korenaga (JGR, 112: B03211, 2007), but are much lower than the 20 TW value derived from the 'modified chondritic Earth' model. Of this, some 5 to 10 TW of heat production is in the continental crust, leaving ≤10 TW of heat production in the mantle. For comparison, recent estimates of U, Th, and K in the depleted mantle imply heat production in the range of 0.7-1.0 pW/kg; if the depleted mantle occupies the entire mantle, this translates into mantle heat production of 3-4 TW. Mantle heat losses are roughly 28 TW, hence the mantle Urey ratio (ratio of heat production to heat loss) is <0.3. If this mantle energy loss is supplied by secular cooling, it implies a cooling rate of >120°C/Ga after accounting for adiabatic contraction, much higher than petrological and geophysical estimates. At present, heat generated by viscous dissipation of the gravitational energy released by sinking slabs is 12 to 15 TW, and <5 TW is released by the cooling core. Of this power, only a fraction, 3.8 to 4.8 TW, can produce new gravitational power to drive convection and plate tectonics. Thus gravitational energy is being consumed at a much higher rate than it is being regenerated through radioactive heating and viscous dissipation. These observations a clear indication that the present rate of slab subduction is not sustainable and that the mantle is in a phase of faster than normal plate motion. The Cretaceous superplume event may have marked the beginning of an episode of faster than average heat loss and seafloor spreading that continues to the present.

  13. Thermodynamic Optimization of an Electric Circuit as a Non-steady Energy Converter

    NASA Astrophysics Data System (ADS)

    Valencia-Ortega, Gabriel; Arias-Hernandez, Luis-Antonio

    2017-04-01

    Electric circuits with transient elements can be good examples of systems where non-steady irreversible processes occur; so in the same way as a steady-state energy converter, we use the formal construction of the first-order irreversible thermodynamic to describe the energetics of these circuits. In this case, we propose an isothermal model of two meshes with transient and passive elements, besides containing two voltage sources (which can be functions of time); this is a non-steady energy converter model. Through the Kirchhoff equations, we can write the circuit phenomenological equations. Then, we apply an integral transformation to linearize the dynamic equations and rewrite them in algebraic form, but in the frequency space. However, the same symmetry for steady states appears (cross effects). Thus, we can study the energetic performance of this converter model by means of two parameters: the "force ratio" and the "coupling degree". Furthermore, it is possible to obtain characteristic functions (dissipation function, power output, efficiency, etc.). They allow us to establish a simple optimal operation regime of this energy converter. As an example, we obtain the converter behavior for the maximum efficient power regime.

  14. Multi-Phase Driver Education Teaching Guide.

    ERIC Educational Resources Information Center

    Hurst-Euless-Bedford Independent School District, Hurst, TX.

    For use in planning and conducting functional multi-phase driver education programs, this teacher's guide consists of four phases of instruction: classroom activities, simulated application, in-car range practice, and in-car public practice. Contents are divided into three instructional sections, with the first combining the classroom activities…

  15. Non-steady interaction of plasma with aircraft in its near wake region

    NASA Astrophysics Data System (ADS)

    Hu, Tao-Ping; Luo, Qing

    2007-01-01

    Non-steady interactions between plasmas and aircraft in its near wake region are investigated in detail. Under the non-static limit, a set of equations that describe these interactions are obtained. The results of the numerical simulation show that the cavitons of transverse plasmas are excited and density cavitons appear when the envelope of plasma becomes sufficiently intensive. This is very important for detecting the moving body that has a `stealth' characteristic.

  16. Identification of Steady and Non-Steady Gait of Humanexoskeleton Walking System

    NASA Astrophysics Data System (ADS)

    Żur, K. K.

    2013-08-01

    In this paper a method of analysis of exoskeleton multistep locomotion was presented by using a computer with the preinstalled DChC program. The paper also presents a way to analytically calculate the ",motion indicator", as well as the algorithm calculating its two derivatives. The algorithm developed by the author processes data collected from the investigation and then a program presents the obtained final results. Research into steady and non-steady multistep locomotion can be used to design two-legged robots of DAR type and exoskeleton control system

  17. LDA study of non-steady flame propagation in a constant volume duct

    SciTech Connect

    Dunn-Rankin, D.; Cheng, R.K.; Sawyer, R.F.

    1984-09-01

    This work investigates the development of tulip shaped flames during laminar flame propagation in a closed duct. In particular the interaction of a laminar flame front with its self-induced non-steady flow field is examined as a possible source of the tulip phenomenon. The flame generated flow is measured with a laser Doppler anemometer (LDA). The flame shape and its position are recorded with high-speed schlieren cinematography. Comparison of the qualitative schlieren and the quantitative LDA data records provides insight into the flame/flow relationship.

  18. Non-steady response of BOD biosensor for the determination of biochemical oxygen demand in wastewater.

    PubMed

    Velling, Siiri; Mashirin, Alexey; Hellat, Karin; Tenno, Toomas

    2011-01-01

    A biochemical oxygen demand (BOD) biosensor for effective and expeditious BOD(7) estimations was constructed and the non-steady phase of the output signal was extensively studied. The modelling approach introduced allows response curve reconstruction and a curve fitting procedure of good quality, resulting in parameters indicating the relationship between response and organic substrate concentration and stability properties of the BOD biosensor. Also, the immobilization matrixes of different thicknesses were characterized to determine their suitability for bio-sensing measurements in non-stationary conditions, as well as for the determination of the mechanical durability of the BOD biosensor in time. The non-steady response of the experimental output of the BOD biosensor was fitted according to the developed model that enables to determine the stability of the biosensor output and dependency on biodegradable organic substrate concentration. The calibration range of the studied BOD biosensor in OECD synthetic wastewater was 15-110 mg O(2) L(-1). Repeatability tests showed relative standard deviation (RSD) values of 2.8% and 5.8% for the parameter τ(d), characterizing the transient output of the amperometric oxygen sensor in time, and τ(s), describing the dependency of the transient response of the BOD biosensor on organic substrate concentration, respectively. BOD biosensor experiments for the evaluation of the biochemical oxygen demand of easily degradable and refractory municipal wastewater showed good concurrence with traditional BOD(7) analysis.

  19. Modelling Galaxies with a 3D Multi-Phase ISM

    NASA Astrophysics Data System (ADS)

    Harfst, Stefan; Theis, Christian; Hensler, Gerhard

    We present a modified TREE-SPH code to model galaxies in three dimensions. The model includes a multi-phase description of the interstellar medium which combines two numerical techniques. A diffuse warm/hot gas phase is modelled by SPH, whereas a cloudy medium is represented by a sticky particle scheme. Interaction processes (such as star formation and feedback), cooling, and mixing by condensation and evaporation, are taken into account. Here we apply our model to the evolution of a Milky Way type galaxy. After an initial stage, a quasi-equilibrium state is reached. It is characterised by a star formation rate of ~1 Msolar yr-1. Condensation and evaporation rates are in balance at 0.1-1 Msolar yr-1.

  20. Measurement of methane fluxes from terrestrial landscapes using static, non-steady state enclosures. Chapter 12

    Treesearch

    Peter Weishampel; Randall. Kolka

    2008-01-01

    Wetlands are a dominant natural source of atmospheric methane (CH4), a potent greenhouse gas whose concentration in the atmosphere has doubled over the past 150 years. Evaluating the impacts of CH4 emissions on global climate and developing policies to mitigate those impacts requires a quantifiable and predictive...

  1. Bioproduction of ethanol in three-phase fluidized fermentors: Modeling of non-steady state kinetics

    SciTech Connect

    Raj, C.B.C.; Ettouney, H.M.; Farag, I.H.

    1987-01-01

    A model is developed to compute the ethanol production, taking into account the reaction kinetics, convection and dispersion of all the reactive species in a fluidized bioreactor. The model predicts the profiles of nutrients, and alcohol as functions of design parameters and operating conditions. A fluidized fermentor was designed and operated to verify the proposed model. Effects of varying the feed nutrient concentration, air velocity and yeast concentration on the total nutrient conversion are investigated. The model incorporates the hydrodynamic postulates of three phase fluidized beds, as well as the Michaelis-Menton type kinetics for ethanol formation. Results are reported in terms of limits on operating conditions, and characteristics of the fluidization medium and its effects on the net product yield. In addition, comparison of theoretical predictions and measured data is presented and discussed.

  2. A surface model of nonlinear, non-steady-state phloem transport.

    PubMed

    Mammeri, Youcef; Sellier, Damien

    2017-08-01

    Phloem transport is the process by which carbohydrates produced by photosynthesis in the leaves get distributed in a plant. According to Münch, the osmotically generated hydrostatic phloem pressure is the force driving the long-distance transport of photoassimilates. Following Thompson and Holbrook[35]'s approach, we develop a mathematical model of coupled water-carbohydrate transport. It is first proven that the model presented here preserves the positivity. The model is then applied to simulate the flow of phloem sap for an organic tree shape, on a 3D surface and in a channel with orthotropic hydraulic properties. Those features represent an significant advance in modelling the pathway for carbohydrate transport in trees.

  3. Lineweaver-Burk, Hanes, Eadie-Hofstee and Dixon plots in non-steady-state situations.

    PubMed

    Frère, J M; Leyh, B; Renard, A

    1983-04-07

    Lineweaver-Burk, Hanes, Eadie-Hofstee and Dixon plots can only be used when a true initial rate is measured. Despite the fact that this point has often been stressed, it is far too often ignored in favour of restricting the assay time to one where low amounts of substrate are used. When one or several irreversible and slow steps occur with an inactivator during the incubation of a ternary enzyme-substrate-inactivator mixture, the rate of the enzyme-catalysed reaction progressively decreases. Even under these conditions, the present computer simulations investigations show that apparently linear Lineweaver-Burk, Hanes, Eadie-Hofstee and Dixon graphs can be obtained when the amount of product formed is mistakenly assumed to represent the true initial rate. Moreover, the observed pattern can change with time, going for instance from non-competitive to competitive. "Ki's" measured under these conditions also vary with time and bear little relationship to the true constants involved in the interaction.

  4. Quantifying measurement uncertainties in ADCP measurements in non-steady, inhomogeneous flow

    NASA Astrophysics Data System (ADS)

    Schäfer, Stefan

    2017-04-01

    The author presents a laboratory study of fixed-platform four-beam ADCP and three-beam ADV measurements in the tailrace of a micro hydro power setup with a 35kW Kaplan-turbine and 2.5m head. The datasets discussed quantify measurement uncertainties of the ADCP measurement technique coming from non-steady, inhomogeneous flow. For constant discharge of 1.5m3/s, two different flow scenarios were investigated: one being the regular tailrace flow downstream the draft tube and the second being a straightened, less inhomogeneous flow, which was generated by the use of a flow straightening device: A rack of diameter 40mm pipe sections was mounted right behind the draft tube. ADCP measurements (sampling rate 1.35Hz) were conducted in three distances behind the draft tube and compared bin-wise to measurements of three simultaneously measuring ADV probes (sampling rate 64Hz). The ADV probes were aligned horizontally and the ADV bins were placed in the centers of two facing ADCP bins and in the vertical under the ADCP probe of the corresponding depth. Rotating the ADV probes by 90° allowed for measurements of the other two facing ADCP bins. For reasons of mutual probe interaction, ADCP and ADV measurements were not conducted at the same time. The datasets were evaluated by using mean and fluctuation velocities. Turbulence parameters were calculated and compared as far as applicable. Uncertainties coming from non-steady flow were estimated with the normalized mean square error und evaluated by comparing long-term measurements of 60 minutes to shorter measurement intervals. Uncertainties coming from inhomogeneous flow were evaluated by comparison of ADCP with ADV data along the ADCP beams where ADCP data were effectively measured and in the vertical under the ADCP probe where velocities of the ADCP measurements were displayed. Errors coming from non-steady flow could be compensated through sufficiently long measurement intervals with high enough sampling rates depending on the

  5. A Methodology for the Parametric Reconstruction of Non-Steady and Noisy Meteorological Time Series

    NASA Astrophysics Data System (ADS)

    Rovira, F.; Palau, J. L.; Millán, M.

    2009-09-01

    Climatic and meteorological time series often show some persistence (in time) in the variability of certain features. One could regard annual, seasonal and diurnal time variability as trivial persistence in the variability of some meteorological magnitudes (as, e.g., global radiation, air temperature above surface, etc.). In these cases, the traditional Fourier transform into frequency space will show the principal harmonics as the components with the largest amplitude. Nevertheless, meteorological measurements often show other non-steady (in time) variability. Some fluctuations in measurements (at different time scales) are driven by processes that prevail on some days (or months) of the year but disappear on others. By decomposing a time series into time-frequency space through the continuous wavelet transformation, one is able to determine both the dominant modes of variability and how those modes vary in time. This study is based on a numerical methodology to analyse non-steady principal harmonics in noisy meteorological time series. This methodology combines both the continuous wavelet transform and the development of a parametric model that includes the time evolution of the principal and the most statistically significant harmonics of the original time series. The parameterisation scheme proposed in this study consists of reproducing the original time series by means of a statistically significant finite sum of sinusoidal signals (waves), each defined by using the three usual parameters: amplitude, frequency and phase. To ensure the statistical significance of the parametric reconstruction of the original signal, we propose a standard statistical t-student analysis of the confidence level of the amplitude in the parametric spectrum for the different wave components. Once we have assured the level of significance of the different waves composing the parametric model, we can obtain the statistically significant principal harmonics (in time) of the original

  6. Rotating water table for the determination of non-steady forces in a turbine stage through modified hydraulic analogy

    NASA Astrophysics Data System (ADS)

    Rao, J. S.; Raghavacharyulu, E.; Seshadri, V.; Rao, V. V. R.

    1983-10-01

    Determination of non-steady forces in a real turbine stage is difficult due to the local flow conditions, for example high pressures, high temperatures and in-accessibility to the region etc. Experimentation in a real turbine is also prohibitive due to the costs involved. An alternate method of arriving at these non-steady forces through the use of modified hydraulic analogy is discussed. A rotating water table facility, developed and fabricated based on the principles of modified hydraulic analogy is described. A flat plate stage is simulated on the rotating water table, and the results obtained are presented.

  7. Toward a Non-Steady Subgrid Flame Model for Turbulent Thermonuclear Combustion (cont.)

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Messer, O. E. B.; Plewa, T.; Khokhlov, A. M.

    2005-05-01

    Simulations of Type Ia supernova explosions are characterized by vastly disparate spatial scales, spanning some 12 orders of magnitude. This large dynamic range cannot be modeled in any single modern direct numerical simulation. Therefore, a subgrid model has to be employed in the supernova explosion simulations to describe physical processes taking place on unresolved scales. We are concerned with the extension of the Khokhlov's subgrid flame model to a non-steady regime. We study the flame surface evolution subject to Rayleigh-Taylor instabilities in periodic domains. We seek correlations between the flame surface creation and destruction processes and basic parameters of the physical system. We found that in the fully developed turbulence the flame surface destruction strength is roughly constant and of the order of 1/L3, where L is the characteristic Rayleigh-Taylor bubble size. The flame surface creation and destruction processes reflect the interplay between the Rayleigh-Taylor instability and the flame's tendency to smooth its surface. We found that this relationship can be well characterized by Froude number. In addition, the flame surface creation strength correlates with the magnitude of the vorticity component in the direction of gravitational acceleration. These findings provide a foundation for the future time-dependent subgrid flame model. We thank J. B. Gallagher, S. Needham, D. Sheeler for their contributions to this project. This research has been supported by the U. S. Department of Energy contract B523820.

  8. Analysis of spray penetration and velocity dissipation for non-steady fuel injection

    SciTech Connect

    Harrington, D.L.

    1984-02-01

    The time histories of spray penetration and velocity for conditions corresponding to non-steady fuel injection in a piston-engine cylinder are described in detail. Regions of influence are established for numerous factors affecting the spray-tip velocity curve, including injection-system characteristics, aerodynamic drag, and in-cylinder air swirl. The necessity of excluding the initial region, which is dominated by injection-system characteristics, from a generalized correlation is shown. Based on extensive experimental data, a universal curve of velocity versus penetration is then developed for the time domain in which the spray-tip velocity is decreasing. For a power-law drag formulation, general relationships for velocity and penetration are developed for any velocity exponent, and current correlations from the literature are interpreted in terms of the resulting functions. The inadequacies of the mathematical forms of both current spray-penetration correlations and correlations based upon power-law drag are then illustrated, and guidelines for developing continuously-differentiable penetration relationships are presented. Utilizing multi-term functions to describe the universal curve, an internally consistent set of relationships for spray-tip penetration and velocity is derived.

  9. Heat transfer and solidification microstructure evolution of continuously cast steel by non-steady physical simulation

    NASA Astrophysics Data System (ADS)

    Lan, Peng; Nguyen, Diem Ai; Lee, Soo-Yeon; Cho, Jung-Wook

    2017-05-01

    The heat transfer and solidification microstructure evolution during continuous casting were experimentally studied in this work. A new approach to physically simulate the steel solidification behavior during continuous casting was developed. Six steel grades with different solidification mode were introduced to elucidate the carbon equivalent dependent mold heat flux, prior austenite grain size and secondary dendrite arm spacing. It is found that the non-steady mold heat fluxes in the experiment against time for all steel grades are comparative to that versus distance in practical continuous casting. Due to the occurrence of L→L+δ→δ+γ→γ transformation with the largest amount of volume contraction in hypo-peritectic steel, it shows the lowest mold heat flux among these six steel grades. It is also demonstrated from the solidification microstructure results that the prior austenite grain size and secondary dendrite arm spacing in the physical simulation are in good agreement with those in continuously cast strand. In addition, the steel with a higher temperature for the onset of δ→γ transformation reveals the larger prior austenite grains resulted from the higher grains growth rate in the post solidification process.

  10. Multi-phase SPH modelling of violent hydrodynamics on GPUs

    NASA Astrophysics Data System (ADS)

    Mokos, Athanasios; Rogers, Benedict D.; Stansby, Peter K.; Domínguez, José M.

    2015-11-01

    This paper presents the acceleration of multi-phase smoothed particle hydrodynamics (SPH) using a graphics processing unit (GPU) enabling large numbers of particles (10-20 million) to be simulated on just a single GPU card. With novel hardware architectures such as a GPU, the optimum approach to implement a multi-phase scheme presents some new challenges. Many more particles must be included in the calculation and there are very different speeds of sound in each phase with the largest speed of sound determining the time step. This requires efficient computation. To take full advantage of the hardware acceleration provided by a single GPU for a multi-phase simulation, four different algorithms are investigated: conditional statements, binary operators, separate particle lists and an intermediate global function. Runtime results show that the optimum approach needs to employ separate cell and neighbour lists for each phase. The profiler shows that this approach leads to a reduction in both memory transactions and arithmetic operations giving significant runtime gains. The four different algorithms are compared to the efficiency of the optimised single-phase GPU code, DualSPHysics, for 2-D and 3-D simulations which indicate that the multi-phase functionality has a significant computational overhead. A comparison with an optimised CPU code shows a speed up of an order of magnitude over an OpenMP simulation with 8 threads and two orders of magnitude over a single thread simulation. A demonstration of the multi-phase SPH GPU code is provided by a 3-D dam break case impacting an obstacle. This shows better agreement with experimental results than an equivalent single-phase code. The multi-phase GPU code enables a convergence study to be undertaken on a single GPU with a large number of particles that otherwise would have required large high performance computing resources.

  11. Multi-Phase Fracture-Matrix Interactions Under Stress Changes

    SciTech Connect

    A.S. Grader; D. Elsworth; P.M. Halleck; F. Alvarao; A. Alajmi; Z. Karpyn; N. Mohammed; S. Al-Enezi

    2005-12-07

    The main objectives of this project are to quantify the changes in fracture porosity and multi-phase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (a) developing the direct experimental measurements of fracture aperture and topology and fluid occupancy using high-resolution x-ray micro-tomography, (b) counter-current fluid transport between the matrix and the fracture, (c) studying the effect of confining stress on the distribution of fracture aperture and two-phase flow, and (d) characterization of shear fractures and their impact on multi-phase flow. The three-dimensional surface that describes the large-scale structure of the fracture in the porous medium can be determined using x-ray micro-tomography with significant accuracy. Several fractures have been scanned and the fracture aperture maps have been extracted. The success of the mapping of fracture aperture was followed by measuring the occupancy of the fracture by two immiscible phases, water and decane, and water and kerosene. The distribution of fracture aperture depends on the effective confining stress, on the nature of the rock, and the type and distribution of the asperities that keep the fracture open. Fracture apertures at different confining stresses were obtained by micro-tomography covering a range of about two thousand psig. Initial analysis of the data shows a significant aperture closure with increase in effective confining stress. Visual and detailed descriptions of the process are shown in the report. Both extensional and shear fractures have been considered. A series of water imbibition tests were conducted in which water was injected into a fracture and its migration into the matrix was monitored with CT and DR x-ray techniques. The objective was to understand the impact of the

  12. Multi-phase reactive transport theory

    SciTech Connect

    Lichtner, P.C.

    1995-07-01

    Physicochemical processes in the near-field region of a high-level waste repository may involve a diverse set of phenomena including flow of liquid and gas, gaseous diffusion, and chemical reaction of the host rock with aqueous solutions at elevated temperatures. This report develops some of the formalism for describing simultaneous multicomponent solute and heat transport in a two-phase system for partially saturated porous media. Diffusion of gaseous species is described using the Dusty Gas Model which provides for simultaneous Knudsen and Fickian diffusion in addition to Darcy flow. A new form of the Dusty Gas Model equations is derived for binary diffusion which separates the total diffusive flux into segregative and nonsegregative components. Migration of a wetting front is analyzed using the quasi-stationary state approximation to the Richards` equation. Heat-pipe phenomena are investigated for both gravity- and capillary-driven reflux of liquid water. An expression for the burnout permeability is derived for a gravity-driven heat-pipe. Finally an estimate is given for the change in porosity and permeability due to mineral dissolution which could occur in the region of condensate formation in a heat-pipe.

  13. Advanced Multi-Phase Flow CFD Model Development for Solid Rocket Motor Flowfield Analysis

    NASA Technical Reports Server (NTRS)

    Liaw, Paul; Chen, Y. S.; Shang, H. M.; Doran, Denise

    1993-01-01

    It is known that the simulations of solid rocket motor internal flow field with AL-based propellants require complex multi-phase turbulent flow model. The objective of this study is to develop an advanced particulate multi-phase flow model which includes the effects of particle dynamics, chemical reaction and hot gas flow turbulence. The inclusion of particle agglomeration, particle/gas reaction and mass transfer, particle collision, coalescence and breakup mechanisms in modeling the particle dynamics will allow the proposed model to realistically simulate the flowfield inside a solid rocket motor. The Finite Difference Navier-Stokes numerical code FDNS is used to simulate the steady-state multi-phase particulate flow field for a 3-zone 2-D axisymmetric ASRM model and a 6-zone 3-D ASRM model at launch conditions. The 2-D model includes aft-end cavity and submerged nozzle. The 3-D model represents the whole ASRM geometry, including additional grain port area in the gas cavity and two inhibitors. FDNS is a pressure based finite difference Navier-Stokes flow solver with time-accurate adaptive second-order upwind schemes, standard and extended k-epsilon models with compressibility corrections, multi zone body-fitted formulations, and turbulence particle interaction model. Eulerian/Lagrangian multi-phase solution method is applied for multi-zone mesh. To simulate the chemical reaction, penalty function corrected efficient finite-rate chemistry integration method is used in FDNS. For the AL particle combustion rate, the Hermsen correlation is employed. To simulate the turbulent dispersion of particles, the Gaussian probability distribution with standard deviation equal to (2k/3)(exp 1/2) is used for the random turbulent velocity components. The computational results reveal that the flow field near the juncture of aft-end cavity and the submerged nozzle is very complex. The effects of the turbulent particles affect the flow field significantly and provide better

  14. Non-steady dynamics of atmospheric turbulence interaction with wind turbine loadings through blade-boundary-layer-resolved CFD

    NASA Astrophysics Data System (ADS)

    Vijayakumar, Ganesh

    precursor simulation as inflow conditions, a second simulation is performed on a smaller domain around the wind turbine using finite volume CFD with a body-fitted grid to compute the unsteady blade loads in response to atmospheric turbulence. Analysis of the precursor LES shows that the advective time scales of energy containing eddies passing through the wind turbine rotor are of order multiple rotation time scales of the rotor. From blade element momentum theory coupled with LES of the ABL, we find that the energy-containing eddies were found to cause large temporal fluctuations (+/-50%) in the integrated moments, primarily due to changes in the local flow angle relative to the local chord sections. A low-dissipation pseudo-spectral algorithm was applied to the ABL LES. A finite volume algorithm was required to resolve the flow features around the complex blade geometry. The effect of the finite volume algorithm on the accuracy of it's prediction of the rough-surface ABL was assessed using the method of Brasseur and Wei [1]. We found that finite volume algorithms need finer horizontal grid resolution to retain the same accuracy as the corresponding pseudo-spectral simulations. These results were used to design our computational framework to accurately propagate the turbulence eddies through the finite volume domain. The ability of our computational framework to capture blade boundary layer dynamics in response to atmospheric turbulence is intimately associated with the extreme care taken in the design of our grid and with the development of a new hybrid URANS-LES turbulence model. The analysis of load fluctuations on a single rotating blade in a daytime atmosphere using blade-boundary-layer-resolved CFD has yielded two key results: (1) Whereas non-steady blade loadings are generally described as the response to non-steadiness in wind speed, our analysis show that time changes in wind vector direction are a much greater contributor to load transients, and strongly impact

  15. A Virtual Reality Technique for Multi-phase Flows

    NASA Astrophysics Data System (ADS)

    Loth, Eric; Sherman, William; Auman, Aric; Navarro, Christopher

    2004-04-01

    A virtual reality (VR) technique has been developed to allow user immersion (stereo-graphic rendering, user tracking and object interactivity) in generic unsteady three-dimensional multi-phase flow data sets. This article describes the structure and logic used to design and construct a VR technique that employs a multi-phase flow-field computed a priori as an input (i.e. simulations are conducted beforehand with a researcher's multi-phase CFD code). The input field for this flow visualization is divided into two parts: the Eulerian three-dimensional grid nodes and velocities for the continuous fluid properties (specified using conventional TECLOT data format) and the Lagrangian time-history trajectory files for the dispersed fluid. While tracking the dispersed phase trajectories as animated spheres of adjustable size and number, the continuous-phase flow can be simultaneously rendered with velocity vectors, iso-contour surfaces and planar flood-contour maps of different variables. The geometric and notional view of the combined visualization of both phases is interactively controlled throughout a user session. The resulting technique is demonstrated with a 3-D unsteady data set of Lagrangian particles dispersing in a Eulerian description of a turbulent boundary layer, stemming from a direct numerical simulation of the Navier-Stokes equations.

  16. Multi-phase Thermohaline Convection in Porous Media

    NASA Astrophysics Data System (ADS)

    Geiger, S.; Driesner, T.; Matthai, S. K.; Heinrich, C. A.

    2003-12-01

    The simultaneous motion of heat and dissolved solutes by aqueous or magmatic fluids through porous or fractured media within the earth's crust is a key factor that drives many important geological processes, such as the formation of large ore deposits, cooling of new-formed oceanic crust along mid-ocean ridges, metamorphism, or the evolution of geothermal systems. The motion of such crustal fluids is usually dominated by convection due to density differences within the fluids that arise from pressure, temperature and compositional variations present in the fluids. Oxygen isotope data and fluid inclusion data indicate that fluids may percolate down to 15 km depth and experience temperatures exceeding 700 {o}C. Although crustal fluids commonly contain various dissolved chemical components and gases, the most abundant solute is salt, i.e. NaCl. Hence, changes in the concentration of NaCl influence the density variations of crustal fluids the most. The presence of NaCl in H2O has decisive effects on the thermodynamics and hydrodynamics of crustal fluids. NaCl-H2O fluids can boil and separate into a high-density brine and low-salinity vapor at much higher temperatures and pressures than the critical temperature and pressure for pure H2O. NaCl-H2O fluids may also become saturated with respect to NaCl such that a solid NaCl phase coexists with a liquid or vapor fluid phase. Because salt advects faster than heat but diffuses slower than heat, the resulting double-diffusive and double-convective motion of salt and heat may lead to non-linear flow instabilities such as periodic or chaotic behavior. While many studies have addressed the theory of convection driven by temperature and/or salinity gradients, they were limited to a Boussinesq approximation and neglected phase separation. In this study we have numerically examined the behavior of multi-phase thermohaline convection in a porous media heated and salted from below using a novel finite element - finite volume

  17. Multi-phase back contacts for CIS solar cells

    DOEpatents

    Rockett, A.A.; Yang, L.C.

    1995-12-19

    Multi-phase, single layer, non-interdiffusing M-Mo back contact metallized films, where M is selected from Cu, Ga, or mixtures thereof, for CIS cells are deposited by a sputtering process on suitable substrates, preferably glass or alumina, to prevent delamination of the CIS from the back contact layer. Typical CIS compositions include CuXSe{sub 2} where X is In or/and Ga. The multi-phase mixture is deposited on the substrate in a manner to provide a columnar microstructure, with micro-vein Cu or/and Ga regions which partially or fully vertically penetrate the entire back contact layer. The CIS semiconductor layer is then deposited by hybrid sputtering and evaporation process. The Cu/Ga-Mo deposition is controlled to produce the single layer two-phase columnar morphology with controllable Cu or Ga vein size less than about 0.01 microns in width. During the subsequent deposition of the CIS layer, the columnar Cu/Ga regions within the molybdenum of the Cu/Ga-Mo back layer tend to partially leach out, and are replaced by columns of CIS. Narrower Cu and/or Ga regions, and those with fewer inner connections between regions, leach out more slowly during the subsequent CIS deposition. This gives a good mechanical and electrical interlock of the CIS layer into the Cu/Ga-Mo back layer. Solar cells employing In-rich CIS semiconductors bonded to the multi-phase columnar microstructure back layer of this invention exhibit vastly improved photo-electrical conversion on the order of 17% greater than Mo alone, improved uniformity of output across the face of the cell, and greater Fill Factor. 15 figs.

  18. Multi-phase back contacts for CIS solar cells

    DOEpatents

    Rockett, Angus A.; Yang, Li-Chung

    1995-01-01

    Multi-phase, single layer, non-interdiffusing M-Mo back contact metallized films, where M is selected from Cu, Ga, or mixtures thereof, for CIS cells are deposited by a sputtering process on suitable substrates, preferably glass or alumina, to prevent delamination of the CIS from the back contact layer. Typical CIS compositions include CuXSe.sub.2 where X is In or/and Ga. The multi-phase mixture is deposited on the substrate in a manner to provide a columnar microstructure, with micro-vein Cu or/and Ga regions which partially or fully vertically penetrate the entire back contact layer. The CIS semiconductor layer is then deposited by hybrid sputtering and evaporation process. The Cu/Ga-Mo deposition is controlled to produce the single layer two-phase columnar morphology with controllable Cu or Ga vein size less than about 0.01 microns in width. During the subsequent deposition of the CIS layer, the columnar Cu/Ga regions within the molybdenum of the Cu/Ga-Mo back layer tend to partially leach out, and are replaced by columns of CIS. Narrower Cu and/or Ga regions, and those with fewer inner connections between regions, leach out more slowly during the subsequent CIS deposition. This gives a good mechanical and electrical interlock of the CIS layer into the Cu/Ga-Mo back layer. Solar cells employing In-rich CIS semiconductors bonded to the multi-phase columnar microstructure back layer of this invention exhibit vastly improved photo-electrical conversion on the order of 17% greater than Mo alone, improved uniformity of output across the face of the cell, and greater Fill Factor.

  19. The control method for the multi-phase traffic model

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Cheng, Rong-Jun; Ma, Yan-Qiang; Ge, Hong-Xia

    2016-04-01

    Based on multi-phase car-following model proposed by Nagatani, the control theory method is used to analyze the stability of the model. The optimal velocity function is improved to have more turning points. The original optimal velocity with one turning point shows two-phase traffic, while the improved model with n turning points exhibits n+1 phase traffic. Control signal is added into the model. Numerical simulation is conducted to show the results for the stability of the model with and without control signal.

  20. Entropic Lattice Boltzmann Methods for Fluid Mechanics: Thermal, Multi-phase and Turbulence

    NASA Astrophysics Data System (ADS)

    Chikatamarla, Shyam; Boesch, F.; Frapolli, N.; Mazloomi, A.; Karlin, I.

    2014-11-01

    With its roots in statistical mechanics and kinetic theory, the lattice Boltzmann method (LBM) is a paradigm-changing innovation, offering for the first time an intrinsically parallel CFD algorithm. Over the past two decades, LBM has achieved numerous results in the field of CFD and is now in a position to challenge state-of-the art CFD techniques. Major restyling of LBM resulted in an unconditionally stable entropic LBM which restored Second Law (Boltzmann H theorem) in the LBM kinetics and thus enabled affordable direct simulations of fluid turbulence. In this talk, we shall review recent advances in ELBM as a practical, modeling-free tool for simulation of complex flow phenomenon. We shall present recent simulations of fluid turbulence including turbulent channel flow, flow past a circular cylinder, creation and dynamics of vortex tubes, and flow past a surface mounted cube. Apart from its achievements in turbulent flow simulations, ELBM has also presented us the opportunity to extend lattice Boltzmann method to higher order lattices which shall be employed for turbulent, multi-phase and thermal flow simulations. A new class of entropy functions are proposed to handle non-ideal equation of state and surface tension terms in multi-phase flows. It is shown the entropy principle brings unconditional stability and thermodynamic consistency to all the three flow regimes considered here. Acknowledgements: ERC Advanced Grant ``ELBM'' and CSCS grant s437 are deeply acknowledged. References:

  1. Multi-phase CFD modeling of solid sorbent carbon capture system

    SciTech Connect

    Ryan, E. M.; DeCroix, D.; Breault, Ronald W.; Xu, W.; Huckaby, E. David

    2013-01-01

    Computational fluid dynamics (CFD) simulations are used to investigate a low temperature post-combustion carbon capture reactor. The CFD models are based on a small scale solid sorbent carbon capture reactor design from ADA-ES and Southern Company. The reactor is a fluidized bed design based on a silica-supported amine sorbent. CFD models using both Eulerian–Eulerian and Eulerian–Lagrangian multi-phase modeling methods are developed to investigate the hydrodynamics and adsorption of carbon dioxide in the reactor. Models developed in both FLUENT® and BARRACUDA are presented to explore the strengths and weaknesses of state of the art CFD codes for modeling multi-phase carbon capture reactors. The results of the simulations show that the FLUENT® Eulerian–Lagrangian simulations (DDPM) are unstable for the given reactor design; while the BARRACUDA Eulerian–Lagrangian model is able to simulate the system given appropriate simplifying assumptions. FLUENT® Eulerian–Eulerian simulations also provide a stable solution for the carbon capture reactor given the appropriate simplifying assumptions.

  2. Multi-Phase CFD Modeling of Solid Sorbent Carbon Capture System

    SciTech Connect

    Ryan, Emily M.; DeCroix, David; Breault, Ronald W.; Xu, Wei; Huckaby, E. D.; Saha, Kringan; Darteville, Sebastien; Sun, Xin

    2013-07-30

    Computational fluid dynamics (CFD) simulations are used to investigate a low temperature post-combustion carbon capture reactor. The CFD models are based on a small scale solid sorbent carbon capture reactor design from ADA-ES and Southern Company. The reactor is a fluidized bed design based on a silica-supported amine sorbent. CFD models using both Eulerian-Eulerian and Eulerian-Lagrangian multi-phase modeling methods are developed to investigate the hydrodynamics and adsorption of carbon dioxide in the reactor. Models developed in both FLUENT® and BARRACUDA are presented to explore the strengths and weaknesses of state of the art CFD codes for modeling multi-phase carbon capture reactors. The results of the simulations show that the FLUENT® Eulerian-Lagrangian simulations (DDPM) are unstable for the given reactor design; while the BARRACUDA Eulerian-Lagrangian model is able to simulate the system given appropriate simplifying assumptions. FLUENT® Eulerian-Eulerian simulations also provide a stable solution for the carbon capture reactor given the appropriate simplifying assumptions.

  3. Multi-phase galaxy formation and quasar absorption systems

    NASA Astrophysics Data System (ADS)

    Maller, Ariyeh H.

    2005-03-01

    The central problem of galaxy formation is understanding the cooling and condensation of gas in dark matter halos. It is now clear that to match observations this requires further physics than the simple assumptions of single phase gas cooling. A model of multi-phase cooling (maller & bullock 2004) can successfully account for the upper cutoff in the masses of galaxies and provides a natural explanation of many types of absorption systems (mo & miralda-escude 1996). Absorption systems are our best probes of the gaseous content of galaxy halos and therefore provide important constraints on models for gas cooling into galaxies. All physical processes that effect gas cooling redistribute gas and therefore are detectable in absorption systems. Detailed studies of the nature of gas in galaxy halos using absorption systems are crucial for building a correct theory of galaxy formation.

  4. Design of multi-phase dynamic chemical networks

    NASA Astrophysics Data System (ADS)

    Chen, Chenrui; Tan, Junjun; Hsieh, Ming-Chien; Pan, Ting; Goodwin, Jay T.; Mehta, Anil K.; Grover, Martha A.; Lynn, David G.

    2017-08-01

    Template-directed polymerization reactions enable the accurate storage and processing of nature's biopolymer information. This mutualistic relationship of nucleic acids and proteins, a network known as life's central dogma, is now marvellously complex, and the progressive steps necessary for creating the initial sequence and chain-length-specific polymer templates are lost to time. Here we design and construct dynamic polymerization networks that exploit metastable prion cross-β phases. Mixed-phase environments have been used for constructing synthetic polymers, but these dynamic phases emerge naturally from the growing peptide oligomers and create environments suitable both to nucleate assembly and select for ordered templates. The resulting templates direct the amplification of a phase containing only chain-length-specific peptide-like oligomers. Such multi-phase biopolymer dynamics reveal pathways for the emergence, self-selection and amplification of chain-length- and possibly sequence-specific biopolymers.

  5. A framework for modeling non-steady-state concentrations of semivolatile organic compounds indoors ― II. Interactions with particulate matter

    EPA Science Inventory

    This paper describes a method for dynamic modeling of the interactions of semivolatile organic compounds (SVOCs) with airborne and settled particulate matter in the indoor environment. This method is fully compatible with the other components within the framework. Despite the unc...

  6. Performance of a biofilter for the removal of high concentrations of styrene under steady and non-steady state conditions.

    PubMed

    Rene, Eldon R; Veiga, María C; Kennes, Christian

    2009-08-30

    The performance of a laboratory scale perlite biofilter inoculated with a mixed culture was evaluated for gas phase styrene removal under various operating conditions. Experiments were carried out by subjecting the biofilter to different flow rates (0.15-0.9 m(3)h(-1)) and concentrations (0.03-17.3 gm(-3)), corresponding to inlet loading rates varying from as low as 3 gm(-3)h(-1) to as high as 1390 gm(-3)h(-1). A maximum elimination capacity (EC) of 382 gm(-3)h(-1) was achieved at an inlet loading rate of 464 gm(-3)h(-1) with a removal efficiency of 82%. The high elimination capacity reached with this system could have been due to the dominant presence of filamentous fungi among others. The impact of relative humidity (RH) (30%, 60% and >92%) on the biofilter performance was evaluated at two constant loading rates, viz., 80 and 260 gm(-3)h(-1), showing that inhibitory effects were only significant when combining the highest loads with the lowest relative humidities. Biomass distribution, moisture content and concentration profiles along the bed height were significantly dependent on the relative humidity of the inlet air and on the loading rate. The dynamic behaviour of the biofilter through vigorous short and long-term shock loads was tested at different process conditions. The biofilter was found to respond apace to rapid changes in loading conditions. The stability of the biomass within the reactor was apparent from the fast response of the biofilter to recuperate and handle intermittent shutdown and restart operations, either with or without nutrient addition.

  7. A framework for modeling non-steady-state concentrations of semivolatile organic compounds indoors ― II. Interactions with particulate matter

    EPA Science Inventory

    This paper describes a method for dynamic modeling of the interactions of semivolatile organic compounds (SVOCs) with airborne and settled particulate matter in the indoor environment. This method is fully compatible with the other components within the framework. Despite the unc...

  8. Multi-phase-field model for surface and phase-boundary diffusion

    NASA Astrophysics Data System (ADS)

    Schiedung, Raphael; Kamachali, Reza Darvishi; Steinbach, Ingo; Varnik, Fathollah

    2017-07-01

    The multi-phase-field approach is generalized to treat capillarity-driven diffusion parallel to the surfaces and phase boundaries, i.e., the boundaries between a condensed phase and its vapor and the boundaries between two or multiple condensed phases. The effect of capillarity is modeled via curvature dependence of the chemical potential whose gradient gives rise to diffusion. The model is used to study thermal grooving on the surface of a polycrystalline body. Decaying oscillations of the surface profile during thermal grooving, postulated by Hillert long ago but reported only in few studies so far, are observed and discussed. Furthermore, annealing of multi-nanoclusters on a deformable free surface is investigated using the proposed model. Results of these simulations suggest that the characteristic craterlike structure with an elevated perimeter, observed in recent experiments, is a transient nonequilibrium state during the annealing process.

  9. MULTI-PHASE FRACTURE-MATRIX INTERACTIONS UNDER STRESS CHANGES

    SciTech Connect

    A.S. Grader; D. Elsworth; P.M. Halleck; F. Alvarado; A. Alajmi; Z. Karpyn; N. Mohammed; S. Al-Enezi

    2005-06-15

    The main objectives of this project are to quantify the changes in fracture porosity and multiphase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (a) developing the direct experimental measurements of fracture aperture and topology and fluid occupancy using high-resolution x-ray micro-tomography, (b) quantifying the effect of confining stress on the distribution of fracture aperture, and (c) characterization of shear fractures and their impact on multi-phase flow. The three-dimensional surface that describes the large-scale structure of the fracture in the porous medium can be determined using x-ray micro-tomography with significant accuracy. Several fractures have been scanned and the fracture aperture maps have been extracted. The success of the mapping of fracture aperture was followed by measuring the occupancy of the fracture by two immiscible phases, water and decane, and water and kerosene. The distribution of fracture aperture depends on the effective confining stress on the nature of the rock and the type and distribution of the asperities that keep the fracture open. Fracture apertures at different confining stresses were obtained by micro-tomography covering a range of about two thousand psig. Initial analysis of the data shows a significant aperture closure with increase in effective confining stress. Visual descriptions of the process are shown in the report while detailed analysis of the behavior of the distribution of fracture aperture is in progress. Both extensional and shear fractures are being considered. The initial multi-phase flow tests were done in extensional fractures. Several rock samples with induced shear fracture are being studies, and some of the new results are presented in this report. These samples are being scanned in order to

  10. MULTI-PHASE FRACTURE-MATRIX INTERACTIONS UNDER STRESS CHANGES

    SciTech Connect

    A.S. Grader; D. Elsworth; P.M. Halleck; F. Alvarado; A. Alajmi; Z. Karpyn; N. Mohammed; S. Al-Enezi

    2005-06-15

    The main objectives of this project are to quantify the changes in fracture porosity and multiphase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (a) developing the direct experimental measurements of fracture aperture and topology and fluid occupancy using high-resolution x-ray micro-tomography, (b) quantifying the effect of confining stress on the distribution of fracture aperture, and (c) characterization of shear fractures and their impact on multi-phase flow. The three-dimensional surface that describes the large-scale structure of the fracture in the porous medium can be determined using x-ray micro-tomography with significant accuracy. Several fractures have been scanned and the fracture aperture maps have been extracted. The success of the mapping of fracture aperture was followed by measuring the occupancy of the fracture by two immiscible phases, water and decane, and water and kerosene. The distribution of fracture aperture depends on the effective confining stress on the nature of the rock and the type and distribution of the asperities that keep the fracture open. Fracture apertures at different confining stresses were obtained by micro-tomography covering a range of about two thousand psig. Initial analysis of the data shows a significant aperture closure with increase in effective confining stress. Visual descriptions of the process are shown in the report while detailed analysis of the behavior of the distribution of fracture aperture is in progress. Both extensional and shear fractures are being considered. The initial multi-phase flow tests were done in extensional fractures. Several rock samples with induced shear fracture are being studied, and some of the new results are presented in this report. These samples are being scanned in order to

  11. Multi-speed multi-phase resolver converter

    NASA Technical Reports Server (NTRS)

    Alhorn, Dean C. (Inventor); Howard, David E. (Inventor)

    1995-01-01

    A multiphase converter circuit generates a plurality of sinusoidal outputs of displaced phase and given speed value from the output of an angular resolver system attachable to a motor excited by these multi-phase outputs, the resolver system having a lower speed value than that of the motor. The angular resolver system provides in parallel format sequential digital numbers indicative of the amount of rotation of the shaft of an angular position sensor associated with the angular resolver system. These numbers are used to excite simultaneously identical addresses of a plurality of addressable memory systems, each memory system having stored therein at sequential addresses sequential values of a sinusoidal wavetrain of a given number of sinusoids. The stored wavetrain values represent sinusoids displaced from each other in phase according to the number of output phases desired. A digital-to-analog converter associated with each memory system converts each accessed word to a corresponding analog value to generate attendant to rotation of the angular resolver a sinusoidal wave of proper phase at each of the plurality of outputs. By properly orienting the angular resolver system with respect to the rotor of the motor, essentially ripple-free torque is supplied to the rotor. The angular resolver system may employ an analog resolver feeding an integrated circuit resolver-to-digital converter to produce the requisite digital values serving as addresses. Alternative versions employing incremental or absolute encoders are also described.

  12. Computer Based Porosity Design by Multi Phase Topology Optimization

    NASA Astrophysics Data System (ADS)

    Burblies, Andreas; Busse, Matthias

    2008-02-01

    A numerical simulation technique called Multi Phase Topology Optimization (MPTO) based on finite element method has been developed and refined by Fraunhofer IFAM during the last five years. MPTO is able to determine the optimum distribution of two or more different materials in components under thermal and mechanical loads. The objective of optimization is to minimize the component's elastic energy. Conventional topology optimization methods which simulate adaptive bone mineralization have got the disadvantage that there is a continuous change of mass by growth processes. MPTO keeps all initial material concentrations and uses methods adapted from molecular dynamics to find energy minimum. Applying MPTO to mechanically loaded components with a high number of different material densities, the optimization results show graded and sometimes anisotropic porosity distributions which are very similar to natural bone structures. Now it is possible to design the macro- and microstructure of a mechanical component in one step. Computer based porosity design structures can be manufactured by new Rapid Prototyping technologies. Fraunhofer IFAM has applied successfully 3D-Printing and Selective Laser Sintering methods in order to produce very stiff light weight components with graded porosities calculated by MPTO.

  13. Improved quark coalescence for a multi-phase transport model

    NASA Astrophysics Data System (ADS)

    He, Yuncun; Lin, Zi-Wei

    2017-07-01

    The string melting version of a multi-phase transport model is often applied to high-energy heavy-ion collisions since the dense matter thus formed is expected to be in parton degrees of freedom. In this work we improve its quark coalescence component, which describes the hadronization of the partonic matter to a hadronic matter. We removed the previous constraint that forced the numbers of mesons, baryons, and antibaryons in an event to be separately conserved through the quark coalescence process. A quark now could form either a meson or a baryon depending on the distance to its coalescence partner(s). We then compare results from the improved model with the experimental data on hadron d N /d y ,pT spectra, and v2 in heavy-ion collisions from √{s NN}=62.4 GeV to 5.02 TeV. We show that, besides being able to describe these observables for low-pTpions and kaons, the improved model also better describes the low-p T baryon observables in general, especially the baryon p T spectra and antibaryon-to-baryon ratios for multistrange baryons.

  14. Multi-phased anaerobic baffled reactor treating food waste.

    PubMed

    Ahamed, A; Chen, C-L; Rajagopal, R; Wu, D; Mao, Y; Ho, I J R; Lim, J W; Wang, J-Y

    2015-04-01

    This study was conducted to identify the performance of a multi-phased anaerobic baffled reactor (MP-ABR) with food waste (FW) as the substrate for biogas production and thereby to promote an efficient energy recovery and treatment method for the wastes with high organic solid content through phase separation. A four-chambered ABR was operated at an HRT of 30 days with an OLR of 0.5-1.0 g-VS/Ld for a period of 175 days at 35 ± 1°C. Consistent overall removal efficiencies of 85.3% (CODt), 94.5% (CODs), 89.6% (VFA) and 86.4% (VS) were observed throughout the experiment displaying a great potential to treat FW. Biogas generated was 215.57 mL/g-VS removed d. Phase separation was observed and supported by the COD and VFA trends, and an efficient recovery of bioenergy from FW was achieved. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Thermorheologically complex behavior of multi-phase viscoelastic materials

    NASA Astrophysics Data System (ADS)

    Brinson, L. C.; Knauss, W. G.

    T HE DYNAMIC correspondence principle of viscoelasticity is used to study the nature of time-temperature behavior of multi-phase composites by means of finite element computation. The composite considered contains viscoelastic inclusions embedded in a viscoelastic matrix. Each phase of the composite is considered to be thermorheologically simple, but the resulting mechanical properties of the composite are thermorheologically complex. The deviation of the composite moduli from thermorheologically simple behavior of the matrix material is shown to occur at frequencies and temperatures where the glass-to-rubber transition of the included phases are reached. Properties of a styrene-butadiene-styrene (SBS) block copolymer are investigated based on the individual phase properties of polystyrene and polybutadiene. To achieve congruence of the results with experimental data, it is necessary to consider a transition phase of properties "intermediate" to those of polystyrene and polybutadiene. Using accurate physical information on the individual phase properties and on the interphase region, it is possible to predict properties of multiphase composites. Although detailed a priori knowledge of such an interphase is usually lacking, it is shown that the computational procedure presented here together with an extended range of test frequencies will aid in estimating the properties of the phase in question.

  16. Multi-phase volcanic resurfacing at Loki Patera on Io

    NASA Astrophysics Data System (ADS)

    de Kleer, K.; Skrutskie, M.; Leisenring, J.; Davies, A. G.; Conrad, A.; de Pater, I.; Resnick, A.; Bailey, V.; Defrère, D.; Hinz, P.; Skemer, A.; Spalding, E.; Vaz, A.; Veillet, C.; Woodward, C. E.

    2017-05-01

    The Jovian moon Io hosts the most powerful persistently active volcano in the Solar System, Loki Patera. The interior of this volcanic, caldera-like feature is composed of a warm, dark floor covering 21,500 square kilometres surrounding a much cooler central ‘island’. The temperature gradient seen across areas of the patera indicates a systematic resurfacing process, which has been seen to occur typically every one to three years since the 1980s. Analysis of past data has indicated that the resurfacing progressed around the patera in an anti-clockwise direction at a rate of one to two kilometres per day, and that it is caused either by episodic eruptions that emplace voluminous lava flows or by a cyclically overturning lava lake contained within the patera. However, spacecraft and telescope observations have been unable to map the emission from the entire patera floor at sufficient spatial resolution to establish the physical processes at play. Here we report temperature and lava cooling age maps of the entire patera floor at a spatial sampling of about two kilometres, derived from ground-based interferometric imaging of thermal emission from Loki Patera obtained on 8 March 2015 UT as the limb of Europa occulted Io. Our results indicate that Loki Patera is resurfaced by a multi-phase process in which two waves propagate and converge around the central island. The different velocities and start times of the waves indicate a non-uniformity in the lava gas content and/or crust bulk density across the patera.

  17. Multi-phase volcanic resurfacing at Loki Patera on Io.

    PubMed

    de Kleer, K; Skrutskie, M; Leisenring, J; Davies, A G; Conrad, A; de Pater, I; Resnick, A; Bailey, V; Defrère, D; Hinz, P; Skemer, A; Spalding, E; Vaz, A; Veillet, C; Woodward, C E

    2017-05-10

    The Jovian moon Io hosts the most powerful persistently active volcano in the Solar System, Loki Patera. The interior of this volcanic, caldera-like feature is composed of a warm, dark floor covering 21,500 square kilometres surrounding a much cooler central 'island'. The temperature gradient seen across areas of the patera indicates a systematic resurfacing process, which has been seen to occur typically every one to three years since the 1980s. Analysis of past data has indicated that the resurfacing progressed around the patera in an anti-clockwise direction at a rate of one to two kilometres per day, and that it is caused either by episodic eruptions that emplace voluminous lava flows or by a cyclically overturning lava lake contained within the patera. However, spacecraft and telescope observations have been unable to map the emission from the entire patera floor at sufficient spatial resolution to establish the physical processes at play. Here we report temperature and lava cooling age maps of the entire patera floor at a spatial sampling of about two kilometres, derived from ground-based interferometric imaging of thermal emission from Loki Patera obtained on 8 March 2015 ut as the limb of Europa occulted Io. Our results indicate that Loki Patera is resurfaced by a multi-phase process in which two waves propagate and converge around the central island. The different velocities and start times of the waves indicate a non-uniformity in the lava gas content and/or crust bulk density across the patera.

  18. MULTI-PHASE FRACTURE-MATRIX INTERACTIONS UNDER STRESS CHANGES

    SciTech Connect

    A.S. Grader; D. Elsworth; P.M. Halleck; F. Alvarad; H. Yasuhara; A. Alajmi

    2002-04-20

    The main objectives of this project are to quantify the changes in fracture porosity and multi-phase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (1) developing the direct experimental measurements of fracture aperture and topology using high-resolution x-ray micro-tomography, (2) modeling of fracture permeability in the presence of asperities and confining stress, and (3) simulation of two-phase fluid flow in a fracture and a layered matrix. The three-dimensional surface that describes the large-scale structure of the fracture in the porous medium can be determined using x-ray micro-tomography with significant accuracy. The distribution of fracture aperture is a difficult issue that we are studying and developing methods of quantification. The difficulties are both numerical and conceptual. Numerically, the three-dimensional data sets include millions, and sometimes, billions of points, and pose a computational challenge. The conceptual difficulties derive from the rough nature of the fracture surfaces, and the heterogeneous nature of the rock matrix. However, the high-resolution obtained by the imaging system provides us a much needed measuring environment on rock samples that are subjected to simultaneous fluid flow and confining stress. The absolute permeability of a fracture depends on the behavior of the asperities that keep it open. A model is being developed that predicts the permeability and average aperture of a fracture as a function of time under steady flow of water including the pressure solution at the asperity contact points. Several two-phase flow experiments in the presence of a fracture tip were performed in the past. At the present time, we are developing an inverse process using a simulation model to understand the fluid flow patterns in

  19. MULTI-PHASE FRACTURE-MATRIX INTERACTIONS UNDER STRESS CHANGES

    SciTech Connect

    A.S. Grader; D. Elsworth; P.M. Halleck; F. Alvarado; H. Yasuhara; A. Alajmi; Z. Karpyn

    2002-10-28

    The main objectives of this project are to quantify the changes in fracture porosity and multiphase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (1) developing the direct experimental measurements of fracture aperture and topology using high-resolution x-ray microtomography, (2) modeling of fracture permeability in the presence of asperities and confining stress, and (3) simulation of two-phase fluid flow in a fracture and a layered matrix. The three-dimensional surface that describes the large-scale structure of the fracture in the porous medium can be determined using x-ray micro-tomography with significant accuracy. The distribution of fracture aperture is a difficult issue that we are studying and developing methods of quantification. The difficulties are both numerical and conceptual. Numerically, the three-dimensional data sets include millions, and sometimes, billions of points, and pose a computational challenge. The conceptual difficulties derive from the rough nature of the fracture surfaces, and the heterogeneous nature of the rock matrix. However, the high-resolution obtained by the imaging system provides us a much needed measuring environment on rock samples that are subjected to simultaneous fluid flow and confining stress. Pilot multi-phase experiments have been performed, proving the ability to detect two phases in certain large fractures. The absolute permeability of a fracture depends on the behavior of the asperities that keep it open. A model is being developed that predicts the permeability and average aperture of a fracture as a function of time under steady flow of water including the pressure solution at the asperity contact points. Several two-phase flow experiments in the presence of a fracture tip were performed in the past. At the

  20. The SW Sextantis-type star 2MASS J01074282+4845188: an unusual bright accretion disk with non-steady emission and a hot white dwarf

    NASA Astrophysics Data System (ADS)

    Khruzina, T.; Dimitrov, D.; Kjurkchieva, D.

    2013-03-01

    Context. Cataclysmic variables (CVs) present a short evolutional stage of binary systems. The nova-like stars are rare objects, especially those with eclipses (only several tens). But precisely these allow to determine the global parameters of their configurations and to learn more about the late stage of stellar evolution. Aims: The light curve solution allows one to determine the global parameters of the newly discovered nova-like eclipsing star 2MASS J01074282+4845188 and to estimate the contribution of the different light sources. Methods: We present new photometric and spectral observations of 2MASS J01074282+4845188. To obtain a light curve solution we used a model of a nova-like star whose emission sources are a white dwarf surrounded by an accretion disk, a secondary star filling its Roche lobe, a hot spot and a hot line. The obtained global parameters are compared with those of the eclipsing nova-like UX UMa. Results: 2MASS J01074282+4845188 shows the deepest permanent eclipse among the known nova-like stars. It is reproduced by covering the very bright accretion disk by the secondary component. The luminosity of the disk is much bigger than that of the rest light sources. The determined high temperature of the disk is typical for that observed during the outbursts of CVs. The primary of 2MASS J01074282+4845188 is one of the hottest white dwarfs in CVs. The temperature of 5090 K of its secondary is also quite high and more appropriate for a long-period SW Sex star. It might be explained by the intense heating from the hot white dwarf and the hot accretion disk of the target. Conclusions: The high mass accretion rate Ṁ = 8 × 10-9 M⊙ yr-1, the broad and single-peaked Hα emission profile, and the presence of an S-wave are sure signs for the SW Sex classification of 2MASS J01074282+4845188. The obtained flat temperature distribution along the disk radius as well as the deviation of the energy distribution from the black-body law are evidence of the non-steady

  1. A semi-analytic model of the turbulent multi-phase interstellar medium

    NASA Astrophysics Data System (ADS)

    Braun, H.; Schmidt, W.

    2012-04-01

    We present a semi-analytic model for the interstellar medium that considers local processes and structures of turbulent star-forming gas. A volume element of the interstellar medium is described as a multi-phase system, comprising a cold and a warm gas phase in effective (thermal plus turbulent) pressure equilibrium and a stellar component. The cooling instability of the warm gas feeds the cold phase, while various heating processes transfer cold gas to the warm phase. The cold phase consists of clumps embedded in diffuse warm gas, where only the molecular fraction of the cold gas may be converted into stars. The fraction of molecular gas is approximately calculated, using a Strömgren-like approach and the efficiency of star formation is determined by the state of the cold gas and the turbulent velocity dispersion on the clump length-scale. Gas can be heated by supernovae and ultraviolet emission of massive stars, according to the evolutionary stages of the stellar populations and the initial mass function. Since turbulence has a critical impact on the shape of the gaseous phases, on the production of molecular hydrogen and on the formation of stars, the consistent treatment of turbulent energy - the kinetic energy of unresolved motions - is an important new feature of our model. Besides turbulence production by supernovae and the cooling instability, we also take into account the forcing by large-scale motions. We formulate a set of ordinary differential equations, which statistically describes star formation and the exchange between the different budgets of mass and energy in a region of the interstellar medium with given mean density, size, metallicity and external turbulence forcing. By exploring the behaviour of the solutions, we find equilibrium states, in which the star formation efficiencies are consistent with observations. Kennicutt-Schmidt-like relations naturally arise from the equilibrium solutions, while conventional star formation models in

  2. J/ψ production in relativistic heavy ion collisions from a multi-phase transport model

    NASA Astrophysics Data System (ADS)

    Zhang, Bin; Li, Bao-An; Ko, C. M.; Lin, Ziwei; Pal, Subrata

    2002-04-01

    J/ψ production due to the presence of multiple charm-anti-charm pairs in relativistic nuclear collisions is studied within the framework of A Multi-Phase Transport (AMPT) model. The direct production of J/ψ particles from charm-anti-charm quark collisions and from D and barD meson collisions is shown to depend sensitively on the dynamics of the hot and dense system produced in relativistic nuclear collisions. The presence of color screening dissociation of J/ψ particles leads to a large decrease of the production of J/ψ from final state interactions. Final hadronic interactions may lead to an extra production of J/ψ over those produced during the partonic stage. We demonstrate that J/ψ production in the hadronic phase depends sensitively on the effective mass of the charm mesons. The number of J/ψ's produced from final state interactions per binary collision in Au+Au collisions is smaller than that in corresponding pp collisions.

  3. Synchrotron Studies Under Extreme Conditions: Tackling the Multi-Phase with the Multi-Anvil

    NASA Astrophysics Data System (ADS)

    Whitaker, M. L.; Chen, H.; Vaughan, M. T.; Weidner, D. J.

    2012-12-01

    Understanding the properties and behaviors of materials and multi-phase aggregates under conditions of high pressure and temperature are vital to unraveling the mysteries that lie beneath the surface of the planet. Advances in in situ experimental techniques utilizing synchrotron radiation at these extreme conditions have helped to provide answers to many fundamental questions that were previously unattainable. In particular, the Multi-Anvil apparatus has proven to be an invaluable tool for studying the morphological characteristics and physical properties of materials under extreme conditions as a function of pressure, temperature, stress, strain, and time. Moreover, the science is still continuing to evolve, and we have begun to step outside the realm of the static into the study of dynamic processes and their real-time responses to changes in the aforementioned variables, and even to the frequency and rate of these changes. This presentation will discuss the evolution and present state of the art in synchrotron-based multi-anvil techniques at the COMPRES-funded X17MAC Facility at the National Synchrotron Light Source, of which Professor R.C. Liebermann has been an integral player during his scientific career, and particularly during his tenure as President of COMPRES.

  4. Numerical analysis for the multi-phase flow of pulverized coal injection inside blast furnace tuyere

    SciTech Connect

    Chen, C.W.

    2005-09-01

    The pulverized coal injection (PCI) system was modified from single lance injection into double lance injection at No. 3 Blast Furnace of CSC. It is beneficial to reduce the cost of coke. However, the injected coal was found very close to the inner wall of the tuyere during the operation, such as to cause the possibility of erosion for the tuyere. In this study a three-dimensional mathematical model has been developed based on a computational fluid dynamics software PHOENICS to simulate the fluid flow phenomena inside blast furnace tuyere. The model was capable of handling steady-state, three-dimensional multi-phase flow of pulverized coal injection. The model was applied to simulate the flow patterns of the injection coal inside the tuyere with two kinds of lance design for the PCI system. The distribution of injection coal was simulated such as to estimate the possibility of erosion for the tuyere. The calculated results agreed with the operating experience of CSC plant and the optimum design of double lance was suggested. The model was also applied to simulate the oxygen concentration distribution with these different oxygen enrichments for the coal/oxygen lance system. The calculated results agreed with the experimental measurement. These test results demonstrate that the model is both reasonably reliable and efficient.

  5. Multi-phase pattern evolution in gas-permeable polydimethylsiloxane (PDMS) microchannels during heating

    NASA Astrophysics Data System (ADS)

    Lu, Yanyan; Wang, Fen; Wang, Hao

    2011-06-01

    The evolution of the multi-phase patterns in water in heated gas-permeable PDMS microchannels was investigated using a heater wire inserted through the channel in design I and embedded alongside the channel in design II. The heating methods created different multi-phase patterns. Bubbles were found in design I generated from the channel walls rather than the wire surface. Interesting droplets-in-bubble pattern, i.e. bunches of micro droplets inside bubbles, was also observed. The channel in design II had a hot side and a cool side with the droplets-in-bubble pattern observed only on the cool side. The evaporation and condensation in the channel created a distillation process that would significantly affect reactants within channel. The multi-phase regimes in the PDMS channels were all summarized with pattern maps and curves. The droplets-in-bubble formation mechanisms were described.

  6. Turbulent Mixing and Combustion of Multi-Phase Reacting Flows in Ramjet and Ducted Rocket Environment.

    DTIC Science & Technology

    1982-10-01

    both the fuel characteristics (gaseous fuels, boron-laden gaseous fuels, liquid fuels, and slurry fuels) and the flow field (axisymmetric-coaxial...D-A133 802 TURBULENT M IXING AND COMBUSTION OF MULTI-PHASE REACTING i/1 FLOWS I N RAMJET*RA U) NAVAL WEAPONS CENTER CHINA LAKE CA M J LEE ET AL. OCT...AFOSR MIPR 82-00010 .w~ TURBULENT MIXING AND COMBUSTION OF MULTI-PHASE REACTING FLOWS IN RAMJET AND DUCTED ROCKET ENVIRONMENT M. J. Lee K.C. Schadow

  7. Robust second-order scheme for multi-phase flow computations

    NASA Astrophysics Data System (ADS)

    Shahbazi, Khosro

    2017-06-01

    A robust high-order scheme for the multi-phase flow computations featuring jumps and discontinuities due to shock waves and phase interfaces is presented. The scheme is based on high-order weighted-essentially non-oscillatory (WENO) finite volume schemes and high-order limiters to ensure the maximum principle or positivity of the various field variables including the density, pressure, and order parameters identifying each phase. The two-phase flow model considered besides the Euler equations of gas dynamics consists of advection of two parameters of the stiffened-gas equation of states, characterizing each phase. The design of the high-order limiter is guided by the findings of Zhang and Shu (2011) [36], and is based on limiting the quadrature values of the density, pressure and order parameters reconstructed using a high-order WENO scheme. The proof of positivity-preserving and accuracy is given, and the convergence and the robustness of the scheme are illustrated using the smooth isentropic vortex problem with very small density and pressure. The effectiveness and robustness of the scheme in computing the challenging problem of shock wave interaction with a cluster of tightly packed air or helium bubbles placed in a body of liquid water is also demonstrated. The superior performance of the high-order schemes over the first-order Lax-Friedrichs scheme for computations of shock-bubble interaction is also shown. The scheme is implemented in two-dimensional space on parallel computers using message passing interface (MPI). The proposed scheme with limiter features approximately 50% higher number of inter-processor message communications compared to the corresponding scheme without limiter, but with only 10% higher total CPU time. The scheme is provably second-order accurate in regions requiring positivity enforcement and higher order in the rest of domain.

  8. A CUDA based parallel multi-phase oil reservoir simulator

    NASA Astrophysics Data System (ADS)

    Zaza, Ayham; Awotunde, Abeeb A.; Fairag, Faisal A.; Al-Mouhamed, Mayez A.

    2016-09-01

    Forward Reservoir Simulation (FRS) is a challenging process that models fluid flow and mass transfer in porous media to draw conclusions about the behavior of certain flow variables and well responses. Besides the operational cost associated with matrix assembly, FRS repeatedly solves huge and computationally expensive sparse, ill-conditioned and unsymmetrical linear system. Moreover, as the computation for practical reservoir dimensions lasts for long times, speeding up the process by taking advantage of parallel platforms is indispensable. By considering the state of art advances in massively parallel computing and the accompanying parallel architecture, this work aims primarily at developing a CUDA-based parallel simulator for oil reservoir. In addition to the initial reported 33 times speed gain compared to the serial version, running experiments showed that BiCGSTAB is a stable and fast solver which could be incorporated in such simulations instead of the more expensive, storage demanding and usually utilized GMRES.

  9. Effect of forward looking sites on a multi-phase lattice hydrodynamic model

    NASA Astrophysics Data System (ADS)

    Redhu, Poonam; Gupta, Arvind Kumar

    2016-03-01

    A new multi-phase lattice hydrodynamic traffic flow model is proposed by considering the effect of multi-forward looking sites on a unidirectional highway. We examined the qualitative properties of proposed model through linear as well as nonlinear stability analysis. It is shown that the multi-anticipation effect can significantly enlarge the stability region on the phase diagram and exhibit three-phase traffic flow. It is also observed that the multi-forward looking sites have prominent influence on traffic flow when driver senses the relative flux of leading vehicles. Theoretical findings are verified using numerical simulation which confirms that the traffic jam is suppressed efficiently by considering the information of leading vehicles in unidirectional multi-phase traffic flow.

  10. Multi-phase extraction of glycoraphanin from broccoli using aminium ionic liquid-based silica.

    PubMed

    Tian, Minglei; Bi, Wentao; Row, Kyung Ho

    2013-01-01

    Glucosinolates, a class of phytochemicals found in broccoli, have attracted recent interest due to the potential health benefits associated with their dietary intake. Glucoraphanin, the most common glucosinolate in broccoli can be converted to a known cancer chemopreventive agent. Multi-phase extraction in solid-phase extraction cartridges was developed to simultaneously extract and separate this compound. Multi-phase extraction with functionalised ionic liquid-based silica as a sorbent was used to simultaneously extract and separate glucoraphanin from broccoli. The sorbent and broccoli sample were packed into a single cartridge, and a fixed volume of water was then used to extract and remove the target compound from the sample to the sorbent over 15 repetitions. The sorbent was then washed with n-hexane to remove any interference and the target compound was eluted with water-1% acetic acid (vol.). Under the optimised condition, 0.038 mg/g of glucoraphanin was obtained by multi-phase extraction with 0.2 g of sorbent. The adsorption isotherm allowed investigation of the interactions between the sorbent and target compound and provided evidence for the accuracy of this method. The low deviation error, small amount of solvents required, highly selective separation and stability of the method justify further research. Copyright © 2012 John Wiley & Sons, Ltd.

  11. Numerical Analysis of Velocity Dispersion in Multi-Phase Fluid-Saturated Porous Rocks

    NASA Astrophysics Data System (ADS)

    Chen, Xuehua; Zhong, Wenli; Gao, Gang; Zou, Wen; He, Zhenhua

    2016-12-01

    Seismic waves are subject to velocity dispersion when they propagate in fluid-saturated porous media. In this work, we explore the velocity dispersion behavior of P- and SV-waves in multi-phase fluid-saturated porous reservoirs while taking into account the effects of multi-phase pore fluids on the effective viscosities that control the wave-induced fluid flow. The effective viscosities associated with the hydrocarbon saturation of a synthetic sandstone reservoir saturated with different pore fluid mixtures are calculated using the Refutas model. We then analyze the frequency-dependent velocity, dispersion variation rate and characteristic frequency for different fluid saturation cases by employing Chapman's dynamic equivalent-medium theory. The results demonstrate that the hydrocarbon proportions and types in multi-phase mixed pore fluids significantly affect the magnitude and characteristic frequencies of velocity dispersion features for both the P- and S-waves. The dispersion anomalies of SV-waves are in general larger than those of the P-waves. This indicates that the velocity dispersion anomalies of SV-waves are equally sensitive to fluid saturation as the P-waves and should not be neglected. The velocities at lower frequencies (e.g., 10 and 100 Hz) within the seismic frequency range show a more remarkable decrease with increasing hydrocarbon proportion than those at higher frequency (1000 Hz). The numerical examples help to improve the understanding of the frequency-dependent AVO inversion from seismic reflection data.

  12. Numerical Analysis of Velocity Dispersion in Multi-Phase Fluid-Saturated Porous Rocks

    NASA Astrophysics Data System (ADS)

    Chen, Xuehua; Zhong, Wenli; Gao, Gang; Zou, Wen; He, Zhenhua

    2017-03-01

    Seismic waves are subject to velocity dispersion when they propagate in fluid-saturated porous media. In this work, we explore the velocity dispersion behavior of P- and SV-waves in multi-phase fluid-saturated porous reservoirs while taking into account the effects of multi-phase pore fluids on the effective viscosities that control the wave-induced fluid flow. The effective viscosities associated with the hydrocarbon saturation of a synthetic sandstone reservoir saturated with different pore fluid mixtures are calculated using the Refutas model. We then analyze the frequency-dependent velocity, dispersion variation rate and characteristic frequency for different fluid saturation cases by employing Chapman's dynamic equivalent-medium theory. The results demonstrate that the hydrocarbon proportions and types in multi-phase mixed pore fluids significantly affect the magnitude and characteristic frequencies of velocity dispersion features for both the P- and S-waves. The dispersion anomalies of SV-waves are in general larger than those of the P-waves. This indicates that the velocity dispersion anomalies of SV-waves are equally sensitive to fluid saturation as the P-waves and should not be neglected. The velocities at lower frequencies (e.g., 10 and 100 Hz) within the seismic frequency range show a more remarkable decrease with increasing hydrocarbon proportion than those at higher frequency (1000 Hz). The numerical examples help to improve the understanding of the frequency-dependent AVO inversion from seismic reflection data.

  13. Factors Controlling the Properties of Multi-Phase Arctic Stratocumulus Clouds

    NASA Technical Reports Server (NTRS)

    Fridlind, Ann; Ackerman, Andrew; Menon, Surabi

    2005-01-01

    The 2004 Multi-Phase Arctic Cloud Experiment (M-PACE) IOP at the ARM NSA site focused on measuring the properties of autumn transition-season arctic stratus and the environmental conditions controlling them, including concentrations of heterogeneous ice nuclei. Our work aims to use a large-eddy simulation (LES) code with embedded size-resolved aerosol and cloud microphysics to identify factors controlling multi-phase arctic stratus. Our preliminary simulations of autumn transition-season clouds observed during the 1994 Beaufort and Arctic Seas Experiment (BASE) indicated that low concentrations of ice nuclei, which were not measured, may have significantly lowered liquid water content and thereby stabilized cloud evolution. However, cloud drop concentrations appeared to be virtually immune to changes in liquid water content, indicating an active Bergeron process with little effect of collection on drop number concentration. We will compare these results with preliminary simulations from October 8-13 during MPACE. The sensitivity of cloud properties to uncertainty in other factors, such as large-scale forcings and aerosol profiles, will also be investigated. Based on the LES simulations with M-PACE data, preliminary results from the NASA GlSS single-column model (SCM) will be used to examine the sensitivity of predicted cloud properties to changing cloud drop number concentrations for multi-phase arctic clouds. Present parametrizations assumed fixed cloud droplet number concentrations and these will be modified using M-PACE data.

  14. Multi-phase functionalization of titanium for enhanced photon absorption in the vis-NIR region

    PubMed Central

    Thakur, Pooja; Tan, Bo; Venkatakrishnan, Krishnan

    2015-01-01

    Inadequate absorption of Near Infrared (NIR) photons by conventional silicon solar cells has been a major stumbling block towards the attainment of a high efficiency “full spectrum” solar cell. An effective enhancement in the absorption of such photons is desired as they account for a considerable portion of the tappable solar energy. In this work, we report a remarkable gain observed in the absorption of photons in the near infrared and visible region (400 nm–1000 nm) by a novel multi-phased oxide of titanium. Synthesised via a single step ultra-fast laser pulse interaction with pure titanium, characterisation studies have identified this oxide of titanium to be multi-phased and composed of Ti3O, (TiO.716)3.76 and TiO2 (rutile). Computed to have an average band gap value of 2.39 eV, this ultrafast laser induced multi-phased titanium oxide has especially exhibited steady absorption capability in the NIR range of 750–1000 nm, which to the best of our knowledge, was never reported before. The unique NIR absorption properties of the laser functionalised titanium coupled with the simplicity and versatility of the ultrafast laser interaction process involved thereby provides tremendous potential towards the photon sensitization of titanium and thereafter for the inception of a “full spectrum” solar device. PMID:26477578

  15. Proper Orthogonal Decomposition on Experimental Multi-phase Flow in a Pipe

    NASA Astrophysics Data System (ADS)

    Viggiano, Bianca; Tutkun, Murat; Cal, Raúl Bayoán

    2016-11-01

    Multi-phase flow in a 10 cm diameter pipe is analyzed using proper orthogonal decomposition. The data were obtained using X-ray computed tomography in the Well Flow Loop at the Institute for Energy Technology in Kjeller, Norway. The system consists of two sources and two detectors; one camera records the vertical beams and one camera records the horizontal beams. The X-ray system allows measurement of phase holdup, cross-sectional phase distributions and gas-liquid interface characteristics within the pipe. The mathematical framework in the context of multi-phase flows is developed. Phase fractions of a two-phase (gas-liquid) flow are analyzed and a reduced order description of the flow is generated. Experimental data deepens the complexity of the analysis with limited known quantities for reconstruction. Comparison between the reconstructed fields and the full data set allows observation of the important features. The mathematical description obtained from the decomposition will deepen the understanding of multi-phase flow characteristics and is applicable to fluidized beds, hydroelectric power and nuclear processes to name a few.

  16. Development of an Efficient Meso- scale Multi-phase Flow Solver in Nuclear Applications

    SciTech Connect

    Lee, Taehun

    2015-10-20

    The proposed research aims at formulating a predictive high-order Lattice Boltzmann Equation for multi-phase flows relevant to nuclear energy related application - namely, saturated and sub-cooled boiling in reactors, and liquid- liquid mixing and extraction for fuel cycle separation. An efficient flow solver will be developed based on the Finite Element based Lattice Boltzmann Method (FE- LBM), accounting for phase-change heat transfer and capable of treating multiple phases over length scales from the submicron to the meter. A thermal LBM will be developed in order to handle adjustable Prandtl number, arbitrary specific heat ratio, a wide range of temperature variations, better numerical stability during liquid-vapor phase change, and full thermo-hydrodynamic consistency. Two-phase FE-LBM will be extended to liquid–liquid–gas multi-phase flows for application to high-fidelity simulations building up from the meso-scale up to the equipment sub-component scale. While several relevant applications exist, the initial applications for demonstration of the efficient methods to be developed as part of this project include numerical investigations of Critical Heat Flux (CHF) phenomena in nuclear reactor fuel bundles, and liquid-liquid mixing and interfacial area generation for liquid-liquid separations. In addition, targeted experiments will be conducted for validation of this advanced multi-phase model.

  17. Factors Controlling the Properties of Multi-Phase Arctic Stratocumulus Clouds

    NASA Technical Reports Server (NTRS)

    Fridlind, Ann; Ackerman, Andrew; Menon, Surabi

    2005-01-01

    The 2004 Multi-Phase Arctic Cloud Experiment (M-PACE) IOP at the ARM NSA site focused on measuring the properties of autumn transition-season arctic stratus and the environmental conditions controlling them, including concentrations of heterogeneous ice nuclei. Our work aims to use a large-eddy simulation (LES) code with embedded size-resolved aerosol and cloud microphysics to identify factors controlling multi-phase arctic stratus. Our preliminary simulations of autumn transition-season clouds observed during the 1994 Beaufort and Arctic Seas Experiment (BASE) indicated that low concentrations of ice nuclei, which were not measured, may have significantly lowered liquid water content and thereby stabilized cloud evolution. However, cloud drop concentrations appeared to be virtually immune to changes in liquid water content, indicating an active Bergeron process with little effect of collection on drop number concentration. We will compare these results with preliminary simulations from October 8-13 during MPACE. The sensitivity of cloud properties to uncertainty in other factors, such as large-scale forcings and aerosol profiles, will also be investigated. Based on the LES simulations with M-PACE data, preliminary results from the NASA GlSS single-column model (SCM) will be used to examine the sensitivity of predicted cloud properties to changing cloud drop number concentrations for multi-phase arctic clouds. Present parametrizations assumed fixed cloud droplet number concentrations and these will be modified using M-PACE data.

  18. MULTI-PHASE CFD MODELING OF A SOLID SORBENT CARBON CAPTURE SYSTEM

    SciTech Connect

    Ryan, Emily M.; Xu, Wei; DeCroix, David; Saha, Kringan; Huckaby, E. D.; Darteville, Sebastien; Sun, Xin

    2012-05-01

    Post-combustion solid sorbent carbon capture systems are being studied via computational modeling as part of the U.S. Department of Energy’s Carbon Capture Simulation Initiative (CCSI). The work focuses on computational modeling of device-scale multi-phase computational fluid dynamics (CFD) simulations for given carbon capture reactor configurations to predict flow properties, outlet compositions, temperature and pressure. The detailed outputs of the device-scale models provide valuable insight into the operation of new carbon capture devices and will help in the design and optimization of carbon capture systems. As a first step in this project we have focused on modeling a 1 kWe solid sorbent carbon capture system using the commercial CFD software ANSYS FLUENT®. Using the multi-phase models available in ANSYS FLUENT®, we are investigating the use of Eulerian-Eulerian and Eulerian-Lagrangian methods for modeling a fluidized bed carbon capture design. The applicability of the dense discrete phase method (DDPM) is being considered along with the more traditional Eulerian-Eulerian multi-phase model. In this paper we will discuss the design of the 1 kWe solid sorbent system and the setup of the DDPM and Eulerian-Eulerian models used to simulate the system. The results of the hydrodynamics in the system will be discussed and the predictions of the DDPM and Eulerian-Eulerian simulations will be compared. A discussion of the sensitivity of the model to boundary and initial conditions, computational meshing, granular pressure, and drag sub-models will also be presented.

  19. Using correlation functions to describe complex multi-phase porous media structures

    NASA Astrophysics Data System (ADS)

    Karsanina, Marina; Sizonenko, Timofey; Korost, Dmitry; Gerke, Kirill

    2017-04-01

    Multi-scale flow and transport modelling relies on multi-scale image/property fusion techniques. Previusly we have rigorously addressed binary porous media description and stochastic reconstruction problems. However, numerous porous media have more than two, usually solids and pores, phases, e.g., clays, organic, heavy minerals and such. In this contribution we develop efficient approaches to utilize correlation functions to describe such muti-phase soil and rock structures using large sets of cluster, linear and probability functions, including cross-correlations. The approach is tested on numerous 3D images, which were segmented into 3 and more relevant phases. It is shown that multi-phase correlation functions are potentially a very powerful tool to describe any type of porous media at hand and this study also provides a basis for multi-phase stochastic reconstruction techniques, necessary for multi-phase image fusion to obtain large 3D images of hierarchical porous media based on, for example, macro and micro X-ray tomography scans and FIB/BIB-SEM and SEM. References: 1) Karsanina, M.V., Gerke, K.M., Skvortsova, E.B. and Mallants, D. (2015) Universal spatial correlation functions for describing and reconstructing soil microstructure. PLoS ONE 10(5), e0126515. 2) Gerke, K. M., & Karsanina, M. V. (2015). Improving stochastic reconstructions by weighting correlation functions in an objective function. EPL (Europhysics Letters),111(5), 56002. 3) Gerke, K. M., Karsanina, M. V., Vasilyev, R. V., & Mallants, D. (2014). Improving pattern reconstruction using directional correlation functions. EPL (Europhysics Letters), 106(6), 66002. 4) Gerke, K.M., Karsanina, M. V, Mallants, D., 2015. Universal Stochastic Multiscale Image Fusion: An Example Application for Shale Rock. Sci. Rep. 5, 15880. doi:10.1038/srep15880

  20. A framework for modeling non-steady-state concentrations of semivolatile organic compounds indoors ― I: Emissions from diffusional sources and sorption by interior surfaces

    EPA Science Inventory

    Over the past two decades, more than 20 mass transfer models have been developed for the sources, sinks, and barriers for volatile and semivolatile organic compounds (VOCs and SVOCs) in the indoor environment. While these models have greatly improved our understanding of VOC and ...

  1. Dioxin Chronology and Fluxes in Sediments of the Houston Ship Channel, Texas: Influences of Non-steady State Sediment Transport and Total Organic Carbon

    NASA Astrophysics Data System (ADS)

    Yeager, K.; Santschi, P.; Raifai, H.; Suarez, M.; Brinkmeyer, R.; Hung, C.; Schindler, K.; Andres, M.; Weaver, E.

    2007-05-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (dioxins) are persistent contaminants that bio-accumulate and pose serious risks to biota and humans. The primary objective of this study was to determine the history and mechanisms of dioxin accumulation in sediments of the Houston Ship Channel (HSC) using analytical data on natural and anthropogenic radionuclides (7Be, 137Cs and 210Pb) and dioxins. Results showed that present-day sedimentary dioxin accumulation rates are orders of magnitude higher than atmospheric inputs to the HSC, as determined from a wetland sediment core (FW1) and direct measurements. Most stations showed dioxin peaks in the near surface, indicating continuing inputs despite federal regulations. Stations with high dioxin inventories (11270 > 11193 > 16499 > 15979 > 11261) reflect accentuated accumulation in the HSC as one moves west towards Buffalo Bayou (11270, 15979), at the confluence of the HSC and the San Jacinto River (11261) and upstream in the San Jacinto River (11193). While station 11270 had the highest dioxin inventory, and nearby station 11261 had the highest sediment accumulation rates and dioxin fluxes, present-day dioxin fluxes at 11270 are less than average fluxes and inventories for station 11261 are less than average inventories, for all sites. These results support the interpretation that the HSC is influenced by episodic sediment resuspension, erosion and lateral transport processes driven by tides, wind, shipping and dredging, which can cause intermittently high accumulations of dioxins.

  2. Dioxin chronology and fluxes in sediments of the Houston Ship Channel, Texas: influences of non-steady-state sediment transport and total organic carbon.

    PubMed

    Yeager, Kevin M; Santschi, Peter H; Rifai, Hanadi S; Suarez, Monica P; Brinkmeyer, Robin; Hung, Chin-Chang; Schindler, Kimberly J; Andres, Michael J; Weaver, Erin A

    2007-08-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (dioxins) are persistent contaminants that bioaccumulate and pose serious risks to humans. The primary objective of this study was to determine the history and mechanisms of dioxin accumulation in sediments of the Houston Ship Channel (HSC) using analytical data on natural and anthropogenic radionuclides (7Be, 137Cs, and 210Pb) and dioxins. Results showed that present-day sedimentary dioxin accumulation rates are orders of magnitude higher than atmospheric inputs to the HSC. Most stations showed dioxin peaks in the near surface, indicating continuing inputs despite federal regulations. Stations with high dioxin inventories reflect accentuated accumulation in the HSC as one moves west toward Houston, at the confluence of the HSC and the San Jacinto River and upstream in the San Jacinto River. These results indicate that a significant quantity of dioxins continues to be released into the environment here or that sedimentary storage and release of previously supplied dioxins is significant, or both. The results support the interpretation that the HSC is influenced by episodic sediment resuspension, erosion and lateral transport processes driven by tides, wind, shipping, and dredging, which can cause intermittently high accumulations of dioxins, and underscores the need for additional research on the roles of sedimentary processes in organic contaminant bioavailability.

  3. A framework for modeling non-steady-state concentrations of semivolatile organic compounds indoors ― I: Emissions from diffusional sources and sorption by interior surfaces

    EPA Science Inventory

    Over the past two decades, more than 20 mass transfer models have been developed for the sources, sinks, and barriers for volatile and semivolatile organic compounds (VOCs and SVOCs) in the indoor environment. While these models have greatly improved our understanding of VOC and ...

  4. A multi-phase level set framework for source reconstruction in bioluminescence tomography

    SciTech Connect

    Huang Heyu; Qu Xiaochao; Liang Jimin; He Xiaowei; Chen Xueli; Yang Da'an; Tian Jie

    2010-07-01

    We propose a novel multi-phase level set algorithm for solving the inverse problem of bioluminescence tomography. The distribution of unknown interior source is considered as piecewise constant and represented by using multiple level set functions. The localization of interior bioluminescence source is implemented by tracing the evolution of level set function. An alternate search scheme is incorporated to ensure the global optimal of reconstruction. Both numerical and physical experiments are performed to evaluate the developed level set reconstruction method. Reconstruction results show that the proposed method can stably resolve the interior source of bioluminescence tomography.

  5. Marketing orientation in hospitals: findings from a multi-phased research study.

    PubMed

    Wrenn, Bruce

    2007-01-01

    It is clear from numerous studies conducted over a wide variety of industries that marketing-oriented organizations perform better than those that do not adopt this business philosophy. Recent studies have confirmed this finding in healthcare organizations as well. What is now coming to light is the way in which a marketing orientation does contribute to better performance in hospitals, and the difficulties marketers face in getting recognition of that fact by non-marketers in their organization. This article reports on a multi-phased research study of the implementation of marketing-oriented behaviors in a hospital setting.

  6. Sampling device for withdrawing a representative sample from single and multi-phase flows

    DOEpatents

    Apley, Walter J.; Cliff, William C.; Creer, James M.

    1984-01-01

    A fluid stream sampling device has been developed for the purpose of obtaining a representative sample from a single or multi-phase fluid flow. This objective is carried out by means of a probe which may be inserted into the fluid stream. Individual samples are withdrawn from the fluid flow by sampling ports with particular spacings, and the sampling parts are coupled to various analytical systems for characterization of the physical, thermal, and chemical properties of the fluid flow as a whole and also individually.

  7. Numerical Simulation of Compressible Multi-phase flows using HLLC extension of AUSM +-up Scheme

    NASA Astrophysics Data System (ADS)

    Dhir, Gaurav; Bodi, Kowsik

    2016-11-01

    Solving Multi-fluid equations has always required an onerous effort from researchers with regards to implementing an appropriate numerical scheme which could capture the various facets of such type of flows along with the interaction between the various phases present. Additionally, multi-phase flows bring with them peculiar mathematical properties such as non-hyperbolicity and non-conservativeness which further increases the complexity involved. Our presentation shall present an insight into the advantages and limitations of several numerical schemes proposed in the past and propose to use the HLLC extension of AUSM +-up approach to model such type of flows. We use the single pressure based stratified flow concept and by presenting several test cases, we prove that our method robustly computes multi-phase flow involving discontinuities, such as shock waves and fluid interfaces. Additionally, we present a formulation to incorporate phase transition within multi-fluid equations and establish the validity of this method by presenting several two dimensional test cases such as the Shock-Water Column Interaction problem, the Water-Shock/Air Bubble Interaction problem and the 2D Underwater Explosion problem. Industrial Research and Consultancy Centre, IIT Bombay.

  8. The topology of evolving rift fault networks: Single-phase vs multi-phase rifts

    NASA Astrophysics Data System (ADS)

    Duffy, Oliver B.; Nixon, Casey W.; Bell, Rebecca E.; Jackson, Christopher A.-L.; Gawthorpe, Rob L.; Sanderson, David J.; Whipp, Paul S.

    2017-03-01

    Rift fault networks can be complex, particularly those developed by multiple periods of non-coaxial extension, comprising non-colinear faults with many interactions. Thus, topology, rather than simple geometry, is required to characterise such networks, as it provides a way to describe the arrangement of individual faults in the network. Topology is analysed here in terms of nodes (isolated I nodes or connected Y or X nodes) and branches (I-I, I-C, C-C branches). In map view, the relative proportions of these parameters vary in natural single- and multi-phase rift fault networks and in scaled physical models at different stages of development and strain. Interactions in single-phase rifting are limited to fault splays and along-strike fault linkage (I node and I-I or I-C branch dominated networks), whereas in multi-phase rifting the topology evolves towards Y node and C-C branch dominated networks, with the degree of connectivity increasing with greater strain. The changes in topology and network connectivity have significant implications for fluid flow and reservoir compartmentalisation studies. Furthermore, topology helps to distinguish single and multiple phase extension (i.e. tectonic histories), and thus provide constraints on the geodynamic context of sedimentary basins.

  9. A liver registration method for segmented multi-phase CT images

    NASA Astrophysics Data System (ADS)

    Shi, Shuyue; Yuan, Rong; Sun, Zhi; Xie, Qingguo

    2015-03-01

    In order to build high quality geometric models for liver containing vascular system, multi-phase CT series used in a computer-aided diagnosis and surgical planning system aims at liver diseases have to be accurately registered. In this paper we model the segmented liver containing vascular system as a complex shape and propose a two-step registration method. Without any tree modeling for vessel this method can carry out a simultaneous registration for both liver tissue and vascular system inside. Firstly a rigid aligning using vessel as feature is applied on the complex shape model while genetic algorithm is used as the optimization method. Secondly we achieve the elastic shape registration by combine the incremental free form deformation (IFFD) with a modified iterative closest point (ICP) algorithm. Inspired by the concept of demons method, we propose to calculate a fastest diffusion vector (FDV) for each control point on the IFFD lattice to replace the points correspondence needed in ICP iterations. Under the iterative framework of the modified ICP, the optimal solution of control points' displacement in every IFFD level can be obtained efficiently. The method has been quantitatively evaluated on clinical multi-phase CT series.

  10. Joint numerical microscale simulations of multi-phase flow and NMR relaxation behaviour in porous media

    NASA Astrophysics Data System (ADS)

    Mohnke, O.; Ahrenholz, B.

    2011-12-01

    Nuclear Magnetic Resonance (NMR) is a useful tool for analyzing gas (methane) and fluids (water, oil) in rock formations in order to derive transport and storage properties such as pore-size distributions or relative permeability. Even though there is considerable NMR data available about hydraulic properties of rock formations, this information is only empirical. Thus, the aim of this paper is to present joint NMR and multi-phase flow simulations in micro-scale pore systems derived from micro-CT images to quantify relationships between NMR parameters and transport and storage properties of partially saturated rocks. Hereby, the NMR differential equations were implemented using an advection/diffusion lattice-Boltzmann method (LBM) where the flow field is computed by a coupled LBM CFD solver. The results of numerical imbibition and drainage experiments quantitatively agree with laboratory experiments with regard to frequently found peak shifts and bimodal NMR decay time distributions related to residual water in films and corners as well as to fluids/gases trapped in large pores. This numerical framework enables one to quantitatively describe NMR surface and bulk relaxation processes, diffusive coupling along with the multi-phase flow properties of partially saturated porous systems. Furthermore, it is a viable alternative to the more time-consuming and less controllable laboratory experiments. Such virtual experimental setups can considerably help to benchmark and validate statistical network models to better understand hydraulic properties of partially saturated rocks by using experimentally obtained NMR data.

  11. Determining the Number of Latent Classes in Single- and Multi-Phase Growth Mixture Models

    PubMed Central

    Kim, Su-Young

    2014-01-01

    Stage-sequential (or multiphase) growth mixture models are useful for delineating potentially different growth processes across multiple phases over time and for determining whether latent subgroups exist within a population. These models are increasingly important as social behavioral scientists are interested in better understanding change processes across distinctively different phases, such as before and after an intervention. One of the less understood issues related to the use of growth mixture models is how to decide on the optimal number of latent classes. The performance of several traditionally used information criteria for determining the number of classes is examined through a Monte Carlo simulation study in single- and multi-phase growth mixture models. For thorough examination, the simulation was carried out in two perspectives: the models and the factors. The simulation in terms of the models was carried out to see the overall performance of the information criteria within and across the models, while the simulation in terms of the factors was carried out to see the effect of each simulation factor on the performance of the information criteria holding the other factors constant. The findings not only support that sample size adjusted BIC (ADBIC) would be a good choice under more realistic conditions, such as low class separation, smaller sample size, and/or missing data, but also increase understanding of the performance of information criteria in single- and multi-phase growth mixture models. PMID:24729675

  12. A statistical approach to the brittle fracture of a multi-phase solid

    NASA Technical Reports Server (NTRS)

    Liu, W. K.; Lua, Y. I.; Belytschko, T.

    1991-01-01

    A stochastic damage model is proposed to quantify the inherent statistical distribution of the fracture toughness of a brittle, multi-phase solid. The model, based on the macrocrack-microcrack interaction, incorporates uncertainties in locations and orientations of microcracks. Due to the high concentration of microcracks near the macro-tip, a higher order analysis based on traction boundary integral equations is formulated first for an arbitrary array of cracks. The effects of uncertainties in locations and orientations of microcracks at a macro-tip are analyzed quantitatively by using the boundary integral equations method in conjunction with the computer simulation of the random microcrack array. The short range interactions resulting from surrounding microcracks closet to the main crack tip are investigated. The effects of microcrack density parameter are also explored in the present study. The validity of the present model is demonstrated by comparing its statistical output with the Neville distribution function, which gives correct fits to sets of experimental data from multi-phase solids.

  13. A study of major mergers using a multi-phase ISM code

    NASA Astrophysics Data System (ADS)

    Weniger, J.; Theis, Ch.; Harfst, S.

    2009-12-01

    Galaxy interactions are a common phenomenon in clusters of galaxies. Especially major mergers are of particular importance, because they can change the morphological type of galaxies. They have an impact on the mass function of galaxies and they trigger star formation - the main driver of the Galactic Matter Cycle. Therefore, we conducted a study of major mergers by means of a multi-phase ISM code. This code is based on a TREE-SPH-code combined with a sticky particle method allowing for star formation controlled by the properties of a multi-phase ISM. This is in contrast to the usually implemented Schmidt law depending mainly on the gas density. Previously, this code was used on isolated galaxies. Since our star formation recipe is not restricted to a special type of galaxy, it is interesting to apply it to interacting galaxies, too. Our study on major mergers includes a research of global properties of the interacting system, namely the star formation rate and the star formation efficiency, the evaporation and condensation rates, as well as the mass exchange of distinct components, namely stars, diffuse ISM, and clouds. Investigating these properties provides insight to interrelations between various physical processes. The results indicate that the star formation efficiency as well as the evaporation and condensation rates are influenced by the interaction.

  14. Multi-phase post-mortem CT-angiography: a pathologic correlation study on cardiovascular sudden death

    PubMed Central

    Turillazzi, Emanuela; Frati, Paola; Pascale, Natascha; Pomara, Cristoforo; Grilli, Giampaolo; Viola, Rocco Valerio; Fineschi, Vittorio

    2016-01-01

    Multi-phase post-mortem CT-angiography (MPMCTA) has the great potential to increase the quality of the post-mortem investigation, especially in the area of sudden death; however, its role as routine complement to the pathology toolbox is still questioned as it needs to be further standardized. The aim of this study is to investigate the contribution of MPMCTA in cases of sudden unexplained death in adults and in particular in sudden cardiovascular death. Sixty-eight sudden unexpected deaths of adults were investigated at our institution between 2012 and 2013. Ten cases underwent MPMCTA and autopsy and were included in the study. Before the angiographic step by complete filling of the vascular system, prior to any manipulation of the body, a non-contrast CT-scan was carried out. Image reconstructions were performed on a CT workstation (Vitrea) and two radiologists experienced with post mortem imaging interpreted the MPMCTA findings. In all 10 cases, we could state a good correlation between combination of post-mortem CT and MPMCTA and autopsy procedures, confirming a high diagnostic sensitivity. With this case series we want to illustrate the advantages offered by performing MPMCTA when facing a sudden death, regardless of specific suspicion for acute coronary syndrome or other vascular or ischemic disease. PMID:27928228

  15. Engineering functionalized multi-phased silicon/silicon oxide nano-biomaterials to passivate the aggressive proliferation of cancer.

    PubMed

    Premnath, P; Tan, B; Venkatakrishnan, K

    2015-07-20

    Currently, the use of nano silicon in cancer therapy is limited as drug delivery vehicles and markers in imaging, not as manipulative/controlling agents. This is due to limited properties that native states of nano silicon and silicon oxides offers. We introduce nano-functionalized multi-phased silicon/silicon oxide biomaterials synthesized via ultrashort pulsed laser synthesis, with tunable properties that possess inherent cancer controlling properties that can passivate the progression of cancer. This nanostructured biomaterial is composed of individual functionalized nanoparticles made of a homogenous hybrid of multiple phases of silicon and silicon oxide in increasing concentration outwards from the core. The chemical properties of the proposed nanostructure such as number of phases, composition of phases and crystal orientation of each functionalized nanoparticle in the three dimensional nanostructure is defined based on precisely tuned ultrashort pulsed laser-material interaction mechanisms. The amorphous rich phased biomaterial shows a 30 fold (95%) reduction in number of cancer cells compared to bulk silicon in 48 hours. Further, the size of the cancer cells reduces by 76% from 24 to 48 hours. This method exposes untapped properties of combination of multiple phases of silicon oxides and its applications in cancer therapy.

  16. Engineering functionalized multi-phased silicon/silicon oxide nano-biomaterials to passivate the aggressive proliferation of cancer

    PubMed Central

    Premnath, P.; Tan, B.; Venkatakrishnan, K.

    2015-01-01

    Currently, the use of nano silicon in cancer therapy is limited as drug delivery vehicles and markers in imaging, not as manipulative/controlling agents. This is due to limited properties that native states of nano silicon and silicon oxides offers. We introduce nano-functionalized multi-phased silicon/silicon oxide biomaterials synthesized via ultrashort pulsed laser synthesis, with tunable properties that possess inherent cancer controlling properties that can passivate the progression of cancer. This nanostructured biomaterial is composed of individual functionalized nanoparticles made of a homogenous hybrid of multiple phases of silicon and silicon oxide in increasing concentration outwards from the core. The chemical properties of the proposed nanostructure such as number of phases, composition of phases and crystal orientation of each functionalized nanoparticle in the three dimensional nanostructure is defined based on precisely tuned ultrashort pulsed laser-material interaction mechanisms. The amorphous rich phased biomaterial shows a 30 fold (95%) reduction in number of cancer cells compared to bulk silicon in 48 hours. Further, the size of the cancer cells reduces by 76% from 24 to 48 hours. This method exposes untapped properties of combination of multiple phases of silicon oxides and its applications in cancer therapy. PMID:26190009

  17. Constitutive Relations for Reactive Transport Modeling: Effects of Chemical Reactions on Multi-Phase Flow Properties

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Liu, H. H.; van Dijke, M. I.; Geiger, S.; Agar, S. M.

    2016-12-01

    The relationship between flow properties and chemical reactions is key to modeling subsurface reactive transport. This study develops closed-form equations to describe the effects of mineral precipitation and dissolution on multiphase flow properties (capillary pressure and relative permeabilities) of porous media. The model accounts for the fact that precipitation/dissolution only takes place in the water-filled part of pore space. The capillary tube concept was used to connect pore-scale changes to macroscopic hydraulic properties. Precipitation/dissolution induces changes in the pore radii of water-filled pores and consequently in the pore-size distribution. The updated pore-size distribution is converted back to a new capillary pressure-water saturation relation from which the new relative permeabilities are calculated. Pore network modeling is conducted on a Berea sandstone to validate the new continuum-scale relations. The pore network modeling results are satisfactorily predicted by the new closed-form equations. Currently the effects of chemical reactions on flow properties are represented as a relation between permeability and porosity in reactive transport modeling. Porosity is updated after chemical calculations from the change of mineral volumes, then permeability change is calculated from the porosity change using an empirical permeability-porosity relation, most commonly the Carman-Kozeny relation, or the Verma-Pruess relation. To the best of our knowledge, there are no closed-form relations available yet for the effects of chemical reactions on multi-phase flow properties, and thus currently these effects cannot be accounted for in reactive transport modeling. This work presents new constitutive relations to represent how chemical reactions affect multi-phase flow properties on the continuum scale based on the conceptual model of parallel capillary tubes. The parameters in our new relations are either pre-existing input in a multi-phase flow

  18. Energetics of the multi-phase fluid flow in a narrow kerf in laser cutting conditions

    NASA Astrophysics Data System (ADS)

    Golyshev, A. A.; Orishich, A. M.; Shulyatyev, V. B.

    2016-10-01

    The energy balance of the multi-phase medium flow is studied experimentally under the laser cutting. Experimental data are generalized due to the condition of minimal roughness of the created surface used as a quality criterion of the melt flow, and also due to the application of dimensionless parameters: Peclet number and dimensionless absorbed laser power. For the first time ever it is found that, regardless the assistant gas (oxygen or nitrogen), laser type (the fiber one with the wavelength of 1.07 µm or CO2-laser with the wavelength of 10.6 µm), the minimal roughness is provided at a certain energy input in a melt unit, about 26 J/mm3. With oxygen, 50% of this input is provided by the radiation, the other 50% - by the exothermic reaction of iron oxidation.

  19. Analysis of acid transport through multi-phase epoxy mortars for wastewater structures.

    PubMed

    Valix, M

    2015-01-01

    The characteristics of acid migration through epoxy mortars were examined. Diffusion coefficients of typical sewer bio-metabolised acids: sulphuric, nitric, citric and oxalic acids were determined by gravimetric sorption method and fitted to the multi-phase Jacob-Jones model. Acid permeation was characterised by hindered pore diffusion with the extent being determined by the polarity of the acid and epoxy, and by the microstructure of the epoxy. Epoxy with higher polarity was able to reduce the diffusion coefficients by 49, while dense phases of the coating reduced the diffusion coefficient by 5,100. These results reflect the relative influence of epoxy polarity and microstructure on their performance as protective liners in sewers.

  20. Ultrasonic tomography for in-process measurements of temperature in a multi-phase medium

    DOEpatents

    Beller, L.S.

    1993-01-26

    A method and apparatus are described for the in-process measurement of internal particulate temperature utilizing ultrasonic tomography techniques to determine the speed of sound through a specimen material. Ultrasonic pulses are transmitted through a material, which can be a multi-phase material, over known flight paths and the ultrasonic pulse transit times through all sectors of the specimen are measured to determine the speed of sound. The speed of sound being a function of temperature, it is possible to establish the correlation between speed of sound and temperature, throughout a cross-section of the material, which correlation is programmed into a computer to provide for a continuous in-process measurement of temperature throughout the specimen.

  1. Ultrasonic tomography for in-process measurements of temperature in a multi-phase medium

    DOEpatents

    Beller, Laurence S.

    1993-01-01

    A method and apparatus for the in-process measurement of internal particulate temperature utilizing ultrasonic tomography techniques to determine the speed of sound through a specimen material. Ultrasonic pulses are transmitted through a material, which can be a multi-phase material, over known flight paths and the ultrasonic pulse transit times through all sectors of the specimen are measured to determine the speed of sound. The speed of sound being a function of temperature, it is possible to establish the correlation between speed of sound and temperature, throughout a cross-section of the material, which correlation is programmed into a computer to provide for a continuous in-process measurement of temperature throughout the specimen.

  2. A Data Management System for Multi-Phase Case-Control Studies

    PubMed Central

    Gibeau, Joanne M.; Steinfeldt, Lois C.; Stine, Mark J.; Tullis, Katherine V.; Lynch, H. Keith

    1983-01-01

    The design of a computerized system for the management of data in multi-phase epidemiologic case-control studies is described. Typical study phases include case-control selection, abstracting of data from medical records, and interview of study subjects or next of kin. In consultation with project personnel, requirements for the system were established: integration of data from all study phases into one data base, accurate follow-up of subjects through the study, sophisticated data editing capabilities, ready accessibility of specified programs to project personnel, and generation of current status and exception reports for project managment. SIR (Scientific Information Retrieval), a commercially available data base management system, was selected as the foundation of this system. The system forms a comprehensive data management system applicable to many types of public health research studies.

  3. Strain rate behaviour of multi-phase and complex-phase steels for automotive applications

    NASA Astrophysics Data System (ADS)

    Cadoni, E.; Singh, N. K.; Singha, M. K.; Gupta, N. K.

    2012-08-01

    A combined study on the mechanical behaviour of multi-phase 800 high yield strength steel (MP800HY) and complex-phase 800 steel (CP800) is carried out under tensile loads in the strain rate range from 0.001s-1 to 750s-1. Quasi-static (0.001s-1) tests are performed on electromechanical machine, whereas, medium (5s-1 and 25s-1) and high strain rate (250s-1, 500s-1 and 750s-1) experiments are conducted on hydro-pneumatic machine (HPM) and modified Hopkinson bar (MHB) setup respectively. The thermal softening behaviors of the materials are investigated at quasi-static condition and the materials' m-parameters of the existing Johnson-Cook model are imposed in authors' previous work. Thereafter, the predicted flow stress by Johnson-Cook model has been compared with the experimental results.

  4. The Meshfree Finite Volume Method with application to multi-phase porous media models

    NASA Astrophysics Data System (ADS)

    Foy, Brody H.; Perré, Patrick; Turner, Ian

    2017-03-01

    Numerical methods form a cornerstone of the analysis and investigation of mathematical models for physical processes. Many classical numerical schemes rely on the application of strict meshing structures to generate accurate solutions, which in some applications are an infeasible constraint. Within this paper we outline a new meshfree numerical scheme, which we call the Meshfree Finite Volume Method (MFVM). The MFVM uses interpolants to approximate fluxes in a disjoint finite volume scheme, allowing for the accurate solution of strong-form PDEs. We present a derivation of the MFVM, and give error bounds on the spatial and temporal approximations used within the scheme. We present a wide variety of applications of the method, showing key features, and advantages over traditional meshed techniques. We close with an application of the method to a non-linear multi-phase wood drying model, showing the potential for solving numerically challenging problems.

  5. A Generalized Multi-Phase Framework for Modeling Cavitation in Cryogenic Fluids

    NASA Technical Reports Server (NTRS)

    Dorney, Dan (Technical Monitor); Hosangadi, Ashvin; Ahuja, Vineet

    2003-01-01

    A generalized multi-phase formulation for cavitation in fluids operating at temperatures elevated relative to their critical temperatures is presented. The thermal effects and the accompanying property variations due to phase change are modeled rigorously. Thermal equilibrium is assumed and fluid thermodynamic properties are specified along the saturation line using the NIST-12 databank. Fundamental changes in the physical characteristics of the cavity when thermal effects become pronounced are identified; the cavity becomes more porous, the interface less distinct, and has increased entrainment when temperature variations are present. Quantitative estimates of temperature and pressure depressions in both liquid nitrogen and liquid hydrogen were computed and compared with experimental data of Hord for hydrofoils. Excellent estimates of the leading edge temperature and pressure depression were obtained while the comparisons in the cavity closure region were reasonable. Liquid nitrogen cavities were consistently found to be in thermal equilibrium while liquid hydrogen cavities exhibited small, but distinct, non-equilibrium effects.

  6. Star formation and multi-phase interstellar medium in the first galaxies

    NASA Astrophysics Data System (ADS)

    Ricotti, M.; Parry, O.; Polisensky, E.; Bovill, M.

    Star formation and metal enrichment in the first galaxies is discussed emphasizing similarities to the properties of dwarf spheroidal galaxies in the Local Universe. I present preliminary results from new radiation-hydrodynamic cosmological simulations for the formation of the first galaxies performed with the ART code. The simulations include a detailed model for star formation in a multi-phase ISM, including H_2 formation catalyzed by H- and on dust grains. The first metals are provided by Population III stars, while Population II star formation takes place in resolved molecular clouds. The properties of the first galaxies in these new simulations are in agreement with previous lower resolution simulations in which was found remarkable similarities between the fossils of the first galaxies and the faintest dwarf spheroidal galaxies in the Local Group.

  7. The Effect of Surface Treated Nanoparticles on Single and Multi-Phase Flow in Porous Media

    NASA Astrophysics Data System (ADS)

    DiCarlo, D. A.; Aminzadeh, B.; Chung, D.; Zhang, X.; Wung, R.; Huh, C.; Bryant, S. L.

    2013-12-01

    Surface treated nanoparticles have been suggested to be an additive to CO2 storage scenarios. This is because 1) the nanoparticles have been shown to freely transport through permeable media, and 2) the nanoparticles can stabilize a CO2 in water foam by adhering to the surface of CO2 bubbles/droplets preventing their coalescence. In terms of storage, The formation of CO2 foam will limit the CO2 mobility which can potentially help limit the CO2 leakage. Here, we will show how nanoparticles in porous media can have many interesting properties in single and multi-phase flow. For multi-phase CO2, we have performed experiments where high pressure liquid CO2 displaces brine and vice versa with and without nanoparticles in the brine. We measure the displacement pattern and in-situ CO2 saturation using CT scanning and measure the pressure drop using pressure transducers. We find that the flow is less preferential and the pressure drop is greater than when nanoparticles are present. This suggest the formation of in-situ foam/emulsion. We also show that on a brine chase, the residual saturation of CO2 is greater in the presence of nanoparticles. In terms of nanoparticle transport, it is observed that nanoparticles accumulate at the front of a brine/octane displacement. We hypothesize that this occurs due to the nanoparticles being size excluded from portions of the pore-space. To determine if this occurs in single phase flow, we have also performed experiments single-phase flow with the nanoparticles and tracer. We find that the nanoparticles arrive roughly 5% faster than the tracer. This also has implications for the positioning of nanoparticles in the pore space and how this can change the effective viscosity of the nanoparticle suspension.

  8. Multi-Phase Defense by the Big-Headed Ant, Pheidole obtusospinosa, Against Raiding Army Ants

    PubMed Central

    Huang, Ming H.

    2010-01-01

    Army ants are well known for their destructive raids of other ant colonies. Some known defensive strategies include nest evacuation, modification of nest architecture, blockade of nest entrances using rocks or debris, and direct combat outside the nest. Since army ants highly prefer Pheidole ants as prey in desert habitats, there may be strong selective pressure on Pheidole to evolve defensive strategies to better survive raids. In the case of P. obtusospinosa Pergande (Hymenoptera: Formicidae), the worker caste system includes super majors in addition to smaller majors and minor workers. Interestingly, P. obtusospinosa and the six other New World Pheidole species described to have polymorphic major workers are all found in the desert southwest and adjacent regions of Mexico, all co-occurring with various species of Neivamyrmex army ants. Pheidole obtusospinosa used a multi-phase defensive strategy against army ant raids that involved their largest major workers. During army ant attacks, these super majors were involved in blocking the nest entrance with their enlarged heads. This is the first description of defensive head-blocking by an ant species that lacks highly modified head morphology, such as a truncated or disc-shaped head. P. obtusospinosa super majors switched effectively between passive headblocking at the nest entrance and aggressive combat outside the nest. If this multi-phase strategy is found to be used by other Pheidole species with polymorphic majors in future studies, it is possible that selective pressure by army ant raids may have been partially responsible for the convergent evolution of this extra worker caste. PMID:20569122

  9. Estimating the importance of multi-phase processing on secondary organic aerosol based on a functional-group resolving volatility basis set approach

    NASA Astrophysics Data System (ADS)

    Knote, C. J.; Hodzic, A.; Aumont, B.; Madronich, S.

    2014-12-01

    Traditional understanding views secondary organic aerosol (SOA) formation in the atmosphere as continuous gas-phase oxidation of precursors such as isoprene, aromatics or alkanes. Recent research found that these oxidation products are also highly water soluble. It is further understood that the liquid-phase of cloud droplets as well as deliquesced particles could mediate SOA formation through chemistry in the aqueous-phase. While the effect of multi-phase processing has been studied in detailed for specific compounds like glyoxal or methylglyoxal, an integrated approach that considers the large number of individual compounds has been missing due to the complexity involved. In our work we explore the effects of multi-phase processing on secondary organic aerosol from an explicit modeling perspective.Volatility and solubility determine in which phase a given molecule will be found under given atmospheric conditions. Volatility has already been used to simplify the description of SOA formation in the gas-phase in what became known as the Volatility Basis Set approach (VBS). Compounds contributing to SOA formation are grouped by volatility and then treated as a whole. A number of studies extended the VBS by adding a second dimension like oxygen to carbon ratio or the mean oxidation state. In our work we use functional groups as second dimension.Using explicit oxidation chemistry modeling (GECKO-A) we derive SOA yields as well as their composition in terms of functional groups for commonly used precursors. We then investigate the effect of simply partitioning functional-group specific organic mass into cloud droplets and deliquesced aerosol based on their estimated solubility. Finally we apply simple chemistry in the aqueous-phase and relate changes in functional groups to changes in volatility and subsequent changes in partitioning between gas- and aerosol-phase.In our presentation we will explore the sensitivites of the multi-phase system in a box model setting with

  10. Numerical modeling of experimental observations on gas formation and multi-phase flow of carbon dioxide in subsurface formations

    NASA Astrophysics Data System (ADS)

    Pawar, R.; Dash, Z.; Sakaki, T.; Plampin, M. R.; Lassen, R. N.; Illangasekare, T. H.; Zyvoloski, G.

    2011-12-01

    One of the concerns related to geologic CO2 sequestration is potential leakage of CO2 and its subsequent migration to shallow groundwater resources leading to geochemical impacts. Developing approaches to monitor CO2 migration in shallow aquifer and mitigate leakage impacts will require improving our understanding of gas phase formation and multi-phase flow subsequent to CO2 leakage in shallow aquifers. We are utilizing an integrated approach combining laboratory experiments and numerical simulations to characterize the multi-phase flow of CO2 in shallow aquifers. The laboratory experiments involve a series of highly controlled experiments in which CO2 dissolved water is injected in homogeneous and heterogeneous soil columns and tanks. The experimental results are used to study the effects of soil properties, temperature, pressure gradients and heterogeneities on gas formation and migration. We utilize the Finite Element Heat and Mass (FEHM) simulator (Zyvoloski et al, 2010) to numerically model the experimental results. The numerical models capture the physics of CO2 exsolution, multi-phase fluid flow as well as sand heterogeneity. Experimental observations of pressure, temperature and gas saturations are used to develop and constrain conceptual models for CO2 gas-phase formation and multi-phase CO2 flow in porous media. This talk will provide details of development of conceptual models based on experimental observation, development of numerical models for laboratory experiments and modelling results.

  11. The Impact of a Multi-Phased Assessment on the Planning, Implementation and Management of Federal Education Programs.

    ERIC Educational Resources Information Center

    Scott, Aurelia C.

    The effects of a multi-phased assessment on the management and modification of Federal special education programs and policy is discussed. The purposes and methodology of the three-part assessment procedures (evaluability assessment, rapid feedback assessment, and the performance monitoring system) are presented. This is followed by a description…

  12. Lattice-Boltzmann simulation of multi-phase phenomena related to fuel cells

    NASA Astrophysics Data System (ADS)

    Akhgar, A.; Khalili, B.; Moa, B.; Rahnama, M.; Djilali, N.

    2017-07-01

    Fuel cells are devices that allow conversion of the chemical potential of a fuel and oxidant to produce electricity. A key component of a fuel cell is the catalyst layer, which facilitates the electrochemical reaction and where transport of reactants, charge, and byproduct heat and water take place. The structure and morphology of the catalyst layer determine its effectiveness and, in turn, strongly impact the overall performance and cost of a fuel cell. This paper discusses two central issue related to catalyst layers involving two-phase flow: liquid water transport in the catalyst layer during fuel cell operation, and fabrication of the catalyst layer from colloidal inks where a process of particle agglomeration takes place and eventually determines the final catalyst layer structure. Insight into these two issues are obtained using lattice-Botzmann based multi-phase simulations with formulations tailored to deal with features including high density ratio gas-liquid flow in complex porous media, and particle-particle and particle-hydrodynamic interactions.

  13. New systematic methodology for incorporating dynamic heat transfer modelling in multi-phase biochemical reactors.

    PubMed

    Fernández-Arévalo, T; Lizarralde, I; Grau, P; Ayesa, E

    2014-09-01

    This paper presents a new modelling methodology for dynamically predicting the heat produced or consumed in the transformations of any biological reactor using Hess's law. Starting from a complete description of model components stoichiometry and formation enthalpies, the proposed modelling methodology has integrated successfully the simultaneous calculation of both the conventional mass balances and the enthalpy change of reaction in an expandable multi-phase matrix structure, which facilitates a detailed prediction of the main heat fluxes in the biochemical reactors. The methodology has been implemented in a plant-wide modelling methodology in order to facilitate the dynamic description of mass and heat throughout the plant. After validation with literature data, as illustrative examples of the capability of the methodology, two case studies have been described. In the first one, a predenitrification-nitrification dynamic process has been analysed, with the aim of demonstrating the easy integration of the methodology in any system. In the second case study, the simulation of a thermal model for an ATAD has shown the potential of the proposed methodology for analysing the effect of ventilation and influent characterization. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Evolution of natural gas composition: Predictive multi-phase reaction-transport modeling

    SciTech Connect

    Ortoleva, P.J.; Chang, K.A.; Maxwell, J.M.

    1995-12-31

    A computational modeling approach is used to investigate reaction and transport processes affecting natural gas composition over geological time. Three basic stages are integrated -- gas generation from organic solids or liquids, interactions during source rock expulsion to the reservoir and reactions within the reservoir. Multi-phase dynamics is handled by solving the fully coupled problem of phase-to-phase transfer, intra-phase organic and inorganic reactions and redox and other reactions between fluid phase molecules and minerals. Effects of capillarity and relative permeability are accounted for. Correlations will be determined between gas composition, temperature history, the mineralogy of rocks with which the gas was in contact and the composition of source organic phases. Questions of H{sub 2}S scavenging by oxidizing minerals and the production or removal of CO{sub 2} are focused upon. Our three spatial dimensional, reaction-transport simulation approach has great promise for testing general concepts and as a practical tool for the exploration and production of natural gas.

  15. Thickness-based adaptive mesh refinement methods for multi-phase flow simulations with thin regions

    SciTech Connect

    Chen, Xiaodong; Yang, Vigor

    2014-07-15

    In numerical simulations of multi-scale, multi-phase flows, grid refinement is required to resolve regions with small scales. A notable example is liquid-jet atomization and subsequent droplet dynamics. It is essential to characterize the detailed flow physics with variable length scales with high fidelity, in order to elucidate the underlying mechanisms. In this paper, two thickness-based mesh refinement schemes are developed based on distance- and topology-oriented criteria for thin regions with confining wall/plane of symmetry and in any situation, respectively. Both techniques are implemented in a general framework with a volume-of-fluid formulation and an adaptive-mesh-refinement capability. The distance-oriented technique compares against a critical value, the ratio of an interfacial cell size to the distance between the mass center of the cell and a reference plane. The topology-oriented technique is developed from digital topology theories to handle more general conditions. The requirement for interfacial mesh refinement can be detected swiftly, without the need of thickness information, equation solving, variable averaging or mesh repairing. The mesh refinement level increases smoothly on demand in thin regions. The schemes have been verified and validated against several benchmark cases to demonstrate their effectiveness and robustness. These include the dynamics of colliding droplets, droplet motions in a microchannel, and atomization of liquid impinging jets. Overall, the thickness-based refinement technique provides highly adaptive meshes for problems with thin regions in an efficient and fully automatic manner.

  16. Energy Dissipation in Multi-phase Infalling Clouds in Galaxy Halos

    SciTech Connect

    Murray, S D; Lin, D C

    2004-06-15

    During the epoch of large galaxy formation, thermal instability leads to the formation of a population of cool fragments which are embedded within a background of tenuous hot gas. The hot gas attains a quasi hydrostatic equilibrium. Although the cool clouds are pressure confined by the hot gas, they fall into the galactic potential, subject to drag from the hot gas. The release of gravitational energy due to the infall of the cool clouds is first converted into their kinetic energy which is subsequently dissipated as heat. The cool clouds therefore represent a potentially significant energy source for the background hot gas, depending upon the ratio of thermal energy deposited within the clouds versus the hot gas. In this paper, we show that most of dissipated energy is deposited in to the tenuous hot halo gas, which provides a source of internal energy to replenish its loss in the hot gas through Bremsstrahlung cooling and conduction into the cool clouds. Through this process, the multi-phase structure of the interstellar medium is maintained.

  17. POROSITY AND BAND-STRENGTH MEASUREMENTS OF MULTI-PHASE COMPOSITE ICES

    SciTech Connect

    Bossa, Jean-Baptiste; Fransen, Coen; Cazaux, Stéphanie; Linnartz, Harold; Maté, Belén; Ortigoso, Juan; Pilling, Sergio; Rocha, Will Robson Monteiro

    2015-11-20

    We use experimental mid-infrared optical constants and extended effective medium approximations to determine the porosity and the band strengths of multi-phase composite ices grown at 30 K. A set of porous H{sub 2}O:CH{sub 4} ices are taken as a prototypical example. As a benchmark and proof of concept, the stoichiometry of the ice constituents is retreived with good accuracy from the refractive indices and the extinction coefficients of the reference binary ice mixtures with known compositions. Accurate band strengths are then calculated from experimental mid-infrared spectra of complex ices. We notice that the presence of pores has only a small effect on the overall band strengths, whereas a water dilution can considerably alter them. Different levels of porosity are observed depending on the abundance of methane used as a gas contaminant premixed with water prior to background deposition. The absorption profiles are also found to vary with deposition rate. To explain this, we use Monte Carlo simulations and we observe that the deposition rate strongly affects the pore size distribution as well as the ice morphology through reorganization processes. Extrapolated to genuine interstellar ices, the methodology presented in this paper can be used to evaluate the porosity and to quantify the relative abundances from observational data.

  18. An Efficient Implementation of the GMC Micromechanics Model for Multi-Phased Materials with Complex Microstructures

    NASA Technical Reports Server (NTRS)

    Pindera, Marek-Jerzy; Bednarcyk, Brett A.

    1997-01-01

    An efficient implementation of the generalized method of cells micromechanics model is presented that allows analysis of periodic unidirectional composites characterized by repeating unit cells containing thousands of subcells. The original formulation, given in terms of Hill's strain concentration matrices that relate average subcell strains to the macroscopic strains, is reformulated in terms of the interfacial subcell tractions as the basic unknowns. This is accomplished by expressing the displacement continuity equations in terms of the stresses and then imposing the traction continuity conditions directly. The result is a mixed formulation wherein the unknown interfacial subcell traction components are related to the macroscopic strain components. Because the stress field throughout the repeating unit cell is piece-wise uniform, the imposition of traction continuity conditions directly in the displacement continuity equations, expressed in terms of stresses, substantially reduces the number of unknown subcell traction (and stress) components, and thus the size of the system of equations that must be solved. Further reduction in the size of the system of continuity equations is obtained by separating the normal and shear traction equations in those instances where the individual subcells are, at most, orthotropic. The reformulated version facilitates detailed analysis of the impact of the fiber cross-section geometry and arrangement on the response of multi-phased unidirectional composites with and without evolving damage. Comparison of execution times obtained with the original and reformulated versions of the generalized method of cells demonstrates the new version's efficiency.

  19. Multi-phased screen for the evaluation of topical skin protectants against various chemicals

    SciTech Connect

    Snider, T.H.; Hobson, D.W.

    1993-05-13

    A multi-phased screen involving both in vivo and in vitro tests was used to evaluate the efficacy of 108 topical skin protectants (TSPs) against dermal exposure to sulfur mustard (HD), pinacolyl methylphosphonofluoridate (soman or GD), thickened soman (TGD), and 0-ethyl S-(2-diisopropylaminoethyl) methylphosphonothioate (VX). Assessment of TSPs in vivo involved the application of chemical agents onto a 0.1 mm thickness of TSP spread on the dorsa of rabbits. For the nerve agents GD, TGD, and VX, acetylcholinesterase (AChE) inhibition in lysed red blood cells sampled periodically to 24 hr after dose application was used as an end point. Efficacy against the vesicating agent HD was assessed using the areas of dermal lesions from 1 microns L dosed at multiple sites on rabbits. The in vitro model involved delivery of 8 microns L HD or nerve agent on candidate TSPs applied at 0.015 mL/sq cm on U.S. Army M-8 chemical agent detection paper. The in vitro end point for TSP efficacy evaluation was the time to M-8 paper color change, indicating time to agent penetration. In vitro/in vivo correlations indicated good agreement for HD, GD, and TGD challenges, but not for VX.

  20. A Multi-Phase Based Fluid-Structure-Microfluidic interaction sensor for Aerodynamic Shear Stress

    NASA Astrophysics Data System (ADS)

    Hughes, Christopher; Dutta, Diganta; Bashirzadeh, Yashar; Ahmed, Kareem; Qian, Shizhi

    2014-11-01

    A novel innovative microfluidic shear stress sensor is developed for measuring shear stress through multi-phase fluid-structure-microfluidic interaction. The device is composed of a microfluidic cavity filled with an electrolyte liquid. Inside the cavity, two electrodes make electrochemical velocimetry measurements of the induced convection. The cavity is sealed with a flexible superhydrophobic membrane. The membrane will dynamically stretch and flex as a result of direct shear cross-flow interaction with the seal structure, forming instability wave modes and inducing fluid motion within the microfluidic cavity. The shear stress on the membrane is measured by sensing the induced convection generated by membrane deflections. The advantages of the sensor over current MEMS based shear stress sensor technology are: a simplified design with no moving parts, optimum relationship between size and sensitivity, no gaps such as those created by micromachining sensors in MEMS processes. We present the findings of a feasibility study of the proposed sensor including wind-tunnel tests, microPIV measurements, electrochemical velocimetry, and simulation data results. The study investigates the sensor in the supersonic and subsonic flow regimes. Supported by a NASA SBIR phase 1 contract.

  1. Porosity and Band-strength Measurements of Multi-phase Composite Ices

    NASA Astrophysics Data System (ADS)

    Bossa, Jean-Baptiste; Maté, Belén; Fransen, Coen; Cazaux, Stéphanie; Pilling, Sergio; Robson Monteiro Rocha, Will; Ortigoso, Juan; Linnartz, Harold

    2015-11-01

    We use experimental mid-infrared optical constants and extended effective medium approximations to determine the porosity and the band strengths of multi-phase composite ices grown at 30 K. A set of porous H2O:CH4 ices are taken as a prototypical example. As a benchmark and proof of concept, the stoichiometry of the ice constituents is retreived with good accuracy from the refractive indices and the extinction coefficients of the reference binary ice mixtures with known compositions. Accurate band strengths are then calculated from experimental mid-infrared spectra of complex ices. We notice that the presence of pores has only a small effect on the overall band strengths, whereas a water dilution can considerably alter them. Different levels of porosity are observed depending on the abundance of methane used as a gas contaminant premixed with water prior to background deposition. The absorption profiles are also found to vary with deposition rate. To explain this, we use Monte Carlo simulations and we observe that the deposition rate strongly affects the pore size distribution as well as the ice morphology through reorganization processes. Extrapolated to genuine interstellar ices, the methodology presented in this paper can be used to evaluate the porosity and to quantify the relative abundances from observational data.

  2. A high-resolution multi-phase delay-locked loop with offset locking technique

    NASA Astrophysics Data System (ADS)

    Chuang, Chi-Nan; Wu, Chun-Yen; Lin, Tsui-Wei

    2016-10-01

    In this work, we propose a new type of high-resolution delay-locked loop (DLL) which achieves the performance of high-resolution output by offset locking techniques without restrictions of intrinsic delay in the delay cell. Compared to traditional multi-phase clock generator, this architecture has the features of small size, low jitters, low-power consumption and high resolution. This DLL has been fabricated in 0.35 μm complementary metal-oxide-semiconductor (CMOS) process. The measured root-mean-square and peak-to-peak jitters are 2.89 ps and 31.1 ps at 250 MHz, respectively. The power dissipation is 68 mW for a supply voltage of 3.3 V. The maximum resolution of this work is 144 p and the intrinsic delay of 0.35 μm CMOS process is 220 ps. Comparing with intrinsic delay, the improvement of maximum resolution is 34.5%.

  3. A novel multi-phase bioreactor for fermentations to produce organic acids from dairy wastes

    SciTech Connect

    Yang, S.T.; Zhu, H.; Li, Y.; Silva, E.M.

    1993-12-31

    A novel, fibrous bed bioreactor is developed for multi-phase fermentation processes. The microbial cells are immobilized in a spiral-wound, fibrous matrix packed in the bioreactor. This innovative, structured packing design allows good contact between two different moving phases (e.g., gas-liquid or liquid-solid) and has many advantages over conventional immobilized cell bioreactors. Because the reactor bed is not completely filled with the solid matrix, the bioreactor can be operated for a long period without developing problems such as clogging and high pressure drop usually associated with conventional packed bed and membrane bioreactors. This novel bioreactor was studied for its use in several organic acid fermentations. Production of propionate, acetate, and lactate from whey permeate was studied. In all cases studied, use of the fibrous bioreactor resulted in superior reactor performance-indicated by a more than tenfold increase in productivity, reduction or elimination of the requirement for nutrient supplementation to whey permeate, and resistance to contamination-as compared to conventional batch fermentation processes. Also, the reactor maintained high productivity throughout long-term continuous operation. No contamination, degeneration, or clogging problems were experienced during a 10-month period of continuous operation. This new bioreactor is thus suitable for industrial uses to improve fermentation processes which currently use conventional bioreactors.

  4. Shaping the micromechanical behavior of multi-phase composites for bone tissue engineering.

    PubMed

    Ranganathan, Shivakumar I; Yoon, Diana M; Henslee, Allan M; Nair, Manitha B; Smid, Christine; Kasper, F Kurtis; Tasciotti, Ennio; Mikos, Antonios G; Decuzzi, Paolo; Ferrari, Mauro

    2010-09-01

    Mechanical stiffness is a fundamental parameter in the rational design of composites for bone tissue engineering in that it affects both the mechanical stability and the osteo-regeneration process at the fracture site. A mathematical model is presented for predicting the effective Young's modulus (E) and shear modulus (G) of a multi-phase biocomposite as a function of the geometry, material properties and volume concentration of each individual phase. It is demonstrated that the shape of the reinforcing particles may dramatically affect the mechanical stiffness: E and G can be maximized by employing particles with large geometrical anisotropy, such as thin platelet-like or long fibrillar-like particles. For a porous poly(propylene fumarate) (60% porosity) scaffold reinforced with silicon particles (10% volume concentration) the Young's (shear) modulus could be increased by more than 10 times by just using thin platelet-like as opposed to classical spherical particles, achieving an effective modulus E approximately 8 GPa (G approximately 3.5 GPa). The mathematical model proposed provides results in good agreement with several experimental test cases and could help in identifying the proper formulation of bone scaffolds, reducing the development time and guiding the experimental testing.

  5. Multifocus microscopy with precise color multi-phase diffractive optics applied in functional neuronal imaging

    PubMed Central

    Abrahamsson, Sara; Ilic, Rob; Wisniewski, Jan; Mehl, Brian; Yu, Liya; Chen, Lei; Davanco, Marcelo; Oudjedi, Laura; Fiche, Jean-Bernard; Hajj, Bassam; Jin, Xin; Pulupa, Joan; Cho, Christine; Mir, Mustafa; El Beheiry, Mohamed; Darzacq, Xavier; Nollmann, Marcelo; Dahan, Maxime; Wu, Carl; Lionnet, Timothée; Liddle, J. Alexander; Bargmann, Cornelia I.

    2016-01-01

    Multifocus microscopy (MFM) allows high-resolution instantaneous three-dimensional (3D) imaging and has been applied to study biological specimens ranging from single molecules inside cells nuclei to entire embryos. We here describe pattern designs and nanofabrication methods for diffractive optics that optimize the light-efficiency of the central optical component of MFM: the diffractive multifocus grating (MFG). We also implement a “precise color” MFM layout with MFGs tailored to individual fluorophores in separate optical arms. The reported advancements enable faster and brighter volumetric time-lapse imaging of biological samples. In live microscopy applications, photon budget is a critical parameter and light-efficiency must be optimized to obtain the fastest possible frame rate while minimizing photodamage. We provide comprehensive descriptions and code for designing diffractive optical devices, and a detailed methods description for nanofabrication of devices. Theoretical efficiencies of reported designs is ≈90% and we have obtained efficiencies of > 80% in MFGs of our own manufacture. We demonstrate the performance of a multi-phase MFG in 3D functional neuronal imaging in living C. elegans. PMID:27231594

  6. Catastrophic glacial multi-phase mass movements: a special type of glacial hazard

    NASA Astrophysics Data System (ADS)

    Petrakov, D. A.; Chernomorets, S. S.; Evans, S. G.; Tutubalina, O. V.

    2008-04-01

    Many glacier-related hazards are well typified and studied, but some events stand out from conventional classifications. The Kolka-Karmadon catastrophic event on 20 September 2002 in North Ossetia, North Caucasus, Russia is used as an example of a complex glacier failure exhibiting characteristics such as high mobility, long runout, ultrarapid movement and multiphase behaviour. We consider terminology protocol for glacier hazard classification and then, using the Kolka-Karmadon event and several other examples from around the world, we propose a new term for this family of events. Catastrophic glacier multi-phase mass movement (CGMM) is described and further illustrated by eight major events from Russia, Georgia, Peru, Chile, and Canada. CGMM have a combination of specific features: extraordinary velocities and long-distance runout despite low path angle; progressive fluidisation along travel path; superelevation and run-up of the moving mass, air blast wave in the avalanche flow phase; entrainment of available materials in its path, and the repeated nature of the event. CGMM events may affect areas remote from glaciers which were previously considered as safe.

  7. Factors associated with unprotected anal sex with multiple non-steady partners in the past 12 months: results from the European Men-Who-Have-Sex-With-Men Internet Survey (EMIS 2010).

    PubMed

    Kramer, Sarah C; Schmidt, Axel Jeremias; Berg, Rigmor C; Furegato, Martina; Hospers, Harm; Folch, Cinta; Marcus, Ulrich

    2016-01-19

    Practising unprotected anal intercourse (UAI) with high numbers of partners is associated with increased risk for acquiring and transmitting HIV and other sexually transmitted infections. Our aim was to describe factors associated with UAI with multiple partners in a large sample of MSM from 38 European countries recruited for an online survey in 2010. Data are from the European Men-Who-Have-Sex-With-Men Internet Survey (EMIS). The analysis was restricted to men who reported any anal sex with a non-steady partner in the past 12 months, and who were either never diagnosed with HIV, or who had been diagnosed with HIV more than 12 months ago, reported a detectable viral load and did not exclusively serosort (n = 91,477). Multivariable logistic regression was used to compare men reporting UAI with four or more (4+) non-steady partners to two comparison groups: a) no UAI with non-steady partners, and b) UAI with 1-3 non-steady partners. Overall, 9.6% of the study population reported UAI with 4+ partners in the past 12 months. In both models, factors consistently associated with this behaviour were: having been diagnosed with HIV, lower educational levels, use of nitrite inhalants, drugs associated with sex and parties, or erectile dysfunction drugs in the past 4 weeks, using sex-on-site venues in the past 4 weeks, buying or selling sex in the past 12 months, having experienced physical violence due to sexual attraction to men in the past 12 months, reporting sexual happiness, being out to all or almost all of one's acquaintances, and knowing that ART reduces HIV transmissibility. Effective antiretroviral treatment drastically reduces HIV transmission for men diagnosed with HIV, irrespective of partner numbers. Apart from reducing partner numbers or increasing condom use no other recommendations are currently in place to reduce the risk of HIV acquisition and onward transmission for HIV-negative men practicing UAI with multiple partners. A range of factors were

  8. Modelling multi-phase liquid-sediment scour and resuspension induced by rapid flows using Smoothed Particle Hydrodynamics (SPH) accelerated with a Graphics Processing Unit (GPU)

    NASA Astrophysics Data System (ADS)

    Fourtakas, G.; Rogers, B. D.

    2016-06-01

    A two-phase numerical model using Smoothed Particle Hydrodynamics (SPH) is applied to two-phase liquid-sediments flows. The absence of a mesh in SPH is ideal for interfacial and highly non-linear flows with changing fragmentation of the interface, mixing and resuspension. The rheology of sediment induced under rapid flows undergoes several states which are only partially described by previous research in SPH. This paper attempts to bridge the gap between the geotechnics, non-Newtonian and Newtonian flows by proposing a model that combines the yielding, shear and suspension layer which are needed to predict accurately the global erosion phenomena, from a hydrodynamics prospective. The numerical SPH scheme is based on the explicit treatment of both phases using Newtonian and the non-Newtonian Bingham-type Herschel-Bulkley-Papanastasiou constitutive model. This is supplemented by the Drucker-Prager yield criterion to predict the onset of yielding of the sediment surface and a concentration suspension model. The multi-phase model has been compared with experimental and 2-D reference numerical models for scour following a dry-bed dam break yielding satisfactory results and improvements over well-known SPH multi-phase models. With 3-D simulations requiring a large number of particles, the code is accelerated with a graphics processing unit (GPU) in the open-source DualSPHysics code. The implementation and optimisation of the code achieved a speed up of x58 over an optimised single thread serial code. A 3-D dam break over a non-cohesive erodible bed simulation with over 4 million particles yields close agreement with experimental scour and water surface profiles.

  9. Simulation of Multi-Phase Transport Properties of Rock Samples: The Influence of Mixed Wettability

    NASA Astrophysics Data System (ADS)

    Schwarz, J. O.; Linden, S.; Becker, J.; Wagner, C.; Wiegmann, A.

    2016-12-01

    Multi-phase transport properties of rock samples depend on the pore structure and the wettability of the mineral phases. Mixed wettability, mineral specific contact angles (θ), is a well-known phenomenon of natural samples that represents a challenge for numerical simulations of rock properties. Our digital rock physics software GeoDict is used to investigate the influence of mixed wettability on the transport properties of rocks with the ultimate goal of improving enhanced oil recovery methods. Pore morphology (PM) methods determine the capillary pressure - saturation curve of a porous media. They are based on modelling the three-dimensional geometric distribution of the fluid phases in the pore space. PM methods are in wide use but were originally limited to a single θ. This restriction does not allow for the complexity of rock samples, because the mixed wettability of the sample influences the distribution of the fluid phases and their potential pathways through the pore space. Recently, this limitation was overcome and demonstrated in 2d for highly porous materials. Our consideration of mineral specific θ in 3d allows for a realistic modelling of rock samples. The mixed wettability PM method was implemented in GeoDict recently. In this study it is applied to a core sample of a Berea sandstone. The phase distributions found with the variable contact model can then be used to determine the capillary pressure-saturation relation, and also to determine the relative permeability of the material. As in the original PM approach, this is done by performing a single-phase flow computation on each intermediate phase distribution. Furthermore, the PM method has been extended to explicitly account for hysteresis effects in cycles of imbibition and drainage. We consider mineral specific θ in our numerical simulations and report the influence of mixed wettability on the transport properties of core samples for a cycle of drainage - imbibition - drainage. Finally, the

  10. Advanced Multi-phase Flow CFD Model Development for Solid Rocket Motor Flowfield Analysis

    NASA Technical Reports Server (NTRS)

    Liaw, Paul; Chen, Yen-Sen

    1995-01-01

    A Navier-Stokes code, finite difference Navier-Stokes (FDNS), is used to analyze the complicated internal flowfield of the SRM (solid rocket motor) to explore the impacts due to the effects of chemical reaction, particle dynamics, and slag accumulation on the solid rocket motor (SRM). The particulate multi-phase flowfield with chemical reaction, particle evaporation, combustion, breakup, and agglomeration models are included in present study to obtain a better understanding of the SRM design. Finite rate chemistry model is applied to simulate the chemical reaction effects. Hermsen correlation model is used for the combustion simulation. The evaporation model introduced by Spalding is utilized to include the heat transfer from the particulate phase to the gase phase due to the evaporation of the particles. A correlation of the minimum particle size for breakup expressed in terms of the Al/Al2O3 surface tension and shear force was employed to simulate the breakup of particles. It is assumed that the breakup occurs when the Weber number exceeds 6. A simple L agglomeration model is used to investigate the particle agglomeration. However, due to the large computer memory requirements for the agglomeration model, only 2D cases are tested with the agglomeration model. The VOF (Volume of Fluid) method is employed to simulate the slag buildup in the aft-end cavity of the redesigned solid rocket motor (RSRM). Monte Carlo method is employed to calculate the turbulent dispersion effect of the particles. The flowfield analysis obtained using the FDNS code in the present research with finite rate chemical reaction, particle evaporation, combustion, breakup, agglomeration, and VOG models will provide a design guide for the potential improvement of the SRM including the use of materials and the shape of nozzle geometry such that a better performance of the SRM can be achieved. The simulation of the slag buildup in the aft-end cavity can assist the designer to improve the design of

  11. Numerical Modelling of Multi-Phase Multi-Component Reactive Transport in the Earth's interior

    NASA Astrophysics Data System (ADS)

    Oliveira, Beñat; Afonso, Juan Carlos; Zlotnik, Sergio; Tilhac, Romain

    2017-04-01

    We present a conceptual and numerical approach to model processes in the Earth's interior that involve multiple phases that simultaneously interact thermally, mechanically and chemically. The approach is truly multiphase in the sense that each dynamic phase is explicitly modelled with an individual set of mass, momentum, energy and chemical mass balance equations coupled via interfacial interaction terms. It is also truly multi-component in the sense that the compositions of the system and its constituent thermodynamic phases are expressed by a full set of fundamental chemical components (e.g. SiO_2, Al_2O_3, MgO, etc) rather than proxies. In contrast to previous approaches these chemical components evolve, react with, and partition into, different phases with different physical properties according to an internally-consistent thermodynamic model. This enables a thermodynamically-consistent coupling of the governing set of balance equations. Interfacial processes such as surface tensions and/or surface energy contributions to the dynamics and energetics of the system are also taken into account. The model presented here describes the evolution of systems governed by Multi-Phase Multi-Component Reactive Transport (MPMCRT) based on Ensemble Averaging and Classical Irreversible Thermodynamics principles. This novel approach provides a flexible platform to study the dynamics and non-linear feedbacks occurring within various natural systems at different scales. This notably includes major- and trace-element transport, diffusion-controlled trace-element re-equilibration or rheological changes associated with melt generation and migration in the Earth's mantle.

  12. Segmentation of hepatic artery in multi-phase liver CT using directional dilation and connectivity analysis

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Schnurr, Alena-Kathrin; Zidowitz, Stephan; Georgii, Joachim; Zhao, Yue; Razavi, Mohammad; Schwier, Michael; Hahn, Horst K.; Hansen, Christian

    2016-03-01

    Segmentation of hepatic arteries in multi-phase computed tomography (CT) images is indispensable in liver surgery planning. During image acquisition, the hepatic artery is enhanced by the injection of contrast agent. The enhanced signals are often not stably acquired due to non-optimal contrast timing. Other vascular structure, such as hepatic vein or portal vein, can be enhanced as well in the arterial phase, which can adversely affect the segmentation results. Furthermore, the arteries might suffer from partial volume effects due to their small diameter. To overcome these difficulties, we propose a framework for robust hepatic artery segmentation requiring a minimal amount of user interaction. First, an efficient multi-scale Hessian-based vesselness filter is applied on the artery phase CT image, aiming to enhance vessel structures with specified diameter range. Second, the vesselness response is processed using a Bayesian classifier to identify the most probable vessel structures. Considering the vesselness filter normally performs not ideally on the vessel bifurcations or the segments corrupted by noise, two vessel-reconnection techniques are proposed. The first technique uses a directional morphological operator to dilate vessel segments along their centerline directions, attempting to fill the gap between broken vascular segments. The second technique analyzes the connectivity of vessel segments and reconnects disconnected segments and branches. Finally, a 3D vessel tree is reconstructed. The algorithm has been evaluated using 18 CT images of the liver. To quantitatively measure the similarities between segmented and reference vessel trees, the skeleton coverage and mean symmetric distance are calculated to quantify the agreement between reference and segmented vessel skeletons, resulting in an average of 0:55+/-0:27 and 12:7+/-7:9 mm (mean standard deviation), respectively.

  13. Surgical interventions with fatal outcome: utility of multi-phase postmortem CT angiography.

    PubMed

    Zerlauth, J-B; Doenz, F; Dominguez, A; Palmiere, C; Uské, A; Meuli, R; Grabherr, S

    2013-02-10

    Cases of fatal outcome after surgical intervention are autopsied to determine the cause of death and to investigate whether medical error caused or contributed to the death. For medico-legal purposes, it is imperative that autopsy findings are documented clearly. Modern imaging techniques such as multi-detector computed tomography (MDCT) and postmortem CT angiography, which is used for vascular system imaging, are useful tools for determining cause of death. The aim of this study was to determine the utility of postmortem CT angiography for the medico-legal death investigation. This study investigated 10 medico-legal cases with a fatal outcome after surgical intervention using multi-phase postmortem whole body CT angiography. A native CT scan was performed as well as three angiographic phases (arterial, venous, and dynamic) using a Virtangio(®) perfusion device and the oily contrast agent, Angiofil(®). The results of conventional autopsy were compared to those from the radiological investigations. We also investigated whether the radiological findings affected the final interpretation of cause-of-death. Causes of death were hemorrhagic shock, intracerebral hemorrhage, septic shock, and a combination of hemorrhage and blood aspiration. The diagnoses were made by conventional autopsy as well as by postmortem CT angiography. Hemorrhage played an important role in eight of ten cases. The radiological exam revealed the exact source of bleeding in seven of the eight cases, whereas conventional autopsy localized the source of bleeding only generally in five of the seven cases. In one case, neither conventional autopsy nor CT angiography identified the source of hemorrhage. We conclude that postmortem CT angiography is extremely useful for investigating deaths following surgical interventions. This technique helps document autopsy findings and allows a second examination if it is needed; specifically, it detects and visualizes the sources of hemorrhages in detail, which

  14. Modeling multi-phase transport in deformable, hygroscopic porous media: Applications to convective drying of lumber

    SciTech Connect

    Asensio, C.M.; Seyed-Yagoobi, J.

    1999-07-01

    A fundamental model of multi-phase flow in deformable, hygroscopic porous media has been developed through application of macroscopic energy and mass conservation equations. Microscopic effects are included via volume-averaging techniques for the three phases present in the porous media: liquid, gas, and solid. The model includes convective and capillary transport of free water, convective and diffusive transport of water vapor and air, and diffusive transport of bound water. Porosity variations in deformable media have been included during development of the governing equations. The model is applied to convective drying of lumber via appropriate boundary conditions and transport parameters which are available in the literature. The governing coupled, non-linear equations are rewritten and solved in terms of three governing variables: moisture content, temperature, and gas phase pressure. The conservation equations presented in vector notation have been simplified to one spatial dimension for solution here. Control-volume formulations are used to discretize the governing partial differential equations and boundary conditions with a power-law scheme used to proportion the diffusive and convective flux contributions across the control volume interfaces. An uncoupled solution strategy is employed although each conservation equation is solved implicitly. Presented model results include predictions of moisture, temperature, and gas phase pressure during drying both as averages over time for convective drying at two different ambient conditions and as distributions within the board at any time for high temperature air drying. Flows of individual moisture species (liquid/free water, water vapor, and bound water) within the board are also presented.

  15. Modeling of multi-phase interactions of reactive nitrogen between snow and air in Antarctica

    NASA Astrophysics Data System (ADS)

    McCrystall, M.; Chan, H. G. V.; Frey, M. M.; King, M. D.

    2016-12-01

    In polar and snow-covered regions, the snowpack is an important link between atmospheric, terrestrial and oceanic systems. Trace gases, including nitrogen oxides, produced via photochemical reactions in snow are partially released to the lower atmosphere with considerable impact on its composition. However, the post-depositional processes that change the chemical composition and physical properties of the snowpack are still poorly understood. Most current snow chemistry models oversimplify as they assume air-liquid interactions and aqueous phase chemistry taking place at the interface between the snow grain and air. Here, we develop a novel temperature dependent multi-phase (gas-liquid-ice) physical exchange model for reactive nitrogen. The model is validated with existing year-round observations of nitrate in the top 0.5-2 cm of snow and the overlying atmosphere at two very different Antarctic locations: Dome C on the East Antarctic Plateau with very low annual mean temperature (-54ºC) and accumulation rate (<30 kg m-2 yr-1); and Halley, a coastal site with at times at or above freezing temperatures during summer, high accumulation rate and high background level of sea salt aerosol. We find that below the eutectic temperature of the H2O/dominant ion mixture the surface snow nitrate is controlled by kinetic adsorption onto the surface of snow grains followed by grain diffusion. Above the eutectic temperature, in addition to the former two processes, thermodynamic equilibrium of HNO3 between interstitial air and liquid water pockets, possibly present at triple junctions or grooves at grain boundaries, greatly enhances the nitrate uptake by snow in agreement with the concentration peak observed in summer.

  16. A parallel multi-block/multi-physics approach for multi-phase flow in porous media

    NASA Astrophysics Data System (ADS)

    Lu, Qin

    The main purpose of this dissertation is to investigate accurate and efficient numerical techniques for simulation of multi-phase/multi-component flow and transport phenomena in porous media which are of major importance in the petroleum and environmental industries. We propose to emphasize a novel numerical methodology, which is called the multi-block algorithm. This algorithm is based on the decomposition of the simulation domain into multiple non-overlapping subdomains (blocks) according to the geological, geometric and physical/chemical properties. One then applies the most suitable grid, numerical scheme and physical model in each subdomain, so that the computational cost is reduced and accuracy is preserved. Across the interface of neighboring subdomains, the consistent primary variables and the continuity of the component mass fluxes are imposed in a weak sense. In this dissertation we first discuss the mathematical and numerical formulations of physical models, such as the implicit black-oil model, the implicit and IMPES two-phase hydrology models. We then formulate the multi-block black-oil model coupling different grids, which can be non-matching on the interface. In addition, we define the multi-model couplings; in particular, the coupling of the implicit and IMPES schemes for two-phase immiscible flow, and the coupling of the implicit three-phase black-oil model and the implicit two-phase hydrology model. Computational examples are presented to demonstrate the scalability of the multi-block/multi-model simulators over the traditional single-block/single-model simulators. Excellent agreements of the results between these two approaches are shown. Parallel computation issues, especially the MPI (Message Passing Interface) multi-communicator implementation and model-based load balancing strategies for the parallelism of the multi-model problem are also considered. Summary of these results is presented in the last chapter.

  17. Strain and Torsion Quantification in Mouse Hearts under Dobutamine Stimulation using 2D Multi-Phase MR DENSE

    PubMed Central

    Zhong, Jia; Yu, Xin

    2010-01-01

    In the current study, a 2D multi-phase MR displacement encoding with stimulated echoes (DENSE) imaging and analysis method was developed for direct quantification of Lagrangian strain in the mouse heart. Using the proposed method, less than 10 ms temporal resolution and 0.56 mm in-plane resolution were achieved. A validation study that compared strain calculation by DENSE and by MR tagging showed high correlation between the two methods (R2 > 0.80). Regional ventricular wall strain and twist were characterized in mouse hearts at baseline and under dobutamine stimulation. Dobutamine stimulation induced significant increase in radial and circumferential strains and torsion at peak-systole. A rapid untwisting was also observed during early diastole. This work demonstrates the capability of characterizing cardiac functional response to dobutamine stimulation in the mouse heart using 2D multi-phase MR DENSE. PMID:20740659

  18. Multi-phase classification by a least-squares support vector machine approach in tomography images of geological samples

    NASA Astrophysics Data System (ADS)

    Khan, Faisal; Enzmann, Frieder; Kersten, Michael

    2016-03-01

    Image processing of X-ray-computed polychromatic cone-beam micro-tomography (μXCT) data of geological samples mainly involves artefact reduction and phase segmentation. For the former, the main beam-hardening (BH) artefact is removed by applying a best-fit quadratic surface algorithm to a given image data set (reconstructed slice), which minimizes the BH offsets of the attenuation data points from that surface. A Matlab code for this approach is provided in the Appendix. The final BH-corrected image is extracted from the residual data or from the difference between the surface elevation values and the original grey-scale values. For the segmentation, we propose a novel least-squares support vector machine (LS-SVM, an algorithm for pixel-based multi-phase classification) approach. A receiver operating characteristic (ROC) analysis was performed on BH-corrected and uncorrected samples to show that BH correction is in fact an important prerequisite for accurate multi-phase classification. The combination of the two approaches was thus used to classify successfully three different more or less complex multi-phase rock core samples.

  19. Microstructure characterization of multi-phase composites and utilization of phase change materials and recycled rubbers in cementitious materials

    NASA Astrophysics Data System (ADS)

    Meshgin, Pania

    2011-12-01

    This research focuses on two important subjects: (1) Characterization of heterogeneous microstructure of multi-phase composites and the effect of microstructural features on effective properties of the material. (2) Utilizations of phase change materials and recycled rubber particles from waste tires to improve thermal properties of insulation materials used in building envelopes. Spatial pattern of multi-phase and multidimensional internal structures of most composite materials are highly random. Quantitative description of the spatial distribution should be developed based on proper statistical models, which characterize the morphological features. For a composite material with multi-phases, the volume fraction of the phases as well as the morphological parameters of the phases have very strong influences on the effective property of the composite. These morphological parameters depend on the microstructure of each phase. This study intends to include the effect of higher order morphological details of the microstructure in the composite models. The higher order statistics, called two-point correlation functions characterize various behaviors of the composite at any two points in a stochastic field. Specifically, correlation functions of mosaic patterns are used in the study for characterizing transport properties of composite materials. One of the most effective methods to improve energy efficiency of buildings is to enhance thermal properties of insulation materials. The idea of using phase change materials and recycled rubber particles such as scrap tires in insulation materials for building envelopes has been studied.

  20. Multi-phase modulation for nematic liquid crystal on silicon backplane spatial light modulators using pulse-width modulation driving scheme

    NASA Astrophysics Data System (ADS)

    Lee, Yongmin; Gourlay, James; Hossack, William J.; Underwood, Ian; Walton, Anthony J.

    2004-06-01

    In phase modulating diffractive optical devices multi-phase modulation provides improved performance over binary modulation. Multi-phase modulation can be achieved by using nematic liquid crystal spatial light modulators (NLCSLM) with pulse-width modulation driven from a binary CMOS backplane. This paper presents the characteristics and the driving scheme of the 512 × 512 Si-backplane SLM for the implementation of the multi-phase modulation while comparing the binary and four-level phase holograms. Diffraction efficiency of 39.7% for binary grating and 72.9% for four-level blazed grating were obtained at the spatial frequency 1.56 lines/mm.

  1. Transient competitive complexation in biological kinetic isotope fractionation explains non-steady isotopic effects: Theory and application to denitrification in soils

    SciTech Connect

    Maggi, F.M.; Riley, W.J.

    2009-06-01

    The theoretical formulation of biological kinetic reactions in isotopic applications often assume first-order or Michaelis-Menten-Monod kinetics under the quasi-steady-state assumption to simplify the system kinetics. However, isotopic e ects have the same order of magnitude as the potential error introduced by these simpli cations. Both formulations lead to a constant fractionation factor which may yield incorrect estimations of the isotopic effect and a misleading interpretation of the isotopic signature of a reaction. We have analyzed the isotopic signature of denitri cation in biogeochemical soil systems by Menyailo and Hungate [2006], where high {sup 15}N{sub 2}O enrichment during N{sub 2}O production and inverse isotope fractionation during N{sub 2}O consumption could not be explained with first-order kinetics and the Rayleigh equation, or with the quasi-steady-state Michaelis-Menten-Monod kinetics. When the quasi-steady-state assumption was relaxed, transient Michaelis-Menten-Monod kinetics accurately reproduced the observations and aided in interpretation of experimental isotopic signatures. These results may imply a substantial revision in using the Rayleigh equation for interpretation of isotopic signatures and in modeling biological kinetic isotope fractionation with first-order kinetics or quasi-steady-state Michaelis-Menten-Monod kinetics.

  2. Deformation and failure of single- and multi-phase silicate liquids: seismic precursors and mechanical work

    NASA Astrophysics Data System (ADS)

    Vasseur, Jeremie; Lavallée, Yan; Hess, Kai-Uwe; Wassermann, Joachim; Dingwell, Donald B.

    2013-04-01

    mechanical work tends to concentrate in specific weak regions facilitating dynamical failure of the material through dissipation of the accumulated strain energy. Applying a statistical Global Linearization Method (GLM) in multi-phase silicate liquids samples leads to a maximum likelihood power-law fit of the accelerating rates of released AEs. The calculated α exponent of the famous empirical Failure Forecast Method (FFM) tends to decrease from 2 towards 1 with increasing porosity, suggesting a shift towards an idealized exponential-like acceleration. Single-phase silicate liquids behave more elastically during deformation without much cracking and suddenly releasing their accumulated strain energy at failure, implying less clear trends in monitored AEs. In a predictive prospective, these results support the fact that failure forecasting power is enhanced by the presence of heterogeneities inside a material.

  3. Development and testing of multi-phase glazes for adhesive bonding to zirconia substrates.

    PubMed

    Ntala, Polyxeni; Chen, Xiaohui; Niggli, Jason; Cattell, Michael

    2010-10-01

    The aims of the study were to develop and test multi-phase glaze coatings for zirconia restorations, so that the surface could be etched and adhesively bonded. Zirconia disc specimens (n=125, 16 mm x 1 mm) were cut from cylinders of Y-TZP (yttria-stabilized tetragonal zirconia polycrystals) ZS-Blanks (Kavo, Everest) and sintered overnight. Specimens were subjected to the recommended firing cycles, and next sandblasted. The specimens were divided into 5 groups of 25, with Group 1 as the sandblasted control. Groups 2-5 were coated with overglaze materials (P25 and IPS e.max Ceram glazes) containing secondary phases. Group 2 was (wt%): 10% hydroxyapatite (HA)/P25 glaze, Group 3: 20% IPS Empress 2 glass-ceramic/glaze, Group 4: 20% IPS Empress 2 glass/glaze and Group 5: 30% IPS Empress 2 glass/glaze. After sintering and etching, Monobond-S and composite resin cylinders (Variolink II, Ivoclar-Vivadent) were applied and light cured on the test surfaces. Specimens were water stored for 7 days. Groups were tested using the shear bond strength (SBS) test at a crosshead speed of 0.5 mm/min. Overglazed and the fractured specimen surfaces were viewed using secondary electron microscopy. Room and high temperature XRD and DSC were carried out to characterize the materials. The mean (SD) SBS (MPa) of the test groups were: Group 1: 7.7 (3.2); Group 2: 5.6 (1.7); Group 3: 11.0 (3.0); Group 4: 8.8 (2.6) and Group 5: 9.1 (2.6). Group 3 was significantly different to the control Group 1 (p<0.05). There was no significant difference in the mean SBS values between Group 1 and Groups 2, 4 and 5 (p>0.05). Group 2 showed statistically lower SBS than Groups 3-5 (p<0.05). Lithium disilicate fibres were present in Groups 3-5 and fine scale fibres were grown in the glaze following a porcelain firing cycle (Groups 4 and 5). XRD indicated a lithium disilicate/minor lithium orthophosphate phase (Group 3), and a tetragonal zirconia phase for the sintered Y-TZP ZS-Blanks. DSC and high temperature

  4. Multi-phase hybrid simulation of energetic particle driven magnetohydrodynamic instabilities in tokamak plasmas

    NASA Astrophysics Data System (ADS)

    Todo, Y.

    2016-11-01

    Magnetohydrodynamic (MHD) instabilities driven by energetic particles in tokamak plasmas and the energetic particle distribution formed with the instabilities, neutral beam injection, and collisions are investigated with hybrid simulations for energetic particles and an MHD fluid. The multi-phase simulation, which is a combination of classical simulation and hybrid simulation, is applied to examine the distribution formation process in the collisional slowing-down time scale of energetic ions for various beam deposition power ({P}{NBI}) and slowing-down time ({τ }{{s}}). The physical parameters other than {P}{NBI} and {τ }{{s}} are similar to those of a Tokamak Fusion Test Reactor (TFTR) experiment (Wong et al 1991 Phys. Rev. Lett. 66 1874). For {P}{NBI} = 10 MW and {τ }{{s}} = 100 ms, which is similar to the TFTR experiment, the bursts of toroidal Alfvén eigenmodes take place with a time interval 2 ms, which is close to that observed in the experiment. The maximum radial velocity amplitude (v r) of the dominant TAE at the bursts in the simulation is {v}{{r}}/{v}{{A}}∼ 3× {10}-3 where v A is the Alfvén velocity at the plasma center. For {P}{NBI} = 5 MW and {τ }{{s}} = 20 ms, the amplitude of the dominant TAE is kept at a constant level {v}{{r}}/{v}{{A}}∼ 4× {10}-4. The intermittency of TAE rises with increasing {P}{NBI} and increasing {τ }{{s}} (= decreasing collision frequency). With increasing volume-averaged classical energetic ion pressure, which is well proportional to {P}{NBI}{τ }{{s}}, the energetic ion confinement degrades monotonically due to the transport by the instabilities. The volume-averaged energetic ion pressure depends only on the volume-averaged classical energetic ion pressure, not independently on {P}{NBI} or {τ }{{s}}. The energetic ion pressure profile resiliency, where the increase in energetic ion pressure profile is saturated, is found for the cases with the highest {P}{NBI}{τ }{{s}} where the TAE bursts take place.

  5. Thermally induced phase transformation in multi-phase iron oxide nanoparticles on vacuum annealing

    NASA Astrophysics Data System (ADS)

    Anupama, A. V.; Keune, W.; Sahoo, B.

    2017-10-01

    The evolution of magnetic phases in multi-phase iron oxide nanoparticles, synthesized via the transferred arc plasma induced gas phase condensation method, was investigated by X-ray diffraction, vibrating sample magnetometry and 57Fe Mössbauer spectroscopy. The particles are proposed to be consisting of three different iron oxide phases: α-Fe2O3, γ-Fe2O3 and Fe3O4. These nanoparticles were exposed to high temperature (∼935 K) under vacuum (10-3 mbar He pressure), and the thermally induced phase transformations were investigated. The Rietveld refinement of the X-ray diffraction data corroborates the least-squares fitting of the transmission Mössbauer spectra in confirming the presence of Fe3O4, γ-Fe2O3 and α-Fe2O3 phases before the thermal treatment, while only Fe3O4 and α-Fe2O3 phases exist after thermal treatment. On thermal annealing in vacuum, conversion from γ-Fe2O3 to Fe3O4 and α-Fe2O3 was observed. Interestingly, we have observed a phase transformation occurring in the temperature range ∼498 K-538 K, which is strikingly lower than the phase transformation temperature of γ-Fe2O3 to α-Fe2O3 (573-623 K) in air. Combining the results of Rietveld refinement of X-ray diffraction patterns and Mössbauer spectroscopy, we have attributed this phase transformation to the phase conversion of a metastable ;defected and strained; d-Fe3O4 phase, present in the as-prepared sample, to the α-Fe2O3 phase. Stabilization of the phases by controlling the phase transformations during the use of different iron-oxide nanoparticles is the key factor to select them for a particular application. Our investigation provides insight into the effect of temperature and chemical nature of the environment, which are the primary factors governing the phase stability, suitability and longevity of the iron oxide nanomaterials prepared by the gas-phase condensation method for various applications.

  6. On a study of the /Delta T/c and C/asterisk/ integrals for fracture analysis under non-steady creep

    NASA Technical Reports Server (NTRS)

    Stonesifer, R. B.; Atluri, S. N.

    1982-01-01

    Applications of a vector quantity, path-independent integral which has an energy interpretation to the characterization of crack-tip fields in the range from fast to slow crack propagation are examined. The crack tip characterization parameter is defined in terms of a conservation integral for an area around the crack tip in a two-dimensional cracked body. The actual physical interpretation of the parameter is shown to be the difference in crack lengths displayed by two identical bodies which have equal load histories. A steady-state value is obtained for the parameter for cases of steady-state creep and is shown to be related to the standard path-independent integral for macroscopic self-similar crack growth under mode I conditions. A finite element model is developed for viscoplastic material models, using an initial strain approach with steps in a size employed in tangent stiffness methods.

  7. Hybrid Solution-Adaptive Unstructured Cartesian Method for Large-Eddy Simulation of Detonation in Multi-Phase Turbulent Reactive Mixtures

    DTIC Science & Technology

    2012-03-27

    pulse- detonation engines ( PDE ), stage separation, supersonic cav- ity oscillations, hypersonic aerodynamics, detonation induced structural...ADAPTIVE UNSTRUCTURED CARTESIAN METHOD FOR LARGE-EDDY SIMULATION OF DETONATION IN MULTI-PHASE TURBULENT REACTIVE MIXTURES 5b. GRANT NUMBER FA9550...CCL Report TR-2012-03-03 Hybrid Solution-Adaptive Unstructured Cartesian Method for Large-Eddy Simulation of Detonation in Multi-Phase Turbulent

  8. Micro-Ct Imaging of Multi-Phase Flow in Carbonates and Sandstones

    NASA Astrophysics Data System (ADS)

    Andrew, M. G.; Bijeljic, B.; Blunt, M. J.

    2013-12-01

    One of the most important mechanisms that limits the escape of CO2 when injected into the subsurface for the purposes of carbon storage is capillary trapping, where CO2 is stranded as pore-scale droplets (ganglia). Prospective storage sites are aquifers or reservoirs that tend to be at conditions where CO2 will reside as a super-critical phase. In order to fully describe physical mechanisms characterising multi-phase flow during and post CO2 injection, experiments need to be conducted at these elevated aquifer/reservoir conditions - this poses a considerable experimental challenge. A novel experimental apparatus has been developed which uses μCT scanning for the non-invasive imaging of the distribution of CO2 in the pore space of rock with resolutions of 7μm at temperatures and pressures representative of the conditions present in prospective saline aquifer CO2 storage sites. The fluids are kept in chemical equilibrium with one-another and with the rock into which they are injected. This is done to prevent the dissolution of the CO2 in the brine to form carbonic acid, which can then react with the rock, particularly carbonates. By eliminating reaction we study the fundamental mechanisms of capillary trapping for an unchanging pore structure. In this study we present a suite of results from three carbonate and two sandstone rock types, showing that, for both cases the CO2 acts as the non-wetting phase and significant quantities of CO2 is trapped. The carbonate examined represent a wide variety of pore topologies with one rock with a very well connected, high porosity pore space (Mt Gambier), one with a lower porosity, poorly connected pore space (Estaillades) and one with a cemented bead pack type pore space (Ketton). Both sandstones (Doddington and Bentheimer) were high permeability granular quartzites. CO2 was injected into each rock, followed by brine injection. After brine injection the entire length of the rock core was scanned, processed and segmented into

  9. Pore-scale Simulation and Imaging of Multi-phase Flow and Transport in Porous Media (Invited)

    NASA Astrophysics Data System (ADS)

    Crawshaw, J.; Welch, N.; Daher, I.; Yang, J.; Shah, S.; Grey, F.; Boek, E.

    2013-12-01

    We combine multi-scale imaging and computer simulation of multi-phase flow and reactive transport in rock samples to enhance our fundamental understanding of long term CO2 storage in rock formations. The imaging techniques include Confocal Laser Scanning Microscopy (CLSM), micro-CT and medical CT scanning, with spatial resolutions ranging from sub-micron to mm respectively. First, we report a new sample preparation technique to study micro-porosity in carbonates using CLSM in 3 dimensions. Second, we use micro-CT scanning to generate high resolution 3D pore space images of carbonate and cap rock samples. In addition, we employ micro-CT to image the processes of evaporation in fractures and cap rock degradation due to exposure to CO2 flow. Third, we use medical CT scanning to image spontaneous imbibition in carbonate rock samples. Our imaging studies are complemented by computer simulations of multi-phase flow and transport, using the 3D pore space images obtained from the scanning experiments. We have developed a massively parallel lattice-Boltzmann (LB) code to calculate the single phase flow field in these pore space images. The resulting flow fields are then used to calculate hydrodynamic dispersion using a novel scheme to predict probability distributions for molecular displacements using the LB method and a streamline algorithm, modified for optimal solid boundary conditions. We calculate solute transport on pore-space images of rock cores with increasing degree of heterogeneity: a bead pack, Bentheimer sandstone and Portland carbonate. We observe that for homogeneous rock samples, such as bead packs, the displacement distribution remains Gaussian with time increasing. In the more heterogeneous rocks, on the other hand, the displacement distribution develops a stagnant part. We observe that the fraction of trapped solute increases from the beadpack (0 %) to Bentheimer sandstone (1.5 %) to Portland carbonate (8.1 %), in excellent agreement with PFG

  10. Comparison of optimization algorithms for parameter estimation of multi-phase flow models with application to geological carbon sequestration

    NASA Astrophysics Data System (ADS)

    Espinet, Antoine J.; Shoemaker, Christine A.

    2013-04-01

    Optimization of multi-phase transport models is important both for calibrating model parameters to observed data and for analyzing management options. We focus on examples of geological carbon sequestration (GCS) process-based multi-phase models. Realistic GCS models can be very computationally expensive not only due to the spatial distribution of the model but also because of the complex nonlinear multi-phase and multi-component transport equations to be solved. As a result we need to have optimization methods that get accurate answers with relatively few simulations. In this analysis we compare a variety of different types of optimization algorithms to understand the best type of algorithms to use for different types of problems. This includes an analysis of which characteristics of the problem are important in choice of algorithm. The goal of this paper is to evaluate which optimization algorithms are the most efficient in a given situation, taking into account shape of the optimization problem (e.g. uni- or multi-modal) and the number of simulations that can be done. The algorithms compared are the widely used derivative-based PEST optimization algorithm, the derivative-based iTOUGH2, the Kriging response surface algorithm EGO, the heuristics-based DDS (Dynamically Dimensioned Search), and the Radial Basis Function surrogate response surface based global optimization algorithms 'GORBIT' and 'Stochastic RBF'. We calibrate a simple homogeneous model '3hom' and two more realistic models '20layer' and '6het'. The latter takes 2 h per simulation. Using rigorous statistical tests, we show that while the derivative-based algorithms of PEST are efficient on the simple 3hom model, it does poorly in comparison to surrogate optimization methods Stochastic RBF and GORBIT on the more realistic models. We then identify the shapes of the optimization surface of the three models using enumerative simulations and discover that 3hom is smooth and unimodal and the more realistic

  11. Determining Individual Phase Properties in a Multi-phase Q&P Steel using Multi-scale Indentation Tests

    SciTech Connect

    Cheng, Guang; Choi, Kyoo Sil; Hu, Xiaohua; Sun, Xin

    2016-01-15

    A new inverse method was developed to predict the stress-strain behaviors of constituent phases in a multi-phase steel using the load-depth curves measured in nanoindentation tests combined with microhardness measurements. A power law hardening response was assumed for each phase, and an empirical relationship between hardness and yield strength was assumed. Adjustment was made to eliminate the indentation size effect and indenter bluntness effect. With the newly developed inverse method and statistical analysis of the hardness histogram for each phase, the average stress-strain curves of individual phases in a quench and partitioning (Q&P) steel, including austenite, tempered martensite and untempered martensite, were calculated and the results were compared with the phase properties obtained by in-situ high energy X-ray diffraction (HEXRD) test. It is demonstrated that multi-scale instrumented indentation tests together with the new inverse method are capable of determining the individual phase flow properties in multi-phase alloys.

  12. Multi-phase micro-scale flow simulation in the electrodes of a PEM fuel cell by lattice Boltzmann method

    NASA Astrophysics Data System (ADS)

    Park, J.; Li, X.

    The gas diffusion layer of a polymer electrolyte membrane (PEM) fuel cell is a porous medium generally made of carbon cloth or paper. The gas diffusion layer has been modeled conventionally as a homogeneous porous medium with a constant permeability in the literature of PEM fuel cell. However, in fact, the permeability of such fibrous porous medium is strongly affected by the fiber orientation having non-isotropic permeability. In this work, the lattice Boltzmann (LB) method is applied to the multi-phase flow phenomenon in the inhomogeneous gas diffusion layer of a PEM fuel cell. The inhomogeneous porous structure of the carbon cloth and carbon paper has been modeled as void space and porous area using Stokes/Brinkman formulation and void space and impermeable fiber distributions obtained from various microscopic images. The permeability of the porous medium is calculated and compared to the experimental measurements in literature showing a good agreement. Simulation results for various fiber distributions indicate that the permeability of the medium is strongly influenced by the effect of fiber orientation. Present lattice Boltzmann flow models are applied to the multi-phase flow simulations by incorporating multi-component LB model with inter-particle interaction forces. The model successfully simulates the complicated unsteady behaviors of liquid droplet motion in the porous medium providing a useful tool to investigate the mechanism of liquid water accumulation/removal in a gas diffusion layer of a PEM fuel cell.

  13. High-Speed Visualization of Evaporation Phenomena from Tungsten Based Electrode in Multi-Phase AC Arc

    NASA Astrophysics Data System (ADS)

    Tanaka, Manabu; Hashizume, Taro; Imatsuji, Tomoyuki; Nawata, Yushi; Watanabe, Takayuki

    2015-09-01

    A multi-phase AC arc has been developed for applications in various fields of engineering because it possesses unique advantages such as high energy efficiency. However, understanding of fundamental phenomena in the multi-phase AC arc is still insufficient for practical use. Purpose of this study is to investigate electrode erosion mechanism by high-speed visualization of the electrode metal vapor in the arc. Results indicated that the electrode mainly evaporated at anodic period, leading to the arc constriction. Moreover, evaporation of W electrode with 2wt% La2O3 at the anodic period was much higher than that with 2wt% ThO2. This can be explained by different properties of these oxide additives. Evaporation of the oxide additive resulted in the arc constriction, which accelerated the evaporation of W electrode. Therefore, addition of La2O3 with lower melting and boiling point than ThO2 lead to stronger arc constriction, resulting in severer evaporation of W electrode.

  14. A new non-overlapping concept to improve the Hybrid Particle Level Set method in multi-phase fluid flows

    NASA Astrophysics Data System (ADS)

    Archer, Philip J.; Bai, Wei

    2015-02-01

    A novel non-overlapping concept is augmented to the Hybrid Particle Level Set (HPLS) method to improve its accuracy and suitability for the modelling of multi-phase fluid flows. The concept addresses shortcomings in the reseeding algorithm, which maintains resolution of the surface at runtime. These shortcomings result in the misplacement of newly seeded particles in the opposite signed domain and necessitate a restriction on the distance that a particle can escape without deletion, which reduces the effectiveness of the method. The non-overlapping concept judges the suitability of potential new particles based on information already contained within the particle representation of the surface. By preventing the misplacement of particles it is possible to significantly relax the distance restriction thereby increasing the accuracy of the HPLS method in multi-phase flows. To demonstrate its robustness and efficiency, the concept is examined with a number of challenging test cases, including both level-set-only simulations and two-phase fluid flows.

  15. Thermodynamic approach to the stability of multi-phase systems: application to the Y2O3-Fe system.

    PubMed

    Samolyuk, G D; Osetsky, Y N

    2015-08-05

    Oxide-metal systems are important in many practical applications, and they are undergoing extensive study using a wide range of techniques. The most accurate theoretical approaches are based on density functional theory (DFT), which is limited to ~10(2) atoms. Multi-scale approaches, e.g. DFT + Monte Carlo, are often used to model oxide metal systems at the atomic level. These approaches can qualitatively describe the kinetics of some processes but not the overall stability of individual phases. In this article, we propose a thermodynamic approach to study equilibrium in multi-phase systems, which can be sequentially enhanced by considering different defects and microstructures. We estimate the thermodynamic equilibrium by minimization of the free energy of the whole multi-phase system using a limited set of defects and microstructural objects for which the properties are calculated by DFT. As an example, we consider Y2O3 + bcc Fe with vacancies in both the Y2O3 and bcc Fe phases, Y substitutions and O interstitials in Fe, Fe impurities, and antisite defects in Y2O3. The output of these calculations is the thermal equilibrium concentration of all the defects for a particular temperature and composition. The results obtained confirmed the high temperature stability of yttria in iron. Model development toward more accurate calculations is discussed.

  16. Thermodynamic approach to the stability of multi-phase systems: application to the Y2O3-Fe system

    NASA Astrophysics Data System (ADS)

    Samolyuk, G. D.; Osetsky, Y. N.

    2015-08-01

    Oxide-metal systems are important in many practical applications, and they are undergoing extensive study using a wide range of techniques. The most accurate theoretical approaches are based on density functional theory (DFT), which is limited to ~102 atoms. Multi-scale approaches, e.g. DFT + Monte Carlo, are often used to model oxide metal systems at the atomic level. These approaches can qualitatively describe the kinetics of some processes but not the overall stability of individual phases. In this article, we propose a thermodynamic approach to study equilibrium in multi-phase systems, which can be sequentially enhanced by considering different defects and microstructures. We estimate the thermodynamic equilibrium by minimization of the free energy of the whole multi-phase system using a limited set of defects and microstructural objects for which the properties are calculated by DFT. As an example, we consider Y2O3 + bcc Fe with vacancies in both the Y2O3 and bcc Fe phases, Y substitutions and O interstitials in Fe, Fe impurities, and antisite defects in Y2O3. The output of these calculations is the thermal equilibrium concentration of all the defects for a particular temperature and composition. The results obtained confirmed the high temperature stability of yttria in iron. Model development toward more accurate calculations is discussed.

  17. Uncovering a Salt Giant. Deep-Sea Record of Mediterranean Messinian Events (DREAM) multi-phase drilling project

    NASA Astrophysics Data System (ADS)

    Camerlenghi, Angelo; Aoisi, Vanni; Lofi, Johanna; Hübscher, Christian; deLange, Gert; Flecker, Rachel; Garcia-Castellanos, Daniel; Gorini, Christian; Gvirtzman, Zohar; Krijgsman, Wout; Lugli, Stefano; Makowsky, Yizhaq; Manzi, Vinicio; McGenity, Terry; Panieri, Giuliana; Rabineau, Marina; Roveri, Marco; Sierro, Francisco Javier; Waldmann, Nicolas

    2014-05-01

    In May 2013, the DREAM MagellanPlus Workshop was held in Brisighella (Italy). The initiative builds from recent activities by various research groups to identify potential sites to perform deep-sea scientific drilling in the Mediterranean Sea across the deep Messinian Salinity Crisis (MSC) sedimentary record. In this workshop three generations of scientists were gathered: those who participated in formulation of the deep desiccated model, through DSDP Leg 13 drilling in 1973; those who are actively involved in present-day MSC research; and the next generation (PhD students and young post-docs). The purpose of the workshop was to identify locations for multiple-site drilling (including riser-drilling) in the Mediterranean Sea that would contribute to solve the several open questions still existing about the causes, processes, timing and consequences at local and planetary scale of an outstanding case of natural environmental change in the recent Earth history: the Messinian Salinity Crisis in the Mediterranean Sea. The product of the workshop is the identification of the structure of an experimental design of site characterization, riser-less and riser drilling, sampling, measurements, and down-hole analyses that will be the core for at least one compelling and feasible multiple phase drilling proposal. Particular focus has been given to reviewing seismic site survey data available from different research groups at pan-Mediterranean basin scale, to the assessment of additional site survey activity including 3D seismics, and to ways of establishing firm links with oil and gas industry. The scientific community behind the DREAM initiative is willing to proceed with the submission to IODP of a Multi-phase Drilling Project including several drilling proposals addressing specific drilling objectives, all linked to the driving objectives of the MSC drilling and understanding . A series of critical drilling targets were identified to address the still open questions

  18. A new general methodology for incorporating physico-chemical transformations into multi-phase wastewater treatment process models.

    PubMed

    Lizarralde, I; Fernández-Arévalo, T; Brouckaert, C; Vanrolleghem, P; Ikumi, D S; Ekama, G A; Ayesa, E; Grau, P

    2015-05-01

    This paper introduces a new general methodology for incorporating physico-chemical and chemical transformations into multi-phase wastewater treatment process models in a systematic and rigorous way under a Plant-Wide modelling (PWM) framework. The methodology presented in this paper requires the selection of the relevant biochemical, chemical and physico-chemical transformations taking place and the definition of the mass transport for the co-existing phases. As an example a mathematical model has been constructed to describe a system for biological COD, nitrogen and phosphorus removal, liquid-gas transfer, precipitation processes, and chemical reactions. The capability of the model has been tested by comparing simulated and experimental results for a nutrient removal system with sludge digestion. Finally, a scenario analysis has been undertaken to show the potential of the obtained mathematical model to study phosphorus recovery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Theory-Guided Materials Design of Multi-Phase Ti-Nb Alloys with Bone-Matching Elastic Properties

    PubMed Central

    Friák, Martin; Counts, William Art; Ma, Duancheng; Sander, Benedikt; Holec, David; Raabe, Dierk; Neugebauer, Jörg

    2012-01-01

    We present a scale-bridging approach for modeling the integral elastic response of polycrystalline composite that is based on a multi-disciplinary combination of (i) parameter-free first-principles calculations of thermodynamic phase stability and single-crystal elastic stiffness; and (ii) homogenization schemes developed for polycrystalline aggregates and composites. The modeling is used as a theory-guided bottom-up materials design strategy and applied to Ti-Nb alloys as promising candidates for biomedical implant applications. The theoretical results (i) show an excellent agreement with experimental data and (ii) reveal a decisive influence of the multi-phase character of the polycrystalline composites on their integral elastic properties. The study shows that the results based on the density functional theory calculations at the atomistic level can be directly used for predictions at the macroscopic scale, effectively scale-jumping several orders of magnitude without using any empirical parameters.

  20. Frequency analysis of porous nano-mechanical mass sensors made of multi-phase nanocrystalline silicon materials

    NASA Astrophysics Data System (ADS)

    Barati, Mohammad Reza; Shahverdi, Hossein

    2017-07-01

    Nanocrystalline materials (NcMs) are multi-phase composites containing nanograins, nanovoids and interface. Dynamic behavior of nanocrystalline silicon mass sensors on an elastic substrate is analyzed based on a two-variable refined plate model. Due to the experimental observation of grains micro-rotation and strain gradients near interfaces, the strain gradient based couple stress theory is employed to describe the size-dependent behavior of the nanocrystalline sensors. A micromechanical model is employed to incorporate the effects of inclusions and their surface energies. Galerkin’s method is implemented to obtain the frequency shifts of the nanocrystalline mass sensor with different boundary conditions. One can see that the nanoparticle mass, nanograins size, nanograins surface energy, nanovoids size, void percentage, interface region, scale parameter, foundation constants and boundary conditions have a great influence on the frequency shifts of nanocrystalline mass sensors.

  1. On the Takayanagi principle for the shape memory effect and thermomechanical behaviors in polymers with multi-phases

    NASA Astrophysics Data System (ADS)

    Lu, Haibao; Yu, Kai; Huang, Wei Min; Leng, Jinsong

    2016-12-01

    We present an explicit model to study the mechanics and physics of the shape memory effect (SME) in polymers based on the Takayanagi principle. The molecular structural characteristics and elastic behavior of shape memory polymers (SMPs) with multi-phases are investigated in terms of the thermomechanical properties of the individual components, of which the contributions are combined by using Takayanagi’s series-parallel model and parallel-series model, respectively. After that, Boltzmann superposition principle is employed to couple the multi-SME, elastic modulus parameter (E) and temperature parameter (T) in SMPs. Furthermore, the extended Takayanagi model is proposed to separate the plasticizing effect and physical swelling effect on the thermo-/chemo-responsive SME in polymers and then compared with the available experimental data reported in the literature. This study is expected to provide a powerful simulation tool for modeling and experimental substantiation of the mechanics and working mechanism of SME in polymers.

  2. Device and method for measuring multi-phase fluid flow in a conduit having an abrupt gradual bend

    DOEpatents

    Ortiz, Marcos German

    1998-01-01

    A system for measuring fluid flow in a conduit having an abrupt bend. The system includes pressure transducers, one disposed in the conduit at the inside of the bend and one or more disposed in the conduit at the outside of the bend but spaced a distance therefrom. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow.

  3. Device and method for measuring multi-phase fluid flow in a conduit having an abrupt gradual bend

    DOEpatents

    Ortiz, M.G.

    1998-02-10

    A system is described for measuring fluid flow in a conduit having an abrupt bend. The system includes pressure transducers, one disposed in the conduit at the inside of the bend and one or more disposed in the conduit at the outside of the bend but spaced a distance therefrom. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.

  4. Advancement and Application of Multi-Phase CFD Modeling to High Speed Supercavitating Flows

    DTIC Science & Technology

    2013-08-13

    model is needed [12]. The geometry of the body is modeled as specified by Schauer [11]. However, since it does not impact the physics under...manager. Furthermore, much gratitude is given to Dr. Mark Maughmer, Dr. Phillip Morris, and Dr. Ralph Noack of The Pennsylvania State University and Dr...of Revolution," California Institute of Technology-Hydrodynamics lab, Report E-12-17, June 1954. [10] Wosnik, M., Schauer , T.J., and Arndt R.E.A

  5. Strong correlation and multi-phase solution in nonequilibrium lattice systems coupled to dissipation medium

    NASA Astrophysics Data System (ADS)

    Han, Jong; Li, Jiajun; Aron, Camille; Kotliar, Gabriel

    2014-03-01

    How does a strongly correlated electronic solid evolve continuously out of equilibrium when an electric field is applied? While this question may seem deceptively simple, it requires rigorous understanding of dissipation. We formulate the nonequilibrium steady-state lattice coupled to fermion baths in the Coulomb gauge. We demonstrate that the Hubbard model solved using the iterative perturbation theory within the dynamical mean-field approximation recovers the DC conductivity independent of the Coulomb interaction in a very narrow linear response regime. Due to the singular dependence of the effective temperature on the damping in the steady-state [2], systems with damping have dramatic field-dependent effect, very different from dissipationless systems. We conclude that the dominant physics in lattice nonequilibrium is not the field vs quasi-particle energy, but rather the Joule heat vs the quasi-particle energy. Furthermore, we show that, in the vicinity of the Mott-insulator transition, the solution supports mixed-phase state scenario which indicates that the electron transport in solids under high-field can be spatially inhomogeneous leading to filamentary conducting paths, as suggested by experiments. Supported by NSF DMR-0907150, NSF DMR-1308141

  6. Multi-phase ionization dynamics of carbon thin film irradiated by high power short pulse laser

    NASA Astrophysics Data System (ADS)

    Kawahito, Daiki; Kishimoto, Yasuaki

    2017-10-01

    The ionization dynamics of a carbon thin film irradiated by a high power short pulse laser in the range of 1019-20 W/cm2 are studied using the extended particle-based integrated code (EPIC), which includes atomic and collisional processes. Two types of ionization dynamics exhibiting different spatio-temporal structures are found to predominantly regulate the process, and arise depending on the laser amplitude. The first is a fast convective propagation for charge states up to C4+, which keeps a steep ionization front. The velocity of the front is of the order of the speed of light. The front formation results from the localized longitudinal electrostatic field and associated field ionization, which in turn propagates inside the film. This convective propagation is triggered when the laser field becomes high enough that electron bunches accelerated by the laser ponderomotive force reach relativistic energies and penetrate inside the film across the surface. The second dynamics is a fast non-diffusive propagation of ionization showing a long plasma density scale length for C5+ and C6+. This process results predominantly from electron impact ionization by high energy electron bunches successively produced by the laser. These electron bunches also excite wake fields that propagate inside the film and contribute to ionizing the film to higher charge states, i.e., C5+ and C6+, especially near the front surface. The effect of field ionization loss, which sensitively influences the ionization dynamics in the relatively low laser power regime, is also discussed.

  7. Practical aspects and applications of the biological effective dose three-dimensional calculation for multi-phase radiotherapy treatment plans

    NASA Astrophysics Data System (ADS)

    Kauweloa, Kevin Ikaika

    The approximate BED (BEDA) is calculated for multi-phase cases due to current treatment planning systems (TPSs) being incapable of performing BED calculations. There has been no study on the mathematical accuracy and precision of BEDA relative to the true BED (BEDT), and how that might negatively impact patient care. The purpose of the first aim was to study the mathematical accuracy and precision in both hypothetical and clinical situations, while the next two aims were to create multi-phase BED optimization ideas for both multi-target liver stereotactic body radiation therapy (SBRT) cases, and gynecological cases where patients are treated with high-dose rate (HDR) brachytherapy along with external beam radiotherapy (EBRT). MATLAB algorithms created for this work were used to mathematically analyze the accuracy and precision of BEDA relative to BEDT in both hypothetical and clinical situations on a 3D basis. The organs-at-risk (OARs) of ten head & neck and ten prostate cancer patients were studied for the clinical situations. The accuracy of BEDA was shown to vary between OARs as well as between patients. The percentage of patients with an overall BEDA percent error less than 1% were, 50% for the Optic Chiasm and Brainstem, 70% for the Left and Right Optic Nerves, as well as the Rectum and Bladder, and 80% for the Normal Brain and Spinal Cord. As seen for each OAR among different patients, there were always cases where the percent error was greater than 1%. This is a cause for concern since the goal of radiation therapy is to reduce the overall uncertainty of treatment, and calculating BEDA distributions increases the treatment uncertainty with percent errors greater than 1%. The revealed inaccuracy and imprecision of BEDA supports the argument to use BEDT. The multi-target liver study involved applying BEDT in order to reduce the number of dose limits to one rather than have one for each fractionation scheme in multi-target liver SBRT treatments. A BEDT limit

  8. Detecting of Multi Phase Inter Turn Short Circuit in the Five Permanent Magnet Synchronous Motor

    NASA Astrophysics Data System (ADS)

    Yassa, N.; Rachek, M.; Djerdir, A.; Becherif, M.

    2016-10-01

    This paper proposes a general model of five phase permanent magnet synchronous machine (PMSM) which is capable of representing the multiphase Inter Turn Short Circuit (ITSC) occurring in several phase simultaneously this model is based on a coupled magnetic circuit approach leading to a differential equations system goveming the induction machine behavior. The obtained time-differential state equations system is implemented under Matlab environment and numerically solved using the fourth order Rung-Kutta method with variable step time corrected at each rotor displacement through the electromagnetic torque. Also, Fast Fourier Transform and (FFT) analysis is performed to the phase current signal to detect the frequency spectrum, Power Spectral Density (PSD) is chosen as a classification method. Its efficiency depends on its ability to discriminate between various faults generating the same range of harmonics in the stator current spectrum and on its ability to evaluate the fault severity. So, in order to improve the efficiency of these diagnosis methods, one needs a relatively accurate model to simulate the five-phase PMSM in the case of inter-tum short circuit fault helping to predict performances andor to extract fault signature in the machine main quantities. Simulation work has been carried out using MATLAB to verify the performance of the proposed detection/diagnosis method.

  9. MULTI-PHASE HIGH TEMPERATURE ALLOYS: EXPLORATION OF LAVES-STRENGTHENED STEELS

    SciTech Connect

    Yamamoto, Yukinori; Brady, Michael P; Lu, Zhao Ping; Liu, Chain T

    2007-01-01

    Exploratory effort was initiated for the development of Fe-base alloys strengthened by intermetallic Laves phase combined with MC (M: metals) carbide for improved elevated-temperature strength in fossil energy system components such as super-heater tubes and industrial gas turbines. Work in FY 2006 was focused on strengthening of Fe-Cr-Ni base austenitic stainless alloys by Fe2Nb Laves-phase precipitates with/without MC carbides, in combination with the improvement of oxidation resistance via Al-modification to promote alumina scale formation. A series of Fe-Cr-Ni-Nb base austenitic alloys with additions of Mo, Al, Si, C, B, etc. were cast and thermomechanically processed, and then tensile creep-rupture tested at the conditions of 750-850oC/70-170 MPa. The Al-modified alloys strengthened by Laves + MC show superior creep strength to that of conventional type 347 stainless steels, and their creep life-limit reaches up to 500 h at 750 oC/100 MPa. These alloys also show an excellent oxidation resistance from 650-800oC in air and air + 10% water vapor environments due to formation of a protective Al2O3 scale. Microstructural analysis of alloys strengthened by only Laves phase revealed that the Laves phase was effective to pin dislocations when the particle size is less than 0.5 m, but the resultant creep rupture lives were relatively short. The Al-modification was also applied to an advanced carbide-strengthened austenitic stainless steel, and it yielded creep resistance comparable to state-of-the-art austenitic alloys such as NF709, together with protective alumina scale formation. Modification of this alloy composition for its creep strength and oxidation resistance will be pursued in FY2007. Preliminary results suggest that the developed alloys with Al-modification combined with MC carbide strengthening are promising as a new class of high-temperature austenitic stainless steels.

  10. Multi-organ segmentation from multi-phase abdominal CT via 4D graphs using enhancement, shape and location optimization.

    PubMed

    Linguraru, Marius George; Pura, John A; Chowdhury, Ananda S; Summers, Ronald M

    2010-01-01

    The interpretation of medical images benefits from anatomical and physiological priors to optimize computer-aided diagnosis (CAD) applications. Diagnosis also relies on the comprehensive analysis of multiple organs and quantitative measures of soft tissue. An automated method optimized for medical image data is presented for the simultaneous segmentation of four abdominal organs from 4D CT data using graph cuts. Contrast-enhanced CT scans were obtained at two phases: non-contrast and portal venous. Intra-patient data were spatially normalized by non-linear registration. Then 4D erosion using population historic information of contrast-enhanced liver, spleen, and kidneys was applied to multi-phase data to initialize the 4D graph and adapt to patient specific data. CT enhancement information and constraints on shape, from Parzen windows, and location, from a probabilistic atlas, were input into a new formulation of a 4D graph. Comparative results demonstrate the effects of appearance and enhancement, and shape and location on organ segmentation.

  11. Incorporating hysteresis in a multi-phase multi-component NAPL modelling framework; a multi-component LNAPL gasoline example

    NASA Astrophysics Data System (ADS)

    Sookhak Lari, Kaveh; Davis, Greg B.; Johnston, Colin D.

    2016-10-01

    The longevity of chemicals in subsurface NAPL releases is a function of their partitioning into different phases. Hysteresis can affect distribution and partitioning of compounds in the vadose zone. We separated and modified hysteresis code from NAPL Simulator (which include hysteresis caused by fluid entrapment and capillary effects) and embedded it into TMVOC. For the first time, the resulting framework is used to model multi-component and multi-phase NAPL release, partitioning and transport. We then applied the verified framework to model effects of hysteresis on partitioning of BTEX, TMB and short and long chain alkanes from a typical gasoline spill. Excluding hysteresis resulted in an expanded LNAPL plume and underestimated the compounds longevity. Hysteresis altered the spatial distribution of LNAPL molar fractions as well as gas flow path and contaminants distribution compared to the non-hysteretic case. The amplifying effect of hysteresis on the longevity of mixtures (and associated risks) should be considered if non-hysteretic relationships are applied.

  12. Multi-phase-field study of the effects of anisotropic grain-boundary properties on polycrystalline grain growth

    NASA Astrophysics Data System (ADS)

    Miyoshi, Eisuke; Takaki, Tomohiro

    2017-09-01

    Numerical studies of the effects of anisotropic (misorientation-dependent) grain-boundary energy and mobility on polycrystalline grain growth have been carried out for decades. However, conclusive knowledge has yet to be obtained even for the simplest two-dimensional case, which is mainly due to limitations in the computational accuracy of the grain-growth models and computer resources that have been employed to date. Our study attempts to address these problems by utilizing a higher-order multi-phase-field (MPF) model, which was developed to accurately simulate grain growth with anisotropic grain-boundary properties. In addition, we also employ general-purpose computing on graphics processing units to accelerate MPF grain-growth simulations. Through a series of simulations of anisotropic grain growth, we succeeded in confirming that both the anisotropies in grain-boundary energy and mobility affect the morphology formed during grain growth. On the other hand, we found the grain growth kinetics in anisotropic systems to follow parabolic law similar to isotropic growth, but only after an initial transient period.

  13. Transitioning from multi-phase to single-phase microfluidics for long-term culture and treatment of multicellular spheroids.

    PubMed

    McMillan, Kay S; Boyd, Marie; Zagnoni, Michele

    2016-09-21

    When compared to methodologies based on low adhesion or hanging drop plates, droplet microfluidics offers several advantages for the formation and culture of multicellular spheroids, such as the potential for higher throughput screening and the use of reduced cell numbers, whilst providing increased stability for plate handling. However, a drawback of the technology is its characteristic compartmentalisation which limits the nutrients available to cells within an emulsion and poses challenges to the exchange of the encapsulated solution, often resulting in short-term cell culture and/or viability issues. The aim of this study was to develop a multi-purpose microfluidic platform that combines the high-throughput characteristics of multi-phase flows with that of ease of perfusion typical of single-phase microfluidics. We developed a versatile system to upscale the formation and long-term culture of multicellular spheroids for testing anticancer treatments, creating an array of fluidically addressable, compact spheroids that could be cultured in either medium or within a gel scaffold. The work provides proof-of-concept results for using this system to test both chemo- and radio-therapeutic protocols using in vitro 3D cancer models.

  14. Multi-phase inversion tectonics related to the Hendijan-Nowrooz-Khafji Fault activity, Zagros Mountains, SW Iran

    NASA Astrophysics Data System (ADS)

    Kazem Shiroodi, Sadjad; Ghafoori, Mohammad; Faghih, Ali; Ghanadian, Mostafa; Lashkaripour, Gholamreza; Hafezi Moghadas, Naser

    2015-11-01

    Distinctive characteristics of inverted structures make them important criteria for the identification of certain structural styles of folded belts. The interpretation of 3D seismic reflection and well data sheds new light on the structural evolution and age of inverted structures associated to the Hendijan-Nowrooz-Khafji Fault within the Persian Gulf Basin and northeastern margin of Afro-Arabian plate. Analysis of thickness variations of growth strata using "T-Z plot" (thickness versus throw plot) method revealed the kinematics of the fault. Obtained results show that the fault has experienced a multi-phase evolutionary history over six different extension and compression deformation events (i.e. positive and negative inversion) between 252.2 and 11.62 Ma. This cyclic activity of the growth fault was resulted from alteration of sedimentary processes during continuous fault slip. The structural development of the study area both during positive and negative inversion geometry styles was ultimately controlled by the relative motion between the Afro-Arabian and Central-Iranian plates.

  15. Non-steady-state living polymerization: a new route to control cationic ring-opening polymerization (CROP) of oxetane via an activation chain end (ACE) mechanism at ambient temperature.

    PubMed

    Bouchékif, Hassen; Philbin, Marcia I; Colclough, Eamon; Amass, Allan J

    2005-08-14

    Well-defined polyoxetane with low polydispersivity has been synthesized via a novel living polymerisation process using 3-phenoxypropyl 1,4-dioxanium hexafluoroantimonate (3-PPD) as a model of a living "monomeric polyoxetane" initiator, in 1,4-dioxane at 35 degrees C.

  16. High-resolution numerical methods for compressible multi-phase flow in hierarchical porous media. Progress report

    SciTech Connect

    Trangenstein, J.A.

    1993-03-15

    This is the first year in the proposed three-year effort to develop high-resolution numerical methods for multi-phase flow in hierarchical porous media. The issues being addressed in this research are: Computational efficiency: Field-scale simulation of enhanced oil recovery, whether for energy production or aquifer remediation, is typically highly under-resolved. This is because rock transport properties vary on many scales, and because current numerical methods have low resolution. Effective media properties: Since porous media are formed through complex geologic processes, they involve significant uncertainty and scale-dependence. Given this uncertainty, knowledge of ensemble averages of flow in porous media can be preferable to knowledge of flow in specific realizations of the reservoir. However, current models of effective properties do not represent the observed behavior very well. Relative permeability models present a good example of this problem. In practice, these models seldom provide realistic representations of hysteresis, interfacial tension effects or three-phase flow; there are no models that represent well all three effects simultaneously. Wave propagation: It is common in the petroleum industry to assume that the models have the same well-posedness properties as the physical system. An example of this fallacy is given by the three-phase relative permeability models; they were widely assumed by the petroleum community to produce hyperbolic systems for the Buckley-Leverett equations, but later the mathematics community proved that these models inherently produce local elliptic regions. Since numerical methods must use the models for computations, oscillations that develop could erroneously be attributed to numerical error rather than modeling difficulties. During this year, we have made significant progress on several tasks aimed at addressing these issues.

  17. A Serological Biopsy Using Five Stomach-Specific Circulating Biomarkers for Gastric Cancer Risk Assessment: A Multi-Phase Study.

    PubMed

    Tu, Huakang; Sun, Liping; Dong, Xiao; Gong, Yuehua; Xu, Qian; Jing, Jingjing; Bostick, Roberd M; Wu, Xifeng; Yuan, Yuan

    2017-05-01

    We aimed to assess a serological biopsy using five stomach-specific circulating biomarkers-pepsinogen I (PGI), PGII, PGI/II ratio, anti-Helicobacter pylori (H. pylori) antibody, and gastrin-17 (G-17)-for identifying high-risk individuals and predicting risk of developing gastric cancer (GC). Among 12,112 participants with prospective follow-up from an ongoing population-based screening program using both serology and gastroscopy in China, we conducted a multi-phase study involving a cross-sectional analysis, a follow-up analysis, and an integrative risk prediction modeling analysis. In the cross-sectional analysis, the five biomarkers (especially PGII, the PGI/II ratio, and H. pylori sero-positivity) were associated with the presence of precancerous gastric lesions or GC at enrollment. In the follow-up analysis, low PGI levels and PGI/II ratios were associated with higher risk of developing GC, and both low (<0.5 pmol/l) and high (>4.7 pmol/l) G-17 levels were associated with higher risk of developing GC, suggesting a J-shaped association. In the risk prediction modeling analysis, the five biomarkers combined yielded a C statistic of 0.803 (95% confidence interval (CI)=0.789-0.816) and improved prediction beyond traditional risk factors (C statistic from 0.580 to 0.811, P<0.001) for identifying precancerous lesions at enrollment, and higher serological biopsy scores based on the five biomarkers at enrollment were associated with higher risk of developing GC during follow-up (P for trend <0.001). A serological biopsy composed of the five stomach-specific circulating biomarkers could be used to identify high-risk individuals for further diagnostic gastroscopy, and to stratify individuals' risk of developing GC and thus to guide targeted screening and precision prevention.

  18. Biological nutrient removal with limited organic matter using a novel anaerobic–anoxic/oxic multi-phased activated sludge process

    PubMed Central

    Naseer, Rusul; Abualhail, Saad; Xiwu, Lu

    2012-01-01

    An anaerobic–anoxic/oxic (A2/O) multi-phased biological process called “phased isolation tank step feed technology (PITSF)” was developed to force the oscillation of organic and nutrient concentrations in process reactors. PITSF can be operated safely with a limited carbon source in terms of low carbon requirements and aeration costs whereas NAR was achieved over 95% in the last aerobic zone through a combination of short HRT and low DO levels. PCR assay was used for XAB quantification to correlate XAB numbers with nutrient removal. PCR assays showed, high NAR was achieved at XAB population 5.2 × 108 cells/g MLVSS in response to complete and partial nitrification process. It was exhibited that low DO with short HRT promoted XAB growth. Simultaneous nitrification and denitrification (SND) via nitrate were observed obviously, SND rate was between 69–72%, at a low DO level of 0.5 mg/l in the first aerobic tank during main phases and the removal efficiency of TN, NH4+-N, COD, TP was 84.7 .97, 88.3 and 96% respectively. The removal efficiencies of TN, NH4+-N, and TP at low C/N ratio and DO level were 84.2, 98.5 and 96.9% respectively which were approximately equal to the complete nitrification–denitrification with the addition of external carbon sources at a normal DO level of (1.5–2.5 mg/l). PMID:23961214

  19. Simultaneous Hydrogen and Methane Production Through Multi-Phase Anaerobic Digestion of Paperboard Mill Wastewater Under Different Operating Conditions.

    PubMed

    Farghaly, Ahmed; Tawfik, Ahmed

    2017-01-01

    Multi-phase anaerobic reactor for H2 and CH4 production from paperboard mill wastewater was studied. The reactor was operated at hydraulic retention times (HRTs) of 12, 18, 24, and 36 h, and organic loading rates (OLRs) of 2.2, 1.5, 1.1, and 0.75 kg chemical oxygen demand (COD)/m(3) day, respectively. HRT of 12 h and OLR of 2.2 kg COD/m(3) day provided maximum hydrogen yield of 42.76 ± 14.5 ml/g CODremoved and volumetric substrate uptake rate (-rS) of 16.51 ± 4.43 mg COD/L h. This corresponded to the highest soluble COD/total COD (SCOD/TCOD) ratio of 56.25 ± 3.3 % and the maximum volatile fatty acid (VFA) yield (YVFA) of 0.21 ± 0.03 g VFA/g COD, confirming that H2 was mainly produced through SCOD conversion. The highest methane yield (18.78 ± 3.8 ml/g CODremoved) and -rS of 21.74 ± 1.34 mgCOD/L h were achieved at an HRT of 36 h and OLR of 0.75 kg COD/m(3) day. The maximum hydrogen production rate (HPR) and methane production rate (MPR) were achieved at carbon to nitrogen (C/N) ratio of 47.9 and 14.3, respectively. This implies the important effect of C/N ratio on the distinction between the dominant microorganism bioactivities responsible for H2 and CH4 production.

  20. Preparation and Oxidation of ZrB2/SiC/Zr2Al4C5 Multi-phase Ceramics with Spark Plasma Sintering

    NASA Astrophysics Data System (ADS)

    Guo, Qilong; Li, Junguo; Ma, Zhiyu; Nie, Ye; Shen, Qiang; Zhang, Lianmeng

    2013-03-01

    The ZrB2/SiC/Zr2Al4C5 multi-phase ceramics were fabricated by spark plasma sintering (SPS) at 1800 °C for 3 min under 20 MPa in an vacuum. Oxidation behavior of multi-phase ceramics were investigated using thermo gravimetric analysis (TGA) from 20 °C to 1500 °C and muffle furnace in stagnant air at 1200 °C. Samples were analyzed after oxidation by X-ray diffraction (XRD), scanning electron microscopy (SEM) along with energy dispersive spectroscopy (EDS) to determine the reaction products and to observe the microstructure. The results showed that the aluminium borate and mullite crystallize on the surface in the samples oxidized. The effect of Zr2Al4C5 content on the oxidation resistance of the ZrB2 ceramics were discussed respectively, and oxidation mechanism was also analysised.

  1. Simultaneous extraction and separation of flavonols and flavones from Chamaecyparis obtusa by multi-phase extraction using an ionic liquid-modified microsphere polymer.

    PubMed

    Tian, Minglei; Bi, Wentao; Row, Kyung Ho

    2012-01-01

    Flavonols and flavones, especially quercitrin, myricetin and amentoflavone, are the main anti-bacterial and anti-cancer compounds in Chamaecyparis obtuse. Multi-phase extraction is a new method that can extract and separate target compounds simultaneously. An amino ionic liquid immobilised microsphere polymer was used as a multi-phase extraction sorbent to extract and separate quercitrin, myricetin and amentoflavone from Chamaecyparis obtusa. The sorbent and Chamaecyparis obtusa powder were packed into a single cartridge. Using a fixed volume of methanol with five repetitions, the target compounds were extracted from the powder to the sorbent. The sorbent was then washed with n-hexane to remove any interfering species and the target compounds were eluted sequentially using water, methanol and methanol containing 1% acetic acid (vol.). Under the optimised conditions, 0.45 mg/g of quercitrin, 0.18 mg/g of myricetin and 0.12 mg/g of amentoflavone from 2.0 g of powder were obtained by multi-phase extraction using 0.3 g of sorbent. The method described has a low deviation error, requires a small amount of solvent and is highly selective and reproducible. Copyright © 2012 John Wiley & Sons, Ltd.

  2. Optimal scan delay depending on contrast material injection duration in abdominal multi-phase computed tomography of pancreas and liver in normal Beagle dogs

    PubMed Central

    Choi, Soo-Young; Lee, In; Seo, Ji-Won; Park, Hyun-Young; Choi, Ho-Jung

    2016-01-01

    This study was conducted to establish the values for optimal fixed scan delays and diagnostic scan delays associated with the bolus-tracking technique using various contrast material injection durations in canine abdominal multi-phase computed tomography (CT). This study consisted of two experiments employing the crossover method. In experiment 1, three dynamic scans at the porta hepatis were performed using 5, 10 and 15 sec injection durations. In experiment 2, two CT scans consisting of five multi-phase series with different scan delays of 5 sec intervals for bolus-tracking were performed using 5, 10 and 15 sec injection duration. Mean arrival times to aortic enhancement peak (12.0, 15.6, and 18.6 sec for 5, 10, and 15 sec, respectively) and pancreatic parenchymal peak (17.8, 25.1, and 29.5 sec) differed among injection durations. The maximum mean attenuation values of aortas and pancreases were shown at the scan section with 0 and 5, 0 and 10 and 5 and 10 sec diagnostic scan delays during each injection duration, respectively. The optimal scan delays of the arterial and pancreatic parenchymal phase in multi-phase CT scan using fixed scan delay or bolus-tracking should be determined with consideration of the injection duration. PMID:27297414

  3. Modeling the Physical Multi-Phase Interactions of HNO3 Between Snow and Air on the Antarctic Plateau (Dome C) and coast (Halley)

    NASA Astrophysics Data System (ADS)

    Chan, Hoi Ga; Frey, Markus M.; King, Martin D.

    2017-04-01

    Nitrogen oxides (NOx = NO + NO2) emissions from nitrate (NO3-) photolysis in snow affect the oxidising capacity of the lower troposphere especially in remote regions of the high latitudes with low pollution levels. The porous structure of snowpack allows the exchange of gases with the atmosphere driven by physicochemical processes, and hence, snow can act as both source and sink of atmospheric chemical trace gases. Current models are limited by poor process understanding and often require tuning parameters. Here, two multi-phase physical models were developed from first principles constrained by observed atmospheric nitrate, HNO3, to describe the air-snow interaction of nitrate. Similar to most of the previous approaches, the first model assumes that below a threshold temperature, To, the air-snow grain interface is pure ice and above To, a disordered interface (DI) emerges assumed to be covering the entire grain surface. The second model assumes that Air-Ice interactions dominate over the entire temperature range below melting and that only above the eutectic temperature, liquid is present in the form of micropockets in grooves. The models are validated with available year-round observations of nitrate in snow and air at a cold site on the Antarctica Plateau (Dome C, 75°06'S, 123°33'E, 3233 m a.s.l.) and at a relatively warm site on the Antarctica coast (Halley, 75°35'S, 26°39'E, 35 m a.s.l). The first model agrees reasonably well with observations at Dome C (Cv(RMSE) = 1.34), but performs poorly at Halley (Cv(RMSE) = 89.28) while the second model reproduces with good agreement observations at both sites without any tuning (Cv(RMSE) = 0.84 at both sites). It is therefore suggested that air-snow interactions of nitrate in the winter are determined by non-equilibrium surface adsorption and co-condensation on ice coupled with solid-state diffusion inside the grain. In summer, however, the air-snow exchange of nitrate is mainly driven by solvation into liquid

  4. An X-ray/SDSS sample. I. Multi-phase outflow incidence and dependence on AGN luminosity

    NASA Astrophysics Data System (ADS)

    Perna, M.; Lanzuisi, G.; Brusa, M.; Mignoli, M.; Cresci, G.

    2017-07-01

    Aims: The connection between the growth of super-massive black holes (SMBHs) and the evolution of their host galaxies is nowadays well established, although the underlying mechanisms explaining their mutual relations are still debated. Multi-phase fast, massive outflows have been postulated to play a crucial role in this process. The aim of this work is to constrain the nature and the fraction of outflowing gas in active galactic nuclei (AGNs) as well as the nuclear conditions possibly at the origin of such phenomena. Methods: We present a large spectroscopic sample of X-ray detected SDSS AGNs at z< 0.8 with a high signal-to-noise ratio in the [O III]λ5007 line to unveil the faint wings of the emission profile associated with AGN-driven outflows. We used X-ray and optical flux ratio diagnostics to select the sample. We derived physical and kinematic characterization by re-analysing optical (and X-ray) spectra. Results: We derive the incidence of ionized ( 40%) and atomic (<1%) outflows covering a wide range of AGN bolometric luminosity from 1042 to 1046 erg/s. We also derive bolometric luminosities and X-ray bolometric corrections to test whether the presence of outflows is associated with an X-ray loudness, as suggested by our recent results obtained by studying high-z QSOs. Conclusions: We study the relations between the outflow velocity inferred from [O III] kinematic analysis and different AGN power tracers, such as black hole mass (MBH), [O III], and X-ray luminosity. We show a well-defined positive trend between outflow velocity and LX, for the first time, over a range of 5 order of magnitudes. Overall, we find that in the QSO-luminosity regime and at MBH> 108M⊙ the fraction of AGNs with outflows becomes >50%. Finally, we discuss our results about X-ray bolometric corrections and outflow incidence in cold and ionized phases in the context of an evolutionary sequence allowing two distinct stages for the feedback phase: first, an initial stage characterized

  5. Numerical study of multi-phase combustion: Ignition and combustion of an isolated boron particle in fluorinated environments

    NASA Astrophysics Data System (ADS)

    Zhou, Wei

    The multi-phase and multi-stage combustion of particulate boron is studied numerically with a time-dependent spherosymmetric numerical model specifically developed for simulating the sequential ignition and combustion of an isolated boron particle in chemically reacting gases. The ignition sub-model describing the oxide layer removal consists of detailed chemistry (36 species and 195 reversible elementary reactions) and multi-component molecular transport in the surrounding gas phase, surface reactions and physical absorptions at the interface of boron oxide/gas, heterogeneous reactions at the interface of boron/boron oxide and condensed-phase transport within the oxide layer. The subsequent combustion sub-model invokes a different surface mechanism on the "clean" surface of a boron particle. Classical governing equations incorporating these complex chemistry and transport phenomena are solved by applying the moving finite element method and the backward differentiation formulas. The most important conclusions drawn from the modeling studies include: (1) The rate controlling steps in gasification of the boron oxide coating are chemisorption and desorption reactions for kinetically-controlled systems and gas-phase transport for diffusive-controlled systems in high temperature environments; the condensed-phase transport is only important for self-sustained, low temperature ignition; (2) The ignition delay time is found to be a linear function of the oxide layer thickness for both kinetically- and diffusive-controlled systems; the oxide layer thickness is proportional to boron particle radii; (3) Fluorine, predominately in the form of hydrogen fluoride, is found to significantly enhance the kinetically-controlled ignition of boron particles; the overall burning times for large boron particles are insensitive to fluorine concentrations; the presence of fluorine could improve the overall heat release by producing stable OBF(g) and BFsb3(g) rather than HOBO(g), which

  6. Multi-Phased, Post-Accident Support of the Fukushima Dai-Ichi Nuclear Power Plant - 12246

    SciTech Connect

    Gay, Arnaud; Gillet, Philippe; Ytournel, Bertrand; Varet, Thierry; David, Laurent; Prevost, Thierry; Redonnet, Carol; Piot, Gregoire; Jouaville, Stephane; Pagis, Georges

    2012-07-01

    operation results to date. AREVA's response to the Fukushima Dai-Ichi crisis was multi-phased: emergency aid and relief supply was sent within days after the accident; AREVA-Veolia engineering teams designed and implemented a water treatment solution in record time, only 3 months; and AREVA continues to support TEPCO and propose solutions for waste management, soil remediation and decontamination of the Fukushima Dai-Ichi site. Despite the huge challenges, the Actiflo{sup TM}-Rad project has been a success: the water treatment unit started on time and performed as expected. The performance is the result of many key elements: AREVA expertise in radioactive effluents decontamination, Veolia know-how in water treatment equipments in crisis environment, and of course AREVA and Veolia teams' creativity. The project success is also due to AREVA and Veolia teams' reactivity and high level of commitment with engineering teams working 24/7 in Japan, France and Germany. AREVA and Veolia deep knowledge of the Japanese industry ensured that the multi-cultural exchanges were not an issue. Finally the excellent overall project management and execution by TEPCO and other Japanese stakeholders was very efficient. The emergency water treatment was a key step of the roadmap towards restoration from the accident at Fukushima Dai-Ichi that TEPCO designed and keeps executing with success. (authors)

  7. Disentangling the history of complex multi-phased shell beds based on the analysis of 3D point cloud data

    NASA Astrophysics Data System (ADS)

    Harzhauser, Mathias; Djuricic, Ana; Mandic, Oleg; Dorninger, Peter; Nothegger, Clemens; Székely, Balázs; Molnár, Gábor; Pfeifer, Norbert

    2015-04-01

    Shell beds are key features in sedimentary records throughout the Phanerozoic. The interplay between burial rates and population productivity is reflected in distinct degrees of shelliness. Consequently, shell beds may provide informations on various physical processes, which led to the accumulation and preservation of hard parts. Many shell beds pass through a complex history of formation being shaped by more than one factor. In shallow marine settings, the composition of shell beds is often strongly influenced by winnowing, reworking and transport. These processes may cause considerable time averaging and the accumulation of specimens, which have lived thousands of years apart. In the best case, the environment remained stable during that time span and the mixing does not mask the overall composition. A major obstacle for the interpretation of shell beds, however, is the amalgamation of shell beds of several depositional units in a single concentration, as typically for tempestites and tsunamites. Disentangling such mixed assemblages requires deep understanding of the ecological requirements of the taxa involved - which is achievable for geologically young shell beds with living relatives - and a statistic approach to quantify the contribution by the various death assemblages. Furthermore it requires understanding of sedimentary processes potentially involved into their formation. Here we present the first attempt to describe and decipher such a multi-phase shell-bed based on a high resolution digital surface model (1 mm) combined with ortho-photos with a resolution of 0.5 mm per pixel. Documenting the oyster reef requires precisely georeferenced data; owing to high redundancy of the point cloud an accuracy of a few mm was achieved. The shell accumulation covers an area of 400 m2 with thousands of specimens, which were excavated by a three months campaign at Stetten in Lower Austria. Formed in an Early Miocene estuary of the Paratethys Sea it is mainly composed

  8. Trade-off analysis of discharge-desiltation-turbidity and ANN analysis on sedimentation of a combined reservoir-reach system under multi-phase and multi-layer conjunctive releasing operation

    NASA Astrophysics Data System (ADS)

    Huang, Chien-Lin; Hsu, Nien-Sheng; Wei, Chih-Chiang; Yao, Chun-Hao

    2017-10-01

    Multi-objective reservoir operation considering the trade-off of discharge-desiltation-turbidity during typhoons and sediment concentration (SC) simulation modeling are the vital components for sustainable reservoir management. The purposes of this study were (1) to analyze the multi-layer release trade-offs between reservoir desiltation and intake turbidity of downstream purification plants and thus propose a superior conjunctive operation strategy and (2) to develop ANFIS-based (adaptive network-based fuzzy inference system) and RTRLNN-based (real-time recurrent learning neural networks) substitute SC simulation models. To this end, this study proposed a methodology to develop (1) a series of multi-phase and multi-layer sediment-flood conjunctive release modes and (2) a specialized SC numerical model for a combined reservoir-reach system. The conjunctive release modes involve (1) an optimization model where the decision variables are multi-phase reduction/scaling ratios and the timings to generate a superior total release hydrograph for flood control (Phase I: phase prior to flood arrival, Phase II/III: phase prior to/subsequent to peak flow) and (2) a combination method with physical limitations regarding separation of the singular hydrograph into multi-layer release hydrographs for sediment control. This study employed the featured signals obtained from statistical quartiles/sediment duration curve in mesh segmentation, and an iterative optimization model with a sediment unit response matrix and corresponding geophysical-based acceleration factors, for efficient parameter calibration. This research applied the developed methodology to the Shihmen Reservoir basin in Taiwan. The trade-off analytical results using Typhoons Sinlaku and Jangmi as case examples revealed that owing to gravity current and re-suspension effects, Phase I + II can de-silt safely without violating the intake's turbidity limitation before reservoir discharge reaches 2238 m3/s; however

  9. Evaluation of molecularly imprinted anion-functionalized poly(ionic liquid)s by multi-phase dispersive extraction of flavonoids from plant.

    PubMed

    Bi, Wentao; Tian, Minglei; Row, Kyung Ho

    2013-01-15

    Molecularly imprinted anion-functionalized poly(ionic liquid)s (MAPILs) were prepared by radical polymerization for the multi-phase dispersive extraction (MPDE) of flavonoids from plants. Poly(ionic liquid)s were functionalized with different anions via anion metathesis to enhance their separation efficiency, called anion-functionalized poly(ionic liquid)s (APILs). A molecularly imprinting technique was introduced to produce specific recognition sites by forming complexes between the template molecules and anion-functionalized ionic liquid monomers to reduce the interactions with the interference substances and increase the selectivity. Multi-phase dispersive extraction (MPDE) was applied for separation instead of the traditional solid phase extraction method. The target compounds were first extracted by three-phase (sample-solvent-sorbent) dispersive extraction and cleaned up after removing the sample matrix. This method significantly decrease in the interference and analysis cost. A suitable sorbent for MPDE could be identified based on the adsorption behaviors of flavonoids on different MAPILs. The mean recovery yields of quercitrin, myricetin, and amentoflavone from Chamaecyparis obtusa under the optimized conditions were 88.07, 93.59, and 95.13%. This is a promising method for the extraction, separation and determination of flavonoids or other polyphenolic compounds from natural and other sources. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. A graphical user interface (GUI) toolkit for the calculation of three-dimensional (3D) multi-phase biological effective dose (BED) distributions including statistical analyses.

    PubMed

    Kauweloa, Kevin I; Gutierrez, Alonso N; Stathakis, Sotirios; Papanikolaou, Niko; Mavroidis, Panayiotis

    2016-07-01

    A toolkit has been developed for calculating the 3-dimensional biological effective dose (BED) distributions in multi-phase, external beam radiotherapy treatments such as those applied in liver stereotactic body radiation therapy (SBRT) and in multi-prescription treatments. This toolkit also provides a wide range of statistical results related to dose and BED distributions. MATLAB 2010a, version 7.10 was used to create this GUI toolkit. The input data consist of the dose distribution matrices, organ contour coordinates, and treatment planning parameters from the treatment planning system (TPS). The toolkit has the capability of calculating the multi-phase BED distributions using different formulas (denoted as true and approximate). Following the calculations of the BED distributions, the dose and BED distributions can be viewed in different projections (e.g. coronal, sagittal and transverse). The different elements of this toolkit are presented and the important steps for the execution of its calculations are illustrated. The toolkit is applied on brain, head & neck and prostate cancer patients, who received primary and boost phases in order to demonstrate its capability in calculating BED distributions, as well as measuring the inaccuracy and imprecision of the approximate BED distributions. Finally, the clinical situations in which the use of the present toolkit would have a significant clinical impact are indicated. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Fine Structure in Multi-Phase Zr8Ni21-Zr7Ni10-Zr2Ni7 Alloy Revealed by Transmission Electron Microscope

    PubMed Central

    Shen, Haoting; Bendersky, Leonid A.; Young, Kwo; Nei, Jean

    2015-01-01

    The microstructure of an annealed alloy with a Zr8Ni21 composition was studied by both scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The presence of three phases, Zr8Ni21, Zr2Ni7, and Zr7Ni10, was confirmed by SEM/X-ray energy dispersive spectroscopy compositional mapping and TEM electron diffraction. Distribution of the phases and their morphology can be linked to a multi-phase structure formed by a sequence of reactions: (1) L → Zr2Ni7 + L’; (2) peritectic Zr2Ni7 + L’ → Zr2Ni7 + Zr8Ni21 + L”; (3) eutectic L” → Zr8Ni21 + Zr7Ni10. The effect of annealing at 960 °C, which was intended to convert a cast structure into a single-phase Zr8Ni21 structure, was only moderate and the resulting alloy was still multi-phased. TEM and crystallographic analysis of the Zr2Ni7 phase show a high density of planar (001) defects that were explained as low-energy boundaries between rotational variants and stacking faults. The crystallographic features arise from the pseudo-hexagonal structure of Zr2Ni7. This highly defective Zr2Ni7 phase was identified as the source of the broad X-ray diffraction peaks at around 38.4° and 44.6° when a Cu-K was used as the radiation source. PMID:28793460

  12. DEVELOPMENT OF MULTI-PHASE AND MULTI-COMPONENT FLOW MODEL WITH REACTION IN POROUS MEDIA FOR RISK ASSESSMENT ON SOIL CONTAMINATION DUE TO MINERAL OIL

    NASA Astrophysics Data System (ADS)

    Sakamoto, Yasuhide; Nishiwaki, Junko; Hara, Junko; Kawabe, Yoshishige; Sugai, Yuichi; Komai, Takeshi

    In late years, soil contamination due to mineral oil in vacant lots of oil factory and oil field has become obvious. Measure for soil contamina tion and risk assessment are neces sary for sustainable development of industrial activity. Especially, in addition to contaminated sites, various exposure paths for human body such as well water, soil and farm crop are supposed. So it is very important to comprehend the transport phenomena of contaminated material under the environments of soil and ground water. In this study, mineral oil as c ontaminated material consisting of mu lti-component such as aliphatic and aromatic series was modeled. Then numerical mode l for transport phenomena in surface soil and aquifer was constructed. On the basis of modeling for mineral oil, our numerical model consists of three-phase (oil, water and gas) forty three-component. This numerical model becomes base program for risk assessment system on soil contamination due to mineral oil. Using this numerical model, we carried out some numerical simulation for a laboratory-scale experiment on oil-water multi-phase flow. Relative permeability that dominate flow behavior in multi-phase condition was formulated and the validity of the numerical model developed in this study was considered.

  13. Multi-phased uplift of the southern margin of the Central Anatolian plateau, Turkey: A record of tectonic and upper mantle processes

    NASA Astrophysics Data System (ADS)

    Schildgen, T. F.; Cosentino, D.; Bookhagen, B.; Niedermann, S.; Yıldırım, C.; Echtler, H.; Wittmann, H.; Strecker, M. R.

    2012-02-01

    Uplifted Neogene marine sediments and Quaternary fluvial terraces in the Mut Basin, southern Turkey, reveal a detailed history of surface uplift along the southern margin of the Central Anatolian plateau from the Late Miocene to the present. New surface exposure ages (10Be, 26Al, and 21Ne) of gravels capping fluvial strath terraces located between 28 and 135 m above the Göksu River in the Mut Basin yield ages ranging from ca. 25 to 130 ka, corresponding to an average incision rate of 0.52 to 0.67 mm/yr. Published biostratigraphic data combined with new interpretations of the fossil assemblages from uplifted marine sediments reveal average uplift rates of 0.25 to 0.37 mm/yr since Late Miocene time (starting between 8 and 5.45 Ma), and 0.72 to 0.74 mm/yr after 1.66 to 1.62 Ma. Together with the terrace abandonment ages, the data imply 0.6 to 0.7 mm/yr uplift rates from 1.6 Ma to the present. The different post-Late Miocene and post-1.6 Ma uplift rates can imply increasing uplift rates through time, or multi-phased uplift with slow uplift or subsidence in between. Longitudinal profiles of rivers in the upper catchment of the Mut and Ermenek basins show no apparent lithologic or fault control on some knickpoints that occur at 1.2 to 1.5 km elevation, implying a transient response to a change in uplift rates. Projections of graded upper relict channel segments to the modern outlet, together with constraints from uplifted marine sediments, show that a slower incision/uplift rate of 0.1 to 0.2 mm/yr preceded the 0.7 mm/yr uplift rate. The river morphology and profile projections therefore reflect multi-phased uplift of the plateau margin, rather than steadily increasing uplift rates. Multi-phased uplift can be explained by lithospheric slab break-off and possibly also the arrival of the Eratosthenes Seamount at the collision zone south of Cyprus.

  14. A new low-dose multi-phase trauma CT protocol and its impact on diagnostic assessment and radiation dose in multi-trauma patients.

    PubMed

    Alagic, Zlatan; Eriksson, Andreas; Drageryd, Erika; Motamed, Sara Rezaei; Wick, Marius C

    2017-04-05

    Computed tomography (CT) examinations, often using high-radiation dosages, are increasingly used in the acute management of polytrauma patients. This study compares a low-dose polytrauma multi-phase whole-body CT (WBCT) protocol on a latest generation of 16-cm detector 258-slice multi-detector CT (MDCT) scanner with advanced dose reduction techniques to a single-phase polytrauma WBCT protocol on a 64-slice MDCT scanner. Between March and September 2015, 109 polytrauma patients (group A) underwent acute WBCT with a low-dose multi-phase WBCT protocol on a 258-slice MDCT whereas 110 polytrauma patients (group B) underwent single-phase trauma CT on a 64-slice MDCT. The diagnostic accuracy to trauma-related injuries, radiation dose, quantitative and semiquantitative image quality parameters, subjective image quality scorings, and workflow time parameters were compared. In group A, statistically significantly more arterial injuries (p = 0.04) and arterial dissections (p = 0.002) were detected. In group A, the mean (±SD) dose length product value was 1681 ± 183 mGy*cm and markedly lower when compared to group B (p < 0.001). The SDs of the mean Houndsfield unit values of the brain, liver, and abdominal aorta were lower in group A (p < 0.001). Mean signal-to-noise ratios (SNRs) for the brain, liver, and abdominal aorta were significantly higher in group A (p < 0.001). Group A had significantly higher image quality scores for all analyzed anatomical locations (p < 0.02). However, the mean time from patient registration until completion of examination was significantly longer for group A (p < 0.001). The low-dose multi-phase CT protocol improves diagnostic accuracy and image quality at markedly reduced radiation. However, due to technical complexities and surplus electronic data provided by the newer low-dose technique, examination time increases, which reduces workflow in acute emergency situations.

  15. Reaction-transport-mechanical (RTM) simulator Sym.CS: Putting together water-rock interaction, multi-phase and heat flow, composite petrophysics model, and fracture mechanics

    NASA Astrophysics Data System (ADS)

    Paolini, C.; Park, A. J.; Mellors, R. J.; Castillo, J.

    2009-12-01

    A typical CO2 sequestration scenario involves the use of multiple simulators for addressing multiphase fluid and heat flow, water-rock interaction and mass-transfer, rock mechanics, and other chemical and physical processes. The benefit of such workflow is that each model can be constrained rigorously; however, the drawback is final modeling results may achieve only a limited extent of the theoretically possible capabilities of each model. Furthermore, such an approach in modeling carbon sequestration cannot capture the nonlinearity of the various chemical and physical processes. Hence, the models can only provide guidelines for carbon sequestration processes with large margins of error. As an alternative, a simulator is being constructed by a multi-disciplinary team with the aim of implementing a large array of fundamental phenomenologies, including, but not limited to: water-rock interaction using elemental mass-balance and explicit mass-transfer and reaction coupling methods; multi-phase and heat flow, including super-critical CO2 and oil; fracture mechanics with anisotropic permeabilities; rheological rock mechanics based on incremental stress theory; and a composite petrophysics model capable of describing changing rock composition and properties. The modules representing the processes will be solved using a layered iteration method, with the goal of capturing the nonlinear feedback among all of the processes. The simulator will be constructed using proven optimization and modular, object-oriented, and service-oriented programming methods. Finally, a novel AJAX (asynchronous JavaScript and XML) user interface is being tested to host the simulator that will allow usage through an Internet browser. Currently, the water-rock interaction, composite petrophysics, and multi-phase fluid and heat flow modules are available for integration. Results of the water-rock interaction and petrophysics coupling has been used to model interaction between a CO2-charged water and

  16. Investigation of morphology selection for CBr4-C2Cl6 alloy in three dimensions with multi-phase field method

    NASA Astrophysics Data System (ADS)

    Yang, YuJuan; Yan, Biao

    2011-05-01

    With the multi-phase field model, the unidirectional solidification with constant velocity growth and variable velocity growth of the CBr4-C2Cl6 eutectic alloy is simulated in three dimensions. The simulated results with constant velocity growth show that with the increase of pulling velocity, the morphology of the CBr4-C2Cl6 alloy evolves in the sequence of lamellar merging →lamellar-rod transition→stable lamellar growth→oscillating growth→lamellar branching. A morphology selection map is established with different pulling velocities, which is confirmed to be correct by the velocity change process. It is shown that all of the morphology transitions, the average interface growth velocity and average interface undercooling show a hysteresis effect against the instant of velocity change. The relationship between the interface average undercooling and interface average growth velocity is consistent with the theoretical value.

  17. Characterization of heterogeneity in the Heletz sandstone from core to pore scale and quantification of its impact on multi-phase flow

    DOE PAGES

    Hingerl, Ferdinand F.; Yang, Feifei; Pini, Ronny; ...

    2016-02-02

    In this paper we present the results of an extensive multiscale characterization of the flow properties and structural and capillary heterogeneities of the Heletz sandstone. We performed petrographic, porosity and capillary pressure measurements on several subsamples. We quantified mm-scale heterogeneity in saturation distributions in a rock core during multi-phase flow using conventional X-ray CT scanning. Core-flooding experiments were conducted under reservoirs conditions (9 MPa, 50 °C) to obtain primary drainage and secondary imbibition relative permeabilities and residual trapping was analyzed and quantified. We provide parameters for relative permeability, capillary pressure and trapping models for further modeling studies. A synchrotron-based microtomographymore » study complements our cm- to mm-scale investigation by providing links between the micromorphology and mm-scale saturation heterogeneities.« less

  18. Vector diffraction analysis of high numerical aperture focused beams modified by two- and three-zone annular multi-phase plates.

    PubMed

    Jabbour, Toufic; Kuebler, Stephen

    2006-02-06

    Vector diffraction theory was applied to study the effect of two- and three-zone annular multi-phase plates (AMPs) on the three-dimensional point-spread-function (PSF) that results when linearly polarized light is focused using a high numerical aperture refractory lens. Conditions are identified for which a three-zone AMP generates a PSF that is axially superresolved by 19% with minimal change in the transverse profile and sufficiently small side lobes that the intensity pattern could be used for advanced photolithographic techniques, such as multi-photon 3D microfabrication, as well as multi-photon imaging. Conditions are also found in which a three-zone AMP generates a PSF that is axially elongated by 510% with only 1% change along the transverse direction. This intensity distribution could be used for sub-micron-scale laser drilling and machining.

  19. Device and method for measuring multi-phase fluid flow and density of fluid in a conduit having a gradual bend

    DOEpatents

    Ortiz, Marcos German; Boucher, Timothy J.

    1998-01-01

    A system for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow.

  20. Device and method for measuring multi-phase fluid flow and density of fluid in a conduit having a gradual bend

    DOEpatents

    Ortiz, M.G.; Boucher, T.J.

    1998-10-27

    A system is described for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.

  1. A proposed computational biomechanics cyber-infrastructure for multi-phase and multi-scale problems: delivering biomechanics to the surgeon.

    PubMed

    Impelluso, Thomas J

    2006-04-01

    This paper presents a new direction for practitioners of computational biomechanics. It provides a description of three prototype software platforms, which demonstrate how the cyber-infrastructure can be used to integrate the algorithms of computational biomechanics to solve multi-phase and multi-scale problems. Then, a development platform is presented. This platform can also deliver integrated biomechanics into the surgical ward for surgical planning. This platform performs these tasks without the need for advanced network software tools: an appendix provides all the simple and fundamental open source and CI technologies that are required. The overarching goal of this paper is to make the potential of the emerging cyber-infrastructure comprehensible and accessible to practitioners of computational biomechanics.

  2. Characterization of heterogeneity in the Heletz sandstone from core to pore scale and quantification of its impact on multi-phase flow

    SciTech Connect

    Hingerl, Ferdinand F.; Yang, Feifei; Pini, Ronny; Xiao, Xianghui; Toney, Michael F.; Liu, Yijin; Benson, Sally M.

    2016-02-02

    In this paper we present the results of an extensive multiscale characterization of the flow properties and structural and capillary heterogeneities of the Heletz sandstone. We performed petrographic, porosity and capillary pressure measurements on several subsamples. We quantified mm-scale heterogeneity in saturation distributions in a rock core during multi-phase flow using conventional X-ray CT scanning. Core-flooding experiments were conducted under reservoirs conditions (9 MPa, 50 °C) to obtain primary drainage and secondary imbibition relative permeabilities and residual trapping was analyzed and quantified. We provide parameters for relative permeability, capillary pressure and trapping models for further modeling studies. A synchrotron-based microtomography study complements our cm- to mm-scale investigation by providing links between the micromorphology and mm-scale saturation heterogeneities.

  3. Role and pitfalls of hepatic helical multi-phase CT scanning in differential diagnosis of small hemangioma and small hepatocellular carcinoma

    PubMed Central

    Yan, Fu-Hua; Zeng, Meng-Su; Zhou, Kang-Rong

    1998-01-01

    AIM: To compare and analyze the contrast enhancement appearance of small hemangioma (SHHE) and small hepatocellular carcinoma (SHCC) with helical multi-phase CT scanning so as to determine their roles and pitfalls in the differential diagnosis of SHHE and SHCC. METHODS: The pre and postcontrast CT scanning of the liver in 73 cases (38 SHHE, 35 SHCC) were carried out. The first phase scan of the entire liver began at 30s after the injection of contrast medium, the second and third phases began at 70s, and 4 min respectively. The contrast enhancement patterns and characteristics of all lesions were observed and compared. RESULTS: In SHHE, 64.29% (27/42) had typical manifestations in two-phase dynamic scanning, such as peripheral dramatic high-density enhancement of the lesions with progressive opacification from the periphery toward the center, 30.95% (13/42) were hyperdense in both phases and 4.76% (2/42) were hypodense in both phases. In the third phase scanning, 96.67% (28/30) of SHHE were hyperdense and isodense. In SHCC 59.52% (25/42) presented typical appearances, such as hyperdense in the first phase and hypodense in the second phase, 23.81% (10/42) were hyperdense in the first phase and isodense in the second phase with 4.76% (2/42) of hypodense in both phases. In the third phase scanning, 85.71% (24/28) of SHCC were hypodense. CONCLUSION: According to the contrast enhancement patterns of SHHE and SHCC in the two-phase or multi-phase scanning by helical CT, diagnosis can be established in the majority of lesions, while some atypical cases needed MRI for further investigation. PMID:11819317

  4. Role and pitfalls of hepatic helical multi-phase CT scanning in differential diagnosis of small hemangioma and small hepatocellular carcinoma.

    PubMed

    Yan, Fu-Hua; Zeng, Meng-Su; Zhou, Kang-Rong

    1998-08-01

    AIM:To compare and analyze the contrast enhancement appearance of small hemangioma (SHHE) and small hepatocellular carcinoma (SHCC) with helical multi-phase CT scanning so as to determine their roles and pitfalls in the differential diagnosis of SHHE and SHCC.METHODS:The pre and postcontrast CT scanning of the liver in 73 cases (38 SHHE, 35 SHCC) were carried out. The first phase scan of the entire liver began at 30s after the injection of contrast medium, the second and third phases began at 70s, and 4min respectively. The contrast enhancement patterns and characteristics of all lesions were observed and compared.RESULTS In SHHE, 64.29% (27/42) had typical manifestations in two-phase dynamic scanning, such as peripheral dramatic high-density enhancement of the lesions with progressive opacification from the periphery toward the center, 30.95% (13/42) were hyperdense in both phases and 4.76% (2/42) were hypodense in both phases. In the third phase scanning, 96.67% (28/30) of SHHE were hyperdense and isodense.In SHCC 59.52% (25/42) presented typical appearances, such as hyperdense in the first phase and hypodense in the second phase, 23.81% (10/42) were hyperdense in the first phase and isodense in the second phase with 4.76% (2/42) of hypodense in both phases. In the third phase scanning, 85.71% (24/28) of SHCC were hypodense.CONCLUSION:According to the contrast enhancement patterns of SHHE and SHCC in the two-phase or multi-phase scanning by helical CT, diagnosis can be established in the majority of lesions, while some atypical cases needed MRI for further investigation.

  5. Multi-phase Uplift of the Indo-Burman Ranges and Western Thrust Belt of Minbu Sub-basin (West Myanmar): Constraints from Apatite Fission Track Data

    NASA Astrophysics Data System (ADS)

    Zhang, P.; Qiu, H.; Mei, L.

    2015-12-01

    The forearc regions in active continental margins are important keys to analysis geodynamic processes such as oceanic crust oblique subduction, mechanism of subduction zone, and sediments recycling. The West Myanmar, interpreted as forearc silver, is the archetype example of such forearc regions subordinate to Sunda arc-trench system, and is widely debated when and how its forearc regions formed. A total of twenty-two samples were obtained from the Indo-Burman Ranges and western thrust belt of Minbu Sub-basin along Taungup-Prome Road in Southwestern Myanmar (Figure 1), and five sandstone samples of them were performed at Apatite to Zircon, Inc. Three samples (M3, M5, and M11) collected from Eocene flysch and metamorphic core at the Indo-Burman Ranges revealed apatite fission track (AFT) ages ranging from 19 to 9 Ma and 6.5 to 2 Ma. Two samples (M20 and M21) acquired from the western thrust belt of Minbu Sub-basin yielded AFT ages ranging from 28 to 13.5 Ma and 7.5 to 3.5 Ma. Time-temperature models based on AFT data suggest four major Cenozoic cooling episodes, Late Oligocene, Early to Middle Miocene, Late Miocene, and Pliocene to Pleistocene. The first to third episode, models suggest the metamorphic core of the Indo-Burman Ranges has experienced multi-phase rapidly uplifted during the early construction of the forearc regions. The latest episode, on which this study focused, indicated a fast westward growth of the Palaeogene accretionary wedge and a eastward propagation deformation of folding and thrusting of the western thrust belt of Minbu Sub-basin. We argued that above multi-phase uplifted and deformation of the forearc regions were results of India/West Burma plate's faster oblique convergence and faster sedimentation along the India/Eurasia suture zone.

  6. Adaptive fully implicit multi-scale finite-volume method for multi-phase flow and transport in heterogeneous porous media

    NASA Astrophysics Data System (ADS)

    Jenny, P.; Lee, S. H.; Tchelepi, H. A.

    2006-09-01

    We describe a sequential fully implicit (SFI) multi-scale finite volume (MSFV) algorithm for nonlinear multi-phase flow and transport in heterogeneous porous media. The method extends the recently developed multiscale approach, which is based on an IMPES (IMplicit Pressure, Explicit Saturation) scheme [P. Jenny, S.H. Lee, H.A. Tchelepi, Adaptive multiscale finite volume method for multi-phase flow and transport, Multiscale, Model. Simul. 3 (2005) 50-64]. That previous method was tested extensively and with a series of difficult test cases, where it was clearly demonstrated that the multiscale results are in excellent agreement with reference fine-scale solutions and that the computational efficiency of the MSFV algorithm is much higher than that of standard reservoir simulators. However, the level of detail and range of property variability included in reservoir characterization models continues to grow. For such models, the explicit treatment of the transport problem (i.e. saturation equations) in the IMPES-based multiscale method imposes severe restrictions on the time step size, and that can become the major computational bottleneck. Here we show how this problem is resolved with our sequential fully implicit (SFI) MSFV algorithm. Simulations of large (million cells) and highly heterogeneous problems show that the results obtained with the implicit multi-scale method are in excellent agreement with reference fine-scale solutions. Moreover, we demonstrate the robustness of the coupling scheme for nonlinear flow and transport, and we show that the MSFV algorithm offers great gains in computational efficiency compared to standard reservoir simulation methods.

  7. Semi-brittle behavior of a multi-phase crust and its influence on the tectonics of icy satellites

    NASA Astrophysics Data System (ADS)

    McCarthy, Christine; Cooper, Reid F.

    2010-05-01

    Our ability to observe and interpret reasonably the tectonics of icy satellites hinges on our understanding of the viscoelastic and plastic rheologies and microstructural evolution of the material comprising their icy outer shells. The morphological diversity observed on the surfaces of the satellites may be due in part to the rheological influence of the various cryominerals that are present in addition to water ice on many of these icy bodies. Our experimental investigation explores the affects of secondary minerals on the phase behavior and physical properties (both plastic and anelastic) of ice at conditions approaching those of the icy satellites. Using uniaxial compression creep experiments (T = 230-250K; P = 0.1 and 50 MPa), we characterize the transient and steady-state deformation behaviors of eutectic aggregates (made via crystallization of liquid solution) of ice-I and MgSO4•11H2O ("MS11"; meridianiite) and compare them to the deformation behaviors of pure polycrystalline ice-I tested at the same conditions on the same apparatus. The ice/hydrate aggregates display a higher sensitivity to stress than does pure polycrystalline ice at the same conditions. One significant role that the second phase plays in ductile deformation is to pin grain growth, keeping grain sizes small and deformation within the grain/colony size sensitive creep regime. The mechanical and microstructural observations from this study indicate that the hydrate phase, which is distinctly stronger than pure ice, additionally offers a framework of support that resists ductile deformation at low stresses; the aggregates display at least an order of magnitude higher effective viscosity than do samples of pure polycrystalline ice at the same conditions up to 6MPa. At higher stresses, however, the hydrate phase promotes semi-brittle flow and cavitation, both of which are forms of strain weakening. Semi-brittle flow in the icy shell of a planetary body would decrease the depth to the brittle

  8. High-resolution numerical methods for compressible multi-phase flow in hierarchical porous media. Progress report, September 1993--September 1994

    SciTech Connect

    Trangenstein, J.A.

    1994-03-15

    This is the second year in the proposed three-year effort to develop high-resolution numerical methods for multi-phase flow in hierarchical porous media. The issues being addressed in this research are: Computational efficiency: Field-scale simulation of enhanced oil recovery, whether for energy production or aquifer remediation, is typically highly under-resolved. This is because rock transport properties vary on many scales, and because current numerical methods have low resolution. Effective media properties: Since porous media are formed through complex geologic processes, they involve significant uncertainty and scale-dependence. Given this uncertainty, knowledge of ensemble averages of flow in porous media can be preferable to knowledge of flow in specific realizations of the reservoir. However, current models of effective properties do not represent the observed behavior very well. Relative permeability models present a good example of this problem. In practice, these models seldom provide realistic representations of hysteresis, interfacial tension effects or three-phase flow; there are no models that represent well all three effects simultaneously.

  9. AOI 1— COMPUTATIONAL ENERGY SCIENCES:MULTIPHASE FLOW RESEARCH High-fidelity multi-phase radiation module for modern coal combustion systems

    SciTech Connect

    Modest, Michael

    2013-11-15

    The effects of radiation in particle-laden flows were the object of the present research. The presence of particles increases optical thickness substantially, making the use of the “optically thin” approximation in most cases a very poor assumption. However, since radiation fluxes peak at intermediate optical thicknesses, overall radiative effects may not necessarily be stronger than in gas combustion. Also, the spectral behavior of particle radiation properties is much more benign, making spectral models simpler (and making the assumption of a gray radiator halfway acceptable, at least for fluidized beds when gas radiation is not large). On the other hand, particles scatter radiation, making the radiative transfer equation (RTE) much more di fficult to solve. The research carried out in this project encompassed three general areas: (i) assessment of relevant radiation properties of particle clouds encountered in fluidized bed and pulverized coal combustors, (ii) development of proper spectral models for gas–particulate mixtures for various types of two-phase combustion flows, and (iii) development of a Radiative Transfer Equation (RTE) solution module for such applications. The resulting models were validated against artificial cases since open literature experimental data were not available. The final models are in modular form tailored toward maximum portability, and were incorporated into two research codes: (i) the open-source CFD code OpenFOAM, which we have extensively used in our previous work, and (ii) the open-source multi-phase flow code MFIX, which is maintained by NETL.

  10. Induction of anoxic microenvironment in multi-phase metabolic shift strategy during periodic discontinuous batch mode operation enhances treatment of azo dye wastewater.

    PubMed

    Nagendranatha Reddy, C; Naresh Kumar, A; Annie Modestra, J; Venkata Mohan, S

    2014-08-01

    Variation in anoxic microenvironment (multi-phase (MP) metabolic shift strategy) during cycle operation of periodic discontinuous batch/sequencing batch (PDBR/SBR) mode operation showed enhanced degradation of recalcitrant azo dye (C.I. Acid Black 10B) at higher dye load (1250mg/l). The process performance was evaluated by varying anoxic phasing period during cycle operation. Before multiphase (BMP) operation with 2.1% of anoxic period showed color/COD removal efficiency of 41.9%/46.3%. Increment in anoxic period responded favorable in enhancing treatment efficiency [AMPI (16.2%), 49.4%/52.4%; AMPII (26.6%), 54.7%/57.2%; AMPIII (34.9%), 58.4%/61.5%]. Relatively higher bio-electrochemical activity, persistent reductive behavior (redox catalytic currents, 0.26/-0.72μA), prevalence of redox shuttlers (Fe-S proteins, cytochromes, quinones) facilitating enhanced electron transfer by minimization of associated losses and higher enzyme activities were observed with induction of anoxic phase. Anoxic condition shifts system microenvironment between oxidation and reduction assisting reduction of dye to its intermediates followed by their mineralization.

  11. Equations of state of metals in WDM region

    NASA Astrophysics Data System (ADS)

    Lomonosov, I. V.

    2017-01-01

    An equation of state (EOS) of metals in the region of warm dense matter (WDM) is discussed. Data for EOS developing includes results of static and dynamic experiments as well as theoretical calculations. The information, obtained in shock compression, isentropic expansion, isobaric expansion and "exploding foils" experiments is analyzed and discussed with the use of the multi-phase EOS for selected metals.

  12. Mt. Kinabalu, Borneo: Source and evolution of a multi-phased post-collisional I-Type granite

    NASA Astrophysics Data System (ADS)

    Burton-Johnson, A.; Macpherson, C. G.

    2012-12-01

    Mt. Kinabalu is an isolated pluton in northern Borneo, in the Malaysian state of Sabah. At 4095m elevation it is the highest peak between the Himalayas and Papua New Guinea. The pluton is an example of a post-collisional I-Type granite, post-dating the end of subduction at the southern margin of the South China Sea by some 7 million years. Aside from its isolated tectonic setting, Mt. Kinabalu gives particular insight in to the three dimensional structure and formation of granitic plutons due to its extreme vertical exposure of 2900m elevation through the multiple units forming the body. The petrogenesis of the pluton has been investigated though combined application of field observations, petrography, geochemistry and geophysics. The major, trace, REE and isotopic elemental compositions and AMS magnetic mineral fabrics have been analysed for samples across the pluton and combined with field observations, U-Pb zircon dating (Cottam et al. 2010) and chemical fractionation indices to give a temporal framework to the pluton's chemical evolution and emplacement. This reveals that Mt. Kinabalu was not intruded as a single large diapir, but as a series of units emplaced in separate pulses over ~ 0.8 My: (i) a small, biotite-rich unit at its highest elevations, (ii) followed only a few hundred thousand years later by the hornblende-rich bulk of the pluton below it along with a number of vertically extensive biotite-rich minor bodies, and (iii) two porphyritic units. A combination of trace element analyses and magnetically susceptible mineral fabrics has further shown that these large units formed from smaller pulses of magma, fractionating below the depth of emplacement. Sr, Nd, Pb and Hf isotopes show that the units fall in to two isotopically distinct groups, with a more radiogenic Sr and Pb and less radiogenic Nd and Hf for the oldest unit compared to the later intrusions. The complete data set, along with inherited U-Pb zircon ages, give two interpretations. Firstly

  13. Non-Steady Combustion of Composite Solid Propellants.

    DTIC Science & Technology

    1983-05-01

    Space Administration by Jet Propulsion Laboratory California Institute of Technology Pasadena, California JPLD-708 MAR 84 °S 82 118 Ap...82-00030, through an agreement with the National Aeronautics and Space Administration, NASA 7-100, Task Order RD-182, Amendment No. 199. The United...surface temperature-temperature sensitivity, ay» or cause it to go through a minimum at an intermediate velocity - decrease concentration expor . _nt

  14. The nature of the interstellar medium of the starburst low-metallicity galaxy Haro 11: a multi-phase model of the infrared emission

    NASA Astrophysics Data System (ADS)

    Cormier, D.; Lebouteiller, V.; Madden, S. C.; Abel, N.; Hony, S.; Galliano, F.; Baes, M.; Barlow, M. J.; Cooray, A.; De Looze, I.; Galametz, M.; Karczewski, O. Ł.; Parkin, T. J.; Rémy, A.; Sauvage, M.; Spinoglio, L.; Wilson, C. D.; Wu, R.

    2012-12-01

    Context. The low-metallicity interstellar medium (ISM) is profoundly different from that of normal systems, being clumpy with low dust abundance and little CO-traced molecular gas. Yet many dwarf galaxies in the nearby universe are actively forming stars. As the complex ISM phases are spatially mixed with each other, detailed modeling is needed to understand the gas emission and subsequent composition and structure of the ISM. Aims: Our goal is to describe the multi-phase ISM of the infrared bright low-metallicity galaxy Haro 11, dissecting the photoionised and photodissociated gas components. Methods: We present observations of the mid-infrared and far-infrared fine-structure cooling lines obtained with the Spitzer/IRS and Herschel/PACS spectrometers. We use the spectral synthesis code Cloudy to methodically model the ionised and neutral gas from which these lines originate. Results: We find that the mid- and far-infrared lines account for ~1% of the total infrared luminosity LTIR, acting as major coolants of the gas. Haro 11 is undergoing a phase of intense star formation, as traced by the brightest line, [O iii] 88 μm, with L [O III] /LTIR ~ 0.3%, and high ratios of [Ne iii]/[Ne ii] and [S iv]/[S iii]. Due to their different origins, the observed lines require a multi-phase modeling comprising: a compact H ii region, dense fragmented photodissociation regions (PDRs), a diffuse extended low-ionisation/neutral gas which has a volume filling factor of at least 90%, and porous warm dust in proximity to the stellar source. For a more realistic picture of the ISM of Haro 11 we would need to model the clumpy source and gas structures. We combine these 4 model components to explain the emission of 17 spectral lines, investigate the global energy balance of the galaxy through its spectral energy distribution, and establish a phase mass inventory. While the ionic emission lines of Haro 11 essentially originate from the dense H ii region component, a diffuse low

  15. A general self-potential model including redox effects, the influence of the Reynolds number, and multi-phase flow. Theory and applications

    NASA Astrophysics Data System (ADS)

    Revil, A.; Linde, N.

    2006-12-01

    We determine the macroscopic transport properties of isotropic microporous media by volume-averaging the local Nernst-Planck and Navier-Stokes equations in non-isothermal conditions incorporating streaming, diffusional, and thermal effects. In porous media, the excess of charge, that counterbalance the charge deficiency of the surface of the minerals, is partitioned between the Gouy-Chapman and the Stern layer. Rather than using Poisson-Boltzmann distributions to describe the ionic concentrations in the pore space of the medium, we rely on Donnan distributions obtained by equating the chemical potentials of the water molecules and ions between a reservoir of ions and the pore space of the medium. The macroscopic Maxwell equations and the macroscopic linear constitutive transport equations are derived in the vicinity of equilibrium assuming that the porous material is deformable. In the vicinity of thermodynamic equilibrium, the cross- coupling phenomena of the macroscopic constitutive equations of transport follow Onsager reciprocity. In addition, all the material properties entering the constitutive equations only depend on two textural properties, the permeability and the electrical formation factor. Extension of this model is then performed incorporating three distinct additional effects (a) extension of the electrokinetic equations at high Reynolds numbers, in the inertial laminar flow regime ; (b) extension of the model to multi-phase flow conditions (under the assumptions that the two fluid phases are continuous), and (3) introduction of electro-redox theory and the development of a fundamental model of bio-battery with application to contaminant plumes. Applications will be discussed shortly regarding (1) fracturing, (2) ground water flow, (c) leakage in embankment dams, and (d) contaminant plumes rich in organic matter (http://www.andre-revil.com).

  16. Multi-phase distribution and comprehensive ecological risk assessment of heavy metal pollutants in a river affected by acid mine drainage.

    PubMed

    Liao, Jianbo; Ru, Xuan; Xie, Binbin; Zhang, Wanhui; Wu, Haizhen; Wu, Chaofei; Wei, Chaohai

    2017-07-01

    To date, there is a lack of a comprehensive research on heavy metals detection and ecological risk assessment in river water, sediments, pore water (PW) and suspended solids (SS). Here, the concentrations of heavy metals, including Cu, Zn, Mn, Cd, Pb and As, and their distribution between the four phases was studied. Samples for analysis were taken from twelve sites of the Hengshi River, Guangdong Province, China, during the rainy and dry seasons. A new comprehensive ecological risk index (CERI) based on considering metal contents, pollution indices, toxicity coefficients and water categories is offered for prediction of potential risk on aquatic organisms. The results of comprehensive analysis showed that the highest concentrations of Cu, Zn and Mn of 6.42, 87.17 and 98.74mg/L, respectively, in PW were comparable with those in water, while concentrations of Cd, Pb and As of 609.5, 2757 and 96.38μg/L, respectively, were 2-5 times higher. The sum of the exchangeable and carbonate fractions of target metals in sediments followed the order of Cd > Mn > Zn > Pb > Cu > As. The distribution of heavy metals in phases followed the order of sediment > SS > water > PW, having the sum content in water and PW lower than 2% of total. The elevated ecological risk for a single metal and the phase were 34,585 for Cd and 1160 for water, respectively, implied Cd as a priority pollutant in the considered area. According to the CERI, the maximum risk value of 769.3 was smaller than 1160 in water, but higher than those in other phases. Out of considering the water categories and contribution coefficients, the CERI was proved to be more reliable for assessing the pollution of rivers with heavy metals. These results imply that the CERI has a potential of adequate assessment of multi-phase composite metals pollution. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Development of Conductivity Sensors for Multi-Phase Flow Local Measurements at the Polytechnic University of Valencia (UPV) and University Jaume I of Castellon (UJI).

    PubMed

    Muñoz-Cobo, José Luis; Chiva, Sergio; Méndez, Santos; Monrós, Guillem; Escrivá, Alberto; Cuadros, José Luis

    2017-05-10

    This paper describes all the procedures and methods currently used at UPV (Universitat Politécnica de Valencia) and UJI (University Jaume I) for the development and use of sensors for multi-phase flow analysis in vertical pipes. This paper also describes the methods that we use to obtain the values of the two-phase flow magnitudes from the sensor signals and the validation and cross-verification methods developed to check the consistency of the results obtained for these magnitudes with the sensors. First, we provide information about the procedures used to build the multi-sensor conductivity probes and some of the tests performed with different materials to avoid sensor degradation issues. In addition, we provide information about the characteristics of the electric circuits that feed the sensors. Then the data acquisition of the conductivity probe, the signal conditioning and the data processing including the device that have been designed to automatize all the measurement process of moving the sensors inside the channels by means of stepper electric motors controlled by computer are shown in operation. Then, we explain the methods used for bubble identification and categorization. Finally, we describe the methodology used to obtain the two-phase flow information from the sensor signals. This includes the following items: void fraction, gas velocity, Sauter mean diameter and interfacial area concentration. The last part of this paper is devoted to the conductance probes developed for the annular flow analysis, which includes the analysis of the interfacial waves produced in annular flow and that requires a different type of sensor.

  18. Development of Conductivity Sensors for Multi-Phase Flow Local Measurements at the Polytechnic University of Valencia (UPV) and University Jaume I of Castellon (UJI)

    PubMed Central

    Muñoz-Cobo, José Luis; Chiva, Sergio; Méndez, Santos; Monrós, Guillem; Escrivá, Alberto; Cuadros, José Luis

    2017-01-01

    This paper describes all the procedures and methods currently used at UPV (Universitat Politécnica de Valencia) and UJI (University Jaume I) for the development and use of sensors for multi-phase flow analysis in vertical pipes. This paper also describes the methods that we use to obtain the values of the two-phase flow magnitudes from the sensor signals and the validation and cross-verification methods developed to check the consistency of the results obtained for these magnitudes with the sensors. First, we provide information about the procedures used to build the multi-sensor conductivity probes and some of the tests performed with different materials to avoid sensor degradation issues. In addition, we provide information about the characteristics of the electric circuits that feed the sensors. Then the data acquisition of the conductivity probe, the signal conditioning and the data processing including the device that have been designed to automatize all the measurement process of moving the sensors inside the channels by means of stepper electric motors controlled by computer are shown in operation. Then, we explain the methods used for bubble identification and categorization. Finally, we describe the methodology used to obtain the two-phase flow information from the sensor signals. This includes the following items: void fraction, gas velocity, Sauter mean diameter and interfacial area concentration. The last part of this paper is devoted to the conductance probes developed for the annular flow analysis, which includes the analysis of the interfacial waves produced in annular flow and that requires a different type of sensor. PMID:28489035

  19. Investigations in Reducing the Computational Expense of Transient 3D Multi-Phase CO2 Wellbore Leakage Simulations: Time-Series Matching versus Multivariate Adaptive Regression Splines

    NASA Astrophysics Data System (ADS)

    Harp, D. R.; Pawar, R.

    2014-12-01

    Depleted oil and gas reserves have abandoned wellbore densities up to 10 per square kilometer (Crow, 2010). These locations are considered to have favorable geological structure and properties for CO2 sequestration. To understand the risk of CO2 leakage along these abandoned wellbores requires the simulation of a comprehensive set of realizations encompassing the potential scenarios. The simulations must capture transient, 3D, multi-phase effects (i.e. supercritical, liquid, and gas CO2 phases along with liquid reservoir and aquifer fluids), and include capillary and buoyant flow. Performing a large number of these simulations becomes computationally burdensome. In order to reduce this computational burden, regression approaches have been used to develop computationally efficient reduced order models to try to capture the general trends of the simulations. In these approaches, model inputs and outputs are collected from the transient simulations at each time step. Recognizing that many of the inputs to the regression approach come from time series (i.e. pressures and CO2 saturations) and that all of the outputs are time series (i.e. CO2 and brine flow rates), we develop a time-series matching approach. In this approach, CO2 and brine flow rate time series are estimated given input time series and parameters by averaging the flow rates of the collected simulations weighted by the similarity of their input time series and parameter. Similarity of both time series and parameters is calculated by the Euclidean distance. Euclidean distances are converted to a generalized likelihood metric, and used to weight the flow-rate time-series averages. We present a comparison of this time series matching approach to the MARS algorithm.

  20. Initiating the Validation of CCIM Processability for Multi-phase all Ceramic (SYNROC) HLW Form: Plan for Test BFY14CCIM-C

    SciTech Connect

    Maio, Vince

    2014-08-01

    This plan covers test BFY14CCIM-C which will be a first–of–its-kind demonstration for the complete non-radioactive surrogate production of multi-phase ceramic (SYNROC) High Level Waste Forms (HLW) using Cold Crucible Induction Melting (CCIM) Technology. The test will occur in the Idaho National Laboratory’s (INL) CCIM Pilot Plant and is tentatively scheduled for the week of September 15, 2014. The purpose of the test is to begin collecting qualitative data for validating the ceramic HLW form processability advantages using CCIM technology- as opposed to existing ceramic–lined Joule Heated Melters (JHM) currently producing BSG HLW forms. The major objectives of BFY14CCIM-C are to complete crystalline melt initiation with a new joule-heated resistive starter ring, sustain inductive melting at temperatures between 1600 to 1700°C for two different relatively high conductive materials representative of the SYNROC ceramic formation inclusive of a HLW surrogate, complete melter tapping and pouring of molten ceramic material in to a preheated 4 inch graphite canister and a similar canister at room temperature. Other goals include assessing the performance of a new crucible specially designed to accommodate the tapping and pouring of pure crystalline forms in contrast to less recalcitrant amorphous glass, assessing the overall operational effectiveness of melt initiation using a resistive starter ring with a dedicated power source, and observing the tapped molten flow and subsequent relatively quick crystallization behavior in pans with areas identical to standard HLW disposal canisters. Surrogate waste compositions with ceramic SYNROC forming additives and their measured properties for inductive melting, testing parameters, pre-test conditions and modifications, data collection requirements, and sampling/post-demonstration analysis requirements for the produced forms are provided and defined.

  1. Influence of the natural colloids on the multi-phase distributions of antibiotics in the surface water from the largest lake in North China.

    PubMed

    Cheng, Dengmiao; Liu, Xinhui; Zhao, Shengnan; Cui, Baoshan; Bai, Junhong; Li, Zhaojun

    2017-02-01

    Understanding antibiotic adsorption on natural colloids is crucial for prediction of the behavior, bioavailability and toxicity of antibiotics in natural waters. In the present study, the filtered water (dissolved phase, <0.7μm) was further separated into colloidal phase (1kDa-0.7μm) and soluble phase (<1kDa) by cross-flow ultrafiltration (CFUF), and the spatial-temporal variation and distribution of six antibiotics in multi-phases were investigated in Baiyangdian Lake. Results indicated that antibiotic concentrations differed significantly with sampling location and time. The mean concentrations of antibiotics ranged between 13.65 and 320.44ngL(-1) in the dissolved phase, and the colloidal phase accounted for 4.7-49.8% of all antibiotics, suggesting that natural colloids play an important role as carriers of antibiotics in aquatic environments. Because of the influence of colloids, the partition coefficients of antibiotics between suspended particulate matter (SPM) and soluble phase (intrinsic partition coefficients, Kp(int)) were found to be 6.18-109.60% higher than corresponding observed partition coefficients (Kp(obs), between SPM and dissolved phase). The mean partition coefficients between colloidal and soluble phase (Kcol.) ranged between 6218 and 117,374Lkg(-1), which were 1-2 orders of magnitude greater than Kp(int) values. In order to explore the adsorption mechanism of antibiotics on colloids, Pearson's correlations were performed. The results showed that log Kcol. were negatively correlated with cations in natural colloids; especially with Mg (r, -0.643, P<0.01) for oxytetracycline (OTC), and with both Ca (-0.595, P<0.01) and Mg (-0.593, P<0.01) in the case of ofloxacin (OFL). This result revealed that the competitive effect between cations and antibiotics was the main factor influencing the adsorption behavior of antibiotics on natural colloids in the lake.

  2. THE EMERGING ROLE OF STATE EDUCATION DEPARTMENTS WITH SPECIFIC IMPLICATIONS FOR DIVISIONS OF VOCATIONAL-TECHNICAL EDUCATION, REPORT OF A NATIONAL CONFERENCE ON STATE DEPARTMENT LEADERSHIP IN VOCATIONAL EDUCATION (FEBRUARY 27-MARCH 2, 1967).

    ERIC Educational Resources Information Center

    RICE, DICK C., ED.; TOTH, POWELL E., ED.

    FIFTY-THREE REPRESENTATIVES OF EDUCATIONAL INSTITUTIONS AND AGENCIES FROM 19 STATES, THE DISTRICT OF COLUMBIA, AND CANADA ATTENDED A CONFERENCE, WHICH WAS THE SECOND PHASE OF A MULTI-PHASE PROJECT TO IDENTIFY STATE LEADERSHIP NEEDS AND DEVELOP LEADERSHIP TRAINING PROGRAMS. THE PURPOSE OF THE CONFERENCE WAS TO CONCEPTUALIZE THE EMERGING ROLE OF THE…

  3. A Mixed-Methods Investigation of Early Childhood Professional Development for Providers and Recipients in the United States

    ERIC Educational Resources Information Center

    Linder, Sandra M.; Rembert, Kellye; Simpson, Amber; Ramey, M. Deanna

    2016-01-01

    This multi-phase mixed-methods study explores provider and recipient perceptions of the current state of early childhood professional development in a southeastern area of the United States. Professional development for the early childhood workforce has been shown to positively influence the quality of early childhood classrooms. This study…

  4. A Mixed-Methods Investigation of Early Childhood Professional Development for Providers and Recipients in the United States

    ERIC Educational Resources Information Center

    Linder, Sandra M.; Rembert, Kellye; Simpson, Amber; Ramey, M. Deanna

    2016-01-01

    This multi-phase mixed-methods study explores provider and recipient perceptions of the current state of early childhood professional development in a southeastern area of the United States. Professional development for the early childhood workforce has been shown to positively influence the quality of early childhood classrooms. This study…

  5. Fast, multi-phase H2O measurements on board of HALO: Results from the novel HAI instrument during the first field campaigns.

    NASA Astrophysics Data System (ADS)

    Buchholz, Bernhard; Afchine, Armin; Krämer, Martina; Ebert, Volker

    2014-05-01

    Water vapor is a key species for many questions in atmospheric research [1] [2] but is also a gas species which is complex to handle. A particular challenge is the simultaneous quantification of gas and condensed phase water. This is especially true for measurements on airborne platforms but also for laboratory experiments [3]. On research aircraft, total water measurement (i.e. the sum of gas-phase and ice-phase) is realized by sampling air with an inlet faced into flight direction ('forward' sampling) and subsequent evaporation of the ice crystals in the heated sampling lines. Gas-phase detection is typically realized using inlets facing against flight direction ('backward' sampling) or 'Rosemount' inlets where an air stream is sampled perpendicular to the high speed airflow through the inlet. For both methods it is believed that no ice crystals reach the downstream hygrometer, but the question remains - especially for Rosemount inlets - if some small ice particles or water droplets may have entered the sampling lines. In addition to the question of proper sampling of the water phases, currently no hygrometer exists that measures all phases with the same measurement principle in one instrument. In the rare occasions that multi-phase measurements are realized, gas-and condensed-phase observations rely on different methods and calibration strategies so that precision and accuracy levels are difficult to compare. The novel HAI (Hygrometer for Atmospheric Investigation) realizes a simultaneous multi-phase hygrometer in a unique concept [4]. Water detection with HAI is based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) with a special evaluation method allowing absolute water vapor measurements without any sensor calibration [5]. The HAI instrument contains two independent dual-channel spectrometers, one at 1.4 μm and one at 2.6 μm which allows to cover a very wide water concentration range from 1 to 30 000 ppmv. Both HAI spectrometers couple one light path

  6. The multi-phase winds of Markarian 231: from the hot, nuclear, ultra-fast wind to the galaxy-scale, molecular outflow

    NASA Astrophysics Data System (ADS)

    Feruglio, C.; Fiore, F.; Carniani, S.; Piconcelli, E.; Zappacosta, L.; Bongiorno, A.; Cicone, C.; Maiolino, R.; Marconi, A.; Menci, N.; Puccetti, S.; Veilleux, S.

    2015-11-01

    Mrk 231 is a nearby ultra-luminous IR galaxy exhibiting a kpc-scale, multi-phase AGN-driven outflow. This galaxy represents the best target to investigate in detail the morphology and energetics of powerful outflows, as well as their still poorly-understood expansion mechanism and impact on the host galaxy. In this work, we present the best sensitivity and angular resolution maps of the molecular disk and outflow of Mrk 231, as traced by CO(2-1) and (3-2) observations obtained with the IRAM/PdBI. In addition, we analyze archival deep Chandra and NuSTAR X-ray observations. We use this unprecedented combination of multi-wavelength data sets to constrain the physical properties of both the molecular disk and outflow, the presence of a highly-ionized ultra-fast nuclear wind, and their connection. The molecular CO(2-1) outflow has a size of 1 kpc, and extends in all directions around the nucleus, being more prominent along the south-west to north-east direction, suggesting a wide-angle biconical geometry. The maximum projected velocity of the outflow is nearly constant out to 1 kpc, thus implying that the density of the outflowing material must decrease from the nucleus outwards as r-2. This suggests that either a large part of the gas leaves the flow during its expansion or that the bulk of the outflow has not yet reached out to 1 kpc, thus implying a limit on its age of 1 Myr. Mapping the mass and energy rates of the molecular outflow yields dot {M} OF = [500-1000] M⊙ yr-1 and Ėkin,OF = [7-10] × 1043 erg s-1. The total kinetic energy of the outflow is Ekin,OF is of the same order of the total energy of the molecular disk, Edisk. Remarkably, our analysis of the X-ray data reveals a nuclear ultra-fast outflow (UFO) with velocity -20 000 km s-1, dot {M}UFO = [0.3-2.1] M⊙ yr-1, and momentum load dot {P}UFO/ dot {P}rad = [0.2-1.6]. We find Ėkin,UFO Ėkin,OF as predicted for outflows undergoing an energy conserving expansion. This suggests that most of the UFO

  7. Using pore-scale imaging and modeling to provide new insights in multi-phase flow, transport and reaction phenomena in porous media (Invited)

    NASA Astrophysics Data System (ADS)

    Bijeljic, B.; Andrew, M. G.; Menke, H. P.; Blunt, M. J.

    2013-12-01

    Advances in X ray imaging techniques made it possible not only to accurately describe solid and fluid(s) distributions in the pore space but also to study dynamics of multi-phase flow and reactive transport in-situ. This has opened up a range of new opportunities to better understand fundamental physics at the pore scale by experiment, and test and validate theoretical models in order to develop predictive tools at the pore scale and use it for upscaling. Firstly, we illustrate this concept by describing a new methodology for predicting non-Fickian transport in millimeter-sized three-dimensional micro-CT images of a beadpack, a sandstone, and a carbonate, representing porous media with an increasing degree of pore-scale complexity. The key strategy is to retain the full information on flow and transport signature of a porous medium by using probability distribution functions (PDFs) of voxel velocities for flow, and both PDFs of particle displacements and PDFs of particle transit times between voxels for transport. For this purpose, direct-simulation flow and transport model is used to analyse the relationship between pore structure, velocity, and the dynamics of the evolving plume. The model predictions for PDFs of particle displacements obtained by the model are in excellent agreement with those measured on similar cores in nuclear magnetic resonance experiments. A key determinant for non-Fickian transport is the spread in velocity distribution in the pore space. Further, we present micro-CT imaging of capillary trapping of scCO2 at reservoir conditions in a range of carbonates and sandstones having different pore structure and demonstrate that substantial quantities of scCO2 can be trapped in the pore space. Higher residual scCO2 saturations are found in sandstones compared to carbonates. The trapped ganglia exhibit different distribution of size, related to the inherent structure of pore space. Pore structures with large, open pores that are well connected lead

  8. Relaxation, multiplicity of steady states, and autooscillations in kinetics of catalytic reactions

    SciTech Connect

    Kol`tsov, N.I.; Fedotov, V.Kh.; Alekseev, B.V.

    1995-01-01

    A review of the authors` recent findings of researche into steady-state and non-steady-state catalytic reactions is given. The method for the estimation of relaxation times for particular reaction classes is generalized. Basic critical phenomena, such as the multiplicity of steady states, are discussed in terms of the structures of reaction schemes. Mechanisms of simplest catalytic oscillators are systematized. The results outlined in this paper are shown to reflect close relations between relaxation characteristics and complex critical phenomena, which are peculiar to catalytic reactions. The discussion is held within the framework of the mass action law.

  9. Performance of simultaneous high temporal resolution quantitative perfusion imaging of bladder tumors and conventional multi-phase urography using a novel free-breathing continuously acquired radial compressed-sensing MRI sequence.

    PubMed

    Parikh, Nainesh; Ream, Justin M; Zhang, Hoi Cheung; Block, Kai Tobias; Chandarana, Hersh; Rosenkrantz, Andrew B

    2016-06-01

    To investigate the feasibility of high temporal resolution quantitative perfusion imaging of bladder tumors performed simultaneously with conventional multi-phase MR urography (MRU) using a novel free-breathing continuously acquired radial MRI sequence with compressed-sensing reconstruction. 22 patients with bladder lesions underwent MRU using GRASP (Golden-angle RAdial Sparse Parallel) acquisition. Multi-phase contrast-enhanced abdominopelvic GRASP was performed during free-breathing (1.4×1.4×3.0mm(3) voxel size; 3:44min acquisition). Two dynamic datasets were retrospectively reconstructed by combining different numbers of sequentially acquired spokes into each dynamic frame: 110 spokes per frame for 25-s temporal resolution (serving as conventional MRU for clinical interpretation) and 8 spokes per frame for 1.7-s resolution. Using 1.7-s resolution images, ROIs were placed within bladder lesions and normal bladder wall, a femoral artery arterial input function was generated, and the Generalized Kinetic Model was applied. Biopsy/cystectomy demonstrated 16 bladder tumors (13 stage≥T2, 3 stage≤T1) and 6 benign lesions. All lesions were well visualized using 25-s clinical multi-phase images. Using 1.7-s resolution images, K(trans) was significantly higher in tumors (0.38±0.24) than normal bladder (0.12±0.02=8, p<0.001) or benign lesions (0.15±0.04, p=0.033). Ratio between K(trans) of lesions and normal bladder was nearly double for tumors than benign lesions (4.3±3.4 vs. 2.2±1.6), and K(trans) was nearly double in stage≥T2 than stage≤T1 tumors (0.44±0.24 vs. 0.24±0.24), although these did not approach significance (p=0.180-0.209), possibly related to small sample size. GRASP allows simultaneous quantitative high temporal resolution perfusion of bladder lesions during clinical MRU examinations using only one contrast injection and without additional scan time. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. HAI: A novel airborne multi-channel hygrometer for fast multi-phase H2O quantification: Performance of the HAI instrument during the first flights on the German HALO aircraft

    NASA Astrophysics Data System (ADS)

    Buchholz, B.; Ebert, V.; Kraemer, M.; Afchine, A.

    2014-12-01

    Common gas phase H2O measurements on fast airborne platforms e.g. using backward facing or "Rosemount"-inlets can lead to a high risk of ice and droplets contamination. In addition, currently no single hygrometer exists that allows a simultaneous, high-speed measurement of all phases (gas, liquid, ice) with the same detection principle. In the rare occasions multi-phase measurements are realized, gas-and condensed-phase observations rely on different methods, instruments and calibration strategies so that precision and accuracy levels are quite difficult to quantify. This is effectively avoided by the novel TDLAS instrument, HAI, Hygrometer for Atmospheric Investigation, which allows a simultaneous, high speed, multi-phase detection without any sensor calibration in a unique "2+2" channel concept. Hai combines two independent wavelength channels, at 1.4 µm and at 2.6 µm, for a wide dynamic range from 1 to 30 000 ppmv, with a simultaneous closed path (extractive) and open path detection. Thus, "Total", i.e. gas-phase plus condensed-phase water is measured by sampling via a forward facing inlet into "closed-path" extractive cells. A selective, sampling-free, high speed gas phase detection is realized via a dual-wavelength "open-path" cell placed outside of the aircraft fuselage. All channels can be sampled with 120 Hz (measurement cycle time Dt=1.6 ms) allowing an unprecedented spatial resolution of 30 cm at 900 km/h. The evaluation of the individual multi-channel raw-data is done post flight, without any channel interdependencies, in calibration-free mode, thus allowing fast, accurate and precise multi-phase water detection in flight. The performance could be shown in more than 200 net flights hours in three scientific flight campaigns (TACTS, ESMVal, ML-CIRRUS) on the new German HALO aircraft. In addition the level of the accuracy of the calibration free evaluation was evaluated at the German national primary water vapor standard.

  11. Capillary states of granular materials in the funicular state

    NASA Astrophysics Data System (ADS)

    Delenne, Jean-Yves; Richefeu, Vincent; Radjai, Farhang

    2013-06-01

    Using a multi-phase lattice Boltzmann model, we investigate the capillary states of a 2D granular packing gradually saturated by condensation from a homogeneously injected vapor phase. The internal stresses induced by surface tension and Laplace pressure are directly calculated from the forces acting on the grains with increasing amount of liquid. The evolution of cohesive strength with the amount of liquid reveals four different states reflecting the connectivity of the liquid phase and local grain environments. It increases in the pendular state, characterized by binary liquid bridges holding the grains together, and within the funicular state with an increasing number of liquid clusters connected to several grains. Beyond 40% of saturation, the cohesive strength falls off due to a decreasing Laplace pressure of liquid clusters.

  12. Study of retained austenite and nano-scale precipitation and their effects on properties of a low alloyed multi-phase steel by the two-step intercritical treatment

    SciTech Connect

    Xie, Z.J.; Han, G. Zhou, W.H.; Zeng, C.Y.; Shang, C.J.

    2016-03-15

    Microstructure evolution and properties were studied in a low carbon low alloyed hot-rolled bainitic steel by annealing and annealing plus tempering. Microstructure of the hot-rolled steel consists of lath bainite and martensite. By annealing at 720 °C for 30 min and water quenching, multi-phase microstructure consisting of intercritical ferrite, tempered bainite/martensite, retained austenite and fresh martensite was obtained. With increasing annealing temperature to 760 °C, microstructure of the steel consisted of intercritical ferrite, fresh martensite without retained austenite. After the second step of tempering at 680 °C for samples annealed both at 720 °C and 760 °C, ~ 8–9% volume fraction of retained austenite was obtained in the multi-phase microstructure. Moreover, fine precipitates of VC with size smaller than 10 nm and copper precipitates with size of ~ 10–50 nm were obtained after tempering. Results from scanning transmission electron microscopy (STEM) give evidence to support that the partitioning of Mn, Ni and Cu is of significance for retained austenite stabilization. Due to the combined contribution of multiphase microstructure, the transformation-induced-plasticity effect of retained austenite and strengthening effect of nanometer-sized precipitates, yield strength greater than 800 MPa, yield to tensile ratio of 0.9, uniform elongation of ~ 9% and good low temperature impact toughness of 147 J at − 40 °C were achieved. - Highlights: • Stable retained austenite was produced in a low alloyed steel. • Partition of Mn, Ni and Cu was confirmed by STEM for austenite stabilization. • Nano-sized VC and Cu precipitates were achieved by second tempering. • High strength–high toughness with low Y/T ratio was obtained.

  13. Simulation Study of Heterogeneous Nucleation at Grain Boundaries During the Austenite-Ferrite Phase Transformation: Comparing the Classical Model with the Multi-Phase Field Nudged Elastic Band Method

    NASA Astrophysics Data System (ADS)

    Song, Huajing; Shi, Rongpei; Wang, Yunzhi; Hoyt, Jeffrey J.

    2016-08-01

    In this work, molecular dynamics (MD) simulations have been used to study the heterogeneous nucleation occurring at grain boundaries (GBs) during the austenite (FCC) phase to ferrite (BCC) phase transformation in a pure Fe polycrystalline system. The critical nucleus properties (including size, shape, and activation energy) determined by classical nucleation theory are compared with those obtained by using a combination of the multi-phase field method (MPFM) and the nudged elastic band (NEB) method. For nucleation events that exhibit low-energy facets completely embedded within the parent FCC phase, there is a good agreement between the MD and the MPFM result with respect to the critical nucleus size, shape, and nucleation energy barrier. For systems where the emerging nucleus contains facets that cross the GB plane, the MPFM-NEB, when compared to MD, yields a better prediction than the classical approach for the nucleus morphology. New observations from the MPFM-NEB method indicate that the critical nucleus shape may change with volume and therefore depends on the nucleation driving force (undercooling).

  14. Synthesis of Energetic Multi-Phase Polymers

    DTIC Science & Technology

    1992-04-30

    mequiv.) with 0.121 g (0.695 mequiv.) TDI and 3 g±L of dibutyltin dilaurate at 600 C for 24h. In a separate experiment, 0.5 mL of methanol was added to...BAMO), equiv. wt. 5000, in 43 mL of dichloroethane were reacted with 2.13 mL of TDI (5 fold excess) and 15 jtL of dibutyltin dilaurate by heating to...of dibutyltin dilaurate to 400 C for 24h. The solvents were removed in vacuo and the solid residue was used directly for analysis. Synthesis of a C30

  15. Mechanims of aerosol particle deposition in the Oro-pharynx under non-steady airflow.

    PubMed

    Sosnowski, Tomasz R; Moskal, Arkadiusz; Gradon, Leon

    2007-01-01

    Comparison of experimental and computational results of aerosol deposition in the oro-pharyngeal cast of human published recently (Sosnowski TR, Moskal A, Gradoń L. (2006) Inhal Toxicol; 18: 773-780) demonstrated the applicability and relevance of considering realistic breathing patterns in analysis of aerosol flow and deposition within the human head airways. This issue is extended in the current paper, focused on a detailed analysis of spatial and temporal distribution of particle deposition in the oro-pharynx during inspiration. CFD modeling was used to determine both the 3D airflow structure and the local particle deposition fluxes at two different inspiratory patterns. Behavior of aerosol (particle size: 0.3-10 micro m, material density: 2200 kg m(-3)) was analyzed applying Lagrangian approach and considering Brownian effects for submicron particles. Results indicate that particles of different sizes are deposited in different parts of the oro-pharynx, depending on the point in the inspiration cycle. Larger particles (3-10 micro m) are separated efficiently in the naso-pharyngeal bend due to inertia, which predominate in the middle phase of inspiration. Submicron particles are deposited more uniformly in the oro-pharyngeal space, and their separation from the air is enhanced in a short transition period between inspiration and expiration. It suggests the importance of mixing of inspired and expired air streams for particle deposition pattern. Comparison of our computational results of deposition to the approximation derived from the in vivo data (Stahlhofen W, Rudolf G, James AC. (1989) J Aerosol Med; 2: 285-308) shows a good agreement for particles, for which the inertia is a predominant mechanism of deposition. The results of this work lead to a more detailed description of the dynamics of oro-pharyngeal aerosol deposition during inspiratory part of the breathing cycle. The recognition of that problem is essential for prediction of toxic or pharmacological local effects of inhaled aerosols.

  16. Multi-compartment modelling for aquifer parameter estimation using natural tracers in non-steady flow

    NASA Astrophysics Data System (ADS)

    Adar, E.; Sorek, S.

    A method is developed for aquifer parameter estimation incorporating dissolved hydrochemical constituents and environmental isotopes. This model is developed for basins with lack of hydrological information but with enough wells to allow for hydraulic head measurements and water sampling for chemical and isotoic analyses. It was developed for aquifer systems with observed hydraulic head fluctuations. The model is based on a distributed parameter approach in which the aquifer is represented by a finte number of cells. Inflows through external aquifer boundaries and internal fluxes are evaluated by optimizing a set of mass balance equations expressing the conservation of water, isotopes and dissolved chemicals. Storativity and transmissivity coefficients are then evaluated by the previously calculated flow components and the periodic changes in hydraulic heads. This paper presents a methodology to enhance the accuracy of estimated physical parameters in heterogeneous and anisotropic aquifers by adding chemical and isotopic information.

  17. Non-steady, Intermittent, Hot Loops in an Active Region Observed with the SDO/AIA

    NASA Astrophysics Data System (ADS)

    Cadavid, Ana C.; Lawrence, J. K.; Christian, D. J.

    2013-07-01

    While there is accumulated evidence of high temperature coronal emission in active region cores that corresponds to structures in equilibrium, other studies have found of evolving loops. We investigate the EUV intensity variations of two low and short coronal loops observed in the core of NOAA AR 11250 on 13 July 2011 between UT 12:02 and 16:32. The loops (32 Mm loop 1, 23 Mm loop 2), run directly between the AR opposite polarities, and are first detectable in the 94Å band (effective temperature ~ 7 MK). Space-time slices present intermittent brightenings evocative of turbulence. Spatial averages over the intermoss loop region lead to light curves used to analyze the temporal evolution of the loops. We find quantities with scaling regimes that are characteristic of intermittent processes. In particular intensity histograms display scaling ranges with slopes ~ -1.8, and spectra also show a scaling region for frequencies 1-8 mHz, with slopes - 3.8 (loop 1) and -2.8 (loop 2). We further investigate the time evolution of the loops in five other AIA EUV channels. The results are separated into two classes. Group A (94Å, 335Å, 211Å) characterized by hotter temperatures 2-6 MK), and group B (193Å, 171Å, 131Å) by cooler temperatures (0.4 - 1.6 MK). In loop 1 (group A) the intensity peaks in the 94Å channel are followed by maxima in the 335 Å channel with a time lag of ~10 min, suggestive of a cooling pattern with an exponential decay. The 211Å maxima follow those in the 335 Å channel, but there is no systematic relation which would indicate a progressive cooling process. In group B the signals in the 171 and 131Å channels track each other closely, and tend to lag behind the 193Å. The three signals follow a general gradual increase reaching a maximum at about the middle of the time series and then decrease. An exponential cooling model can also be associated with the 193 and 171Å pair. For loop 2 the observations in the group B light curves present similar properties as in loop 1. In contrast the intensity curves in group A only show one distinct case which could be a candidate for exponential decay via a 94 Å to 335 Å cooling process.Abstract (2,250 Maximum Characters): While there is accumulated evidence of high temperature coronal emission in active region cores that corresponds to structures in equilibrium, other studies have found of evolving loops. We investigate the EUV intensity variations of two low and short coronal loops observed in the core of NOAA AR 11250 on 13 July 2011 between UT 12:02 and 16:32. The loops (32 Mm loop 1, 23 Mm loop 2), run directly between the AR opposite polarities, and are first detectable in the 94Å band (effective temperature ~ 7 MK). Space-time slices present intermittent brightenings evocative of turbulence. Spatial averages over the intermoss loop region lead to light curves used to analyze the temporal evolution of the loops. We find quantities with scaling regimes that are characteristic of intermittent processes. In particular intensity histograms display scaling ranges with slopes ~ -1.8, and spectra also show a scaling region for frequencies 1-8 mHz, with slopes - 3.8 (loop 1) and -2.8 (loop 2). We further investigate the time evolution of the loops in five other AIA EUV channels. The results are separated into two classes. Group A (94Å, 335Å, 211Å) characterized by hotter temperatures 2-6 MK), and group B (193Å, 171Å, 131Å) by cooler temperatures (0.4 - 1.6 MK). In loop 1 (group A) the intensity peaks in the 94Å channel are followed by maxima in the 335 Å channel with a time lag of ~10 min, suggestive of a cooling pattern with an exponential decay. The 211Å maxima follow those in the 335 Å channel, but there is no systematic relation which would indicate a progressive cooling process. In group B the signals in the 171 and 131Å channels track each other closely, and tend to lag behind the 193Å. The three signals follow a general gradual increase reaching a maximum at about the middle of the time series and then decrease. An exponential cooling model can also be associated with the 193 and 171Å pair. For loop 2 the observations in the group B light curves present similar properties as in loop 1. In contrast the intensity curves in group A only show one distinct case which could be a candidate for exponential decay via a 94 Å to 335 Å cooling process.

  18. An Uncertainty Quantification System for Tabular Equations of State

    NASA Astrophysics Data System (ADS)

    Carpenter, John; Robinson, Allen; Debusschere, Bert; Mattsson, Ann; Drake, Richard; Rider, William

    2013-06-01

    Providing analysts with information regarding the accuracy of computational models is key for enabling predictive design and engineering. Uncertainty in material models can make significant contributions to the overall uncertainty in calculations. As a first step toward tackling this large problem, we present an uncertainty quantification system for tabular equations of state (EOS). First a posterior distribution of EOS model parameters is inferred using Bayes rule and a set of experimental and computational data. EOS tables are generated for parameter states sampled from the posterior distribution. A new unstructured triangular table format allows for capturing multi-phase model behavior. A principal component analysis then reduces this set of tables to a mean table and most significant perturbations. This final set of tables is provided to hydrocodes for performing simulations using standard non-intrusive uncertainty propagation methods. A multi-phase aluminum model is used to demonstrate the system. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  19. Silicon nitride equation of state

    NASA Astrophysics Data System (ADS)

    Brown, Robert C.; Swaminathan, Pazhayannur K.

    2017-01-01

    This report presents the development of a global, multi-phase equation of state (EOS) for the ceramic silicon nitride (Si3N4).1 Structural forms include amorphous silicon nitride normally used as a thin film and three crystalline polymorphs. Crystalline phases include hexagonal α-Si3N4, hexagonal β-Si3N4, and the cubic spinel c-Si3N4. Decomposition at about 1900 °C results in a liquid silicon phase and gas phase products such as molecular nitrogen, atomic nitrogen, and atomic silicon. The silicon nitride EOS was developed using EOSPro which is a new and extended version of the PANDA II code. Both codes are valuable tools and have been used successfully for a variety of material classes. Both PANDA II and EOSPro can generate a tabular EOS that can be used in conjunction with hydrocodes. The paper describes the development efforts for the component solid phases and presents results obtained using the EOSPro phase transition model to investigate the solid-solid phase transitions in relation to the available shock data that have indicated a complex and slow time dependent phase change to the c-Si3N4 phase. Furthermore, the EOSPro mixture model is used to develop a model for the decomposition products; however, the need for a kinetic approach is suggested to combine with the single component solid models to simulate and further investigate the global phase coexistences.

  20. Silicon Nitride Equation of State

    NASA Astrophysics Data System (ADS)

    Swaminathan, Pazhayannur; Brown, Robert

    2015-06-01

    This report presents the development a global, multi-phase equation of state (EOS) for the ceramic silicon nitride (Si3N4) . Structural forms include amorphous silicon nitride normally used as a thin film and three crystalline polymorphs. Crystalline phases include hexagonal α-Si3N4, hexagonalβ-Si3N4, and the cubic spinel c-Si3N4. Decomposition at about 1900 °C results in a liquid silicon phase and gas phase products such as molecular nitrogen, atomic nitrogen, and atomic silicon. The silicon nitride EOS was developed using EOSPro which is a new and extended version of the PANDA II code. Both codes are valuable tools and have been used successfully for a variety of material classes. Both PANDA II and EOSPro can generate a tabular EOS that can be used in conjunction with hydrocodes. The paper describes the development efforts for the component solid phases and presents results obtained using the EOSPro phase transition model to investigate the solid-solid phase transitions in relation to the available shock data. Furthermore, the EOSPro mixture model is used to develop a model for the decomposition products and then combined with the single component solid models to study the global phase diagram. Sponsored by the NASA Goddard Space Flight Center Living With a Star program office.

  1. A simplified approach to estimating the maximal lactate steady state.

    PubMed

    Snyder, A C; Woulfe, T; Welsh, R; Foster, C

    1994-01-01

    The exercise intensity associated with an elevated but stable blood lactate (HLa) concentration during constant load work (the maximal steady state, MSS) has received attention as a candidate for the "optimal" exercise intensity for endurance training. Identification of MSS ordinarily demands direct measurement of HLa or respiratory metabolism. The purpose of this study was to test the ability of heart rate (HR) to identify MSS during steady state exercise, similar to that used in conventional exercise prescription. Trained runners (n = 9) and cyclists (n = 12) performed incremental and steady state exercise. MSS was defined as the highest intensity in which blood lactate concentration increased < 1.0 mM from minutes 10 to 30. The next higher intensity workbout completed was defined as > MSS. HR models related to the presence or absence of steady state conditions were developed from the upper 95% confidence interval of MSS and the lower 95% confidence interval of > MSS. Cross validation of the model to predict MSS was performed using 21 running and 45 cycling exercise bouts in a separate group. Using the MSS upper 95% confidence interval model 84% and 76% of workbouts were correctly predicted in cyclists and runners, respectively. Using the > MSS lower 95% confidence interval model, 76% and 81% of workbouts were correctly predicted in cyclists and runners, respectively. Prediction errors tended to incorrectly predict non-steady state conditions when steady state had occurred (16/26) (62%). We conclude that use of these simple HR models may predict MSS with sufficient accuracy to be useful when direct HLa measurement is not available.

  2. Transport and Interfacial Phenomena in Multi-Phase Combustion Systems

    DTIC Science & Technology

    2000-02-01

    Incandescence (LII) for soot measurements at atmospheric pressure and high pressures; (B) Thermophoresis -based’ particle diagnostic techniques; (C) Simulation...Filippov and Rosner, 1998, 1999, Filippov et al. 1999). Our Thermophoresis /soot deposition research has led to a novel and quite convenient method (called

  3. Crustal Viscosity Structure Estimated from Multi-Phase Mixing Theory

    NASA Astrophysics Data System (ADS)

    Shinevar, W. J.; Behn, M. D.; Hirth, G.

    2014-12-01

    Estimates of lower crustal viscosity are typically constrained by analyses of isostatic rebound, post seismic creep, and laboratory-derived flow laws for crustal rocks and minerals. Here we follow a new approach for calculating the viscosity structure of the lower continental crust. We use Perple_X to calculate mineral assemblages for different crustal compositions. Effective viscosity is then calculated using the rheologic mixing model of Huet et al. (2014) incorporating flow laws for each mineral phase. Calculations are performed along geotherms appropriate for the Basin and Range, Tibetan Plateau, Colorado Plateau, and the San Andreas Fault. To assess the role of crustal composition on viscosity, we examined two compositional gradients extending from an upper crust with ~67 wt% SiO2 to a lower crust that is either: (i) basaltic with ~53 wt% SiO2 (Rudnick and Gao, 2003), or (ii) andesitic with ~64% SiO2 (Hacker et al., 2011). In all cases, the middle continental crust has a viscosity that is 2-3 orders of magnitude greater than that inferred for wet quartz, a common proxy for mid-crustal viscosities. An andesitic lower crust results in viscosities of 1020-1021 Pa-s and 1021-1022 Pa-s for hotter and colder crustal geotherms, respectively. A mafic lower crust predicts viscosities that are an order of magnitude higher for the same geotherm. In all cases, the viscosity calculated from the mixing model decreases less with depth compared to single-phase estimates. Lastly, for anhydrous conditions in which alpha quartz is stable, we find that there is a strong correlation between Vp/Vs and bulk viscosity; in contrast, little to no correlation exists for hydrous conditions.

  4. Synthesis of Energetic Single Phase and Multi-Phase Polymers

    DTIC Science & Technology

    1989-05-01

    made by condensation of 13 with excess malonyl chloride, were reacted with trifluoroethanol, t - butanol , and trimethylsilyl azide, respectively1 The...trifluoroethanol and t - butanol treated polymers were analyzed by H-NMR for CF3CH2 and (CH3 )3C content. Molecular weights of 27,000 and 18,000 were...poly( methyl methacrylate ) 46400 45000 - 31.50 MN of the poly(isoprene) samples were supplied by th- vendor. M of the other samples were determined

  5. Shock initiated reactions of reactive multi-phase blast explosives

    NASA Astrophysics Data System (ADS)

    Wilson, Dennis; Granier, John; Johnson, Richard; Littrell, Donald

    2017-01-01

    This paper describes a new class of non-ideal explosive compositions made of perfluoropolyether (PFPE), nanoaluminum, and a micron-size, high mass density, reactive metal. Unlike high explosives, these compositions release energy via a fast self-oxidized combustion wave rather than a true self-sustaining detonation. Their reaction rates are shock dependent and they can be overdriven to change their energy release rate. These compositions are fuel rich and have an extended aerobic energy release phase. The term "reactive multiphase blast" refers to the post-dispersion blast behavior: multiphase in that there are a gas phase that imparts pressure and a solid (particulate) phase that imparts energy and momentum [1]; and reactive in that the hot metal particles react with atmospheric oxygen and the explosive gas products to give an extended pressure pulse. Tantalum-based RMBX formulations were tested in two spherical core-shell configurations - an RMBX shell exploded by a high explosive core, and an RMBX core imploded by a high explosive shell. The fireball and blast characteristics were compared to a C-4 baseline charge.

  6. Multi-Phase Modeling of Rainbird Water Injection

    NASA Technical Reports Server (NTRS)

    Vu, Bruce T.; Moss, Nicholas; Sampson, Zoe

    2014-01-01

    This paper describes the use of a Volume of Fluid (VOF) multiphase model to simulate the water injected from a rainbird nozzle used in the sound suppression system during launch. The simulations help determine the projectile motion for different water flow rates employed at the pad, as it is critical to know if water will splash on the first-stage rocket engine during liftoff.

  7. Stochastic Rotation Dynamics simulations of wetting multi-phase flows

    NASA Astrophysics Data System (ADS)

    Hiller, Thomas; Sanchez de La Lama, Marta; Brinkmann, Martin

    2016-06-01

    Multi-color Stochastic Rotation Dynamics (SRDmc) has been introduced by Inoue et al. [1,2] as a particle based simulation method to study the flow of emulsion droplets in non-wetting microchannels. In this work, we extend the multi-color method to also account for different wetting conditions. This is achieved by assigning the color information not only to fluid particles but also to virtual wall particles that are required to enforce proper no-slip boundary conditions. To extend the scope of the original SRDmc algorithm to e.g. immiscible two-phase flow with viscosity contrast we implement an angular momentum conserving scheme (SRD+mc). We perform extensive benchmark simulations to show that a mono-phase SRDmc fluid exhibits bulk properties identical to a standard SRD fluid and that SRDmc fluids are applicable to a wide range of immiscible two-phase flows. To quantify the adhesion of a SRD+mc fluid in contact to the walls we measure the apparent contact angle from sessile droplets in mechanical equilibrium. For a further verification of our wettability implementation we compare the dewetting of a liquid film from a wetting stripe to experimental and numerical studies of interfacial morphologies on chemically structured surfaces.

  8. Seismic attenuation in multi-phase coexistence regions

    NASA Astrophysics Data System (ADS)

    Matas, J.; Ricard, Y. R.; Chambat, F.; Durand, S.

    2009-12-01

    Accurate description of seismic attenuation in the mantle becomes an increasingly important ingredient for realistic modeling of mantle structure. While seismological studies focused on globally dominant shear attenuation, only little is known about the compressional attenuation. In the mantle, structural transformations of mineralogical phases, associated with significant density increase, occur across regions having a finite width. Inside these regions, the elastic bulk modulus sampled by seismic waves differs significantly from the long-term bulk modulus seen by a viscous flow. The long-term incompressibility may be very low because of the density change related to various phase changes. We discuss differences between the classical theory of sound attenuation in a reacting fluid and the case of seismic propagation in a two-phase loop. A simple analytical model of a two-phase loop is developed to show that phase change should affect, both the bulk and the shear attenuation. The amplitude of this effect is comparable for both quantities. It implies that the seismic attenuation may be locally very diffrent from the usually adopted values. We show that attenuation occurs over two different time scales. Based on estimations of the phase kinetics in the case of the olivine-wadsleyite phase change, the low frequency attenuation occurs for periods larger than hundreds of years but the high frequency band occurs between 1 min and 1 hour in the domain of surface waves and seismic modes. We predict a minimum attenuation quality factor between 1-10 in the middle of the phase loop. However, kinetic rates of mantle phase transitions are not well known. We argue that measured normal mode attenuation can be used to put additional constrains on the phase change kinetics. Assuming a 10 km thickness of the olivine-to-wadsleyite phase transition, its kinetic rate should be either smaller than 11 seconds or greater than 11 minutes.

  9. Simulation of Compressible Multi-Phase Turbulent Reacting Flows

    DTIC Science & Technology

    2008-09-01

    ρẼ + P ) ũi + qi − ũjτij +Hsgsi + σ sgs i ] = 0 (3.3) ∂ρỸk ∂t + ∂ ∂xi [ ρ ( Ỹkũi + ỸkṼi,k ) + Y sgsi ,k + θ sgs i,k ] = 0 k = 1, ..., Ns...ρ ( Ẽui − Ẽũi ) + ( uiP − ũiP̄ ) (3.16) σsgsi = (ujτij − ũjτij) (3.17) Y sgsi ,k = ρ ( ũiYk − ũiỸk ) (3.18) The closure strategy to model the...Y sgsi ,k is also modeled using an eddy- diffusivity assumption, as: Y sgsi ,k = − ρνt Sct ∂Ỹk ∂xi (3.21) Thus, to close the filtered equations of

  10. Multi-phase simulations of coaxial injector combustion

    NASA Technical Reports Server (NTRS)

    Liang, P. Y.; Ungewitter, R. J.

    1992-01-01

    A multiphase computational fluid dynamics code (ARICC-3D) is presented and results of two simulations are discussed. The numerical framework of the CFD code is reviewed as well as some of the two-phase physical submodels. The simulations performed include a single coaxial element injector and a multielement injector using LOX/Hydrogen reactants. The single element injector simulation verified the interaction among the code's submodels. The multielement injector simulation transient results include the chamber response to a transverse pressure wave with and without a chamber baffle. The results of these simulations demonstrate the current capabilities and their limitations to model complex two-phase combustion phenomena. Possible ways to exceed these limitations are suggested.

  11. Permitting Multi-Phase Construction Under PSD Regulations

    EPA Pesticide Factsheets

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  12. Synthesis of Energetic Single Phase and Multi-Phase Polymers

    DTIC Science & Technology

    1988-03-31

    Carbamate (16).- A solution of toluene -2,4- diisocyanate (10.82g, 0.0622 mol), 2-nitrophenol (2.7 8g, 0.020 mol), and dibutyltin dilaurate (2 drops) in...capping hydroxy-terminated FPF-I with diisocyanates and linking these "soft blocks" with nitrodiols, and with nitrodiol polyformals. Several of these...polymers have TPE characteristics. Simple chain-extension of hydroxy-terminated FPF-l with diisocyanates such as TDI, 3,3- dinitropentane diisocyanate , 3

  13. Synthesis of Energetic Single Phase and Multi-Phase Polymers

    DTIC Science & Technology

    1990-03-31

    blocks with estimated melting points of 50-109 C were synthesized, including the 1:1 adduct of docosanol and toluene diisocyanate (TDI), 20 DISTRIBUTION...of Docosanol and Toluene -2,4- diisocyanate (13).- Under a N atmosphere, 5.00 g of docosanol (15.3 mmol) were dissolved in -25 mL oi dry dichloroethane...melting point of 117-1190 C. 1:1 Adduct of iH,llH,llH-eicosafluoroundecanol and Toluene -2,4- diisocyanate , (16).- 2.Og of alcohol (3.77 mmol) were dissolved

  14. Multi-phase halogen chemistry in the tropical Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Sommariva, R.; von Glasow, R.

    2012-04-01

    We used a one-dimensional model to simulate the chemical evolution of air masses in the eastern tropical Atlantic Ocean (Cape Verde region), with a focus on halogen chemistry. The model results were compared to the observations of inorganic halogen (particularly chlorine and bromine) species made in this region. The model could reproduce the measurements of chlorine species, especially under unpolluted conditions, but it overestimated sea-salt chloride and bromine species. Agrement with the measurements could be improved by taking into account the reactivity with aldehydes and the effects of DMS and Saharan dust on aerosol pH; an hypothetical HOX -> X- aqueous-phase reaction could also improve the agreement with measured Cl2 and HOCl, particularly under semi-polluted conditions. The results showed that halogen levels and speciation are very sensitive to cloud processing, although the model could not reproduce the observations under cloudy conditions. The model results were used to calculate the impact of the observed levels of halogens: Cl accounted for 5.4 - 11.6% of total methane sinks and halogens (mostly bromine and iodine) accounted for 35 - 40% of total ozone destruction.

  15. Cryogenic Homogenization and Sampling of Heterogeneous Multi-Phase Feedstock

    SciTech Connect

    Doyle, Glenn M.; Ideker, Virgene D.; Siegwarth, James D.

    1999-09-21

    An apparatus and process for producing a homogeneous analytical sample from a heterogeneous feedstock by: providing the mixed feedstock, reducing the temperature of the feedstock to a temperature below a critical temperature, reducing the size of the feedstock components, blending the reduced size feedstock to form a homogeneous mixture; and obtaining a representative sample of the homogeneous mixture. The size reduction and blending steps are performed at temperatures below the critical temperature in order to retain organic compounds in the form of solvents, oils, or liquids that may be adsorbed onto or absorbed into the solid components of the mixture, while also improving the efficiency of the size reduction. Preferably, the critical temperature is less than 77K (-196 C). Further, with the process of this invention the representative sample maybe maintained below the critical temperature until being analyzed.

  16. Are upwind techniques in multi-phase flow models necessary?

    SciTech Connect

    Park, C.-H.; Boettcher, N.; Wang, W.; Kolditz, O.

    2011-09-10

    Two alternatives of primary variables are compared for two-phase flow in heterogeneous media by solving fully established benchmarks. The first combination utilizes pressure of the wetting fluid and saturation of the non-wetting fluid as primary variables, while the second employs capillary pressure of the wetting fluid and pressure of the non-wetting fluid. While the standard Galerkin finite element method (SGFEM) is known to fail in the physical reproduction of two-phase flow in heterogeneous media (unless employing a fully upwind correction), the second scheme with capillary pressure as a primary variable without applying an upwind technique produces correct physical fluid behaviour in heterogeneous media, as observed from experiments.

  17. A multi-phase network situational awareness cognitive task analysis

    SciTech Connect

    Erbacher, Robert; Frincke, Deborah A.; Wong, Pak C.; Moody, Sarah; Fink, Glenn A.

    2010-06-16

    Abstract The goal of our project is to create a set of next-generation cyber situational-awareness capabilities with applications to other domains in the long term. The objective is to improve the decision-making process to enable decision makers to choose better actions. To this end, we put extensive effort into making certain that we had feedback from network analysts and managers and understand what their genuine needs are. This article discusses the cognitive task-analysis methodology that we followed to acquire feedback from the analysts. This article also provides the details we acquired from the analysts on their processes, goals, concerns, the data and metadata that they analyze. Finally, we describe the generation of a novel task-flow diagram representing the activities of the target user base.

  18. A Study of Multi-Phase Guided Remedial Learning

    ERIC Educational Resources Information Center

    Wu, YuLung

    2014-01-01

    In Taiwan, courses in the current online learning environment enroll at least 40-100 students, and it is difficult for teachers to manage the learning situation of each student. The proposed system treats learning portfolio, knowledge structure, and ability indicator of students as the key points of learning situations. The system integrates the…

  19. Dynamic remapping decisions in multi-phase parallel computations

    NASA Technical Reports Server (NTRS)

    Nicol, D. M.; Reynolds, P. F., Jr.

    1986-01-01

    The effectiveness of any given mapping of workload to processors in a parallel system is dependent on the stochastic behavior of the workload. Program behavior is often characterized by a sequence of phases, with phase changes occurring unpredictably. During a phase, the behavior is fairly stable, but may become quite different during the next phase. Thus a workload assignment generated for one phase may hinder performance during the next phase. We consider the problem of deciding whether to remap a paralled computation in the face of uncertainty in remapping's utility. Fundamentally, it is necessary to balance the expected remapping performance gain against the delay cost of remapping. This paper treats this problem formally by constructing a probabilistic model of a computation with at most two phases. We use stochastic dynamic programming to show that the remapping decision policy which minimizes the expected running time of the computation has an extremely simple structure: the optimal decision at any step is followed by comparing the probability of remapping gain against a threshold. This theoretical result stresses the importance of detecting a phase change, and assessing the possibility of gain from remapping. We also empirically study the sensitivity of optimal performance to imprecise decision threshold. Under a wide range of model parameter values, we find nearly optimal performance if remapping is chosen simply when the gain probability is high. These results strongly suggest that except in extreme cases, the remapping decision problem is essentially that of dynamically determining whether gain can be achieved by remapping after a phase change; precise quantification of the decision model parameters is not necessary.

  20. Cryogenic homogenization and sampling of heterogeneous multi-phase feedstock

    DOEpatents

    Doyle, Glenn Michael; Ideker, Virgene Linda; Siegwarth, James David

    2002-01-01

    An apparatus and process for producing a homogeneous analytical sample from a heterogenous feedstock by: providing the mixed feedstock, reducing the temperature of the feedstock to a temperature below a critical temperature, reducing the size of the feedstock components, blending the reduced size feedstock to form a homogeneous mixture; and obtaining a representative sample of the homogeneous mixture. The size reduction and blending steps are performed at temperatures below the critical temperature in order to retain organic compounds in the form of solvents, oils, or liquids that may be adsorbed onto or absorbed into the solid components of the mixture, while also improving the efficiency of the size reduction. Preferably, the critical temperature is less than 77 K (-196.degree. C.). Further, with the process of this invention the representative sample may be maintained below the critical temperature until being analyzed.

  1. Hybrid LES of Detonations in Reacting Multi-Phase Mixtures

    DTIC Science & Technology

    2009-02-28

    SUPPLEMENTARY NOTES 14. ABSTRACT A Large -Eddy Simulation (LES) methodology adapted to the resolution of high Reynolds number turbulent flows in...SUBJECT TERMS Large Eddy Simulation, hybrid shock capturing, compressible turbulence, shock-shear interactions 16. SECURITY CLASSIFICATION OF: a... Large scale structures for the reference JICF 125 5.13 Contours of temperature gradients magnitude and of Mach number field for the reference

  2. Multi-phase simulations of coaxial injector combustion

    NASA Technical Reports Server (NTRS)

    Liang, P. Y.; Ungewitter, R. J.

    1992-01-01

    A multiphase computational fluid dynamics code (ARICC-3D) is presented and results of two simulations are discussed. The numerical framework of the CFD code is reviewed as well as some of the two-phase physical submodels. The simulations performed include a single coaxial element injector and a multielement injector using LOX/Hydrogen reactants. The single element injector simulation verified the interaction among the code's submodels. The multielement injector simulation transient results include the chamber response to a transverse pressure wave with and without a chamber baffle. The results of these simulations demonstrate the current capabilities and their limitations to model complex two-phase combustion phenomena. Possible ways to exceed these limitations are suggested.

  3. A Study of Multi-Phase Guided Remedial Learning

    ERIC Educational Resources Information Center

    Wu, YuLung

    2014-01-01

    In Taiwan, courses in the current online learning environment enroll at least 40-100 students, and it is difficult for teachers to manage the learning situation of each student. The proposed system treats learning portfolio, knowledge structure, and ability indicator of students as the key points of learning situations. The system integrates the…

  4. Simulation of Inviscid Compressible Multi-Phase Flow with Condensation

    NASA Technical Reports Server (NTRS)

    Kelleners, Philip

    2003-01-01

    Condensation of vapours in rapid expansions of compressible gases is investigated. In the case of high temperature gradients the condensation will start at conditions well away from thermodynamic equilibrium of the fluid. In those cases homogeneous condensation is dominant over heterogeneous condensation. The present work is concerned with development of a simulation tool for computation of high speed compressible flows with homogeneous condensation. The resulting ow solver should preferably be accurate and robust to be used for simulation of industrial flows in general geometries.

  5. Computer aided design of multi-phase switched reluctance motor

    NASA Astrophysics Data System (ADS)

    Sheth, N. K.; Rajagopal, K. R.

    2005-05-01

    In this paper, a comprehensive computer-aided design (CAD) procedure of multiphase switched reluctance motor (SRM) is presented. Better approach for calculation of the outer dimensions, phase inductance, flux linkage and losses, and also a different concept for calculating the average torque of the motor are incorporated in the CAD program. The average torque is calculated based on the most effective 15° (for 8/6 SRM) of the static torque profile of the motor. A sample design of a 5hp SRM is presented in detail and the design is validated by conducting a two-dimensional finite element analysis of the motor.

  6. Curvature Measurement and Tracking of Nonwetting Phase Trapping and Pressure State in Porous Media

    NASA Astrophysics Data System (ADS)

    Wildenschild, D.; Li, T.; Schlüter, S.

    2015-12-01

    X-ray microtomography images are used to predict capillary pressure of trapped phase via interfacial curvature measurement and applying the Young-LaPlace equation. We have made several improvements to previous algorithms by removing interface segments that are affected by proximity to the solid surface, and by using distance-weighted curvature estimates. The algorithm shows significant improvement over previous quantification and allows for a close match to externally-measured capillary pressure values obtained using pressure transducers. The data also allows us to track the pressure state of trapped nonwetting phase and illustrates the dependence of pressure state of trapped objects (nonwetting phase blobs) on pore morphology as opposed to the bulk fluid pressure when the object is trapped. Individual objects can be followed during several drainage and imbibition cycles, and curvature changes followed as the object expands or contracts. This has important implications for how we understand trapping in multi-phase porous medium systems.

  7. Non-steady peristaltic propulsion with exponential variable viscosity: a study of transport through the digestive system.

    PubMed

    Tripathi, Dharmendra; Pandey, S K; Siddiqui, Abdul; Bég, O Anwar

    2014-01-01

    A theoretical study is presented for transient peristaltic flow of an incompressible fluid with variable viscosity in a finite length cylindrical tube as a simulation of transport in physiological vessels and biomimetic peristaltic pumps. The current axisymmetric analysis is qualitatively similar to two-dimensional analysis but exhibits quantitative variations. The current analysis is motivated towards further elucidating the physiological migration of gastric suspensions (food bolus) in the human digestive system. It also applies to variable viscosity industrial fluid (waste) peristaltic pumping systems. First, an axisymmetric model is analysed in the limit of large wavelength ([Formula: see text]) and low Reynolds number ([Formula: see text]) for axial velocity, radial velocity, pressure, hydromechanical efficiency and stream function in terms of radial vibration of the wall ([Formula: see text]), amplitude of the wave ([Formula: see text]), averaged flow rate ([Formula: see text]) and variable viscosity ([Formula: see text]). Subsequently, the peristaltic flow of a fluid with an exponential viscosity model is examined, which is based on the analytical solutions for pressure, wall shear stress, hydromechanical efficiency and streamline patterns in the finite length tube. The results are found to correlate well with earlier studies using a constant viscosity formulation. This study reveals some important features in the flow characteristics including the observation that pressure as well as both number and size of lower trapped bolus increases. Furthermore, the study indicates that hydromechanical efficiency reduces with increasing magnitude of viscosity parameter.

  8. A simple apparatus for the experimental study of non-steady flow thrust-augmenter ejector configurations

    NASA Technical Reports Server (NTRS)

    Khare, J. M.; Kentfield, J. A. C.

    1979-01-01

    A flexible, and easily modified, test rig is described which allows a one dimensional nonsteady flow stream to be generated, economically from a steady flow source of compressed air. This nonsteady flow is used as the primary stream in a nonsteady flow ejector constituting part of the test equipment. Standard piezo-electric pressure transducers etc. allow local pressures to be studied, as functions of time, in both the primary and secondary (mixed) flow portions of the apparatus. Provision is also made for measuring the primary and secondary mass flows and the thrust generated. Sample results obtained with the equipment are presented.

  9. Enceladus is not in Steady State

    NASA Astrophysics Data System (ADS)

    Cheunchitra, T.; Stevenson, D. J.

    2016-12-01

    shell can be thicker on average if there is net freezing at present but in that case it is difficult to explain the observed topography and gravity. A more likely scenario is that Enceladus has more melting beneath the poles than the current freezing (if any) beneath the equator. In that non-steady state model, the current ice thickness can be compatible with all current data.

  10. Efficacy of the biomaterials 3wt%-nanostrontium-hydroxyapatite-enhanced calcium phosphate cement (nanoSr-CPC) and nanoSr-CPC-incorporated simvastatin-loaded poly(lactic-co-glycolic-acid) microspheres in osteogenesis improvement: An explorative multi-phase experimental in vitro/vivo study.

    PubMed

    Masaeli, Reza; Jafarzadeh Kashi, Tahereh Sadat; Dinarvand, Rassoul; Rakhshan, Vahid; Shahoon, Hossein; Hooshmand, Behzad; Mashhadi Abbas, Fatemeh; Raz, Majid; Rajabnejad, Alireza; Eslami, Hossein; Khoshroo, Kimia; Tahriri, Mohammadreza; Tayebi, Lobat

    2016-12-01

    The purpose of this multi-phase explorative in vivo animal/surgical and in vitro multi-test experimental study was to (1) create a 3wt%-nanostrontium hydroxyapatite-enhanced calcium phosphate cement (Sr-HA/CPC) for increasing bone formation and (2) creating a simvastatin-loaded poly(lactic-co-glycolic acid) (SIM-loaded PLGA) microspheres plus CPC composite (SIM-loaded PLGA+nanostrontium-CPC). The third goal was the extensive assessment of multiple in vitro and in vivo characteristics of the above experimental explorative products in vitro and in vivo (animal and surgical studies). Physical and chemical properties of the prepared Sr-HA/CPC were evaluated. MTT assay and alkaline phosphatase activities, and radiological and histological examinations of Sr-HA/CPC, CPC and negative control were compared. X-ray diffraction (XRD) indicated that crystallinity of the prepared cement increased by increasing the powder-to-liquid ratio. Incorporation of Sr-HA into CPC increased MTT assay (biocompatibility) and ALP activity (P<0.05). Histomorphometry showed greater bone formation after 4weeks, after implantation of Sr-HA/CPC in 10 rats compared to implantations of CPC or empty defects in the same rats (n=30, ANOVA P<0.05). METHODS AND RESULTS PERTAINING TO SIM-LOADED PLGA MICROSPHERES+NANOSTRONTIUM-CPC COMPOSITE: After SEM assessment, the produced composite of microspheres and enhanced CPC were implanted for 8weeks in 10 rabbits, along with positive and negative controls, enhanced CPC, and enhanced CPC plus SIM (n=50). In the control group, only a small amount of bone had been regenerated (localized at the boundary of the defect); whereas, other groups showed new bone formation within and around the materials. A significant difference was found in the osteogenesis induced by the groups sham control (16.96±1.01), bone materials (32.28±4.03), nanostrontium-CPC (24.84±2.6), nanostrontium-CPC-simvastatin (40.12±3.29), and SIM-loaded PLGA+nanostrontium-CPC (44.8±6.45) (ANOVA P

  11. Effects of aging in catastrophe on the steady state and dynamics of a microtubule population

    NASA Astrophysics Data System (ADS)

    Jemseena, V.; Gopalakrishnan, Manoj

    2015-05-01

    Several independent observations have suggested that the catastrophe transition in microtubules is not a first-order process, as is usually assumed. Recent in vitro observations by Gardner et al. [M. K. Gardner et al., Cell 147, 1092 (2011), 10.1016/j.cell.2011.10.037] showed that microtubule catastrophe takes place via multiple steps and the frequency increases with the age of the filament. Here we investigate, via numerical simulations and mathematical calculations, some of the consequences of the age dependence of catastrophe on the dynamics of microtubules as a function of the aging rate, for two different models of aging: exponential growth, but saturating asymptotically, and purely linear growth. The boundary demarcating the steady-state and non-steady-state regimes in the dynamics is derived analytically in both cases. Numerical simulations, supported by analytical calculations in the linear model, show that aging leads to nonexponential length distributions in steady state. More importantly, oscillations ensue in microtubule length and velocity. The regularity of oscillations, as characterized by the negative dip in the autocorrelation function, is reduced by increasing the frequency of rescue events. Our study shows that the age dependence of catastrophe could function as an intrinsic mechanism to generate oscillatory dynamics in a microtubule population, distinct from hitherto identified ones.

  12. Time-Resolved Single-State Measurements of the Electronic Structure of Isochoric Heated Copper

    SciTech Connect

    Nelson, A J; Dunn, J; Widmann, K; Ao, T; Ping, Y; Hunter, J; Ng, A

    2004-10-22

    Time-resolved x-ray photoelectron spectroscopy is used to probe the non-steady-state evolution of the valence band electronic structure of laser heated ultra-thin (50 nm) Cu. Single-shot x-ray laser induced time-of-flight photoelectron spectroscopy with picosecond time resolution is used in conjunction with optical measurements of the disassembly dynamics that have shown the existence of a metastable liquid phase in fs-laser heated Cu foils persisting 4-5 ps. This metastable phase is studied using a 527 nm wavelength 400 fs laser pulse containing 0.1-2.5 mJ laser energy focused in a large 500 x 700 {micro}m{sup 2} spot to create heated conditions of 0.07-1.8 x 10{sup 12} W cm{sup -2} intensity. Valence band photoemission spectra showing the changing occupancy of the Cu 3d level with heating are presented. These are the first picosecond x-ray laser time-resolved photoemission spectra of laser-heated ultra-thin Cu foil showing changes in electronic structure. The ultrafast nature of this technique lends itself to true single-state measurements of shocked and heated materials.

  13. Modeling of the transient mobility in disordered organic semiconductors with a Gaussian density of states

    NASA Astrophysics Data System (ADS)

    Germs, W. Chr.; van der Holst, J. J. M.; van Mensfoort, S. L. M.; Bobbert, P. A.; Coehoorn, R.

    2011-10-01

    The charge-carrier mobility in organic semiconductors is often studied using non-steady-state experiments. However, energetic disorder can severely hamper the analysis due to the occurrence of a strong time dependence of the mobility caused by carrier relaxation. The multiple-trapping model is known to provide an accurate description of this effect. However, the value of the conduction level energy and the hopping attempt rate, which enter the model as free parameters, are not a priori known for a given material. We show how for the case of a Gaussian density of states both parameters can be deduced from the parameter values used to describe the measured dc current-voltage characteristics within the framework of the extended Gaussian disorder model. The approach is validated using three-dimensional Monte Carlo modeling. In the analysis, the charge-density dependence of the time-dependent mobility is included. The model is shown to successfully predict the low-frequency differential capacitance of sandwich-type devices based on a polyfluorene copolymer.

  14. A mathematical model of pan evaporation under steady state conditions

    NASA Astrophysics Data System (ADS)

    Lim, Wee Ho; Roderick, Michael L.; Farquhar, Graham D.

    2016-09-01

    In the context of changing climate, global pan evaporation records have shown a spatially-averaged trend of ∼ -2 to ∼ -3 mm a-2 over the past 30-50 years. This global phenomenon has motivated the development of the "PenPan" model (Rotstayn et al., 2006). However, the original PenPan model has yet to receive an independent experimental evaluation. Hence, we constructed an instrumented US Class A pan at Canberra Airport (Australia) and monitored it over a three-year period (2007-2010) to uncover the physics of pan evaporation under non-steady state conditions. The experimental investigations of pan evaporation enabled theoretical formulation and parameterisation of the aerodynamic function considering the wind, properties of air and (with or without) the bird guard effect. The energy balance investigation allowed for detailed formulation of the short- and long-wave radiation associated with the albedos and the emissivities of the pan water surface and the pan wall. Here, we synthesise and generalise those earlier works to develop a new model called the "PenPan-V2" model for application under steady state conditions (i.e., uses a monthly time step). Two versions (PenPan-V2C and PenPan-V2S) are tested using pan evaporation data available across the Australian continent. Both versions outperformed the original PenPan model with better representation of both the evaporation rate and the underlying physics of a US Class A pan. The results show the improved solar geometry related calculations (e.g., albedo, area) for the pan system led to a clear improvement in representing the seasonal cycle of pan evaporation. For general applications, the PenPan-V2S is simpler and suited for applications including an evaluation of long-term trends in pan evaporation.

  15. State Profiles.

    ERIC Educational Resources Information Center

    State-Federal Information Clearinghouse for Exceptional Children, Reston, VA.

    State-by-state public policy profiles are provided by the Council for Exceptional Children's State-Federal Information Clearinghouse. These profiles summarize the present legal base for the delivery of educational services to handicapped children in the United States. Included in each profile is information from various avenues used to establish…

  16. Automated Generation of Tabular Equations of State with Uncertainty Information

    NASA Astrophysics Data System (ADS)

    Carpenter, John H.; Robinson, Allen C.; Debusschere, Bert J.; Mattsson, Ann E.

    2015-06-01

    As computational science pushes toward higher fidelity prediction, understanding the uncertainty associated with closure models, such as the equation of state (EOS), has become a key focus. Traditional EOS development often involves a fair amount of art, where expert modelers may appear as magicians, providing what is felt to be the closest possible representation of the truth. Automation of the development process gives a means by which one may demystify the art of EOS, while simultaneously obtaining uncertainty information in a manner that is both quantifiable and reproducible. We describe our progress on the implementation of such a system to provide tabular EOS tables with uncertainty information to hydrocodes. Key challenges include encoding the artistic expert opinion into an algorithmic form and preserving the analytic models and uncertainty information in a manner that is both accurate and computationally efficient. Results are demonstrated on a multi-phase aluminum model. *Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  17. State Publications.

    ERIC Educational Resources Information Center

    Jobe, Janita

    1993-01-01

    Presents an annotated bibliography of 100 state government publications published in 1992-93, listed alphabetically by state, that reflect major areas of state government involvement. Subject areas include environmental efforts, health care and health insurance, economic conditions, and history and culture. (LRW)

  18. State of the States 2013

    ERIC Educational Resources Information Center

    Journal of Education Finance, 2014

    2014-01-01

    Presenters at the State of the States Roundtable session at the 2014 National Education Finance Conference in Louisville were invited to submit their papers for publication. These papers address the following topics: (1) State issues affecting P-12 and/or higher education funding; (2) Funding priorities/trends for P-12 and/or higher education; (3)…

  19. State of the States 2014

    ERIC Educational Resources Information Center

    Journal of Education Finance, 2015

    2015-01-01

    Presenters at the State of the States Roundtable session at the 2014 National Education Finance Conference in Louisville were invited to submit their papers for publication. These papers address the following topics: (1) State issues affecting P-12 and/or higher education funding; (2) Funding priorities/trends for P-12 and/or higher education; (3)…

  20. State of the States 2013

    ERIC Educational Resources Information Center

    Journal of Education Finance, 2014

    2014-01-01

    Presenters at the State of the States Roundtable session at the 2014 National Education Finance Conference in Louisville were invited to submit their papers for publication. These papers address the following topics: (1) State issues affecting P-12 and/or higher education funding; (2) Funding priorities/trends for P-12 and/or higher education; (3)…

  1. State of the States 2014

    ERIC Educational Resources Information Center

    Journal of Education Finance, 2015

    2015-01-01

    Presenters at the State of the States Roundtable session at the 2014 National Education Finance Conference in Louisville were invited to submit their papers for publication. These papers address the following topics: (1) State issues affecting P-12 and/or higher education funding; (2) Funding priorities/trends for P-12 and/or higher education; (3)…

  2. A New Wide-Range Equation of State for Xenon

    NASA Astrophysics Data System (ADS)

    Carpenter, John H.

    2011-06-01

    We describe the development of a new wide-range equation of state (EOS) for xenon. Three different prior EOS models predicted significant variations in behavior along the high pressure Hugoniot from an initial liquid state at 163.5 K and 2.97 g/cm3, which is near the triple point. Experimental measurements on Sandia's Z machine as well as density functional theory based molecular dynamics calculations both invalidate the prior EOS models in the pressure range from 200 to 840 GPa. The reason behind these EOS model disagreements is found to lie in the contribution from the thermal electronic models. A new EOS, based upon the standard separation of the Helmholtz free energy into ionic and electronic components, is constructed by combining the successful parts of prior models with a semi-empirical electronic model. Both the fluid and fcc solid phases are combined in a wide-range, multi-phase table. The new EOS is tabulated on a fine temperature and density grid, to preserve phase boundary information, and is available as table number 5191 in the LANL SESAME database. Improvements over prior EOS models are found not only along the Hugoniot, but also along the melting curve and in the region of the liquid-vapor critical point. *Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  3. Heat Transfer Analysis of an Optimized, Flexible Holder System for Freeze-Drying in Dual Chamber Cartridges Using Different State-of-the-Art PAT Tools.

    PubMed

    Korpus, Christoph; Pikal, Michael; Friess, Wolfgang

    2016-11-01

    The aim of this study was to determine the heat transfer characteristics of an optimized flexible holder device, using Tunable Diode Laser Absorption Spectroscopy, the Pressure Rise Test, and the gravimetric procedure. Two different controlled nucleation methods were tested, and an improved sublimation process, "preheated plate," was developed. Tunable Diode Laser Absorption Spectroscopy identified an initial sublimation burst phase. Accordingly, steady-state equations were adapted for the gravimetric procedure, to account for this initial non-steady-state period. The heat transfer coefficient, KDCC, describing the transfer from the holder to the DCC, was the only heat transfer coefficient showing a clear pressure dependence with values ranging from 3.81E-04 cal/(g·cm(2)·K) at 40 mTorr to 7.38E-04 cal/(g·cm(2)·K) at 200 mTorr. The heat transfer coefficient, Ktot, reflecting the overall energy transfer via the holder, increased by around 24% from 40 to 200 mTorr. This resulted in a pressure-independent sublimation rate of around 42 ± 1.06 mg/h over the whole pressure range. Hence, this pressure-dependent increase in energy transfer completely compensated the decrease in driving force of sublimation. The "flexible holder" shows a substantially reduced impact of atypical radiation, improved drying homogeneity, and ultimately a better transferability of the freeze-drying cycle for process optimization.

  4. Fate and Impact of Contaminants in Sediments of the NE United States

    NASA Astrophysics Data System (ADS)

    Buchholtz Ten Brink, M. R.; Butman, B.; Bothner, M.; Poppe, L.; Murray, R. W.; Varekamp, J.; Thomas, E.; Mecray, E. L.; Harris, C. K.; Signell, R.

    2002-12-01

    Estuaries and coastal sediments may be the ultimate sink for particle-reactive contaminants and excess nutrients.Their distribution in these sediments of the northeastern United States is a function of the location and magnitude of contaminant sources, which are correlated with population distribution and the history of land use, and of the dynamic physical and geochemical processes that occur in the sediments and on the sea floor. New York Bight, Long Island Sound, Massachusetts Bay, and the coastal regions of the Gulf of Maine have heterogeneous geology and bathymetry, variable currents, and each encompasses areas of both increasing and decreasing human impact. Chemical and geophysical mapping indicates that contaminants introduced into the environment during the past 250 years of population growth and industrial activity are present in muddy deposits up to 2 m thick, and are dispersed with fine-grained sediment throughout the region. Lower concentrations of regulated contaminants (e.g., metals such as Hg, Pb, and Cu) in the most recently deposited sediments verify the effectiveness of source reduction. Decreases in sediment metal concentrations, however, are not always accompanied by a decrease in sewage tracers and nutrient loading because of continuous population growth. Bottom currents focus and remobilize sediments periodically, creating complex patterns of habitat and sedimentation, large gradients in contaminant distributions, and non-steady state geochemical conditions. Results from analysis of over 200 sediment cores in coastal waters of the Northeast identify areas where contaminated sediments have accumulated in the last few centuries. Benthic populations in some of these areas have been impacted by local substrate changes, toxicity, hypoxia, and anoxia. The existing contaminant pool is often mobile. A multi-disciplinary approach, including predictive models that include changing sources and physical, chemical, and biological transport processes, is

  5. Practitioner States.

    ERIC Educational Resources Information Center

    1996

    This document contains four papers presented at a symposium on practitioner states moderated by Kay Bull at the 1996 conference of the Academy of Human Resource Development (AHRD). "The Effect of Locus of Control and Performance-Contingent Incentives on Productivity and Job Satisfaction in Self-Managing Teams" (Bonnie E. Garson, Douglas…

  6. Stately Saturn

    NASA Image and Video Library

    2009-12-25

    Saturn, stately and resplendent in this natural color view taken by NASA Cassini spacecraft, dwarfs the icy moon Rhea. Rhea orbits beyond the rings on the right of the image. Tethys shadow is visible on the planet on the left of the image.

  7. State Treasure

    ERIC Educational Resources Information Center

    Olson, Cathy Applefeld

    2013-01-01

    When a music teacher is named Teacher of the Year for an entire state, one just know a special story awaits. The narrative of Heidi Welch, director of music at Hillsboro-Deering High School in New Hampshire, does not disappoint. Welch, who grew up in abject poverty and was often homeless, developed her love of music through memorizing and singing…

  8. Workfare States.

    ERIC Educational Resources Information Center

    Peck, Jamie

    This book discusses the evolution of workfare policies in the United States, Canada, and the United Kingdom. Chapter 1 defines the term "workfare" and examines the concepts of transnationalizing workfare and workfarist labor regulation. Chapter 2 establishes workfare's theoretical context and explores the relationship between welfare…

  9. State Treasure

    ERIC Educational Resources Information Center

    Olson, Cathy Applefeld

    2013-01-01

    When a music teacher is named Teacher of the Year for an entire state, one just know a special story awaits. The narrative of Heidi Welch, director of music at Hillsboro-Deering High School in New Hampshire, does not disappoint. Welch, who grew up in abject poverty and was often homeless, developed her love of music through memorizing and singing…

  10. Influence of non steady gravity on natural convection during micro-gravity solidification of semiconductors. I - Time scale analysis. II - Implications for crystal growth experiments

    NASA Technical Reports Server (NTRS)

    Griffin, P. R.; Motakef, S.

    1989-01-01

    Consideration is given to the influence of temporal variations in the magnitude of gravity on natural convection during unidirectional solidification of semiconductors. It is shown that the response time to step changes in g at low Rayleigh numbers is controlled by the momentum diffusive time scale. At higher Rayleigh numbers, the response time to increases in g is reduced because of inertial effects. The degree of perturbation of flow fields by transients in the gravitational acceleration on the Space Shuttle and the Space Station is determined. The analysis is used to derive the requirements for crystal growth experiments conducted on low duration low-g vehicles. Also, the effectiveness of sounding rockets and KC-135 aircraft for microgravity experiments is examined.

  11. Influence of non steady gravity on natural convection during micro-gravity solidification of semiconductors. I - Time scale analysis. II - Implications for crystal growth experiments

    NASA Technical Reports Server (NTRS)

    Griffin, P. R.; Motakef, S.

    1989-01-01

    Consideration is given to the influence of temporal variations in the magnitude of gravity on natural convection during unidirectional solidification of semiconductors. It is shown that the response time to step changes in g at low Rayleigh numbers is controlled by the momentum diffusive time scale. At higher Rayleigh numbers, the response time to increases in g is reduced because of inertial effects. The degree of perturbation of flow fields by transients in the gravitational acceleration on the Space Shuttle and the Space Station is determined. The analysis is used to derive the requirements for crystal growth experiments conducted on low duration low-g vehicles. Also, the effectiveness of sounding rockets and KC-135 aircraft for microgravity experiments is examined.

  12. Variable Density Flow Modeling for Simulation Framework for Regional Geologic CO{sub 2} Storage Along Arches Province of Midwestern United States

    SciTech Connect

    Joel Sminchak

    2011-09-30

    The Arches Province in the Midwestern U.S. has been identified as a major area for carbon dioxide (CO{sub 2}) storage applications because of the intersection of Mt. Simon sandstone reservoir thickness and permeability. To better understand large-scale CO{sub 2} storage infrastructure requirements in the Arches Province, variable density scoping level modeling was completed. Three main tasks were completed for the variable density modeling: Single-phase, variable density groundwater flow modeling; Scoping level multi-phase simulations; and Preliminary basin-scale multi-phase simulations. The variable density modeling task was successful in evaluating appropriate input data for the Arches Province numerical simulations. Data from the geocellular model developed earlier in the project were translated into preliminary numerical models. These models were calibrated to observed conditions in the Mt. Simon, suggesting a suitable geologic depiction of the system. The initial models were used to assess boundary conditions, calibrate to reservoir conditions, examine grid dimensions, evaluate upscaling items, and develop regional storage field scenarios. The task also provided practical information on items related to CO{sub 2} storage applications in the Arches Province such as pressure buildup estimates, well spacing limitations, and injection field arrangements. The Arches Simulation project is a three-year effort and part of the United States Department of Energy (U.S. DOE)/National Energy Technology Laboratory (NETL) program on innovative and advanced technologies and protocols for monitoring/verification/accounting (MVA), simulation, and risk assessment of CO{sub 2} sequestration in geologic formations. The overall objective of the project is to develop a simulation framework for regional geologic CO{sub 2} storage infrastructure along the Arches Province of the Midwestern U.S.

  13. State of the States 2016: Arts Education State Policy Summary

    ERIC Educational Resources Information Center

    Aragon, Stephanie

    2016-01-01

    The "State of the States 2016" summarizes state policies for arts education identified in statute or administrative code for all 50 states and the District of Columbia. Information is based on a comprehensive search of state education statute and codes on each state's relevant websites. Complete results from this review are available in…

  14. Taxa-specific eco-sensitivity in relation to phytoplankton bloom stability and ecologically relevant lake state

    NASA Astrophysics Data System (ADS)

    Napiórkowska-Krzebietke, Agnieszka; Dunalska, Julita A.; Zębek, Elżbieta

    2017-05-01

    Phytoplankton (including plant-like, animal-like algae and Cyanobacteria) blooms have recently become a serious global threat to the sustenance of ecosystems, to human and animal health and to economy. This study focused on the composition and stability of blooms as well as their taxa-specific ecological sensitivity to the main causal factors (especially phosphorus and nitrogen) in degraded urban lakes. The analyzed lakes were assessed with respect to the trophic state as well as ecological status. Total phytoplankton biomass (ranging from 1.5 to 181.3 mg dm-3) was typical of blooms of different intensity, which can appear during a whole growing season but are the most severe in early or late summer. Our results suggested that steady-state and non-steady-state bloom assemblages including mono-, bi- and multi-species or heterogeneous blooms may occur in urban lakes. The most intense blooms were formed by the genera of Cyanobacteria: Microcystis, Limnothrix, Pseudanabaena, Planktothrix, Bacillariophyta: Cyclotella and Dinophyta mainly Ceratium and Peridinium. Considering the sensitivity of phytoplankton assemblages, a new eco-sensitivity factor was proposed (E-SF), based on the concept of Phytoplankton Trophic Index composed of trophic scores of phytoplankton taxa along the eutrophication gradient. The E-SF values of 0.5, 1.3, 6.7 and 15.1 were recognized in lakes having a high, good, moderate or poor ecological status, respectively. For lake restoration, each type of bloom should be considered separately because of different sensitivities of taxa and relationships with environmental variables. Proper recognition of the taxa-specific response to abiotic (especially to N and P enrichment) and biotic factors could have significant implications for further water protection and management.

  15. Plasma apolipoprotein B-48 transport in obese men: a new tracer kinetic study in the postprandial state.

    PubMed

    Wong, Annette T Y; Chan, Dick C; Pang, Jing; Watts, Gerald F; Barrett, P Hugh R

    2014-01-01

    The mechanisms responsible for impaired chylomicron metabolism have not been adequately investigated in obese subjects. We aimed to compare apolipoprotein (apo) B-48 kinetics in obese and lean men by developing a new model to describe the kinetics of apoB-48 particles in the postprandial state. Seven obese and 13 age-matched lean men were given an oral fat load. apoB-48 tracer to tracee ratios were measured after intravenous d3-leucine administration using gas chromatography-mass spectrometry. Kinetic parameters were derived using a multicompartmental model. Plasma total and incremental apoB-48 0-10 hour areas under the curve as well as apoB-48 secretion and fractional catabolic rate. Compared with lean men, fasting plasma triglyceride (+148%) and apoB-48 (+110%) concentrations as well as plasma total and incremental triglycerides (+184% and +185%, respectively) and apoB-48 (+182% and 224%, respectively) areas under the curve were significantly higher in obese men (P<.05 for all). The obese men also had significantly (P<.05 for all) higher secretion rates of apoB-48 in the fasted state (+145%) as well as at 3 hours (+70%), 4 hours (+82%), 5 hours (+82%), 6 hours (+76%), and 8 hours (+61%) in response to the fat load. This was associated with a greater number of apoB-48-containing particles secreted over the 10-hour study period in the obese men, compared with lean men (+125%, P<.01). The fractional catabolic rate of apoB-48 was significantly lower in the obese men compared with the lean men (-33%, P<.05) CONCLUSION: We demonstrate that postprandial hypertriglyceridemia in central obesity relates to an overproduction and impaired catabolism of apoB-48-containing lipoproteins. These findings are based on a new, physiologically relevant, kinetic model, which describes the non-steady-state postprandial metabolism of apoB-48.

  16. State of the States, 2012: Arts Education State Policy Summary

    ERIC Educational Resources Information Center

    Arts Education Partnership (NJ1), 2012

    2012-01-01

    The "State of the States 2012" summarizes state policies for arts education identified in statute or code for all 50 states and the District of Columbia. Information is based primarily on results from the AEP Arts Education State Policy Survey conducted in 2010-11, and updated in April 2012.

  17. Graybox and adaptative dynamic neural network identification models to infer the steady state efficiency of solar thermal collectors starting from the transient condition

    SciTech Connect

    Roberto, Baccoli; Ubaldo, Carlini; Stefano, Mariotti; Roberto, Innamorati; Elisa, Solinas; Paolo, Mura

    2010-06-15

    This paper deals with the development of methods for non steady state test of solar thermal collectors. Our goal is to infer performances in steady-state conditions in terms of the efficiency curve when measures in transient conditions are the only ones available. We take into consideration the method of identification of a system in dynamic conditions by applying a Graybox Identification Model and a Dynamic Adaptative Linear Neural Network (ALNN) model. The study targets the solar collector with evacuated pipes, such as Dewar pipes. The mathematical description that supervises the functioning of the solar collector in transient conditions is developed using the equation of the energy balance, with the aim of determining the order and architecture of the two models. The input and output vectors of the two models are constructed, considering the measures of 4 days of solar radiation, flow mass, environment and heat-transfer fluid temperature in the inlet and outlet from the thermal solar collector. The efficiency curves derived from the two models are detected in correspondence to the test and validation points. The two synthetic simulated efficiency curves are compared with the actual efficiency curve certified by the Swiss Institute Solartechnik Puffung Forschung which tested the solar collector performance in steady-state conditions according to the UNI-EN 12975 standard. An acquisition set of measurements of only 4 days in the transient condition was enough to trace through a Graybox State Space Model the efficiency curve of the tested solar thermal collector, with a relative error of synthetic values with respect to efficiency certified by SPF, lower than 0.5%, while with the ALNN model the error is lower than 2.2% with respect to certified one. (author)

  18. Investigation of parameter estimation and impact of injection rate on relative permeability measurements for supercritical CO2 and water by unsteady-state method

    NASA Astrophysics Data System (ADS)

    Hiratsuka, Y.; Yamamoto, H.

    2014-12-01

    CCS (Carbon dioxide Capture and Storage) is a promising option for mitigating climate changes. To predict the behavior of injected CO2 in a deep reservoir, relative permeability of supercritical CO2 and water of the reservoir rock is one of the most fundamental and influential properties. For determining the relative permeability, we employed the unsteady state method, in which the relative permeability is determined based on history matching of transient monitoring data with a multi-phase flow model. The unsteady-state method is relatively simple and short, but obviously its accuracy strongly depends on the flow model assumed in the history matching. In this study, we conducted relative permeability measurements of supercritical CO2-water system for Berea sandstone with the unsteady-state method under a reservoir condition at a 1km depth (P= 9.5MPa, T = 44˚C). Automatic history matching was performed with an inversion simulator iTOUGH2/ECO2N for multi-phase flow system of supercritical CO2, NaCl, and water. A sensitivity analysis of relative permeability parameters for CO2 and water was carried out to better understand the uniqueness and the uncertainty of the optimum solution estimated by the history matching. Among the parameters of the Corey-type curve employed in this study, while the end-point permeability could be optimized in a limited range, the other parameters were correlated and their combinations were not unique. However it was found that any combination of these parameters results in nearly identical shapes of the curve in the range of CO2 saturation in this study (0 to 60%). The optimally estimated curve from the unsteady-method was well comparable with those from the steady-state method acquired in the previous studies. Our experiment also focuses on the impact of injection rate on the estimates of relative permeability, as it is known that the injection rate could have a significant effect on fluid distribution such as viscous fingering with

  19. A Model of the Turbulent Electric Dynamo in Multi-Phase Media

    NASA Astrophysics Data System (ADS)

    Dementyeva, Svetlana; Mareev, Evgeny

    2016-04-01

    Many terrestrial and astrophysical phenomena witness the conversion of kinetic energy into electric energy (the energy of the quasi-stationary electric field) in conducting media, which is natural to treat as manifestations of electric dynamo by analogy with well-known theory of magnetic dynamo. Such phenomena include thunderstorms and lightning in the Earth's atmosphere and atmospheres of other planets, electric activity caused by dust storms in terrestrial and Martian atmospheres, snow storms, electrical discharges occurring in technological setups, connected with intense mixing of aerosol particles like in the milling industry. We have developed a model of the large-scale turbulent electric dynamo in a weakly conducting medium, containing two heavy-particle components. We have distinguished two main classes of charging mechanisms (inductive and non-inductive) in accordance with the dependence or independence of the electric charge, transferred during a particle collision, on the electric field intensity and considered the simplified models which demonstrate the possibility of dynamo realization and its specific peculiarities for these mechanisms. Dynamo (the large-scale electric field growth) appears due to the charge separation between the colliding and rebounding particles. This process is may be greatly intensified by the turbulent mixing of particles with different masses and, consequently, different inertia. The particle charge fluctuations themselves (small-scale dynamo), however, do not automatically mean growth of the large-scale electric field without a large-scale asymmetry. Such an asymmetry arises due to the dependence of the transferred charge magnitude on the electric field intensity in the case of the inductive mechanism of charge separation, or due to the gravity and convection for non-inductive mechanisms. We have found that in the case of the inductive mechanism the large-scale dynamo occurs if the medium conductivity is small enough while the electrification process determined by the turbulence intensity and particles sizes is strong enough. The electric field strength grows exponentially. For the non-inductive mechanism we have found the conditions when the electric field strength grows but linearly in time. Our results show that turbulent electric dynamo could play a substantial role in the electrification processes for different mechanisms of charge generation and separation. Thunderstorms and lightning are the most frequent and spectacular manifestations of electric dynamo in the atmosphere, but turbulent electric dynamo may also be the reason of electric discharges occurring in dust and snow storms or even in technological setups with intense mixing of small particles.

  20. A multi-phase, micro-dispersion reactor for the continuous production of methane gas hydrate

    SciTech Connect

    Taboada Serrano, Patricia L; Ulrich, Shannon M; Szymcek, Phillip; McCallum, Scott; Phelps, Tommy Joe; Palumbo, Anthony Vito; Tsouris, Costas

    2009-01-01

    A continuous-jet hydrate reactor originally developed to generate a CO2 hydrate stream has been modified to continuously produce CH4 hydrate. The reactor has been tested in the Seafloor Process Simulator (SPS), a 72-L pressure vessel available at Oak Ridge National Laboratory. During experiments, the reactor was submerged in water inside the SPS and received water from the surrounding through a submersible pump and CH4 externally through a gas booster pump. Thermodynamic conditions in the hydrate stability regime were employed in the experiments. The reactor produced a continuous stream of CH4 hydrate, and based on pressure values and amount of gas injected, the conversion of gas to hydrate was estimated. A conversion of up to 70% was achieved using this reactor.

  1. Effects of Microalloying in Multi Phase Steels for Car Body Manufacture

    NASA Astrophysics Data System (ADS)

    Bleck, Wolfgang; Phiu-On, Kriangyut

    Microalloying elements like Al, B, Nb, Ti, V can be used to optimise the microstructure evolution and the mechanical properties of advanced high strength steels (AHSS). Microalloying elements are characterised by small additions < 0.1 mass% and their ability to form carbides or nitrides. They can increase strength by grain refinement and precipitation hardening, retard or accelerate transformations and affect the diffusion kinetics. Thus, by their addition the AHSS with their high requirements to process control can be adopted to existing processing lines. Different combinations of microstructural phases and different chemical compositions have been investigated for AHSS in order to combine high strength with excellent formability.

  2. Kinematic Synthesis of Planar Five-Bar Mechanisms for Multi-Phase Motion Generation

    NASA Astrophysics Data System (ADS)

    Russell, Kevin; Sodhi, Raj S.

    This work presents a method to design planar five-bar mechanisms to achieve multiple phases of prescribed rigid body path points. Using this method, these mechanisms are designed to achieve multiple phases of prescribed rigid body path points using the same hardware. This synthesis method accommodates one DOF belted, geared and chain driven five bar mechanisms or two DOF five-bar mechanisms. By prescribing the angular positions of one driving link with respect to the synthesized moving pivot positions of the other driving link, the positions of both driving links are timed. The parameters of one driving link and the links to be determined in this mechanism are synthesized using constant length constraint equations given the prescribed rigid body path points. The example problem in this work considers a two-phase moving pivot adjustment (with constant link lengths) of a planar five bar mechanism.

  3. Interactive tools for inpatient medication tracking: a multi-phase study with cardiothoracic surgery patients

    PubMed Central

    Woollen, Janet; Prey, Jennifer; Restaino, Susan; Bakken, Suzanne; Feiner, Steven; Sackeim, Alexander; Vawdrey, David K

    2016-01-01

    Objective Prior studies of computing applications that support patients’ medication knowledge and self-management offer valuable insights into effective application design, but do not address inpatient settings. This study is the first to explore the design and usefulness of patient-facing tools supporting inpatient medication management and tracking. Materials and Methods We designed myNYP Inpatient, a custom personal health record application, through an iterative, user-centered approach. Medication-tracking tools in myNYP Inpatient include interactive views of home and hospital medication data and features for commenting on these data. In a two-phase pilot study, patients used the tools during cardiothoracic postoperative care at Columbia University Medical Center. In Phase One, we provided 20 patients with the application for 24–48 h and conducted a closing interview after this period. In Phase Two, we conducted semi-structured interviews with 12 patients and 5 clinical pharmacists who evaluated refinements to the tools based on the feedback received during Phase One. Results Patients reported that the medication-tracking tools were useful. During Phase One, 14 of the 20 participants used the tools actively, to review medication lists and log comments and questions about their medications. Patients’ interview responses and audit logs revealed that they made frequent use of the hospital medications feature and found electronic reporting of questions and comments useful. We also uncovered important considerations for subsequent design of such tools. In Phase Two, the patients and pharmacists participating in the study confirmed the usability and usefulness of the refined tools. Conclusions Inpatient medication-tracking tools, when designed to meet patients’ needs, can play an important role in fostering patient participation in their own care and patient-provider communication during a hospital stay. PMID:26744489

  4. Multi-phase structural and tectonic evolution of the Andaman Sea Region

    NASA Astrophysics Data System (ADS)

    Masterton, Sheona; Hill, Catherine; Sagi, David Adam; Webb, Peter; Sevastjanova, Inga

    2017-04-01

    We present a new regional tectonic interpretation for Myanmar and the Andaman Sea, built within the framework of global plate motions. In our model the Present Day Andaman Sea region has been subjected to multiple phases of extension, culminating in its mid-Miocene to Present Day opening as a rhomboidal pull-apart basin. The Andaman Sea region is historically thought to have developed as a consequence of back-arc opening associated with plate convergence at the Andaman-Nicobar subduction system. We have undertaken detailed structural interpretation of potential field, Landsat and SRTM data, supported by 2-D crustal models of the Andaman Sea. From this analysis we identified several major north-south striking faults and a series of northeast-southwest striking structures across the region. We have also mapped the extent of the Andaman-Nicobar Accretionary Prism, a fore arc trough and volcanic arc, which we associate with a phase of traditional trench-parallel back-arc extension from the Paleocene to the middle Miocene. A regional tectonic event occurred during the middle Miocene that caused the cessation of back-arc extension in the Present Day Andaman Sea and an eastward shift in the locus of arc-related volcanism. At that time, N-S striking faults onshore and offshore Myanmar were reactivated with widespread right-lateral motion. This motion, accompanied by extension along new NE-SW striking faults, facilitated the opening of the Central Andaman Basin as a pull-apart basin (rhombochasm) in which a strike-slip tectonic regime has a greater impact on the mode of opening than the subduction process. The integration of our plate model solution within a global framework allows identification of major plate reorganisation events and their impact on a regional scale. We therefore attribute the onset of pull-apart opening in the Andaman Sea to ongoing clockwise rotation of the western Sundaland margin throughout the late Paleogene and early Miocene, possibly driven by the opening of the South China Sea to the east. Consequently, the obliquity of plate convergence along this margin increased, ultimately resulting in a change from minor strain partitioning to hyper oblique convergence and full strain partitioning by the mid-Miocene. Investigation into the effects of slab-steepening and dynamic subsidence in the Indochina region could be used as further tests of our proposed tectonic evolution of the Andaman Sea.

  5. Significance of chamber pressure to complex multi-phase physics in jet engine fuel injection processes

    NASA Astrophysics Data System (ADS)

    Dahms, Rainer; Oefelein, Joseph

    2014-11-01

    Injection processes in jet engines at chamber pressures in excess of the thermodynamic critical pressure of the liquid fuel are not well understood. Under some conditions, a distinct two-phase interface may not exist anymore which eliminates the presence of classical spray atomization phenomena. A comprehensive model for jet engine fuel injections is derived to quantify the conditions under which the interfacial dynamics transition to diffusion-dominated mixing processes without surface tension. At certain conditions, the model shows two-phase interfaces with substantially increased thicknesses and distinctively reduced mean free paths in comparison to ambient pressure conditions. Then, the underlying assumptions of a distinct two-phase interface do not apply anymore and the interface along with its surface tension is shown to deteriorate as it broadens substantially. As a consequence of this physical complexity, the conceptual view of spray atomization and evaporation as an appropriate model for jet engine injection processes is, contrary to conventional wisdom, questionable at certain operating conditions. Instead, a Large Eddy Simulation using a dense-fluid approximation is applied which takes the complex thermo-physics of real-fluid behavior into account.

  6. Supervising and Controlling Unmanned Systems: A Multi-Phase Study with Subject Matter Experts.

    PubMed

    Porat, Talya; Oron-Gilad, Tal; Rottem-Hovev, Michal; Silbiger, Jacob

    2016-01-01

    Proliferation in the use of Unmanned Aerial Systems (UASs) in civil and military operations has presented a multitude of human factors challenges; from how to bridge the gap between demand and availability of trained operators, to how to organize and present data in meaningful ways. Utilizing the Design Research Methodology (DRM), a series of closely related studies with subject matter experts (SMEs) demonstrate how the focus of research gradually shifted from "how many systems can a single operator control" to "how to distribute missions among operators and systems in an efficient way". The first set of studies aimed to explore the modal number, i.e., how many systems can a single operator supervise and control. It was found that an experienced operator can supervise up to 15 UASs efficiently using moderate levels of automation, and control (mission and payload management) up to three systems. Once this limit was reached, a single operator's performance was compared to a team controlling the same number of systems. In general, teams led to better performances. Hence, shifting design efforts toward developing tools that support teamwork environments of multiple operators with multiple UASs (MOMU). In MOMU settings, when the tasks are similar or when areas of interest overlap, one operator seems to have an advantage over a team who needs to collaborate and coordinate. However, in all other cases, a team was advantageous over a single operator. Other findings and implications, as well as future directions for research are discussed.

  7. 4-kW multi-phase battery powered power supply

    NASA Astrophysics Data System (ADS)

    Ponomarev, A. V.; Korzhenevskiy, S. R.; Komarskiy, A. A.; Chepusov, A. S.; Mamontov, Y. I.; Ponomarev, S. V.

    2017-05-01

    A method was developed for building the powerful battery power supplies. Using the method, the battery power supply with a 4 kW max power and up to 93% efficiency was developed to supply the “Yasen” X-ray apparatus. Two 60 A·h series-connected starter lead-acid batteries were used as a primary power supply. A DC output voltage of the source is stable over the entire power range and equals to 310 V. The power supply is based on a 5-phase HF-inverter. There is no difficulty in designing such power supplies with different power outputs. It can be done by the increasing or the decreasing number of phases (of inverter channels). This approach is not limited by the increased number of the inverter channels. The maximum output power will be determined by the battery characteristics only. The power supply is mounted on a mobile trolley, to increase the mobility of the entire set of equipment. The unit dimensions are 410×320×440, the weight is about 40 kg. The unit is forced air-cooled. A power operating mode is short and periodic.

  8. Non-Invasive Characterization Of A Flowing Multi-Phase Fluid Using Ultrasonic Interferometry

    DOEpatents

    Sinha, Dipen N.

    2005-11-01

    An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.

  9. Fast high-resolution prediction of multi-phase flow in fractured formations

    NASA Astrophysics Data System (ADS)

    Pau, George Shu Heng; Finsterle, Stefan; Zhang, Yingqi

    2016-02-01

    The success of a thermal water flood for enhanced oil recovery (EOR) depends on a detailed representation of the geometrical and hydraulic properties of the fracture network, which induces discrete, channelized flow behavior. The resulting high-resolution model is typically computationally very demanding. Here, we use the Proper Orthogonal Decomposition Mapping Method to reconstruct high-resolution solutions based on efficient low-resolution solutions. The method requires training a reduced order model (ROM) using high- and low-resolution solutions determined for a relatively short simulation time. For a cyclic EOR operation, the oil production rate and the heterogeneous structure of the oil saturation are accurately reproduced even after 105 cycles, reducing the computational cost by at least 85%. The method described is general and can be potentially utilized with any multiphase flow model.

  10. Multi-dimensional modeling of pressurization and expulsion of multi-phase hydrogen propellant

    NASA Technical Reports Server (NTRS)

    1993-01-01

    A multidimensional computational model of the pressurization process in a slush hydrogen propellant storage tank was developed and its accuracy evaluated by comparison to experimental data measured for a 5 ft diameter spherical tank. The fluid mechanic, thermodynamic, and heat transfer processes within the ullage are represented by a finite-volume model. the heat and mass fluxes at the ullage boundary were computed in auxiliary analyses and specified as input to the finite-volume model. the model was shown to be in reasonable agreement with the experimental data. A parameter study was undertaken to examine the dependence of the pressurization process on initial ullage temperature distribution and pressurant mass flow rate. It is shown that for a given heat flux rate at the ullage boundary, the pressurization process is nearly independent of initial temperature distribution. The mass flow rate study revealed decreasing pressurant mass requirements with increasing pressurant mass flow rate. Further, significant differences were identified between the ullage temperature and velocity fields predicted for pressurization of slush and those predicted for pressurization of liquid hydrogen. A simplified model of the pressurization process was constructed in search of a dimensionless characterization of the pressurization process. It is shown that the relationship derived from this simplified model collapses all of the pressure history data generated during this study into a single curve.

  11. Enhancement of SOFC Cathode Electrochemical Performance Using Multi-Phase Interfaces

    SciTech Connect

    Morgan, Dane

    2015-09-30

    This work explored the use of oxide heterostructures for enhancing the catalytic and degradation properties of solid oxide fuel cell (SOFC) cathode electrodes. We focused on heterostructures of Ruddlesden-Popper and perovskite phases. Building on previous work showing enhancement of the Ruddlesden-Popper (La,Sr)2CoO4 / perovskite (La,Sr)CoO3 heterostructure compared to pure (La,Sr)CoO3 we explored the application of related heterostructures of Ruddlesden-Popper phases on perovskite (La,Sr)(Co,Fe)O3. Our approaches included thin-film electrodes, physical and electrochemical characterization, elementary reaction kinetics modeling, and ab initio simulations. We demonstrated that Sr segregation to surfaces is likely playing a critical role in the performance of (La,Sr)CoO3 and (La,Sr)(Co,Fe)O3 and that modification of this Sr segregation may be the mechanism by which Ruddlesden-Popper coatings enhance performances. We determined that (La,Sr)(Co,Fe)O3 could be enhanced in thin films by about 10× by forming a heterostructure simultaneously with (La,Sr)2CoO4 and (La,Sr)CoO3. We hope that future work will develop this heterostructure for use as a bulk porous electrode.

  12. CFD of mixing of multi-phase flow in a bioreactor using population balance model.

    PubMed

    Sarkar, Jayati; Shekhawat, Lalita Kanwar; Loomba, Varun; Rathore, Anurag S

    2016-05-01

    Mixing in bioreactors is known to be crucial for achieving efficient mass and heat transfer, both of which thereby impact not only growth of cells but also product quality. In a typical bioreactor, the rate of transport of oxygen from air is the limiting factor. While higher impeller speeds can enhance mixing, they can also cause severe cell damage. Hence, it is crucial to understand the hydrodynamics in a bioreactor to achieve optimal performance. This article presents a novel approach involving use of computational fluid dynamics (CFD) to model the hydrodynamics of an aerated stirred bioreactor for production of a monoclonal antibody therapeutic via mammalian cell culture. This is achieved by estimating the volume averaged mass transfer coefficient (kL a) under varying conditions of the process parameters. The process parameters that have been examined include the impeller rotational speed and the flow rate of the incoming gas through the sparger inlet. To undermine the two-phase flow and turbulence, an Eulerian-Eulerian multiphase model and k-ε turbulence model have been used, respectively. These have further been coupled with population balance model to incorporate the various interphase interactions that lead to coalescence and breakage of bubbles. We have successfully demonstrated the utility of CFD as a tool to predict size distribution of bubbles as a function of process parameters and an efficient approach for obtaining optimized mixing conditions in the reactor. The proposed approach is significantly time and resource efficient when compared to the hit and trial, all experimental approach that is presently used. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:613-628, 2016. © 2016 American Institute of Chemical Engineers.

  13. Monitoring strain and damage in multi-phase composite materials using electrical resistance methods

    NASA Astrophysics Data System (ADS)

    Grammatikos, S. A.; Gkikas, G.; Paipetis, A.

    2011-04-01

    The variation of the electrical properties of fiber reinforced polymers when subjected to load offer the ability of strain and damage monitoring. This is performed via electrical resistance and electrical potential measurements. On the other hand Carbon Nanotubes (CNTs) have proved to be an efficient additive to polymers and matrices of composites with respect to structural enhancement and improvement of the electrical properties. The induction of CNTs increases the conductivity of the matrix, transforming it to an antistatic or a conducting phase. The key issue of the structural and electrical properties optimization is the dispersion quality of the nano-scale in the polymer phase. Well dispersed CNTs provide an electrical network within the insulating matrix. If the fibers are conductive, the CNT network mediates the electrical anisotropy and reduces the critical flaw size that is detectable by the change in conductivity. Thus, the network performs as an inherent sensor in the composite structure, since every invisible crack or delamination is manifested as an increase in the electrical resistance. The scope of this work is to further exploit the information provided by the electrical properties with a view to identify strain variation and global damage via bulk resistance measurements. The aforementioned techniques were employed to monitor, strain and damage in fiber reinforced composite laminates both with and without conductive nanofillers.

  14. Space debris fragments impact on multi-phase fluid filled containments

    NASA Astrophysics Data System (ADS)

    Smirnova, M. N.; Kondrat'ev, K. A.

    2012-10-01

    The paper develops a model for evaluating results of high velocity fragment or bullet interaction with thin walled fluid-filled containments. The closed form solution formulas for determining wall perforation and dynamics of impactor deceleration after wall perforation in the fluid filled containment are provided. Fragment subsonic motion in compressible fluid was studied being the function of the depth of perforation under the water level in case the containment was partially filled with water and partially with gas having a distinct fluid-gas interface. Approximation formulas were developed making it possible to simulate resistance and drag forces being functions of governing parameters. The resistance and lift forces strongly depend on the depth of body motion under free surface. Due to that reason the response of containment on high velocity perforation depends on amount of fluid. The developed models are verified with results of experiments. The obtained solutions are applicable for evaluation of the consequences of high velocity impact of space debris elements on different space structures, and developing concepts for effective shields design.

  15. Experimental and Numerical Study of Pore-Scale Multi-Phase Flow Dynamics

    NASA Astrophysics Data System (ADS)

    Tartakovsky, A. M.; Ling, B.; Oostrom, M.; Bao, J.; Kim, K.; Trask, N.; Battiato, I.

    2015-12-01

    Understanding multiphase fluid flow is critical for many applications, including CO2 sequestration, bioremediation, and oil recovery. Micro-fluidic experiments and pore-scale simulations become important tools in studying multiphase flow in porous media. At the same time, many pore-scale numerical models lack rigorous validation and verification, and micro-fluidic experiments are hard to reproduce due to physical instabilities and challenges in precisely controlling the experiments. We performed a set of microcell experiments and determined conditions necessary to obtain reproducible pore-scale evolution of the fluid-fluid interfaces during both infiltration and drainage phases. Next, we modeled the experiments using Finite Volume and Smoothed Particle Hydrodynamics codes. The point-by-point comparison of the experimental results and numerical simulations revealed advantages and disadvantages of these two methods in capturing the overall behavior and pore-scale phenomena, including residual saturations, formation of thin films, fluid bridges and various fluid trapping mechanisms.

  16. Temporal and Spatial Constraints on Multi-Phase Crustal Rotation in the Forearc of Northern Chile

    NASA Astrophysics Data System (ADS)

    Dashwood, B.; Taylor, G. K.

    2004-12-01

    The forearc of northern Chile between ~23-29oS records some of the largest paleomagnetically detected crustal rotations reported to date in the Central Andes. In contrast to much of the rest of the Central Andes rotations appear to pre-date the main uplift and shortening of the Andean plateau between 25 Ma and the present time. We report new studies in which we have endeavoured to investigate the scale of the rotated area and timing of the rotation in the forearc area between 27-30oS. Several authors have documented clockwise rotations in Mesozoic to Eocene units of up to 55o which, previously, appeared to decrease very sharply from about 30o of rotation at 28oS to near zero at ~30oS near La Serena. We present new data from over 120 sites from a range of Mesozoic to Eocene units in both the Coastal Cordillera and Precordillera. New data from two Paleocene plutons in the Tres Cruces area (29oS) combined with existing information from contemporary plutons (66-62Ma) from as far north as Inca De Oro (26oS) show the rotation to decrease smoothly suggesting a continuum in the deformation gradient controlling the rotations between these latitudes. These data also suggest that there was a distinct, if small ~10o, rotation in Cretaceous times. In order to better constrain the age of the main rotation we also present new data from Triassic to Eocene units in the La Guardia area, east of the city of Copiapó (27oS), in which we are able to demonstrate a variation in rotation during the period 60-40 Ma. In total these data strongly suggest to us that the large rotations of this region vary relatively uniformly and slowly with distance N-S and that a substantial part of this rotation pre-dates both the Andean orogeny and also the Incaic Orogeny of this part of the Central Andes. We suggest that the bulk of rotation was associated with the period of maximum obliquity of convergence between the Nazca and South American plates between 50-40 Ma. In addition, in the older rocks, of the Coastal Cordillera there is a small late Early Cretaceous component of rotation.

  17. Multi-Phase Combustion and Transport Processes Under the Influence of Acoustic Excitation

    DTIC Science & Technology

    2014-01-01

    use of fuels derived from a range of sources (coal, natural gas, etc.) from the Fischer-Tropsch (FT) process [53]. Ethanol and biodiesel have led the...recent expansion of the biofuel industry. Since 2000, global ethanol and biodiesel production has increased by more than 200% and 500%, respectively

  18. Air-Based Remediation Workshop - Section 5 Multi-Phase Extraction And Product Recovery

    EPA Science Inventory

    Pursuant to the EPA-AIT Implementing Arrangement 7 for Technical Environmental Collaboration, Activity 11 "Remediation of Contaminated Sites," the USEPA Office of International Affairs Organized a Forced Air Remediation Workshop in Taipei to deliver expert training to the Environ...

  19. Advances in Highly Constrained Multi-Phase Trajectory Generation using the General Pseudospectral Optimization Software (GPOPS)

    DTIC Science & Technology

    2013-08-01

    AIAA Guidance, Navigation, and Control Conference, Boston, Massachusetts, 19-22 August 2013. 14. ABSTRACT Recent events in hypersonic glide vehicle ...constraints. A three-stage booster aerodynamic and propulsion model and a hypersonic glide vehicle aerodynamic and ablation model were implemented in the...32611, USA Recent events in hypersonic glide vehicle programs have necessitated a new approach to examine possible flight test trajectories to include

  20. Multi-Phase US Spread and Habitat Switching of a Post-Columbian Invasive, Sorghum halepense

    PubMed Central

    Barney, Jacob N.; Atwater, Daniel Z.; Pederson, Gary A.; Pederson, Jeffrey F.; Chandler, J. Mike; Cox, T. Stan; Cox, Sheila; Dotray, Peter; Kopec, David; Smith, Steven E.; Schroeder, Jill; Wright, Steven D.; Jiao, Yuannian; Kong, Wenqian; Goff, Valorie; Auckland, Susan; Rainville, Lisa K.; Pierce, Gary J.; Lemke, Cornelia; Compton, Rosana; Phillips, Christine; Kerr, Alexandra; Mettler, Matthew; Paterson, Andrew H.

    2016-01-01

    Johnsongrass (Sorghum halepense) is a striking example of a post-Columbian founder event. This natural experiment within ecological time-scales provides a unique opportunity for understanding patterns of continent-wide genetic diversity following range expansion. Microsatellite markers were used for population genetic analyses including leaf-optimized Neighbor-Joining tree, pairwise FST, mismatch analysis, principle coordinate analysis, Tajima’s D, Fu’s F and Bayesian clusterings of population structure. Evidence indicates two geographically distant introductions of divergent genotypes, which spread across much of the US in <200 years. Based on geophylogeny, gene flow patterns can be inferred to have involved five phases. Centers of genetic diversity have shifted from two introduction sites separated by ~2000 miles toward the middle of the range, consistent with admixture between genotypes from the respective introductions. Genotyping provides evidence for a ‘habitat switch’ from agricultural to non-agricultural systems and may contribute to both Johnsongrass ubiquity and aggressiveness. Despite lower and more structured diversity at the invasion front, Johnsongrass continues to advance northward into cooler and drier habitats. Association genetic approaches may permit identification of alleles contributing to the habitat switch or other traits important to weed/invasive management and/or crop improvement. PMID:27755565

  1. Improving Magnitude Detection Thresholds Using Multi-Station Multi-Event, and Multi-Phase Methods

    DTIC Science & Technology

    2008-07-31

    applied to different tectonic settings and for what percentage of the seismicity. 111 million correlations were performed on Lg-waves for the events in...a significant detection spike. 30 24. Figure 24. Example of an aftershock (spike at 2400 samples) detected after a mainshock (spike at 1500...false alarms in 36 days for a SNR of 0.32. The significant result of this study is that a correlation detector has more than an order of magnitude

  2. Supervising and Controlling Unmanned Systems: A Multi-Phase Study with Subject Matter Experts

    PubMed Central

    Porat, Talya; Oron-Gilad, Tal; Rottem-Hovev, Michal; Silbiger, Jacob

    2016-01-01

    Proliferation in the use of Unmanned Aerial Systems (UASs) in civil and military operations has presented a multitude of human factors challenges; from how to bridge the gap between demand and availability of trained operators, to how to organize and present data in meaningful ways. Utilizing the Design Research Methodology (DRM), a series of closely related studies with subject matter experts (SMEs) demonstrate how the focus of research gradually shifted from “how many systems can a single operator control” to “how to distribute missions among operators and systems in an efficient way”. The first set of studies aimed to explore the modal number, i.e., how many systems can a single operator supervise and control. It was found that an experienced operator can supervise up to 15 UASs efficiently using moderate levels of automation, and control (mission and payload management) up to three systems. Once this limit was reached, a single operator's performance was compared to a team controlling the same number of systems. In general, teams led to better performances. Hence, shifting design efforts toward developing tools that support teamwork environments of multiple operators with multiple UASs (MOMU). In MOMU settings, when the tasks are similar or when areas of interest overlap, one operator seems to have an advantage over a team who needs to collaborate and coordinate. However, in all other cases, a team was advantageous over a single operator. Other findings and implications, as well as future directions for research are discussed. PMID:27252662

  3. Air-Based Remediation Workshop - Section 5 Multi-Phase Extraction And Product Recovery

    EPA Science Inventory

    Pursuant to the EPA-AIT Implementing Arrangement 7 for Technical Environmental Collaboration, Activity 11 "Remediation of Contaminated Sites," the USEPA Office of International Affairs Organized a Forced Air Remediation Workshop in Taipei to deliver expert training to the Environ...

  4. In-air microfluidics: Drop and jet coalescence enables rapid multi-phase 3D printing

    NASA Astrophysics Data System (ADS)

    Visser, Claas Willem; Kamperman, Tom; Lohse, Detlef; Karperien, Marcel; University of Twente Collaboration

    2016-11-01

    For the first time, we connect and integrate the fields of microfluidics and additive manufacturing, by presenting a unifying technology that we call In-air microfluidics (IAMF). We impact two liquid jets or a jet and a droplet train while flying in-air, and control their coalescence and solidification. This approach enables producing monodisperse emulsions, particles, and fibers with controlled shape and size (10 to 300 µm) and production rates 100x higher than droplet microfluidics. A single device is sufficient to process a variety of materials, and to produce different particle or fiber shapes, in marked contrast to current microfluidic devices or printers. In-air microfluidics also enables rapid deposition onto substrates, for example to form 3D printed (bio)materials which are partly-liquid but still shape-stable.

  5. Study of multi-phase flow characteristics in an MHD power train

    SciTech Connect

    Chang, S.L.; Lottes, S.A.; Bouillard, J.X.; Petrick, M.

    1993-08-01

    Computer simulation was used to predict two-phase flow processes in the CDIF MHD power train system. The predictions were used to evaluate the effects of operating and design parameters on the performance of the system and a parametric evaluation provides information to enhance the performance of the system. Major components of the system under investigation are the two-stage combustor, the converging/diverging nozzle, the supersonic MHD channel, and the diffuser. Flow in each component was simulated using a computer code. Integrating the computer codes, the two-phase flow processes in the system was calculated. Recently, the computer codes were used to investigate problems of nozzle erosion and the non-uniform iron oxide coverage on the cathode wall in the channel. A limited parametric study was conducted. The results indicated that (1) among the three nozzle geometries under investigation a {number_sign}5 nozzle has the smoothest flow development in the nozzle and has the lowest droplet deposition on wall and (2) smaller particle size and lower injection velocity tend to disperse the iron oxide particles more uniformly in the nozzle.

  6. Stratigraphy and multi-phase tectonic history of the Chukchi Borderland from MCS data

    NASA Astrophysics Data System (ADS)

    Ilhan, I.; Coakley, B.

    2012-12-01

    The Chukchi Edges project was designed to establish the relationship between the Chukchi Shelf and Borderland and indirectly test theories of opening for the Canada Basin. During this cruise, ~5300 km of 2D multi-channel seismic profiles and other geophysical measurements (swath bathymetry, gravity, magnetics, sonobuoy refraction seismic) were collected from the RV Marcus G. Langseth across the transition between the Chukchi Shelf and Chukchi Borderland. These profiles reveal extended basins separated by faulted high-standing blocks. Basin stratigraphy can be subdivided on the basis of gross stratal geometry, reflection terminations and inferred unconformities. The wedge-shaped synrift sequences terminate against the basement highs and/or major faults, burying the basement topography. The inferred postrift seismic units are more nearly tabular, but thicken locally due to compaction of underlying synrift sediments. Reflection character is dominated by alternating high and low amplitude continuous reflectors which may be consistent with pelagic or turbidite sediments. Chaotic units are also observed, which may indicate mass-flow deposits. The truncated sediments over the basement highs of the Chukchi Shelf, Chukchi Plateau and Northwind Ridge suggest major erosion due both to glacial planation and earlier erosional events perhaps associated with basement uplift prior to or during rifting and extension. It is believed that the bulk of the synrift sediments are Mesozoic in age. Certainly Cenozoic sediments are also preserved in these basins, but the position of the boundary is uncertain. Locally, continuous reflectors are observed underlying the rift basin fill. These older units, of very uncertain age, would, if sampled, provide constraint on the history and affinities of the Chukchi Borderland. In addition to the extensional basins, a number of small symmetric basins are observed on the flanks of the Chukchi Plateau. These basins may be transtensional and argue for a 2nd phase of tectonism, which overprinted the obvious extensional fabric of the Borderland. This is supported by the observation of uplifted postrift sediments on the flanks of some of the intermedial basement highs.

  7. Constraining the Multi-Phase Gas Content of Galaxies in the Local Cosmic Web

    NASA Astrophysics Data System (ADS)

    Stark, David; Kannappan, S. J.; Wei, L. H.; Baker, A. J.; Haynes, M. P.; Giovanelli, R.; Heitsch, F.; RESOLVE Team; ALFALFA Team

    2010-01-01

    The RESOLVE (REsolved Spectroscopy Of a Local VolumE) Survey is a census of gas, stars, and dark matter in 1500 galaxies down to dwarf-scale baryonic masses of 109 Msun, occupying a range of cluster, group, and filament environments in the local cosmic web. We discuss strategies to estimate the gas mass in HI, H2, and warmer phases. RESOLVE falls largely within the footprint of the ongoing ALFALFA survey, allowing us to acquire accurate HI data for much of the sample. Any missing HI masses will be estimated from color and environment data, based on trends calibrated using the ALFALFA data set. Initially, our constraints on the molecular gas component will be largely indirect, based on either AKARI FIR data or a new technique presented here that links CO-derived H2/HI ratios to stellar-mass normalized color gradients. We discuss additional strategies under development to better measure molecular gas and constrain the mass in warmer phases. In particular, we describe observational constraints on the nature of additional gas that is detected dynamically in a sample of very blue, gas-dominated galaxies, possibly representing a warm-hot phase or a low-metallicity molecular component. Obtaining a full gas census for the RESOLVE survey will allow us to model gas phase transitions and star formation, specifically examining how baryonic mass component ratios and conversion timescales depend on galaxy mass and environment.

  8. Quantitative 'real-time' imaging of multi-phase flow in ceramic monoliths.

    PubMed

    Sederman, A J; Mantle, M D; Gladden, L F

    2003-01-01

    An extension of the RARE technique has been developed which acquires multiple images from a single radio-frequency excitation. This pulse sequence has been used to image, in real-time, gas flow through stagnant liquid within parallel-channel ceramic monoliths. From these images, gas-phase volume fractions, and distributions of gas bubble length and velocity as a function of gas flow rate (50-300 cm3 min(-1)) and channel size (300 and 400 channels per square inch, cpsi) are obtained directly. Increasing the gas flow rate increased the number of large bubbles and the average bubble velocity. A bimodal distribution in the bubble velocities was observed for flow within the larger channel size (300 cpsi) in contrast to a broad unimodal distribution characterizing two-phase flow within the smaller channel size (400 cpsi).

  9. Multi-Phase Solvation Model for Biological Membranes: Molecular Action Mechanism of Amphotericin B.

    PubMed

    Falcón-González, J M; Jiménez-Domínguez, G; Ortega-Blake, I; Carrillo-Tripp, M

    2017-07-11

    Amphotericin B (AmB) is still the most effective drug for the treatment of systemic fungal infections in humans. Despite significant theoretical and experimental efforts trying to understand its molecular mechanism of action, the answer has remained elusive. In this work, we present a computational methodology to test the current membrane related hypotheses, namely, transmembrane ion channel, adsorption, and sterol sponge. We use a thermodynamic approach in which we represent the membrane by a multiphase solvation model with atomic detail (MMPSM) and calculate the free energy of transferring the drug between phases with different dielectric properties. Furthermore, we compare AmB to a chemical analogue with increased safety, an l-histidine methyl ester of AmB. Our findings reveal that both drugs dimerize in all solvents studied here. Also, it is energetically unfavorable for the drugs to penetrate into the hydrophobic core of the membrane, unless their concentration is high. Finally, it is thermodynamically possible that the sterols migrate from the membrane into a drug droplet adsorbed at the surface of the bilayer. In light of our results, several effects could take place in the complex antibiotic process. We suggest a molecular mechanism that connects all three hypotheses through a drug concentration dependence and propose that the drug promotes the formation of membrane toroidal pores. Because MMPSM is of general interest, we made it available at http://tripplab.com/tools/mmpsm .

  10. Multi-phase Absorption in Lenticular Galaxies: On the Outskirts of NGC 4203

    NASA Astrophysics Data System (ADS)

    Miller, E. D.; Ellison, S. L.; Murphy, M. T.; Bregman, J. N.

    2004-12-01

    We present UV and optical spectroscopy of the quasar Ton 1480, which is projected behind the outer HI ring of the lenticular galaxy NGC 4203. The spectra from HST, FUSE, and the VLT/UVES show absorption from a variety of low- and high-ionization species, including HI, NI, OI, NaI, CII, MgII, SiII, CaII, FeII, SiIII, CIV (marginal), and OVI. This absorber appears to be a Lyman limit system, with log(NH) = 19.7 calculated from the Ly series lines. The line centers for the low-ionization lines, mostly observed at low spectral resolution, indicate absorption at velocities similar to the HI ring/disk. The high-resolution UVES observation of CaII shows additional line components shifted -70 to -100 km/s from the HI velocity. OVI absorption is also seen near these velocities, and both lines can arise in either a superposed high-velocity cloud or, as this is close to the systemic velocity (1086 km/s), an extended gaseous halo. In addition, the NaI/CaII ratio is very low ( ˜ 0.2), implying a lack of Ca depletion onto dust grains in this part of the galaxy. We discuss the implications of our results in the context of relaxed early-type galaxies and quasar absorption line systems in general.

  11. Multi-phase evolution of gnammas (weathering pits) in a Holocene deglacial granite landscape, Minnesota (USA)

    USGS Publications Warehouse

    Dominguez-Villar, D.; Jennings, C.E.

    2008-01-01

    The morphometry of 85 gnammas (weathering pits) from Big Stone County in western Minnesota allows the assessment of the relative ages of the gnamma population. The ratio between maximum and minimum depths is independent of the initial size of the cavity and only depends on the weathering evolution. Therefore, the distribution of depth ratios can be used to assess the gnamma population age and the history of weathering. The asymmetrical distribution of depth ratios measured in Big Stone County forms three distinct populations. When these sets are analyzed independently, the correlation (r2) between maximum and minimum depths is greater than 0-95. Each single population has a normal distribution of depth ratios and the average depth ratios (??-value) for each population are ??1 = 1.60 ?? 0-05, ??2 = 2.09 + 0.04 and ??3 = 2.42 ?? 0.08. The initiation of gnamma formation followed the exhumation of the granite in the region. This granite was till and saprolite covered upon retreat of the ice from the Last Glacial Maximum. Nearby outcrops are striated, but the study site remained buried until it was exhumed by paleofloods issuing from a proglacial lake. These Holocene-aged gnammas in western Minnesota were compared with gnammas of other ages from around the world. Our new results are in accordance with the hypothesis that ??-values represent the evolution of gnammas with time under temperate- to cold-climate dynamics. Phases of the formation of new gnammas may result from changes in weathering processes related to climate changes. Copyright ?? 2007 John Wiley & Sons, Ltd.

  12. A multi-phased study of optimisation methodologies and radiation dose savings for head CT examinations.

    PubMed

    Zarb, Francis; McEntee, Mark F; Rainford, Louise

    2015-03-01

    The impact of optimisation methods on dose reductions for head computerised tomography was undertaken in three phases for two manufacturer models. Phase 1: a Catphan(®)600 was employed to evaluate protocols where the impact of parameter manipulation on dose and image quality was gauged by psychophysical measurements of contrast and spatial resolution in terms of contrast discs and line pairs. mA, kV and pitch were systematically altered until the optimisation threshold was identified. Phantom studies provide dose comparisons during optimisation but lack anatomical detail. Phase 2: optimised protocols were tested on a porcine model permitting further dose reductions over phantom findings providing anatomical structures for image quality evaluation using relative visual grading analysis of anatomical criteria. Phase 3: patient images using pre- and post-optimised protocols were clinically audited using visual grading characteristic analysis and ordinal regression analysis providing a robust analysis of image quality data prior to clinical implementation.

  13. Monitoring Soil Moisture in a Coal Mining Area with Multi-Phase Landsat Images

    NASA Astrophysics Data System (ADS)

    Kong, J. L.; Xian, T.; Yang, J.; Chen, L.; Yang, X. T.

    2016-06-01

    The coal development zone of Northern Shaanxi, China is one of the eight largest coal mines in the world, also the national energy and chemical bases. However, the coal mining leads to ground surface deformation and previous studies show that in collapse fissure zone soil water losses almost 50% compared with non-fissure zone. The main objective of this study is to develop a retrieval model that is reliable and sensitive to soil moisture in the whole coal mining zone of Northern Shaanxi based upon the soil sample parameters collected from in situ site investigation, spectral data gathered simultaneously and the images of Landsat7 ETM. The model uses different phases of Landsat data to retrieve soil moisture and analyze the patterns of spatial and temporal variations of soil moisture caused by ground deformation in the coal mining areas. The study indicated that band4 of Landsat7 ETM is the most sensitive band for soil moisture retrieval using the spectrum method. The quadratic model developed by remote sensing reflectance (Rrs4) (corresponding to the band4) is the best pattern with the correlation coefficient of 0.858 between the observed and the estimated soil moisture. Two-phase Landsat7 ETM data of 2002 and 2009 and one phase Landsat8 OLI data of 2015 for the study area were selected to retrieve soil moisture information. The result showed that the mean relative error was 35.16% and the root-mean-squared error (RMSE) was 0.58%. The changes of the spatial distribution of inversed soil moisture revealed that the trend of soil moisture contents of the study area was in general being gradually reduced from 2002 to 2015. The study results can serve as the baseline for monitoring environmental impacts on soil moisture in the regions due to coal mining.

  14. Coherent state topological cluster state production

    NASA Astrophysics Data System (ADS)

    Myers, C. R.; Ralph, T. C.

    2011-11-01

    We present results illustrating the construction of three-dimensional (3D) topological cluster states with coherent state logic. Such a construction would be ideally suited for wave-guide implementations of optical quantum information processing. We investigate the use of a deterministic controlled-Z gate, showing that given large enough initial cat states, it is possible to build large 3D cluster states. We model X and Z basis measurements by displaced photon number detections and x-quadrature homodyne detections, respectively. We investigate whether teleportation can aid in cluster state construction and whether this introduction of located loss errors fits within the topological cluster state framework.

  15. In-Situ Characterization of Tissue Blood Flow, Blood Content, and Water State Using New Techniques in Magnetic Resonance Imaging.

    NASA Astrophysics Data System (ADS)

    Conturo, Thomas Edward

    foldover in magnified images was eliminated by exciting limited regions with orthogonal pi/2 and pi pulses. Off-midline regions were imaged by tandemly offsetting the phase-encoding and excitation. Artifacts due to non-steady-state conditions were demonstrated. The approach to steady state was defined by operators and vectors, and any repeated series of RF pulses was proven to produce a steady-state. The vector difference between the magnetization and its steady state value is relatively constant during the approach. The repetition time relative to T_1 is the main determinant of approach rate, and off-resonant RF pulses incoherent with the magnetization produce a more rapid approach than on-resonant pulses.

  16. United States Department of State Strategic Plan

    DTIC Science & Technology

    1998-01-01

    targets for worldwide reduction or elimination of the cultiva- tion, production, and commercial-scale import of cocaine, opium, heroin, mari- juana ...international sanctions against state sponsors of terrorism and urges their strict enforcement. State presses state spon- sors to abandon their support for

  17. State Variations in United States Divorce Rates

    ERIC Educational Resources Information Center

    Fenelon, Bill

    1971-01-01

    The "frontier atmosphere" explanation of high divorce rates in western areas of the United States was partially vindicated when comparisons were made between divorce rates in states having high migration rates and lower social costs with those states having low migration rates and higher social costs. (Author/CG)

  18. State of the States in Developmental Disabilities

    ERIC Educational Resources Information Center

    Braddock, David; Hemp, Richard; Rizzolo, Mary Kay

    2008-01-01

    This is the latest edition of the "State of the States in Developmental Disabilities" study--a thorough and the only one of its kind investigation on public spending, revenues, and programmatic trends of intellectual and developmental programs and services within the United States since 1977. Directed by leading researcher, Dr. David…

  19. State of the States in Developmental Disabilities

    ERIC Educational Resources Information Center

    Braddock, David; Hemp, Richard; Rizzolo, Mary Kay

    2008-01-01

    This is the latest edition of the "State of the States in Developmental Disabilities" study--a thorough and the only one of its kind investigation on public spending, revenues, and programmatic trends of intellectual and developmental programs and services within the United States since 1977. Directed by leading researcher, Dr. David…

  20. Stats of the States

    MedlinePlus

    ... rates for fatal drug poisonings. Death Rates from Firearm Injuries: United States, 2013 - The latest state-based age-adjusted death rates for firearm-related fatalities. Death Rates from Homicide: United States, ...

  1. State Emergency Response Commissions

    EPA Pesticide Factsheets

    The Governor of each state has designated a State Emergency Response Commission (SERC) that is responsible for implementing the Emergency Planning and Community Right-to-Know Act (EPCRA) provisions within its state.

  2. Absolutely classical spin states

    NASA Astrophysics Data System (ADS)

    Bohnet-Waldraff, F.; Giraud, O.; Braun, D.

    2017-01-01

    We introduce the concept of "absolutely classical" spin states, in analogy to absolutely separable states of bipartite quantum systems. Absolutely classical states are states that remain classical (i.e., a convex sum of projectors on coherent states of a spin j ) under any unitary transformation applied to them. We investigate the maximal size of the ball of absolutely classical states centered on the maximally mixed state and derive a lower bound for its radius as a function of the total spin quantum number. We also obtain a numerical estimate of this maximal radius and compare it to the case of absolutely separable states.

  3. The Pennsylvania State University

    ERIC Educational Resources Information Center

    Burlingame, Philip J.; Dowhower, Andrea L.

    2009-01-01

    Founded in 1855 as the Farmer's High School, the Pennsylvania State University (Penn State) began as a small college in Centre County providing agricultural education to young men from regional farm families. Penn State became a land-grant university in 1863 following passage of the Morrill Act. Today, Penn State enrolls more than 83,000 students…

  4. State Fiscal Pressures

    ERIC Educational Resources Information Center

    Fields, Cheryl

    2005-01-01

    As most state governments were beginning their fiscal years on July 1, it looked like another tight year for state spending in many regions--and, by implication, also for appropriations for higher education institutions and state student assistance programs. The National Conference of State Legislatures (NCSL) spring report…

  5. State Legislatures, State Universities and Self Preservation.

    ERIC Educational Resources Information Center

    Graham, D. Robert

    The changing relationship between state legislatures and universities is cause for concern. State governments are aware of their fading influence on universities and are making increasingly critical assessments of their educational programs. Their contributions to budgets of public colleges and universities increased between 1954 and 1964, but the…

  6. Doorway states and billiards

    SciTech Connect

    Franco-Villafane, J. A.; Mendez-Sanchez, R. A.; Flores, J.; Mateos, J. L.; Novaro, O.; Seligman, T. H.

    2010-12-23

    Whenever a distinct state is immersed in a sea of complicated and dense states, the strength of the distinct state, which we refer to as a doorway, is distributed in their neighboring states. We analyze this mechanism for 2-D billiards with different geometries. One of them is symmetric and integrable, another is symmetric but chaotic, and the third has a capricious form. The fact that the doorway-state mechanism is valid for such highly diverse cases, proves that it is robust.

  7. Product-State Approximations to Quantum States

    NASA Astrophysics Data System (ADS)

    Brandão, Fernando G. S. L.; Harrow, Aram W.

    2016-02-01

    We show that for any many-body quantum state there exists an unentangled quantum state such that most of the two-body reduced density matrices are close to those of the original state. This is a statement about the monogamy of entanglement, which cannot be shared without limit in the same way as classical correlation. Our main application is to Hamiltonians that are sums of two-body terms. For such Hamiltonians we show that there exist product states with energy that is close to the ground-state energy whenever the interaction graph of the Hamiltonian has high degree. This proves the validity of mean-field theory and gives an explicitly bounded approximation error. If we allow states that are entangled within small clusters of systems but product across clusters then good approximations exist when the Hamiltonian satisfies one or more of the following properties: (1) high degree, (2) small expansion, or (3) a ground state where the blocks in the partition have sublinear entanglement. Previously this was known only in the case of small expansion or in the regime where the entanglement was close to zero. Our approximations allow an extensive error in energy, which is the scale considered by the quantum PCP (probabilistically checkable proof) and NLTS (no low-energy trivial-state) conjectures. Thus our results put restrictions on the possible Hamiltonians that could be used for a possible proof of the qPCP or NLTS conjectures. By contrast the classical PCP constructions are often based on constraint graphs with high degree. Likewise we show that the parallel repetition that is possible with classical constraint satisfaction problems cannot also be possible for quantum Hamiltonians, unless qPCP is false. The main technical tool behind our results is a collection of new classical and quantum de Finetti theorems which do not make any symmetry assumptions on the underlying states.

  8. State-Chart Autocoder

    NASA Technical Reports Server (NTRS)

    Clark, Kenneth; Watney, Garth; Murray, Alexander; Benowitz, Edward

    2007-01-01

    A computer program translates Unified Modeling Language (UML) representations of state charts into source code in the C, C++, and Python computing languages. ( State charts signifies graphical descriptions of states and state transitions of a spacecraft or other complex system.) The UML representations constituting the input to this program are generated by using a UML-compliant graphical design program to draw the state charts. The generated source code is consistent with the "quantum programming" approach, which is so named because it involves discrete states and state transitions that have features in common with states and state transitions in quantum mechanics. Quantum programming enables efficient implementation of state charts, suitable for real-time embedded flight software. In addition to source code, the autocoder program generates a graphical-user-interface (GUI) program that, in turn, generates a display of state transitions in response to events triggered by the user. The GUI program is wrapped around, and can be used to exercise the state-chart behavior of, the generated source code. Once the expected state-chart behavior is confirmed, the generated source code can be augmented with a software interface to the rest of the software with which the source code is required to interact.

  9. State Analysis Database Tool

    NASA Technical Reports Server (NTRS)

    Rasmussen, Robert; Bennett, Matthew

    2006-01-01

    The State Analysis Database Tool software establishes a productive environment for collaboration among software and system engineers engaged in the development of complex interacting systems. The tool embodies State Analysis, a model-based system engineering methodology founded on a state-based control architecture (see figure). A state represents a momentary condition of an evolving system, and a model may describe how a state evolves and is affected by other states. The State Analysis methodology is a process for capturing system and software requirements in the form of explicit models and states, and defining goal-based operational plans consistent with the models. Requirements, models, and operational concerns have traditionally been documented in a variety of system engineering artifacts that address different aspects of a mission s lifecycle. In State Analysis, requirements, models, and operations information are State Analysis artifacts that are consistent and stored in a State Analysis Database. The tool includes a back-end database, a multi-platform front-end client, and Web-based administrative functions. The tool is structured to prompt an engineer to follow the State Analysis methodology, to encourage state discovery and model description, and to make software requirements and operations plans consistent with model descriptions.

  10. Groundwater recharge simulation under the steady-state and transient climate conditions

    NASA Astrophysics Data System (ADS)

    Pozdniakov, S.; Lykhina, N.

    2010-03-01

    Groundwater recharge simulation under the steady-state and transient climate conditions Diffusive groundwater recharge is a vertical water flux through the water table, i.e. through the boundary between the unsaturated and saturated zones. This flux features temporal and spatial changes due to variations in the climatic conditions, landscape the state of vegetation, and the spatial variability of vadoze zone characteristics. In a changing climate the non-steady state series of climatic characteristics will affect on the groundwater recharge.. A well-tested approach to calculating water flux through the vadoze zone is the application of Richard’s equations for a heterogeneous one-domain porosity continuum with specially formulated atmospheric boundary conditions at the ground surface. In this approach the climatic parameters are reflected in upper boundary conditions, while the recharge series is the flux through the low boundary. In this work developed by authors code Surfbal that simulates water cycle at surface of topsoil to take into account the various condition of precipitation transformation at the surface in different seasons under different vegetation cover including snow accumulation in winter and melting in spring is used to generate upper boundary condition at surface of topsoil for world-wide known Hydrus-1D code (Simunek et al, 2008). To estimate the proposal climate change effect we performed Surfbal and Hydrus simulation using the steady state climatic condition and transient condition due to global warming on example of Moscow region, Russia. The following scenario of climate change in 21 century in Moscow region was selected: the annual temperature will increase on 4C during 100 year and annual precipitation will increase on 10% (Solomon et al, 2007). Within the year the maximum increasing of temperature and precipitation falls on winter time, while in middle of summer temperature will remain almost the same as observed now and monthly

  11. Malaria Treatment (United States)

    MedlinePlus

    ... a CDC Malaria Branch clinician. malaria@cdc.gov Malaria Treatment (United States) Recommend on Facebook Tweet Share Compartir Treatment of Malaria: Guidelines For Clinicians (United States) Download PDF version ...

  12. Comparative State Politics.

    ERIC Educational Resources Information Center

    Brooks, Gary H.

    1981-01-01

    Describes a college course dealing with comparative state politics. Students learn about the way in which political scientists employ the study of American state politics as a "laboratory" for the development of scientific explanations of political phenomena. (RM)

  13. Coma / Vegetative State

    MedlinePlus

    ... Vegetative State Legal Issues Sleeping Problems Anxiety & Stress Concussion / Mild TBI Living with Traumatic Brain Injury Speech & ... Conscious States After Severe Brain Injury Brain Trauma, Concussion, and Coma What Is the Glasgow Coma Scale? ...

  14. State Goals Overview

    EPA Pesticide Factsheets

    This presentation includes information on Best System of Emission Reduction (BSER), state flexibility and compliance options, examples of how to determine and calculate goals, on-the-way reductions, and a walk through of state goal derivation.

  15. States of Matter

    NASA Image and Video Library

    NASA scientists and engineers utilize the basic principles of the states of matter on a daily basis. The states and properties of matter are very important to the design and construction of NASA sp...

  16. State Energy Policy Newsletter

    EPA Pesticide Factsheets

    This page allows users to sign up for a weekly summary of state energy policy news for state agency staff involved in advancing clean energy opportunities and developing climate change mitigation policies and programs.

  17. State-ing the Facts: Exploring the United States.

    ERIC Educational Resources Information Center

    Bay, Jennifer M.; Bledsoe, Ann M.; Reys, Robert E.

    1998-01-01

    Presents activities on estimation, scaling, area of nonstandard shapes, algebraic thinking, and real-life situations using the United States of America. These activities make it possible to integrate mathematics and social studies. Uses technology by employing geometry software packages such as The Geometer's Sketchpad, Cabri, and Geometric…

  18. 7 CFR 1220.615 - State and United States.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false State and United States. 1220.615 Section 1220.615... CONSUMER INFORMATION Procedures To Request a Referendum Definitions § 1220.615 State and United States. State and United States include the 50 States of the United States of America, the District of...

  19. Triggers of State Failure

    DTIC Science & Technology

    2010-03-01

    forms, and is limited to the most acute cases of state failure in which the apparatus of the state collapses. A state trying, and failing, to provide...and the writ of government does not practically extend beyond the city limits of the capital. A failing state may be on the trend towards collapse...provide reasonable accuracy in post-dictive analysis, but are of limited use for short-term predictions as changes do not happen quickly, not are they

  20. One State, Two State, Red State, Blue State: Education Funding Accounts for Outcome Differences

    ERIC Educational Resources Information Center

    Meece, Darrell

    2008-01-01

    Using publically available data, states coded as "blue" based upon results from the 2004 presidential election were significantly higher in education funding than were states coded as "red." Students in blue states scored significantly higher on outcome measures of math and reading in grades four and eight in 2004 and 2007 than did students in red…

  1. State Taxes in 1968.

    ERIC Educational Resources Information Center

    Roderick, Ellen; Goodenough, Linda

    This report describes tax revenues in fiscal year 1968 and tax legislation enacted during the calendar year 1968, for all 50 States. The amount and percent of the total for major sources of tax revenue during fiscal 1968 are listed by State as are the amount per capita and percent change in the States' total tax revenues from 1967 to 1968. Major…

  2. State Taxes in 1967.

    ERIC Educational Resources Information Center

    Bodley, Joanne H.

    This report describes tax revenues in fiscal year 1967 and tax legislation enacted during the calendar year 1967, for all 50 States. The amount and percent of the total for major sources of tax revenue during fiscal 1967 are listed by State as are the amount per capita and percent change in the States' total tax revenues from 1966 to 1967. Major…

  3. State Standards and Evolution

    ERIC Educational Resources Information Center

    Moore, Randy

    2004-01-01

    Throughout the United States various individuals and groups have tried to subvert science education by removing or weakening the treatment of evolution in state science-education standards. Most states' science-education standards support the teaching of evolution, but many in the general public and some policymakers want science classrooms to…

  4. Model State Efforts.

    ERIC Educational Resources Information Center

    Morgan, Gwen

    Models of state involvement in training child care providers are briefly discussed and the employers' role in training is explored. Six criteria for states that are taken as models are identified, and four are described. Various state activities are described for each criterion. It is noted that little is known about employer and other private…

  5. State Standards and Evolution

    ERIC Educational Resources Information Center

    Moore, Randy

    2004-01-01

    Throughout the United States various individuals and groups have tried to subvert science education by removing or weakening the treatment of evolution in state science-education standards. Most states' science-education standards support the teaching of evolution, but many in the general public and some policymakers want science classrooms to…

  6. [California State Archives.

    ERIC Educational Resources Information Center

    Rea, Jay W.

    The first paper on the California State Archives treats the administrative status, legal basis of the archives program, and organization of the archives program. The problem areas in this States' archival program are discussed at length. The second paper gives a crude sketch of the legal and administrative history of the California State Archives,…

  7. Changing State Digital Libraries

    ERIC Educational Resources Information Center

    Pappas, Marjorie L.

    2006-01-01

    Research has shown that state virtual or digital libraries are evolving into websites that are loaded with free resources, subscription databases, and instructional tools. In this article, the author explores these evolving libraries based on the following questions: (1) How user-friendly are the state digital libraries?; (2) How do state digital…

  8. Model State Efforts.

    ERIC Educational Resources Information Center

    Morgan, Gwen

    Models of state involvement in training child care providers are briefly discussed and the employers' role in training is explored. Six criteria for states that are taken as models are identified, and four are described. Various state activities are described for each criterion. It is noted that little is known about employer and other private…

  9. Oxidation state in chondrites

    NASA Technical Reports Server (NTRS)

    Rubin, Alan E.; Fegley, Bruce; Brett, Robin

    1988-01-01

    An evaluation is made of extant data on chondrite oxidation states and intrinsic O fugacities. A variety of oxidation states are exhibited by the chondritic meteorites; petrologic and chemical data may be used to arrange the major chondrite groups in order of oxidation state. The intrinsic O fugacity measurements on chondrite whole-rock samples are noted to display a corresponding ordering of oxidation states. Metamorphosed chondrites and igneous meteorites that were substantially altered by metamorphic reactions, outgassing, and igneous processes may preserve information on the oxidation state and size of their parent bodies.

  10. Tripartite quantum state sharing.

    PubMed

    Lance, Andrew M; Symul, Thomas; Bowen, Warwick P; Sanders, Barry C; Lam, Ping Koy

    2004-04-30

    We demonstrate a multipartite protocol to securely distribute and reconstruct a quantum state. A secret quantum state is encoded into a tripartite entangled state and distributed to three players. By collaborating, any two of the three players can reconstruct the state, while individual players obtain nothing. We characterize this (2,3) threshold quantum state sharing scheme in terms of fidelity, signal transfer, and reconstruction noise. We demonstrate a fidelity averaged over all reconstruction permutations of 0.73+/-0.04, a level achievable only using quantum resources.

  11. Fault Tolerant State Machines

    NASA Technical Reports Server (NTRS)

    Burke, Gary R.; Taft, Stephanie

    2004-01-01

    State machines are commonly used to control sequential logic in FPGAs and ASKS. An errant state machine can cause considerable damage to the device it is controlling. For example in space applications, the FPGA might be controlling Pyros, which when fired at the wrong time will cause a mission failure. Even a well designed state machine can be subject to random errors us a result of SEUs from the radiation environment in space. There are various ways to encode the states of a state machine, and the type of encoding makes a large difference in the susceptibility of the state machine to radiation. In this paper we compare 4 methods of state machine encoding and find which method gives the best fault tolerance, as well as determining the resources needed for each method.

  12. Quantum-state decorrelation

    NASA Astrophysics Data System (ADS)

    D'Ariano, G. M.; Demkowicz-Dobrzański, R.; Perinotti, P.; Sacchi, M. F.

    2008-03-01

    We address the general problem of removing correlations from quantum states while preserving local quantum information as much as possible. We provide a complete solution in the case of two qubits by evaluating the minimum amount of noise that is necessary to decorrelate covariant sets of bipartite states. We show that two harmonic oscillators in an arbitrary Gaussian state can be decorrelated by a Gaussian covariant map. Finally, for finite-dimensional Hilbert spaces, we prove that states obtained from most cloning channels (e.g., universal and phase-covariant cloning) can be decorrelated only at the expense of a complete erasure of information about the copied state. More generally, in finite dimension, cloning without correlations is impossible for continuous sets of states. On the contrary, for continuous variables cloning, a slight modification of the customary setup for cloning coherent states allows one to obtain clones without correlations.

  13. State Technologies Advancement Collaborative

    SciTech Connect

    David S. Terry

    2012-01-30

    The U. S. Department of Energy (DOE), National Association of State Energy Officials (NASEO), and Association of State Energy Research and Technology Transfer Institutions (ASERTTI) signed an intergovernmental agreement on November 14, 2002, that allowed states and territories and the Federal Government to better collaborate on energy research, development, demonstration and deployment (RDD&D) projects. The agreement established the State Technologies Advancement Collaborative (STAC) which allowed the states and DOE to move RDD&D forward using an innovative competitive project selection and funding process. A cooperative agreement between DOE and NASEO served as the contracting instrument for this innovative federal-state partnership obligating funds from DOE's Office of Energy Efficiency and Renewable Energy and Office of Fossil Energy to plan, fund, and implement RDD&D projects that were consistent with the common priorities of the states and DOE. DOE's Golden Field Office provided Federal oversight and guidance for the STAC cooperative agreement. The STAC program was built on the foundation of prior Federal-State efforts to collaborate on and engage in joint planning for RDD&D. Although STAC builds on existing, successful programs, it is important to note that it was not intended to replace other successful joint DOE/State initiatives such as the State Energy Program or EERE Special Projects. Overall the STAC process was used to fund, through three competitive solicitations, 35 successful multi-state research, development, deployment, and demonstration projects with an overall average non-federal cost share of 43%. Twenty-two states were awarded at least one prime contract, and organizations in all 50 states and some territories were involved as subcontractors in at least one STAC project. Projects were funded in seven program areas: (1) Building Technologies, (2) Industrial Technologies, (3) Transportation Technologies, (4) Distributed Energy Resources, (5

  14. Quantum spin liquid states

    NASA Astrophysics Data System (ADS)

    Zhou, Yi; Kanoda, Kazushi; Ng, Tai-Kai

    2017-04-01

    This is an introductory review of the physics of quantum spin liquid states. Quantum magnetism is a rapidly evolving field, and recent developments reveal that the ground states and low-energy physics of frustrated spin systems may develop many exotic behaviors once we leave the regime of semiclassical approaches. The purpose of this article is to introduce these developments. The article begins by explaining how semiclassical approaches fail once quantum mechanics become important and then describe the alternative approaches for addressing the problem. Mainly spin-1 /2 systems are discussed, and most of the time is spent in this article on one particular set of plausible spin liquid states in which spins are represented by fermions. These states are spin-singlet states and may be viewed as an extension of Fermi liquid states to Mott insulators, and they are usually classified in the category of so-called S U (2 ), U (1 ), or Z2 spin liquid states. A review is given of the basic theory regarding these states and the extensions of these states to include the effect of spin-orbit coupling and to higher spin (S >1 /2 ) systems. Two other important approaches with strong influences on the understanding of spin liquid states are also introduced: (i) matrix product states and projected entangled pair states and (ii) the Kitaev honeycomb model. Experimental progress concerning spin liquid states in realistic materials, including anisotropic triangular-lattice systems [κ -(ET )2Cu2(CN )3 and EtMe3Sb [Pd (dmit )2]2 ], kagome-lattice system [ZnCu3(OH )6Cl2 ], and hyperkagome lattice system (Na4 Ir3 O8 ), is reviewed and compared against the corresponding theories.

  15. Arkansas: The State of the State.

    ERIC Educational Resources Information Center

    Schoppmeyer, Martin W.

    In a poor state such as Arkansas, progress is often a slow and painful process. Particularly in the area of teacher salaries, school funding plans are often thwarted by budget shortfalls. Court decisions and efforts to stabilize and equalize school funding and local property taxes have led to political battles over taxation. Constitutional…

  16. The State of State MATH Standards, 2005

    ERIC Educational Resources Information Center

    Klein, David; Braams, Bastiaan J.; Parker,Thomas; Quirk, William; Schmid, Wilfried; Wilson, W. Stephen

    2005-01-01

    Two decades after the United States was diagnosed as "a nation at risk," academic standards for our primary and secondary schools are more important than ever?and their quality matters enormously. In 1983, as nearly every American knows, the National Commission on Excellence in Education declared that "The educational foundations of our society…

  17. The State of State Science Standards, 2012

    ERIC Educational Resources Information Center

    Lerner, Lawrence S.; Goodenough, Ursula; Lynch, John; Schwartz, Martha; Schwartz, Richard

    2012-01-01

    This report examines K-12 science standards for fifty states and the District of Columbia, as well as the science assessment framework of the National Assessment of Educational Progress (NAEP). The reviewers' aim is to evaluate them for their intrinsic clarity, completeness, and scientific correctness. Their earlier evaluations, as well as those…

  18. The State of State Science Standards, 2005

    ERIC Educational Resources Information Center

    Gross, Paul R.

    2005-01-01

    Until now, the No Child Left Behind Act of 2001 (NCLB) has focused everyone's attention on reading and math--and on whether schools are making "adequate yearly progress" in those two core subjects. Although some states incorporate additional subjects into their own accountability systems, reading and math have dominated most discussions of state…

  19. The State of State Science Standards, 2005

    ERIC Educational Resources Information Center

    Gross, Paul R.

    2005-01-01

    Until now, the No Child Left Behind Act of 2001 (NCLB) has focused everyone's attention on reading and math--and on whether schools are making "adequate yearly progress" in those two core subjects. Although some states incorporate additional subjects into their own accountability systems, reading and math have dominated most discussions of state…

  20. Quantum State Engineering Via Coherent-State Superpositions

    NASA Technical Reports Server (NTRS)

    Janszky, Jozsef; Adam, P.; Szabo, S.; Domokos, P.

    1996-01-01

    The quantum interference between the two parts of the optical Schrodinger-cat state makes possible to construct a wide class of quantum states via discrete superpositions of coherent states. Even a small number of coherent states can approximate the given quantum states at a high accuracy when the distance between the coherent states is optimized, e. g. nearly perfect Fock state can be constructed by discrete superpositions of n + 1 coherent states lying in the vicinity of the vacuum state.

  1. Quantum State Smoothing

    NASA Astrophysics Data System (ADS)

    Guevara, Ivonne; Wiseman, Howard

    2015-10-01

    Smoothing is an estimation method whereby a classical state (probability distribution for classical variables) at a given time is conditioned on all-time (both earlier and later) observations. Here we define a smoothed quantum state for a partially monitored open quantum system, conditioned on an all-time monitoring-derived record. We calculate the smoothed distribution for a hypothetical unobserved record which, when added to the real record, would complete the monitoring, yielding a pure-state "quantum trajectory." Averaging the pure state over this smoothed distribution yields the (mixed) smoothed quantum state. We study how the choice of actual unraveling affects the purity increase over that of the conventional (filtered) state conditioned only on the past record.

  2. Quantum State Smoothing.

    PubMed

    Guevara, Ivonne; Wiseman, Howard

    2015-10-30

    Smoothing is an estimation method whereby a classical state (probability distribution for classical variables) at a given time is conditioned on all-time (both earlier and later) observations. Here we define a smoothed quantum state for a partially monitored open quantum system, conditioned on an all-time monitoring-derived record. We calculate the smoothed distribution for a hypothetical unobserved record which, when added to the real record, would complete the monitoring, yielding a pure-state "quantum trajectory." Averaging the pure state over this smoothed distribution yields the (mixed) smoothed quantum state. We study how the choice of actual unraveling affects the purity increase over that of the conventional (filtered) state conditioned only on the past record.

  3. States and synaptic algebras

    NASA Astrophysics Data System (ADS)

    Foulis, David J.; Jenčová, Anna; Pulmannová, Sylvia

    2017-02-01

    Different versions of the notion of a state have been formulated for various so-called quantum structures. In this paper, we investigate the interplay among states on synaptic algebras and on its sub-structures. A synaptic algebra is a generalization of the partially ordered Jordan algebra of all bounded self-adjoint operators on a Hilbert space. The paper culminates with a characterization of extremal states on a commutative generalized Hermitian algebra, a special kind of synaptic algebra.

  4. New squeezed landau states

    NASA Technical Reports Server (NTRS)

    Aragone, C.

    1993-01-01

    We introduce a new set of squeezed states through the coupled two-mode squeezed operator. It is shown that their behavior is simpler than the correlated coherent states introduced by Dodonov, Kurmyshev, and Man'ko in order to quantum mechanically describe the Landau system, i.e., a planar charged particle in a uniform magnetic field. We compare results for both sets of squeezed states.

  5. State summaries: Indiana

    USGS Publications Warehouse

    Shaffer, K.R.

    2006-01-01

    In 2005, the Indiana industrial minerals industry generated $789 million, a record high for the state and an increase of 2.2% from 2004. Among all states, Indiana ranked 24th. Mineral commodities produced in the state included crushed limestone and dolomite, construction sand and gravel, industrial sand, dimension limestone, dimension sandstone, gypsum, common clay and shale, freshwater pearls, peat, lime, and masonry and portland cement.

  6. State Demolition Information

    EPA Pesticide Factsheets

    Contact information and guidances for each state and selected territories's environmental agencies and programs relevant to large-scale residential demolition including asbestos, lead, and open burning.

  7. Sleep State Switching

    PubMed Central

    Saper, Clifford B.; Fuller, Patrick M.; Pedersen, Nigel P.; Lu, Jun; Scammell, Thomas E.

    2010-01-01

    We take for granted the ability to fall asleep or to snap out of sleep into wakefulness, but these changes in behavioral state require specific switching mechanisms in the brain that allow well-defined state transitions. In this review, we examine the basic circuitry underlying the regulation of sleep and wakefulness, and discuss a theoretical framework wherein the interactions between reciprocal neuronal circuits enable relatively rapid and complete state transitions. We also review how homeostatic, circadian, and allostatic drives help regulate sleep state switching, and discuss how breakdown of the switching mechanism may contribute to sleep disorders such as narcolepsy. PMID:21172606

  8. Optimally Squeezed Spin States

    NASA Astrophysics Data System (ADS)

    Rojo, Alberto

    2004-03-01

    We consider optimally spin-squeezed states that maximize the sensitivity of the Ramsey spectroscopy, and for which the signal to noise ratio scales as the number of particles N. Using the variational principle we prove that these states are eigensolutions of the Hamiltonian H(λ)=λ S_z^2-S_x, and that, for large N, the states become equivalent to the quadrature squeezed states of the harmonic oscillator. We present numerical results that illustrate the validity of the equivalence. We also present results of spin squeezing via atom-field interactions within the context of the Tavis-Cummings model. An ensemble of N two-level atoms interacts with a quantized cavity field. For all the atoms initially in their ground states, it is shown that spin squeezing of both the atoms and the field can be achieved provided the initial state of the cavity field has coherence between number states differing by 2. Most of the discussion is restricted to the case of a cavity field initially in a coherent state, but initial squeezed states for the field are also discussed. An analytic solution is found that is valid in the limit that the number of atoms is much greater than unity. References: A. G. Rojo, Phys. Rev A, 68, 013807 (2003); Claudiu Genes, P. R. Berman, and A. G. Rojo Phys. Rev. A 68, 043809 (2003).

  9. State initiatives in state-Federal relations

    SciTech Connect

    Standish, T.K.

    1980-05-01

    Based upon historical analysis, this paper examines the proper role of regulation at the state, regional, and federal levels of government. Four areas of inquiry are highlighted by the so-called crises in public utility industries. The first question is whether there should be a shift from passive to active regulation. Second, is increased regulatory power needed at regional and Federal levels of government in order to achieve an appropriate balance between state, regional, and Federal government, or does overcentralization breed economic inefficiency and autocratic decisions. Third, should regulators have a higher degree of power and control over private-utility companies to accomplish objectives mandated by state legislatures and Congress, or is the real problem that private incentives have not been given enough leeway to solve the problems that confront us. And, fourth, if we are to address today's opportunities, should planning efficiency and public interest norms displace the time-honored competitive-market standards of economic efficiency and social justice as the basis for regulatory decisions. At the root of these issues, there is a clash between those arguing for the use of a planning paradigm to solve economic problems and those advocating reliance upon market forces. Economic imperatives lead us to expect a continuation of a trend which resolves the market/nonmarket balance in favor of more government participation. Hence, the scope of state initiatives and the range of opportunities for policy action, will in fact, be defined by economic forces larger than the current debate on the issues. 8 references.

  10. Centennial State Libraries, 1998.

    ERIC Educational Resources Information Center

    Parent, Kathleen D., Ed.

    1998-01-01

    This document consists of 12 consecutive issues of the monthly "Centennial State Libraries" newsletter, of the Colorado Department of Education, State Library and Adult Education Office. The issues cover the year 1998. Each issue of the newsletter--except the August issue which is an Annual Report--includes some or all of the following…

  11. Iowa State Fair.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1994-01-01

    This issue of the "Goldfinch" focuses on the Iowa state fair. The magazine begins with a map of the fair as it looks today. The article explains that the first Iowa state fair was held in 1854. After traveling from town to town for several years, the fair settled in the capital city of Des Moines in 1878. Eight years later, in 1886, the…

  12. Kent State Scores

    ERIC Educational Resources Information Center

    Downing, Kate

    1975-01-01

    Kent State University (Kent, Ohio), through recent State grants, is able to provide increased services to its nearly 800 physically disabled students. Their program includes transportation assistance, architectural improvements, tape service for the blind, a course on sexuality for the physically impaired, student volunteers, and athletic…

  13. States Address Achievement Gaps.

    ERIC Educational Resources Information Center

    Christie, Kathy

    2002-01-01

    Summarizes 2 state initiatives to address the achievement gap: North Carolina's report by the Advisory Commission on Raising Achievement and Closing Gaps, containing an 11-point strategy, and Kentucky's legislation putting in place 10 specific processes. The North Carolina report is available at www.dpi.state.nc.us.closingthegap; Kentucky's…

  14. States of Consciousness

    PubMed Central

    Bell, Carl C.

    1980-01-01

    The art of psychiatry offers many different viewpoints from which to catalog behavior and thinking styles and, therefore, many physicians tend to have difficulty in conceptualizing features of behavioral medicine. A classification of states of consciousness with clinical examples of such states is presented to aid in a more clear understanding of human behavior. PMID:7365821

  15. Four Corners, United States

    NASA Image and Video Library

    2011-09-17

    This image from NASA Terra satellite shows the only place in the United States where four states come together: the four corners area in the western U.S. At a barren, desert location, Utah, Colorado, Arizona, and New Mexico share a common point.

  16. Chiropractic. New York State.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Office of the Professions.

    A reference guide to laws, rules, and regulations that govern the chiropractic practice in New York State is presented. After an overview of professional regulation in the state, licensing requirements/procedures for chiropractors are described. Provisions of Title VIII, Articles 130 and 132, of the Education Law are also covered, along with…

  17. State alternative route designations

    SciTech Connect

    Not Available

    1989-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select alternative routes. First,the state must establish a ``state routing agency,`` defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice of DOT of any alternative route designation before the routes are deemed effective.

  18. State alternative route designations

    SciTech Connect

    Not Available

    1989-07-01

    Pursuant to the Hazardous Materials Transportation Act (HMTA), the Department of Transportation (DOT) has promulgated a comprehensive set of regulations regarding the highway transportation of high-level radioactive materials. These regulations, under HM-164 and HM-164A, establish interstate highways as the preferred routes for the transportation of radioactive materials within and through the states. The regulations also provide a methodology by which a state may select alternative routes. First,the state must establish a state routing agency,'' defined as an entity authorized to use the state legal process to impose routing requirements on carriers of radioactive material (49 CFR 171.8). Once identified, the state routing agency must select routes in accordance with Large Quantity Shipments of Radioactive Materials or an equivalent routing analysis. Adjoining states and localities should be consulted on the impact of proposed alternative routes as a prerequisite of final route selection. Lastly, the states must provide written notice of DOT of any alternative route designation before the routes are deemed effective.

  19. State summaries: California

    USGS Publications Warehouse

    Kohl, S. G.

    2006-01-01

    According to the United States Geological Survey (USGS), California ranked second behind Arizona among the states in nonfuel mineral production during 2005. It accounted for 7% of the US's total. The market value of mineral production for California amounted to $3.7 billion. During the year, California produced 30 varieties of industrial minerals. The nonfuel minerals came from 820 active mines.

  20. State and local governments

    NASA Technical Reports Server (NTRS)

    Barnes, Dennis

    1990-01-01

    The Virginia Space Grant Consortium approach to a close working relation to state and local governments is presented as a model for consideration. State government relations are especially important in that this is a primary resource in securing matching funds. Avenues for establishing these relationships are listed and discussed.

  1. Education and Fragile States

    ERIC Educational Resources Information Center

    Kirk, Jackie

    2007-01-01

    Within the fragile states agendas and policies of development agencies and organisations education is of concern; education is a social service sector in which the impacts of state fragility are significant, in terms of access and quality of provision for children, working conditions and support for teachers, good governance and legitimacy for the…

  2. Getting State Legislation Enacted

    ERIC Educational Resources Information Center

    Ochs, Mike

    2005-01-01

    One of the most important tasks an organization can take on is assisting in getting a law passed at the state level. Many times, passing a state law can be a critical first step to passing federal legislation on the same topic. Completing the various steps to bring a law to Congress can take anywhere from five to ten years, or even longer. Because…

  3. Dissociative state and competence.

    PubMed

    Lin, Yu-Ju; Hsieh, Ming-Hsien; Liu, Shi-Kai

    2007-10-01

    This report presents the results of forensic evaluation of the civil competence of a case of alleged dissociative identity disorder (DID) and discusses whether such dissociative states substantially jeopardize civil competence. A 40-year-old woman claimed that she had had many personalities since her college days. From the age of 37 to 40, she shopped excessively, which left her with millions of dollars of debt. She ascribed her shopping to a certain identity state, over which she had no control. (In this article, we use the term identity state to replace personality as an objective description of a mental state.) She thus raised the petition of civil incompetence. During the forensic evaluation, it was found that the identity states were relatively stable and mutually aware of each other. The switch into another identity state was sometimes under voluntary control. The subject showed consistency and continuity in behavioral patterns across the different identity states, and no matter which identity state she was in, there was no evidence of impairment in her factual knowledge of social situations and her capacity for managing personal affairs. We hence concluded that she was civilly competent despite the claimed DID. Considering that the existence and diagnosis of DID are still under dispute and a diagnosis of DID alone is not sufficient to interdict a persons civil right, important clinical and forensic issues remain to be answered.

  4. Chiropractic. New York State.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Office of the Professions.

    A reference guide to laws, rules, and regulations that govern the chiropractic practice in New York State is presented. After an overview of professional regulation in the state, licensing requirements/procedures for chiropractors are described. Provisions of Title VIII, Articles 130 and 132, of the Education Law are also covered, along with…

  5. Semiconductor Oxide Interface States.

    DTIC Science & Technology

    1981-05-01

    essentially coincides. The density of state curves of the interface states based on the Terman method are shown in Fig. 7 for the three conditions: (i...terrestrial applications. A visit was made at the NASA Lewis Research Center with Dr. Brandhorst on August 31, 1979. The PI has attended DOE meetings on

  6. Church and State.

    ERIC Educational Resources Information Center

    National Forum: Phi Kappa Phi Journal, 1988

    1988-01-01

    Church and state is discussed in four articles: "Recent Threats to Religious Liberty" (Dean M. Kelley, pp.16-22); "Municipal Church-State Litigation and the Issue of Standing" (Kenneth S. Saladin, pp. 23-25); "Prayer in Public Schools: The Court's Decisions" (Leo Pfeffer, pp. 26-29); and "Religion and Public…

  7. Qubit state discrimination

    SciTech Connect

    Deconinck, Matthieu E.

    2010-06-15

    We show how one can solve the problem of discriminating between qubit states. We use the quantum state discrimination duality theorem and the Bloch sphere representation of qubits, which allows for an easy geometric and analytical representation of the optimal guessing strategies.

  8. Slippery Wenzel State.

    PubMed

    Dai, Xianming; Stogin, Birgitt Boschitsch; Yang, Shikuan; Wong, Tak-Sing

    2015-09-22

    Enhancing the mobility of liquid droplets on rough surfaces is of great interest in industry, with applications ranging from condensation heat transfer to water harvesting to the prevention of icing and frosting. The mobility of a liquid droplet on a rough solid surface has long been associated with its wetting state. When liquid drops are sitting on the top of the solid textures and air is trapped underneath, they are in the Cassie state. When the drops impregnate the solid textures, they are in the Wenzel state. While the Cassie state has long been associated with high droplet mobility and the Wenzel state with droplet pinning, our work challenges this existing convention by showing that both Cassie and Wenzel state droplets can be highly mobile on nanotexture-enabled slippery rough surfaces. Our surfaces were developed by engineering hierachical nano- and microscale textures and infusing liquid lubricant into the nanotextures alone to create a highly slippery rough surface. We have shown that droplet mobility can be maintained even after the Cassie-to-Wenzel transition. Moreover, the discovery of the slippery Wenzel state allows us to assess the fundamental limits of the classical and recent Wenzel models at the highest experimental precision to date, which could not be achieved by any other conventional rough surface. Our results show that the classical Wenzel eq (1936) cannot predict the wetting behaviors of highly wetting liquids in the Wenzel state.

  9. Healthcare. State Report

    ERIC Educational Resources Information Center

    Carnevale, Anthony P.; Smith, Nicole; Gulish, Artem; Beach, Bennett H.

    2012-01-01

    This report projects education requirements linked to forecasted job growth in healthcare by state and the District of Columbia from 2010 through 2020. It complements a larger national report which projects educational demand for healthcare for the same time period. The national report shows that with or without Obamacare, the United States will…

  10. Solid-state configurations

    NASA Technical Reports Server (NTRS)

    Schroeder, K. G.

    1980-01-01

    Two prototype solid-state phased array systems concepts developed for the solar power satellite (SPS) are described. In both concepts, the beam was centered on the rectenna by means of phase conjugation of a pilot signal emanating from the ground. Also discussed are results of solid state studies.

  11. State Court Organization, 1980.

    ERIC Educational Resources Information Center

    National Center for State Courts, Williamsburg, VA.

    Information on state court organization as of January 1, 1980, in the 50 states, American Samoa, the District of Columbia, Guam, Puerto Rico, and the Virgin Islands is provided. Data were collected from published sources and through questionnaires. There are two major parts. Part I consists of 36 tables containing comparative data from all the…

  12. Grid State Estimation Tool

    SciTech Connect

    2014-10-09

    This software code is designed to track generator state variables in real time using the Ensemble Kalman Filter method with the aid of PMU measurements. This code can also be used to calibrate dynamic model parameters by augmenting parameters in the state variable vector.

  13. Solid State Division

    SciTech Connect

    Green, P.H.; Watson, D.M.

    1989-08-01

    This report contains brief discussions on work done in the Solid State Division of Oak Ridge National Laboratory. The topics covered are: Theoretical Solid State Physics; Neutron scattering; Physical properties of materials; The synthesis and characterization of materials; Ion beam and laser processing; and Structure of solids and surfaces. (LSP)

  14. The state of offshore

    SciTech Connect

    Nelson, B.F.

    1991-01-01

    In this book, the author explains the factors behind state involvement in offshore petroleum activities. From his analysis of government workings in Great Britain and Norway, he concludes that state intervention is determined by complex interactions among government officials, economic interests, and environmental pressures.

  15. State Workforce Policy Initiative.

    ERIC Educational Resources Information Center

    Public/Private Ventures, Philadelphia, PA.

    Surging demand for workers, growing income inequality, and passage of welfare reforms have made work force development one of the United States' key national concerns. Public/Private Ventures has been working with various states to design work force development strategies that seek to address the concerns of many work force development specialists…

  16. Church and State.

    ERIC Educational Resources Information Center

    National Forum: Phi Kappa Phi Journal, 1988

    1988-01-01

    Church and state is discussed in four articles: "Recent Threats to Religious Liberty" (Dean M. Kelley, pp.16-22); "Municipal Church-State Litigation and the Issue of Standing" (Kenneth S. Saladin, pp. 23-25); "Prayer in Public Schools: The Court's Decisions" (Leo Pfeffer, pp. 26-29); and "Religion and Public…

  17. Cooperation Among State Agencies

    ERIC Educational Resources Information Center

    Wattenbarger, James L.; Hansen, Dean M.

    1975-01-01

    Most states have separate agencies to deal with vocational education, adult education, and community colleges. Because current procedures for interagency cooperation are inadequate and often nonproductive, there is a need for a national or extra-state catalyst to encourage cooperation in a positive way. Five strategies for cooperation are…

  18. Compatibility of Subsystem States

    NASA Astrophysics Data System (ADS)

    Butterley, Paul; Sudbery, Anthony; Szulc, Jason

    2006-01-01

    We examine the possible states of subsystems of a system of bits or qubits. In the classical case (bits), this means the possible marginal distributions of a probability distribution on a finite number of binary variables; we give necessary and sufficient conditions for a set of probability distributions on all proper subsets of the variables to be the marginals of a single distribution on the full set. In the quantum case (qubits), we consider mixed states of subsets of a set of qubits; in the case of three qubits, we find quantum Bell inequalities -- necessary conditions for a set of two-qubit states to be the reduced states of a single mixed state of three qubits. We conjecture that these conditions are also sufficient.

  19. Quantum State Magnification

    NASA Astrophysics Data System (ADS)

    Engelsen, Nils; Hosten, Onur; Krishnakumar, Rajiv; Kasevich, Mark

    2016-05-01

    The standard quantum limit (SQL) for quantum metrology has been surpassed by as much as a factor of 100 using entangled states. However, in order to utilize these states, highly engineered, low-noise state readout is required. Here we present a new method to bypass this requirement in a wide variety of physical systems. We implement the protocol experimentally in a system using the clock states of 5 ×105 87 Rb atoms. Through a nonlinear, optical cavity-mediated interaction we generate spin squeezed states. A small microwave rotation followed by an additional optical cavity interaction stage allow us to exploit the full sensitivity of the squeezed states with a fluorescence detection system. Though the technical noise floor of our fluorescence detection is 15dB above the SQL, we show metrology at 8dB below the SQL. This is the first time squeezed states prepared in a cavity are read out by fluorescence imaging. The method described can be used in any system with a suitable nonlinear interaction.

  20. Variational Transition State Theory

    SciTech Connect

    Truhlar, Donald G.

    2016-09-29

    This is the final report on a project involving the development and applications of variational transition state theory. This project involved the development of variational transition state theory for gas-phase reactions, including optimized multidimensional tunneling contributions and the application of this theory to gas-phase reactions with a special emphasis on developing reaction rate theory in directions that are important for applications to combustion. The development of variational transition state theory with optimized multidimensional tunneling as a useful computational tool for combustion kinetics involved eight objectives.

  1. USGS Alaska State Mosaic

    USGS Publications Warehouse

    ,

    2008-01-01

    The Alaska State Mosaic consists of portions of scenes from the Multi-Resolution Land Characteristics 2001 (MRLC 2001) collection. The 172 selected scenes have been geometrically and radiometrically aligned to produce a seamless, relatively cloud-free image of the State. The scenes were acquired between July 1999 and September 2002, resampled to 120-meter pixels, and cropped to the State boundary. They were reprojected into a standard Alaska Albers projection with the U.S. National Elevation Dataset (NED) used to correct for relief.

  2. Bipartite Composite Fermion States

    NASA Astrophysics Data System (ADS)

    Sreejith, G. J.; Tőke, C.; Wójs, A.; Jain, J. K.

    2011-08-01

    We study a class of ansatz wave functions in which composite fermions form two correlated “partitions.” These “bipartite” composite fermion states are demonstrated to be very accurate for electrons in a strong magnetic field interacting via a short-range 3-body interaction potential over a broad range of filling factors. Furthermore, this approach gives accurate approximations for the exact Coulomb ground state at 2+3/5 and 2+4/7 and is thus a promising candidate for the observed fractional quantum Hall states at the hole conjugate fractions at 2+2/5 and 2+3/7.

  3. Bipartite composite fermion States.

    PubMed

    Sreejith, G J; Toke, C; Wójs, A; Jain, J K

    2011-08-19

    We study a class of ansatz wave functions in which composite fermions form two correlated "partitions." These "bipartite" composite fermion states are demonstrated to be very accurate for electrons in a strong magnetic field interacting via a short-range 3-body interaction potential over a broad range of filling factors. Furthermore, this approach gives accurate approximations for the exact Coulomb ground state at 2+3/5 and 2+4/7 and is thus a promising candidate for the observed fractional quantum Hall states at the hole conjugate fractions at 2+2/5 and 2+3/7.

  4. State summaries: Kentucky

    USGS Publications Warehouse

    Greb, S.F.; Anderson, W.H.

    2006-01-01

    Kentucky mines coal, limestone, clay, sand and gravel. Coal mining operations are carried out mainly in the Western Kentucky Coal Field and the Eastern Kentucky Coal field. As to nonfuel minerals, Mississippian limestones are mined in the Mississippian Plateaus Region and along Pine Mountain in southeastern Kentucky. Ordovician and Silurian limestones are mined from the central part of the state. Clay minerals that are mined in the state include common clay, ceramic and ball clays, refractory clay and shale. Just like in 2004, mining activities in the state remain significant.

  5. United States housing, 2012

    Treesearch

    Delton Alderman

    2013-01-01

    Provides current and historical information on housing market in the United States. Information includes trends for housing permits and starts, housing completions for single and multifamily units, and sales and construction. This report will be updated annually.

  6. On neutrino flavor states

    NASA Astrophysics Data System (ADS)

    Ho, Chiu Man

    2012-12-01

    We review the issues associated with the construction of neutrino flavor states. We then provide a consistent proof that the flavor states are approximately well-defined only if neutrinos are ultra-relativistic or the mass differences are negligible compared to energy. However, we show that weak interactions can be consistently described by only neutrino mass eigenstates. Meanwhile, the second quantization of neutrino flavor fields generally has no physical relevance as their masses are indefinite. Therefore, the flavor states are not physical quantum states and they should simply be interpreted as definitions to denote specific linear combinations of mass eigenstates involved in weak interactions. We also briefly discuss the implication of this work for the mixing between active and heavy sterile neutrinos.

  7. NetState

    SciTech Connect

    Durgin, Nancy; Mai, Yuqing; Hutchins, James

    2005-09-01

    NetState is a distributed network monitoring system. It uses passive sensors to develop status information on a target network. Two major features provided by NetState are version and port tracking. Version tracking maintains information about software and operating systems versions. Port tracking identifies information about active TOP and UDP ports. Multiple NetState sniffers can be deployed, one at each entry point of the target network. The sniffers monitor network traffic, then send the information to the NetState server. The information is stored in centralized database which can then be accessed via standard SQL database queries or this web-based GUI, for further analysis and display.

  8. The Organic Solid State.

    ERIC Educational Resources Information Center

    Cowan, Dwaine O.; Wlygul, Frank M.

    1986-01-01

    Reviews interesting and useful electrical, magnetic, and optical properties of the organic solid state. Offers speculation as to areas of fruitful research. Discusses organic superconductors, conducting organic polymers, organic metals, and traces recent history of creation of organic metals. (JM)

  9. The Organic Solid State.

    ERIC Educational Resources Information Center

    Cowan, Dwaine O.; Wlygul, Frank M.

    1986-01-01

    Reviews interesting and useful electrical, magnetic, and optical properties of the organic solid state. Offers speculation as to areas of fruitful research. Discusses organic superconductors, conducting organic polymers, organic metals, and traces recent history of creation of organic metals. (JM)

  10. Covering the State Legislature

    ERIC Educational Resources Information Center

    Hook, Stephen C.

    1975-01-01

    Describes how journalism majors at Ball State University are required to cover the annual sessions of the Indiana legislature, and discusses some of the experiences and problems that were encountered. (RB)

  11. The Ohio State University.

    ERIC Educational Resources Information Center

    CAUSE/EFFECT, 1978

    1978-01-01

    The three computer service facilities at Ohio State University in Columbus are described. Computer services are provided for: instructional purposes, public service activities, university management, the hospital information system, and student services. (BH)

  12. State Health Facts

    MedlinePlus

    ... Choose Category - or - Choose Location Demographics and the Economy Health Costs & Budgets Health Coverage & Uninsured Health Insurance & ... each state, limitations applied to those benefits, cost-sharing charges, and the reimbursement methodologies used for those ...

  13. State Health Facts

    MedlinePlus

    ... the Economy Health Costs & Budgets Health Coverage & Uninsured Health Insurance & Managed Care Health Reform Health Status HIV/AIDS ... Abortion Policies October 5, 2017 State Restriction of Health Insurance Coverage of Abortion September 22, 2017 Total Number ...

  14. State Agency Roster.

    ERIC Educational Resources Information Center

    School Library Media Annual (SLMA), 1993

    1993-01-01

    Presents a directory of agencies that consult with school library media specialists for the 50 states, the District of Columbia, Northern Mariana Islands, Pacific Islands Trust Territory, Puerto Rico, and the Virgin Islands. (LRW)

  15. State Agency Roster.

    ERIC Educational Resources Information Center

    School Library Media Annual (SLMA), 1992

    1992-01-01

    Lists addresses and telephone numbers for state agencies and associated personnel dealing with school library media specialists. The District of Columbia, the Northern Mariana Islands, the Pacific Islands Trust Territory, Puerto Rico, and the Virgin Islands are included. (LRW)

  16. State Air Quality Standards.

    ERIC Educational Resources Information Center

    Pollution Engineering, 1978

    1978-01-01

    This article presents in tabular form the air quality standards for sulfur dioxide, carbon monoxide, nitrogen dioxide, photochemicals, non-methane hydrocarbons and particulates for each of the 50 states and the District of Columbia. (CS)

  17. State Air Quality Standards.

    ERIC Educational Resources Information Center

    Pollution Engineering, 1978

    1978-01-01

    This article presents in tabular form the air quality standards for sulfur dioxide, carbon monoxide, nitrogen dioxide, photochemicals, non-methane hydrocarbons and particulates for each of the 50 states and the District of Columbia. (CS)

  18. Topological Photonic States

    NASA Astrophysics Data System (ADS)

    He, Cheng; Lin, Liang; Sun, Xiao-Chen; Liu, Xiao-Ping; Lu, Ming-Hui; Chen, Yan-Feng

    2014-01-01

    As exotic phenomena in optics, topological states in photonic crystals have drawn much attention due to their fundamental significance and great potential applications. Because of the broken time-reversal symmetry under the influence of an external magnetic field, the photonic crystals composed of magneto-optical materials will lead to the degeneracy lifting and show particular topological characters of energy bands. The upper and lower bulk bands have nonzero integer topological numbers. The gapless edge states can be realized to connect two bulk states. This topological photonic states originated from the topological property can be analogous to the integer quantum Hall effect in an electronic system. The gapless edge state only possesses a single sign of gradient in the whole Brillouin zone, and thus the group velocity is only in one direction leading to the one-way energy flow, which is robust to disorder and impurity due to the nontrivial topological nature of the corresponding electromagnetic states. Furthermore, this one-way edge state would cross the Brillouin center with nonzero group velocity, where the negative-zero-positive phase velocity can be used to realize some interesting phenomena such as tunneling and backward phase propagation. On the other hand, under the protection of time-reversal symmetry, a pair of gapless edge states can also be constructed by using magnetic-electric coupling meta-materials, exhibiting Fermion-like spin helix topological edge states, which can be regarded as an optical counterpart of topological insulator originating from the spin-orbit coupling. The aim of this article is to have a comprehensive review of recent research literatures published in this emerging field of photonic topological phenomena. Photonic topological states and their related phenomena are presented and analyzed, including the chiral edge states, polarization dependent transportation, unidirectional waveguide and nonreciprocal optical transmission, all

  19. State summaries: Idaho

    USGS Publications Warehouse

    Gillerman, V.S.; Weaver, M.J.; Bennett, E.H.

    2006-01-01

    According to the United States Geological Survey (USGS), Idaho's preliminary nonfuel mineral production value jumped to $893 million in 2005. Principal minerals by value included molybdenum concentrates, phosphate rock, sand and gravel, silver and portland cement. The state ranked second in phosphate and garnet production, third in silver and pumice, fourth in molybdenum concentrate production, and 21st overall. Majority of mining increases for the year were spurred by demand for metals by China's growing economy.

  20. Solid state switch

    DOEpatents

    Merritt, Bernard T.; Dreifuerst, Gary R.

    1994-01-01

    A solid state switch, with reverse conducting thyristors, is designed to operate at 20 kV hold-off voltage, 1500 A peak, 1.0 .mu.s pulsewidth, and 4500 pps, to replace thyratrons. The solid state switch is more reliable, more economical, and more easily repaired. The switch includes a stack of circuit card assemblies, a magnetic assist and a trigger chassis. Each circuit card assembly contains a reverse conducting thyristor, a resistor capacitor network, and triggering circuitry.