Science.gov

Sample records for air filling fraction

  1. Hamiltonian theory of fractionally filled Chern bands

    NASA Astrophysics Data System (ADS)

    Murthy, Ganpathy; Shankar, R.

    2012-11-01

    There is convincing numerical evidence that fractional quantum-Hall-like ground states arise in fractionally filled Chern bands. Here, we show that the Hamiltonian theory of composite fermions (CF) can be as useful in describing these states as it was in describing the fractional quantum Hall effect (FQHE) in the continuum. We are able to introduce CFs into the fractionally filled Chern-band problem in two stages. First, we construct an algebraically exact mapping which expresses the electron density projected to the Chern band ρFCB as a sum of Girvin-MacDonald-Platzman density operators ρGMP that obey the magnetic translation algebra. Next, following our Hamiltonian treatment of the FQH problem, we rewrite the operators ρGMP in terms of CF variables which reproduce the same algebra. This naturally produces a unique Hartree-Fock ground state for the CFs, which can be used as a springboard for computing gaps, response functions, temperature-dependent phenomena, and the influence of disorder. We give two concrete examples, one of which has no analog in the continuum FQHE with ν=(1)/(5) and σxy=(2)/(5). Our approach can be easily extended to fractionally filled, strongly interacting two-dimensional time-reversal-invariant topological insulators.

  2. Composite fermions for fractionally filled Chern bands

    NASA Astrophysics Data System (ADS)

    Shankar, R.

    2012-02-01

    We consider fractionally filled bands with a non-zero Chern index that exhibit the Fractional Quantum Hall Effect in zero external fieldootnotetextR. Roy and S. Sondhi, Physics 4, 46 (2011) and papers reviewed therein. a possibility supported by numerical work.ootnotetextIbid. Analytic treatments are complicated by a non-constant Berry flux and the absence of Composite Fermions (CF), which would not only single out preferred fractions, but also allow us compute numerous response functions at nonzero frequencies, wavelengths and temperature using either Chern-Simons field theory or our Hamiltonian formalism.ootnotetextG. Murthy and R. Shankar, Rev. Mod. Phys., 75, 1101, (2003) We describe a way to introduce CF's by embedding the Chern band in an auxiliary problem involving Landau levels. The embedded band can be designed to approximate a prescribed Chern density in k space which determines the commutation relations of the charge densities and hence preserve all dynamical and algebraic aspects of the original problem. We find some states for which the filling fraction and dimensionless Hall conductance are not equal. The approach extends to two-dimensional time-reversal invariant topological insulators and to composite bosons.

  3. Optimal filling fraction of Ta2O5 inverse opals

    NASA Astrophysics Data System (ADS)

    Tubio, C. R.; Guitian, F.; Gil, A.

    2013-12-01

    Tantalum pentoxide (Ta2O5) inverse opals were prepared by combining the self-assembly process and sol-gel chemistry-based opal infiltration. The inverse opal was made by the infiltration of a tantalum(V) ethoxide solution in the interstices of the polystyrene colloidal crystal template, and then removing the original opal template by calcination. The infiltration process as well as the optimal precursor concentration has been investigated in order to obtain Ta2O5 inverse opals with the optimal filling fraction. The effects of processing, template sphere size, morphology, structural properties, filling fraction and composition of the inverse opal are provided by scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy analysis (EDS) and powder X-ray diffraction (XRD). The results correlate the concentration of the precursor with the filling fraction of the template.

  4. Hall Crystal States in Fractionally Filled Chern Bands

    NASA Astrophysics Data System (ADS)

    Murthy, Ganpathy; Shankar, Ramamurti

    2012-02-01

    Two-dimensional time-reversal-invariant topological insulators can be thought of as a time-reversed pair of Chern bands. Numerical evidence shows the existence of states at fractional filling which are analogous to FQH states[1]. In [2] it was noted that at small momenta, the algebra of the density operators projected to the Chern band resembles the magnetic translation algebra. The authors have constructed a mapping[3] between Chern bands and a Landau level in a periodic potential which works at all momenta. This mapping is dynamically faithful, and reproduces the commutators of the projected density operator. There turn out to be Hall Crystal states, characterized by a Hall conductance, and another integer which described the charged dragged when the potential is adiabatically moved by a lattice unit. Using the Hamiltonian formalism developed by the authors some time ago for the FQHE[4], we calculate gaps and collective mode dispersions for such states. 1. D. N. Sheng et al, arxiv:1102.2568, N. Regnault and B. A. Bernevig, arxiv:1105.4867. 2. S. Parameswaran, R. Roy, and S. L. Sondhi, arxiv:1106.4025. 3. G. Murthy and R. Shankar, arxiv:1108.5501 4. G. Murthy and R. Shankar, Rev. Mod. Phys. 75, 1101 (2003)

  5. Quasiparticle Tunneling in the Fractional Quantum Hall effect at filling fraction ν=5/2

    NASA Astrophysics Data System (ADS)

    Radu, Iuliana P.

    2009-03-01

    In a two-dimensional electron gas (2DEG), in the fractional quantum Hall regime, the quasiparticles are predicted to have fractional charge and statistics, as well as modified Coulomb interactions. The state at filling fraction ν=5/2 is predicted by some theories to have non-abelian statistics, a property that might be exploited for topological quantum computing. However, alternative models with abelian properties have been proposed as well. Weak quasiparticle tunneling between counter-propagating edges is one of the methods that can be used to learn about the properties of the state and potentially distinguish between models describing it. We employ an electrostatically defined quantum point contact (QPC) fabricated on a high mobility GaAs/AlGaAs 2DEG to create a constriction where quasiparticles can tunnel between counter-propagating edges. We study the temperature and dc bias dependence of the tunneling conductance, while preserving the same filling fraction in the constriction and the bulk of the sample. The data show scaling of the bias-dependent tunneling over a range of temperatures, in agreement with the theory of weak quasiparticle tunneling, and we extract values for the effective charge and interaction parameter of the quasiparticles. The ranges of values obtained are consistent with those predicted by certain models describing the 5/2 state, indicating as more probable a non-abelian state. This work was done in collaboration with J. B. Miller, C. M. Marcus, M. A. Kastner, L. N. Pfeiffer and K. W. West. This work was supported in part by the Army Research Office (W911NF-05-1-0062), the Nanoscale Science and Engineering Center program of NSF (PHY-0117795), NSF (DMR-0701386), the Center for Materials Science and Engineering program of NSF (DMR-0213282) at MIT, the Microsoft Corporation Project Q, and the Center for Nanoscale Systems at Harvard University.

  6. Restoration of middle-ear input in fluid-filled middle ears by controlled introduction of air or a novel air-filled implant.

    PubMed

    Ravicz, Michael E; Chien, Wade W; Rosowski, John J

    2015-10-01

    The effect of small amounts of air on sound-induced umbo velocity in an otherwise saline-filled middle ear (ME) was investigated to examine the efficacy of a novel balloon-like air-filled ME implant suitable for patients with chronically non-aerated MEs. In this study, air bubbles or air-filled implants were introduced into saline-filled human cadaveric MEs. Umbo velocity, a convenient measure of ME response, served as an indicator of hearing sensitivity. Filling the ME with saline reduced umbo velocity by 25-30 dB at low frequencies and more at high frequencies, consistent with earlier work (Ravicz et al., Hear. Res. 195: 103-130 (2004)). Small amounts of air (∼30 μl) in the otherwise saline-filled ME increased umbo velocity substantially, to levels only 10-15 dB lower than in the dry ME, in a frequency- and location-dependent manner: air in contact with the tympanic membrane (TM) increased umbo velocity at all frequencies, while air located away from the TM increased umbo velocity only below about 500 Hz. The air-filled implant also affected umbo velocity in a manner similar to an air bubble of equivalent compliance. Inserting additional implants into the ME had the same effect as increasing air volume. These results suggest these middle-ear implants would significantly reduce conductive hearing loss in patients with chronically fluid-filled MEs.

  7. Effect of filling fraction on the performance of sponge-based moving bed biofilm reactor.

    PubMed

    Zhang, Xinbo; Chen, Xun; Zhang, Chunqing; Wen, Haitao; Guo, Wenshan; Ngo, Huu Hao

    2016-11-01

    Cubic-shaped polyurethane sponges (15×15×15mm) in the form of biofilm carriers were used in a moving bed biofilm reactor (MBBR) for treating synthetic domestic wastewater. Results indicated there was no significant difference in total organic carbon (TOC) and ammonia (NH4(+)-N) removal at different filling fractions. Three reactors exhibited high removal efficiencies of over 93% TOC and 95% NH4(+)-N on average at an HRT of 12h and aeration flow of 0.09m(3)/h. However, total nitrogen (TN) removal and simultaneous nitrification and denitrification (SND) increased with increasing the filling fraction. TN removal averaged at 77.2, 85.5% and 86.7% in 10%, 20% and 30% filling fraction reactor, respectively. Correspondingly, SND were 85.5±8.7%, 91.3±9.4% and 93.3±10.2%. Moreover, it was observed that sponge carriers in the 20% filling fraction reactor achieved the maximum biomass amount per gram sponge, followed by the 10% and 30% filling fraction reactors. PMID:27567965

  8. Effect of filling fraction on the performance of sponge-based moving bed biofilm reactor.

    PubMed

    Zhang, Xinbo; Chen, Xun; Zhang, Chunqing; Wen, Haitao; Guo, Wenshan; Ngo, Huu Hao

    2016-11-01

    Cubic-shaped polyurethane sponges (15×15×15mm) in the form of biofilm carriers were used in a moving bed biofilm reactor (MBBR) for treating synthetic domestic wastewater. Results indicated there was no significant difference in total organic carbon (TOC) and ammonia (NH4(+)-N) removal at different filling fractions. Three reactors exhibited high removal efficiencies of over 93% TOC and 95% NH4(+)-N on average at an HRT of 12h and aeration flow of 0.09m(3)/h. However, total nitrogen (TN) removal and simultaneous nitrification and denitrification (SND) increased with increasing the filling fraction. TN removal averaged at 77.2, 85.5% and 86.7% in 10%, 20% and 30% filling fraction reactor, respectively. Correspondingly, SND were 85.5±8.7%, 91.3±9.4% and 93.3±10.2%. Moreover, it was observed that sponge carriers in the 20% filling fraction reactor achieved the maximum biomass amount per gram sponge, followed by the 10% and 30% filling fraction reactors.

  9. Transient behavior of granular materials with symmetric conditions for tumbler shapes and fill fractions

    NASA Astrophysics Data System (ADS)

    Pohlman, Nicholas; Si, Yun

    2014-11-01

    The typical granular motion in circular tumblers is considered steady-state since there are no features to disrupt the top surface layer dimension. In polygon tumblers, however, the flowing layer is perpetually changing length, which creates unsteady conditions with corresponding change in the flow behavior. Prior work showed the minimization of free surface energy is independent of tumbler dimension, particle size, and rotation rate. This subsequent research reports on experiments where dimensional symmetry of the free surface in triangular and square tumblers with varying fill fractions do not necessarily produce the symmetric flow behaviors. Results of the quasi-2D tumbler experiment show that other dimensions aligned with gravity and the instantaneous free surface influence the phase when extrema for angle of repose and other flow features occur. The conclusion is that 50% fill fraction may produce geometric symmetry of dimensions, but the symmetry point of flow likely occurs at a lower fill fraction.

  10. Fractional-filling Mott domains in two-dimensional optical superlattices

    SciTech Connect

    Buonsante, P.; Penna, V.; Vezzani, A.

    2005-09-15

    Ultracold bosons in optical superlattices are expected to exhibit fractional-filling insulating phases for sufficiently large repulsive interactions. On strictly one-dimensional systems, the exact mapping between hard-core bosons and free spinless fermions shows that any periodic modulation in the lattice parameters causes the presence of fractional-filling insulator domains. Here, we focus on two recently proposed realistic two-dimensional structures where such mapping does not hold, i.e., the two-leg ladder and the trimerized kagome lattice. Based on a cell strong-coupling perturbation technique, we provide quantitatively satisfactory phase diagrams for these structures, and give estimates for the occurrence of the fractional-filling insulator domains in terms of the intercell to intracell hopping amplitude ratio.

  11. Estimation of water-filled and air-filled porosity in the unsaturated zone, Yucca Mountain, Nevada

    USGS Publications Warehouse

    Nelson, Philip H.

    1993-01-01

    The responses of density and dielectric logs are formulated in terms if the matrix properties, air-filled porosity and water-filled porosity. Porosity values obtained from logs from borehole USW G-2 are in reasonable agreement with estimates from core determinations.

  12. Fractionalized charge excitations in a spin liquid on partially filled pyrochlore lattices.

    PubMed

    Chen, Gang; Kee, Hae-Young; Kim, Yong Baek

    2014-11-01

    We study the Mott transition from a metal to cluster Mott insulators in the 1/4- and 1/8-filled pyrochlore lattice systems [corrected]. It is shown that such Mott transitions can arise due to charge localization in clusters or in tetrahedron units, driven by the nearest-neighbor repulsive interaction. The resulting cluster Mott insulator is a quantum spin liquid with a spinon Fermi surface, but at the same time a novel fractionalized charge liquid with charge excitations carrying half the electron charge. There exist two emergent U(1) gauge fields or "photons" that mediate interactions between spinons and charge excitations, and between fractionalized charge excitations themselves, respectively. In particular, it is suggested that the emergent photons associated with the fractionalized charge excitations can be measured in x-ray scattering experiments. Various other experimental signatures of the exotic cluster Mott insulator are discussed in light of candidate materials with partially filled bands on the pyrochlore lattice.

  13. Fractional Distillation of Air and Other Demonstrations with Condensed Gases

    ERIC Educational Resources Information Center

    Oliver-Hoyo, Maria; Switzer, William L., III; Eierman, Robert

    2005-01-01

    The learning objectives of the fractional distillation of air and other demonstrations includes observing N2, O2, CO2 and H2O in air, studying the fractional separation of components based on boiling point differences and so on. The materials, reagent and equipment preparation, experimental procedures, hazards of the demonstration are also…

  14. Wave intensity analysis in air-filled flexible vessels.

    PubMed

    Clavica, Francesco; Parker, Kim H; Khir, Ashraf W

    2015-02-26

    Wave intensity analysis (WIA) is an analytical technique generally used to investigate the propagation of waves in the cardiovascular system. Despite its increasing usage in the cardiovascular system, to our knowledge WIA has never been applied to the respiratory system. Given the analogies between arteries and airways (i.e. fluid flow in flexible vessels), the aim of this work is to test the applicability of WIA with gas flow instead of liquid flow. The models employed in this study are similar to earlier studies used for arterial investigations. Simultaneous pressure (P) and velocity (U) measurements were initially made in a single tube and then in several flexible tubes connected in series. Wave speed was calculated using the foot-to-foot method (cf), which was used to separate analytically the measured P and U waveforms into their forward and backward components. Further, the data were used to calculate wave intensity, which was also separated into its forward and backward components. Although the measured wave speed was relatively high, the results showed that the onsets and the nature of reflections (compression/expansion) derived with WIA, corresponded well to those anticipated using the theory of waves in liquid-filled elastic tubes. On average the difference between the experimental and theoretical arrival time of reflection was 6.1% and 3.6% for the single vessel and multivessel experiment, respectively. The results suggest that WIA can provide relatively accurate information on reflections in air-filled flexible tubes, warranting further studies to explore the full potential of this technique in the respiratory system. PMID:25595424

  15. Wave intensity analysis in air-filled flexible vessels.

    PubMed

    Clavica, Francesco; Parker, Kim H; Khir, Ashraf W

    2015-02-26

    Wave intensity analysis (WIA) is an analytical technique generally used to investigate the propagation of waves in the cardiovascular system. Despite its increasing usage in the cardiovascular system, to our knowledge WIA has never been applied to the respiratory system. Given the analogies between arteries and airways (i.e. fluid flow in flexible vessels), the aim of this work is to test the applicability of WIA with gas flow instead of liquid flow. The models employed in this study are similar to earlier studies used for arterial investigations. Simultaneous pressure (P) and velocity (U) measurements were initially made in a single tube and then in several flexible tubes connected in series. Wave speed was calculated using the foot-to-foot method (cf), which was used to separate analytically the measured P and U waveforms into their forward and backward components. Further, the data were used to calculate wave intensity, which was also separated into its forward and backward components. Although the measured wave speed was relatively high, the results showed that the onsets and the nature of reflections (compression/expansion) derived with WIA, corresponded well to those anticipated using the theory of waves in liquid-filled elastic tubes. On average the difference between the experimental and theoretical arrival time of reflection was 6.1% and 3.6% for the single vessel and multivessel experiment, respectively. The results suggest that WIA can provide relatively accurate information on reflections in air-filled flexible tubes, warranting further studies to explore the full potential of this technique in the respiratory system.

  16. Mode-based microparticle conveyor belt in air-filled hollow-core photonic crystal fiber.

    PubMed

    Schmidt, Oliver A; Euser, Tijmen G; Russell, Philip St J

    2013-12-01

    We show how microparticles can be moved over long distances and precisely positioned in a low-loss air-filled hollow-core photonic crystal fiber using a coherent superposition of two co-propagating spatial modes, balanced by a backward-propagating fundamental mode. This creates a series of trapping positions spaced by half the beat-length between the forward-propagating modes (typically a fraction of a millimeter). The system allows a trapped microparticle to be moved along the fiber by continuously tuning the relative phase between the two forward-propagating modes. This mode-based optical conveyor belt combines long-range transport of microparticles with a positional accuracy of 1 µm. The technique also has potential uses in waveguide-based optofluidic systems. PMID:24514492

  17. Properties of Non-Abelian Fractional Quantum Hall States at Filling ν=k/r

    NASA Astrophysics Data System (ADS)

    Bernevig, B. Andrei; Haldane, F. D. M.

    2008-12-01

    We compute the physical properties of non-Abelian fractional quantum Hall (FQH) states described by Jack polynomials at general filling ν=k/r. For r=2, these states are the Zk Read-Rezayi parafermions, whereas for r>2 they represent new FQH states. The r=k+1 states, multiplied by a Vandermonde determinant, are a non-Abelian alternative construction of states at fermionic filling 2/5,3/7,4/9,…. We obtain the thermal Hall coefficient, the quantum dimensions, the electron scaling exponent, and the non-Abelian quasihole propagator. The properties of the r>2 Jack polynomials indicate they are correlators of fields of nonunitary conformal field theories (CFT), but the CFT-FQH connection fails when invoked to compute physical properties such as the quasihole propagator. The quasihole wave function, written as a coherent state representation of Jack polynomials, has an identical structure for all non-Abelian states.

  18. Fractional quantum Hall effect at Landau level filling ν = 4/11

    SciTech Connect

    Pan, W.; Baldwin, K. W.; West, K. W.; Pfeiffer, L. N.; Tsui, D. C.

    2015-01-09

    In this study, we report low temperature electronic transport results on the fractional quantum Hall effect of composite fermions at Landau level filling ν = 4/11 in a very high mobility and low density sample. Measurements were carried out at temperatures down to 15mK, where an activated magnetoresistance Rxx and a quantized Hall resistance Rxy, within 1% of the expected value of h/(4/11)e2, were observed. The temperature dependence of the Rxx minimum at 4/11 yields an activation energy gap of ~ 7 mK. Developing Hall plateaus were also observed at the neighboring states at ν = 3/8 and 5/13.

  19. Fractional quantum Hall effect at Landau level filling ν = 4/11

    DOE PAGES

    Pan, W.; Baldwin, K. W.; West, K. W.; Pfeiffer, L. N.; Tsui, D. C.

    2015-01-09

    In this study, we report low temperature electronic transport results on the fractional quantum Hall effect of composite fermions at Landau level filling ν = 4/11 in a very high mobility and low density sample. Measurements were carried out at temperatures down to 15mK, where an activated magnetoresistance Rxx and a quantized Hall resistance Rxy, within 1% of the expected value of h/(4/11)e2, were observed. The temperature dependence of the Rxx minimum at 4/11 yields an activation energy gap of ~ 7 mK. Developing Hall plateaus were also observed at the neighboring states at ν = 3/8 and 5/13.

  20. Mathematical model of an air-filled alpha stirling refrigerator

    NASA Astrophysics Data System (ADS)

    McFarlane, Patrick; Semperlotti, Fabio; Sen, Mihir

    2013-10-01

    This work develops a mathematical model for an alpha Stirling refrigerator with air as the working fluid and will be useful in optimizing the mechanical design of these machines. Two pistons cyclically compress and expand air while moving sinusoidally in separate chambers connected by a regenerator, thus creating a temperature difference across the system. A complete non-linear mathematical model of the machine, including air thermodynamics, and heat transfer from the walls, as well as heat transfer and fluid resistance in the regenerator, is developed. Non-dimensional groups are derived, and the mathematical model is numerically solved. The heat transfer and work are found for both chambers, and the coefficient of performance of each chamber is calculated. Important design parameters are varied and their effect on refrigerator performance determined. This sensitivity analysis, which shows what the significant parameters are, is a useful tool for the design of practical Stirling refrigeration systems.

  1. Substances To Fill Lighter-Than-Air Balloons

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    1995-01-01

    Various combinations of solid and liquid chemicals proposed as sources of hydrogen and other gases for inflating lighter-than-air balloons. In all cases energy used to propel balloon upward or downward comes from temperature differences in planet's atmosphere itself. Phase changes and/or reversible chemical reactions used to vary quantities of gases in balloons as functions of pressure and temperature and, as functions of altitude: provides means to control altitude of balloon.

  2. Response of air-filled ion chambers to high-intensity radiation pulses

    SciTech Connect

    Plum, M.; Brown, D.

    1993-06-01

    Ion chambers are one of the most popular types of detectors used for beam loss-monitor systems. To provide a foundation for the development of future loss-monitor systems, and to fully characterize the ion chambers in use at LAMPF, we have studied the response of air-filled cylindrical ion chambers to high-intensity, short-duration radiation pulses. The most intense pulses were about 180 rad in 250 ns (the equivalent steady-state dose rate was about 700 Mrad/h). We filled our chambers with nitrogen gas at 760 Torr and air at 600 Torr. The ion chambers were driven into extreme nonlinear response. We hope these data will be used to design loss-monitor systems based on air-filled ion chambers, thus eliminating the need for gas-flow systems and/or airtight ion chambers.

  3. Response of air-filled ion chambers to high-intensity radiation pulses

    SciTech Connect

    Plum, M.; Brown, D.

    1993-01-01

    Ion chambers are one of the most popular types of detectors used for beam loss-monitor systems. To provide a foundation for the development of future loss-monitor systems, and to fully characterize the ion chambers in use at LAMPF, we have studied the response of air-filled cylindrical ion chambers to high-intensity, short-duration radiation pulses. The most intense pulses were about 180 rad in 250 ns (the equivalent steady-state dose rate was about 700 Mrad/h). We filled our chambers with nitrogen gas at 760 Torr and air at 600 Torr. The ion chambers were driven into extreme nonlinear response. We hope these data will be used to design loss-monitor systems based on air-filled ion chambers, thus eliminating the need for gas-flow systems and/or airtight ion chambers.

  4. Size Control and Fractionation of Ionic Liquid Filled Polymersomes with Glassy and Rubbery Bilayer Membranes.

    PubMed

    So, Soonyong; Lodge, Timothy P

    2016-05-17

    We demonstrate control over the size of ionic liquid (IL) filled polymeric vesicles (polymersomes) by three distinct methods: mechanical extrusion, cosolvent-based processing in an IL, and fractionation of polymersomes in a biphasic system of IL and water. For the representative ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([EMIM][TFSI])), the size and dispersity of polymersomes formed from 1,2-polybutadiene-b-poly(ethylene oxide) (PB-PEO) and polystyrene-b-poly(ethylene oxide) (PS-PEO) diblock copolymers were shown to be sensitive to assembly conditions. During mechanical extrusion through a polycarbonate membrane, the relatively larger polymersomes were broken up and reorganized into vesicles with mean size comparable to the membrane pore (100 nm radius); the distribution width also decreased significantly after only a few passes. Other routes were studied using the solvent-switch or cosolvent (CS) method, whereby the initial content of the cosolvent and the PEO block length of PS-PEO were systemically changed. The nonvolatility of the ionic liquid directly led to the desired concentration of polymersomes in the ionic liquid using a single step, without the dialysis conventionally used in aqueous systems, and the mean vesicle size depended on the amount of cosolvent employed. Finally, selective phase transfer of PS-PEO polymersomes based on size was used to extract larger polymersomes from the IL to the aqueous phase via interfacial tension controlled phase transfer. The interfacial tension between the PS membrane and the aqueous phase was varied with the concentration of sodium chloride (NaCl) in the aqueous phase; then the larger polymersomes were selectively separated to the aqueous phase due to differences in shielding of the hydrophobic core (PS) coverage by the hydrophilic corona brush (PEO). This novel fractionation is a simple separation process without any special apparatus and can help to prepare monodisperse polymersomes

  5. Size Control and Fractionation of Ionic Liquid Filled Polymersomes with Glassy and Rubbery Bilayer Membranes.

    PubMed

    So, Soonyong; Lodge, Timothy P

    2016-05-17

    We demonstrate control over the size of ionic liquid (IL) filled polymeric vesicles (polymersomes) by three distinct methods: mechanical extrusion, cosolvent-based processing in an IL, and fractionation of polymersomes in a biphasic system of IL and water. For the representative ionic liquid (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([EMIM][TFSI])), the size and dispersity of polymersomes formed from 1,2-polybutadiene-b-poly(ethylene oxide) (PB-PEO) and polystyrene-b-poly(ethylene oxide) (PS-PEO) diblock copolymers were shown to be sensitive to assembly conditions. During mechanical extrusion through a polycarbonate membrane, the relatively larger polymersomes were broken up and reorganized into vesicles with mean size comparable to the membrane pore (100 nm radius); the distribution width also decreased significantly after only a few passes. Other routes were studied using the solvent-switch or cosolvent (CS) method, whereby the initial content of the cosolvent and the PEO block length of PS-PEO were systemically changed. The nonvolatility of the ionic liquid directly led to the desired concentration of polymersomes in the ionic liquid using a single step, without the dialysis conventionally used in aqueous systems, and the mean vesicle size depended on the amount of cosolvent employed. Finally, selective phase transfer of PS-PEO polymersomes based on size was used to extract larger polymersomes from the IL to the aqueous phase via interfacial tension controlled phase transfer. The interfacial tension between the PS membrane and the aqueous phase was varied with the concentration of sodium chloride (NaCl) in the aqueous phase; then the larger polymersomes were selectively separated to the aqueous phase due to differences in shielding of the hydrophobic core (PS) coverage by the hydrophilic corona brush (PEO). This novel fractionation is a simple separation process without any special apparatus and can help to prepare monodisperse polymersomes

  6. Exceeding the filling fraction limit: An approach to enhancement of thermoelectric properties of filled - Co4Sb12 skutterudite

    NASA Astrophysics Data System (ADS)

    Graff, Jennifer Whitney

    Currently the world energy usage has nearly tripled since 1950 and is projected to grow at a rate of 1.5% per year and predicted to at least double from the beginning of the millennium to 2050. The United States alone is currently consuming more energy than it can produce (≈ 97 Quadrillion BTU's consumed in 2011).(1) Presently, fossil fuels make up over 85% of our energy landscape, including both the stationary grid (like coal and nuclear power plants) and the mobile grid (automobiles using gas and oil). This presents a major demand for developing methods of saving, storing, and renewing energy. Answers to these existing energy demands must come from a variety of renewable sources including: solar, wind, biomass, geothermal and others. But currently, most renewable sources are only a small part of the big energy picture. One approach to this exponentially growing problem, lies within high efficiency (15%-20%) thermoelectric (TE) materials which address small, yet very important and specific, parts of a bigger problem. Specifically, Co4Sb12-based skutterudites, an increasingly favorable thermoelectric material for mid to high temperature applications (currently used in General Motors TE Generator devices). These materials have the ability to be 'tuned' or controlled thermally and electrically through doping and filling mechanisms, as you will see in this dissertation. However, one of the major drawbacks of TE materials is the difficulty in optimizing both electrical and thermal properties simultaneously. Typically, different control parameters are used in order to enhance the electrical and thermal properties individually. It is very rare to observe optimization of both in a TE material via one control parameter. However, the work presented herein successfully augments all TE properties, with one control variable, by using an approach that can be applied to all doped skutterudites and clathrate materials. Skutterudites are novel materials in that they are a binary

  7. Use of palm mid-fraction in dark chocolate as base filling centre at different storage temperatures.

    PubMed

    Jinap, S; Ali, A A; Man, Y B; Suria, A M

    2000-11-01

    Dark chocolates filled with palm mid-fraction (PMF) were stored at different temperatures to evaluate the physical and chemical changes. Storage at low temperature (18 degrees C) reduces the PMF migration to negligible extent. Higher storage temperatures (30 and 35 degrees C) increased the PMF migration from the filling centre into the chocolate coating. As a consequence of fat migration, fatty acid composition, triglyceride composition, hardness, solid fat content, melting point and polymorphic structure changed, leading to bloom formation, which started by fat migration and was influenced by recrystallization tendency within the chocolate coating.

  8. Competing states for the fractional quantum Hall effect in the 1/3-filled second Landau level

    NASA Astrophysics Data System (ADS)

    Jeong, Jae-Seung; Lu, Hantao; Hashimoto, Kenji; Chung, Suk Bum; Park, Kwon

    We study the nature of the fractional quantum Hall state in the 1/3-filled second Landau level at filling factor 7/3 via exact diagonalization. We show a series of transitions in the energy spectrum from a Laughlin-type spectrum, to an intermediate compressible spectrum, to a reentrant incompressible spectrum, and to a compressible spectrum with decrease of the Haldane pseudopotential. To search for a trial state describing the 7/3 state, we compute the overlap of the exact 7/3 ground state with various competing states including the Laughlin state, the particle-hole conjugate of the Z4 parafermion state, the fermionic Haffnian state, the antisymmetrized product state of two composite fermion seas (CFSs) at 1/6 filling, and the antisymmetrized correlated state of two CFSs at 1/4 filling, which are obtained as an antisymmetrized projection of the bilayer quantum Hall states. Specifically, we prove that the fermionic Haffnian state is equivalent to the antisymmetrized projection of the Halperin (551) state.

  9. Superperiods in Interference of eÕ3 Laughlin Quasiparticles Encircling Filling 2/5 FractionalQuantum Hall Island

    SciTech Connect

    Lin, P.V.; Camino, F.; Goldman, V.J.

    2009-12-01

    We report experiments in a large, 2.5 {mu}m diameter Fabry-Perot quantum Hall interferometer with two tunneling constrictions. Interference fringes are observed as conductance oscillations as a function of applied magnetic field (the Aharonov-Bohm flux through the electron island) or a global backgate voltage (electronic charge in the island). Depletion is such that in the fractional quantum Hall regime, filling 1/3 current-carrying chiral edge channels pass through constrictions when the island filling is 2/5. The interferometer device is calibrated with fermionic electrons in the integer quantum Hall regime. In the fractional regime, we observe magnetic flux and charge periods 5h/e and 2e, respectively, corresponding to creation of ten e/5 Laughlin quasiparticles in the island. These results agree with our prior report of the superperiods in a much smaller interferometer device. The observed experimental periods are interpreted as imposed by anyonic statistical interaction of fractionally charged quasiparticles.

  10. Neonatal Presentation of an Air-Filled Neck Mass that Enlarges with Valsalva: A Case Report

    PubMed Central

    Patel, Jasminkumar Bharatbhai; Kilbride, Howard; Paulson, Lorien

    2015-01-01

    Branchial cleft cysts are common causes of congenital neck masses in the pediatric population. However, neonatal presentation of branchial cleft cysts is uncommon, but recognizable secondary to acute respiratory distress from airway compression or complications secondary to infection. We report a 1-day-old infant presenting with an air-filled neck mass that enlarged with Valsalva and was not associated with respiratory distress. The infant was found to have a third branchial cleft cyst with an internal opening into the pyriform sinus. The cyst was conservatively managed with endoscopic surgical decompression and cauterization of the tract and opening. We review the embryology of branchial cleft cysts and current management. PMID:26495186

  11. Measurements of two types of dilatational waves in an air-filled unconsolidated sand

    SciTech Connect

    Hickey, C.J.; Sabatier, J.M.

    1997-07-01

    This study consists of laboratory measurements of dilatational waves propagating through an air-filled unconsolidated sand. One excitation technique consists of a loudspeaker suspended in the air above the packing of sand. A second excitation technique uses a mechanical shaker in contact with the sand. The transmitted signals are received using microphones and geophones located at various depths within the sand. An interpretation based on measured phase speeds indicates that the transmitted energy from the suspended loudspeaker source is partitioned primarily but not exclusively into the type-II dilatational wave. This wave attenuates rapidly and is only detected at depths of less than about 15 cm for this particular sample. At the deeper depths the detected signal is associated with the type-I dilatational wave. The mechanical shaker produces only a type-I dilatational wave. Both the geophone and microphone sensors can detect both types of dilatational waves. {copyright} {ital 1997 Acoustical Society of America.}

  12. Reconfigurable optothermal microparticle trap in air-filled hollow-core photonic crystal fiber.

    PubMed

    Schmidt, O A; Garbos, M K; Euser, T G; Russell, P St J

    2012-07-13

    We report a novel optothermal trapping mechanism that occurs in air-filled hollow-core photonic crystal fiber. In the confined environment of the core, the motion of a laser-guided particle is strongly influenced by the thermal-gradient-driven flow of air along the core surface. Known as "thermal creep flow," this can be induced either statically by local heating, or dynamically by the absorption (at a black mark placed on the fiber surface) of light scattered by the moving particle. The optothermal force on the particle, which can be accurately measured in hollow-core fiber by balancing it against the radiation forces, turns out to exceed the conventional thermophoretic force by 2 orders of magnitude. The system makes it possible to measure pN-scale forces accurately and to explore thermally driven flow in micron-scale structures. PMID:23030165

  13. RECORDING FLAME SPEED DATA OF FUEL AND AIR RATIO MIXTURES - THE HORIZONTAL GLASS TUBE IS FILLED WITH

    NASA Technical Reports Server (NTRS)

    1949-01-01

    RECORDING FLAME SPEED DATA OF FUEL AND AIR RATIO MIXTURES - THE HORIZONTAL GLASS TUBE IS FILLED WITH A HOMOGENOUS MIXTURE OF FUEL AND AIR - THE RATE OF FLAME TRAVEL IS PICKED UP BY PHOTO CELLS SHOWN ABOVE THE TUBE AND RECORDED ON THE ELECTRONIC TIME

  14. Gauge choices in the Hamiltonian theory of fractionally filled Chern bands

    NASA Astrophysics Data System (ADS)

    Murthy, Ganpathy; Shankar, R.

    2014-05-01

    In the Hamiltonian approach to Chern bands one constructs an algebraically exact mapping which expresses the electron density projected to the Chern band ρFCB as a sum of Girvin-MacDonald-Platzman density operators ρGMP. The ρGMP operators, which obey the magnetic translation algebra, are expressed in terms of auxiliary composite fermion (CF) variables, while preserving the algebra. This produces, in a natural way, a unique Hartree-Fock ground state for the CFs, which can be used as a springboard for various computations. In previous presentations we had not realized that this procedure, which works in any gauge, in principle, is greatly optimized by one family of gauges introduced by Y.-L. Wu, N. Regnault, and B. A. Bernevig [Phys. Rev. B 86, 085129 (2012), 10.1103/PhysRevB.86.085129; Phys. Rev. Lett. 110, 106802 (2013), 10.1103/PhysRevLett.110.106802] in their exact diagonalization program for Laughlin-like fractions. Here we explain in detail why their gauge choices also enable us to obtain better variational energies in our Hamiltonian approach. We illustrate the ideas with some results on the Haldane model, comparing our results to exact diagonalizations.

  15. High-resolution ion pulse ionization chamber with air filling for the 222Rn decays detection

    NASA Astrophysics Data System (ADS)

    Gavrilyuk, Yu. M.; Gangapshev, A. M.; Gezhaev, A. M.; Etezov, R. A.; Kazalov, V. V.; Kuzminov, V. V.; Panasenko, S. I.; Ratkevich, S. S.; Tekueva, D. A.; Yakimenko, S. P.

    2015-11-01

    The construction and characteristics of the cylindrical ion pulse ionization chamber (CIPIC) with a working volume of 3.2 L are described. The chamber is intended to register α-particles from the 222Rn and its daughter's decays in the filled air sample. The detector is less sensitive to electromagnetic pick-ups and mechanical noises. The digital pulse processing method is proposed to improve the energy resolution of the ion pulse ionization chamber. An energy resolution of 1.6% has been achieved for the 5.49 MeV α-line. The dependence of the energy resolution on high voltage and working media pressure has been investigated and the results are presented.

  16. Flow patterns of natural convection in an air-filled vertical cavity

    NASA Astrophysics Data System (ADS)

    Wakitani, Shunichi

    1998-08-01

    Flow patterns of two-dimensional natural convection in a vertical air-filled tall cavity with differentially heated sidewalls are investigated. Numerical simulations based on a finite difference method are carried out for a wide range of Rayleigh numbers and aspect ratios from the onset of the steady multicellular flow, through the reverse transition to the unicellular pattern, to the unsteady multicellular flow. For aspect ratios (height/width) from 10 to 24, the various cellular structures characterized by the number of secondary cells are clarified from the simulations by means of gradually increasing Rayleigh number to 106. Unsteady multicellular solutions are found in some region of Rayleigh numbers less than those at which the reverse transition has occurred.

  17. Interaction of finite-amplitude sound with air-filled porous materials

    NASA Technical Reports Server (NTRS)

    Nelson, D. A.

    1985-01-01

    The propagation of high intensity sound waves through an air-filled porus material was studied. The material is assumed: (1) to be rigid, incompressible, and homogeneous, and (2) to be adequately described by two properties: resistivity r and porosity. The resulting wave equation is still nonlinear, however, because of the u sgn(u) term in the resistivity. The equation is solved in the frequency domain as an infinite set of coupled inhomogeneous Helmholtz equations, one for each harmonic. An approximate but analytical solution leads to predictions of excess attenuation, saturation, and phase speed reduction for the fundamental component. A more general numerical solution is used to calculate the propagation curves for the higher harmonics. The u sgn(u) nonlinearity produces a cubic distortion pattern; when the input signal is a pure tone, only odd harmonic distortion products are generated.

  18. Imaging air volume fraction in sea ice using non-destructive X-ray tomography

    NASA Astrophysics Data System (ADS)

    Crabeck, Odile; Galley, Ryan; Delille, Bruno; Else, Brent; Geilfus, Nicolas-Xavier; Lemes, Marcos; Des Roches, Mathieu; Francus, Pierre; Tison, Jean-Louis; Rysgaard, Søren

    2016-05-01

    Although the presence of a gas phase in sea ice creates the potential for gas exchange with the atmosphere, the distribution of gas bubbles and transport of gases within the sea ice are still poorly understood. Currently no straightforward technique exists to measure the vertical distribution of air volume fraction in sea ice. Here, we present a new fast and non-destructive X-ray computed tomography technique to quantify the air volume fraction and produce separate images of air volume inclusions in sea ice. The technique was performed on relatively thin (4-22 cm) sea ice collected from an experimental ice tank. While most of the internal layers showed air volume fractions < 2 %, the ice-air interface (top 2 cm) systematically showed values up to 5 %. We suggest that the air volume fraction is a function of both the bulk ice gas saturation factor and the brine volume fraction. We differentiate micro bubbles (Ø < 1 mm), large bubbles (1 mm < Ø < 5 mm) and macro bubbles (Ø > 5 mm). While micro bubbles were the most abundant type of gas bubbles, most of the air porosity observed resulted from the presence of large and macro bubbles. The ice texture (granular and columnar) as well as the permeability state of ice are important factors controlling the air volume fraction. The technique developed is suited for studies related to gas transport and bubble migration.

  19. Numerical Analysis of Air Pressure Effects on the Flow Pattern during the Filling of a Vertical Die Cavity

    NASA Astrophysics Data System (ADS)

    Hernández-Ortega, J. J.; Zamora, R.; López, J.; Faura, F.

    2011-05-01

    Porosity due to air entrapment in the molten metal during the injection process is one of the most important problems encountered in die-casting processes. The causes of air entrapment can be attributed mainly to the evolution of the free surface of the fluid flow during the filling and the use of inadequate air evacuation systems. Different studies of the main characteristics of the flow during the filling of a vertical die cavity can be found in the literature. In most of these studies, the effects of the air on the flow of molten metal during the injection are usually neglected. However, under certain conditions, specially when there is a poor evacuation of air through vents, these effects may substantially affect the filling pattern and the final amount of air trapped in the molten metal. The aim of this work is to study numerically the effects of air on the fluid flow during the early stages of the filling of a vertical die cavity with rectangular shape. To this end, numerical simulations of the fluid flow in the die cavity are carried out using a commercial CFD code (FLOW-3D) based on the SOLA-VOF approach to solve the coupling between the momentum and mass conservation equations and to treat the free surface. The main characteristics of the flow are analyzed for a wide range of operating conditions. Also, filling visualization experiments are carried out on a test bench for validation purpose using water as working fluid in a transparent die model and a high-speed camera. The viability of the numerical model used in the simulations is finally discussed.

  20. Design and analysis of stepped impedance transformer from air filled waveguide to dielectric filled waveguide for high power microwave window applications

    NASA Astrophysics Data System (ADS)

    Sindam, Bashaiah; Sharma, P. K.; Raju, K. C. James

    2014-03-01

    This paper describes a design to achieve good microwave power transmission from an air filled rectangular waveguide to a narrow dielectric filled waveguide using a stepped impedance transformer. A novel material Ba(Zn1/3Ta2/3)O3 (BZT) having high dielectric constant and low dielectric loss has been proposed as a microwave window. The advantages of using such dielectric resonator materials for these applications is that they make the size reduction of such microwave components possible without unleashing microwave dissipation. A high density (more than 97%) and good microwave dielectric properties are obtained for BZT samples through the solid state reaction method. The obtained dielectric parameters are used to calculate the dimensions of the narrow dielectric window section in waveguide geometry and the resulting dielectric window structure is simulated using the IMST Empire simulator. The maximum power transmission is obtained by the simulated structure with a dielectric filled waveguide window of thickness 7.4 mm at 3.7 GHz with bandwidth of 780 MHz, which corresponds to an insertion loss (S21) magnitude of 0.008 dB, and the return loss (S11) obtained at the same frequency is -43 dB. The microwave dielectric properties of the material used as well as the simulated results for the BZT based window are studied and compared with those of a conventional window.

  1. Autonomous generation of a thermoacoustic solitary wave in an air-filled tube

    NASA Astrophysics Data System (ADS)

    Shimizu, Dai; Sugimoto, Nobumasa

    2016-10-01

    Experiments are performed to demonstrate the autonomous generation of an acoustic solitary wave in an air-filled, looped tube with an array of Helmholtz resonators. The solitary wave is generated spontaneously due to thermoacoustic instability by a pair of stacks installed in the tube and subject to a temperature gradient axially. No external drivers are used to create initial disturbances. Once the solitary wave is generated, it keeps on propagating to circulate along the loop endlessly. The stacks, which are made of ceramics and of many pores of square cross section, are placed in the tube diametrically on exactly the opposite side of the loop, and they are sandwiched by hot and cold (ambient) heat exchangers. When the temperature gradient along both stacks is appropriate, pulses of smooth profiles are generated and propagated in both directions of the tube. From good agreements of not only the pressure profile measured but also the propagation speed with the theory, the pulse is identified as the acoustic solitary wave, and it can be called thermoacoustic solitary wave or thermoacoustic soliton corresponding to the soliton solution of the K-dV equation in one limit.

  2. Effects of the Nd:YAG laser, air-abrasion, and acid-etchant on filling materials.

    PubMed

    Türkmen, C; Sazak, H; Günday, M

    2006-01-01

    The purpose of this study was to determine any inadvertent effects of the neodymium: yttrium-aluminium-garnet (Nd:YAG) laser, air-abrasion, and ortho-phosphoric acid on some conventionally used dental filling materials [amalgam, composite resin, compomer, glass-ionomer cement (GIC), and ceromer], when they were used for purposes of margin etching and assessed according to standard enamel etching parameters using a total of five fillings. The surfaces of the filling materials were polished. One sample from each material group was exposed to laser (at 0.75 J, 15 pps) and air abrasion (with Al-oxide powder, 60 psi) for 2 s and to the 37% ortho-phosphoric acid for 60 s. The exposed materials were examined under Scanning Electron Microscopy (SEM). After laser treatment most specimens showed recrystallized areas, the GIC surface being the most affected. There were some pores and cavities on the amalgam surface following laser treatment. The abraded surfaces showed mechanical abrasions. The acid etchant showed the least effect. During the application of laser or air-abrasion, the adjacent tooth or filling surface must be protected or the dentist must be careful.

  3. Distribution of brominated flame retardants in different dust fractions in air from an electronics recycling facility.

    PubMed

    Julander, Anneli; Westberg, Håkan; Engwall, Magnus; van Bavel, Bert

    2005-11-01

    Twelve air samples were collected from an electronic recycling facility in Sweden representing three different dust fractions; respirable, total and inhalable dust. Four samples were collected from each fraction. The highest concentration of polybrominated diphenyl ether (PBDE) #209 (ten bromine atoms) was found in the samples from the inhalable dust fraction (ID), which was 10 times higher than for the "total dust" fraction (TD). The concentration ranges were 157.6-208.6; 13.9-16.7; and 2.8-3.3 ng/m3 for inhalable, total and respirable fractions, respectively. The second most abundant PBDE congener was PBDE #183 (seven bromine atoms), followed by the second most abundant substance 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) in all samples. In addition, decabromodiphenyl ethane (DeBDethane) was tentatively identified in five of the samples. Because of the large differences in air concentrations between the three fractions in ID, TD and RD, it is suggested that the inhalable instead of "total dust" fraction should be used to assess air concentrations, in particular for the larger and higher brominated flame retardants (BFRs).

  4. Air-filled postcranial bones in theropod dinosaurs: physiological implications and the 'reptile'-bird transition.

    PubMed

    Benson, Roger B J; Butler, Richard J; Carrano, Matthew T; O'Connor, Patrick M

    2012-02-01

    Pneumatic (air-filled) postcranial bones are unique to birds among extant tetrapods. Unambiguous skeletal correlates of postcranial pneumaticity first appeared in the Late Triassic (approximately 210 million years ago), when they evolved independently in several groups of bird-line archosaurs (ornithodirans). These include the theropod dinosaurs (of which birds are extant representatives), the pterosaurs, and sauropodomorph dinosaurs. Postulated functions of skeletal pneumatisation include weight reduction in large-bodied or flying taxa, and density reduction resulting in energetic savings during foraging and locomotion. However, the influence of these hypotheses on the early evolution of pneumaticity has not been studied in detail previously. We review recent work on the significance of pneumaticity for understanding the biology of extinct ornithodirans, and present detailed new data on the proportion of the skeleton that was pneumatised in 131 non-avian theropods and Archaeopteryx. This includes all taxa known from significant postcranial remains. Pneumaticity of the cervical and anterior dorsal vertebrae occurred early in theropod evolution. This 'common pattern' was conserved on the line leading to birds, and is likely present in Archaeopteryx. Increases in skeletal pneumaticity occurred independently in as many as 12 lineages, highlighting a remarkably high number of parallel acquisitions of a bird-like feature among non-avian theropods. Using a quantitative comparative framework, we show that evolutionary increases in skeletal pneumaticity are significantly concentrated in lineages with large body size, suggesting that mass reduction in response to gravitational constraints at large body sizes influenced the early evolution of pneumaticity. However, the body size threshold for extensive pneumatisation is lower in theropod lineages more closely related to birds (maniraptorans). Thus, relaxation of the relationship between body size and pneumatisation preceded

  5. Metastable inhomogeneous vortex configuration with non-uniform filling fraction inside a blind hole array patterned in a BSCCO single crystal and concentrating magnetic flux inside it

    NASA Astrophysics Data System (ADS)

    Shaw, Gorky; Banerjee, S. S.; Tamegai, T.; Suderow, Hermann

    2016-06-01

    Using magneto-optical imaging, we map the local magnetic field distribution inside a hexagonally ordered array of blind holes patterned in BSCCO single crystals. The nature of the spatial distribution of local magnetic field and shielding currents across the array reveals the presence of a non-uniform vortex configuration partially matched with the blind holes at sub-matching fields. We observe that the filling fraction is different in two different regions of the array. The mean vortex configuration within the array is described as a patchy vortex configuration with the patches having different mean filling fraction. The patchy nature of the vortex configuration is more pronounced at partial filling of the array at low fields while the configuration becomes more uniform with a unique filling fraction at higher fields. The metastable nature of this patchy vortex configuration is revealed by the application of magnetic field pulses of fixed height or individual pulses of varying height to the array. The metastability of the vortex configuration allows a relatively easy way of producing flux reorganization and flux focusing effects within the blind hole array. The effect of the magnetic field pulses modifies the vortex configuration within the array and produces a uniform enhancement in the shielding current around the patterned array edges. The enhanced shielding current concentrates magnetic flux within the array by driving vortices away from the edges and towards the center of the array. The enhanced shielding current also prevents the uninhibited entry of vortices into the array. We propose that the metastable patchy vortex configuration within the blind hole array is due to a non-uniform pinning landscape leading to non-uniform filling of individual blind holes.

  6. Quantification of VX vapor in ambient air by liquid chromatography isotope dilution tandem mass spectrometric analysis of glass bead filled sampling tubes.

    PubMed

    Evans, Ronald A; Smith, Wendy L; Nguyen, Nam-Phuong; Crouse, Kathy L; Crouse, Charles L; Norman, Steven D; Jakubowski, E Michael

    2011-02-15

    An analysis method has been developed for determining low parts-per-quadrillion by volume (ppqv) concentrations of nerve agent VX vapor actively sampled from ambient air. The method utilizes glass bead filled depot area air monitoring system (DAAMS) sampling tubes with isopropyl alcohol extraction and isotope dilution using liquid chromatography coupled with a triple-quadrupole mass spectrometer (LC/MS/MS) with positive ion electrospray ionization for quantitation. The dynamic range was from one-tenth of the worker population limit (WPL) to the short-term exposure limit (STEL) for a 24 L air sample taken over a 1 h period. The precision and accuracy of the method were evaluated using liquid-spiked tubes, and the collection characteristics of the DAAMS tubes were assessed by collecting trace level vapor generated in a 1000 L continuous flow chamber. The method described here has significant improvements over currently employed thermal desorption techniques that utilize a silver fluoride pad during sampling to convert VX to a higher volatility G-analogue for gas chromatographic analysis. The benefits of this method are the ability to directly analyze VX with improved selectivity and sensitivity, the injection of a fraction of the extract, quantitation using an isotopically labeled internal standard, and a short instrument cycle time.

  7. Urban air quality assessment using monitoring data of fractionized aerosol samples, chemometrics and meteorological conditions.

    PubMed

    Yotova, Galina I; Tsitouridou, Roxani; Tsakovski, Stefan L; Simeonov, Vasil D

    2016-01-01

    The present article deals with assessment of urban air by using monitoring data for 10 different aerosol fractions (0.015-16 μm) collected at a typical urban site in City of Thessaloniki, Greece. The data set was subject to multivariate statistical analysis (cluster analysis and principal components analysis) and, additionally, to HYSPLIT back trajectory modeling in order to assess in a better way the impact of the weather conditions on the pollution sources identified. A specific element of the study is the effort to clarify the role of outliers in the data set. The reason for the appearance of outliers is strongly related to the atmospheric condition on the particular sampling days leading to enhanced concentration of pollutants (secondary emissions, sea sprays, road and soil dust, combustion processes) especially for ultra fine and coarse particles. It is also shown that three major sources affect the urban air quality of the location studied-sea sprays, mineral dust and anthropogenic influences (agricultural activity, combustion processes, and industrial sources). The level of impact is related to certain extent to the aerosol fraction size. The assessment of the meteorological conditions leads to defining of four downwind patterns affecting the air quality (Pelagic, Western and Central Europe, Eastern and Northeastern Europe and Africa and Southern Europe). Thus, the present study offers a complete urban air assessment taking into account the weather conditions, pollution sources and aerosol fractioning.

  8. Detecting CO2 and CH4 Urban Emissions using Column-Integrated Dry Air mole Fractions, In-Situ Tower Dry Air Mole Fractions, and WRF Modeling

    NASA Astrophysics Data System (ADS)

    Hillyard, P. W.; Lauvaux, T.; Podolske, J. R.; Iraci, L. T.; Miles, N. L.; Richardson, S.; Davis, K.; Roehl, C. M.; Wunch, D.; Wennberg, P. O.; Blavier, J. F.; Allen, N.; Barrow, E.; Deng, A.

    2015-12-01

    Total column measurements of atmospheric gases are important because of their ability to be performed via satellites that provide global coverage. Here we will present measurements of CO2 and CH4 dry air mole fractions obtained using a Fourier Transform Spectrometer (FTS) as part of the Total Carbon Column Observing Nework (TCCON). These measurements were performed in Indianapolis as part of the Indianapolis Flux Experiment (INFLUX). We will extract urban emission signals using high resolution modeling and in-situ tower measurements of CO2 and CH4 mixing ratios. In addition to quantifying the influence of surface emissions on the column measurements, we will also decompose the atmospheric columns into sub-layers to identify the origin of air masses at various altitudes. We will show that the variability in the origins of air masses increases the complexity of the observed signals in the column, which limits our ability to combine surface and column measurements. This work will also highlight the potential application of using total column measurements to detect local urban signals. We conclude that the deployment of multiple column sensors is required in order to measure the upwind (background) and downwind (urban) conditions. Such work provides a test case for using these methods with satellite measurements such as GOSAT and OCO-2 that provide global coverage.

  9. Accuracy of Geophysical Parameters Derived from AIRS/AMSU as a Function of Fractional Cloud Cover

    NASA Technical Reports Server (NTRS)

    Susskind, Joel; Barnet, Chris; Blaisdell, John; Iredell, Lena; Keita, Fricky; Kouvaris, Lou; Molnar, Gyula; Chahine, Moustafa

    2006-01-01

    AIRS was launched on EOS Aqua on May 4,2002, together with AMSU A and HSB, to form a next generation polar orbiting infrared and microwave atmospheric sounding system. The primary products of AIRS/AMSU are twice daily global fields of atmospheric temperature-humidity profiles, ozone profiles, sea/land surface skin temperature, and cloud related parameters including OLR. The sounding goals of AIRS are to produce 1 km tropospheric layer mean temperatures with an rms error of lK, and layer precipitable water with an rms error of 20 percent, in cases with up to 80 percent effective cloud cover. The basic theory used to analyze Atmospheric InfraRed Sounder/Advanced Microwave Sounding Unit/Humidity Sounder Brazil (AIRS/AMSU/HSB) data in the presence of clouds, called the at-launch algorithm, was described previously. Pre-launch simulation studies using this algorithm indicated that these results should be achievable. Some modifications have been made to the at-launch retrieval algorithm as described in this paper. Sample fields of parameters retrieved from AIRS/AMSU/HSB data are presented and validated as a function of retrieved fractional cloud cover. As in simulation, the degradation of retrieval accuracy with increasing cloud cover is small and the RMS accuracy of lower tropospheric temperature retrieved with 80 percent cloud cover is about 0.5 K poorer than for clear cases. HSB failed in February 2003, and consequently HSB channel radiances are not used in the results shown in this paper. The AIRS/AMSU retrieval algorithm described in this paper, called Version 4, become operational at the Goddard DAAC (Distributed Active Archive Center) in April 2003 and is being used to analyze near-real time AIRS/AMSU data. Historical AIRS/AMSU data, going backwards from March 2005 through September 2002, is also being analyzed by the DAAC using the Version 4 algorithm.

  10. EFFECTS OF OXYGEN AND AIR MIXING ON VOID FRACTIONS IN A LARGE SCALE SYSTEM

    SciTech Connect

    Leishear, R; Hector Guerrero, H; Michael Restivo, M

    2008-09-11

    Oxygen and air mixing with spargers was performed in a 30 foot tall by 30 inch diameter column, to investigate mass transfer as air sparged up through the column and removed saturated oxygen from solution. The mixing techniques required to support this research are the focus of this paper. The fluids tested included water, water with an antifoam agent (AFA), and a high, solids content, Bingham plastic, nuclear waste simulant with AFA, referred to as AZ01 simulant, which is non-radioactive. Mixing of fluids in the column was performed using a recirculation system and an air sparger. The re-circulation system consisted of the column, a re-circulating pump, and associated piping. The air sparger was fabricated from a two inch diameter pipe concentrically installed in the column and open near the bottom of the column. The column contents were slowly re-circulated while fluids were mixed with the air sparger. Samples were rheologically tested to ensure effective mixing, as required. Once the fluids were adequately mixed, oxygen was homogeneously added through the re-circulation loop using a sintered metal oxygen sparger followed by a static mixer. Then the air sparger was re-actuated to remove oxygen from solution as air bubbled up through solution. To monitor mixing effectiveness several variables were monitored, which included flow rates, oxygen concentration, differential pressures along the column height, fluid levels, and void fractions, which are defined as the percent of dissolved gas divided by the total volume of gas and liquid. Research showed that mixing was uniform for water and water with AFA, but mixing for the AZ101 fluid was far more complex. Although mixing of AZ101 was uniform throughout most of the column, gas entrapment and settling of solids significantly affected test results. The detailed test results presented here provide some insight into the complexities of mixing and void fractions for different fluids and how the mixing process itself

  11. Nonlinear compression of high energy fiber amplifier pulses in air-filled hypocycloid-core Kagome fiber.

    PubMed

    Guichard, Florent; Giree, Achut; Zaouter, Yoann; Hanna, Marc; Machinet, Guillaume; Debord, Benoît; Gérôme, Frédéric; Dupriez, Pascal; Druon, Frédéric; Hönninger, Clemens; Mottay, Eric; Benabid, Fetah; Georges, Patrick

    2015-03-23

    We report on the generation of 34 fs and 50 µJ pulses from a high energy fiber amplifier system with nonlinear compression in an air-filled hypocycloid-core Kagome fiber. The unique properties of such fibers allow bridging the gap between solid core fibers-based and hollow capillary-based post-compression setups, thereby operating with pulse energies obtained with current state-of-the-art fiber systems. The overall transmission of the compression setup is over 70%. Together with Yb-doped fiber amplifier technologies, Kagome fibers therefore appear as a promising tool for efficient generation of pulses with durations below 50 fs, energies ranging from 10 to several hundreds of µJ, and high average powers.

  12. Isolating scattering resonances of an air-filled spherical shell using iterative, single-channel time reversal.

    PubMed

    Waters, Zachary J; Dzikowicz, Benjamin R; Simpson, Harry J

    2012-01-01

    Iterative, single-channel time reversal is employed to isolate backscattering resonances of an air-filled spherical shell in a frequency range of 0.5-20 kHz. Numerical simulations of free-field target scattering suggest improved isolation of the dominant target response frequency in the presence of varying levels of stochastic noise, compared to processing returns from a single transmission and also coherent averaging. To test the efficacy of the technique in a realistic littoral environment, monostatic scattering experiments are conducted in the Gulf of Mexico near Panama City, Florida. The time reversal technique is applied to returns from a hollow spherical shell target sitting proud on a sandy bottom in 14 m deep water. Distinct resonances in the scattering response of the target are isolated, depending upon the bandwidth of the sonar system utilized.

  13. Recovery of Extracellular Lipolytic Enzymes from Macrophomina phaseolina by Foam Fractionation with Air

    PubMed Central

    Germani, José Carlos

    2013-01-01

    Macrophomina phaseolina was cultivated in complex and simple media for the production of extracellular lipolytic enzymes. Culture supernatants were batch foam fractionated for the recovery of these enzymes, and column design and operation included the use of P 2 frit (porosity 40 to 100 μm), air as sparging gas at variable flow rates, and Triton X-100 added at the beginning or gradually in aliquots. Samples taken at intervals showed the progress of the kinetic and the efficiency parameters. Best results were obtained with the simple medium supernatant by combining the stepwise addition of small amounts of the surfactant with the variation of the air flow rates along the separation. Inert proteins were foamed out first, and the subsequent foamate was enriched in the enzymes, showing estimated activity recovery (R), enrichment ratio (E), and purification factor (P) of 45%, 34.7, and 2.9, respectively. Lipases were present in the enriched foamate. PMID:23738054

  14. Response of ozone to changes in hydrocarbon and nitrogen oxide concentrations in outdoor smog chambers filled with Los Angeles air

    NASA Astrophysics Data System (ADS)

    Kelly, Nelson A.; Gunst, Richard F.

    During the summer portion of the 1987 Southern California Air Quality Study (SCAQS), outdoor smog chamber experiments were performed on Los Angeles air to determine the response of maximum ozone levels, O 3(max), to changes in the initial concentrations of hydrocarbons, HC, and nitrogen oxides, NO x. These captive-air experiments were conducted in downtown Los Angeles and in the downwind suburb of Claremont. Typically, eight chambers were filled with LA air in the morning. In some chambers the initial HC and/or NO x concentrations were changed by 25% to 50% by adding various combinations of a mixture of HC, clean air, or NO x. The O 3 concentration in each chamber was monitored throughout the day to determine O 3(max). An empirical mathematical model for O 3(max) was developed from regression fits to the initial HC and NO x concentrations and to the average daily temperature at both sites. This is the first time that a mathematical expression for the O 3-precursor relationship and the positive effect of temperature on O 3(max) have been quantified using captive-air experiments. An ozone isopleth diagram prepared from the empirical model was qualitatively similar to those prepared from photochemical mechanisms. This constitutes the first solely empirical corroboration of the O 3 contour shape for Los Angeles. To comply with the Federal Ozone Standard in LA, O 3(max) must be reduced by approximately 50%. Several strategies for reducing O 3(max) by 50% were evaluated using the empirical model. For the average initial conditions that we measured in LA, the most efficient strategy is one that reduces HC by 55-75%, depending on the ambient HC/NO x ratio. Any accompanying reduction in NO x would be counter-productive to the benefits of HC reductions. In fact, reducing HC and NO x simultaneously requires larger percentage reductions for both than the reduction required when HC alone is reduced. The HC-reduction strategy is the most efficient on average, but no single

  15. On the air-filled effective porosity parameter of Rogers and Nielson's (1991) bulk radon diffusion coefficient in unsaturated soils.

    PubMed

    Saâdi, Zakaria

    2014-05-01

    The radon exhalation rate at the earth's surface from soil or rock with radium as its source is the main mechanism behind the radon activity concentrations observed in both indoor and outdoor environments. During the last two decades, many subsurface radon transport models have used Rogers and Nielson's formula for modeling the unsaturated soil bulk radon diffusion coefficient. This formula uses an "air-filled effective porosity" to account for radon adsorption and radon dissolution in the groundwater. This formula is reviewed here, and its hypotheses are examined for accuracy in dealing with subsurface radon transport problems. The author shows its limitations by comparing one dimensional steady-state analytical solutions of the two-phase (air/water) transport equation (Fick's law) with Rogers and Nielson's formula. For radon diffusion-dominated transport, the calculated Rogers and Nielson's radon exhalation rate is shown to be unrealistic as it is independent of the values of the radon adsorption and groundwater dissolution coefficients. For convective and diffusive transport, radon exhalation rates calculated using Fick's law and this formula agree only for high values of gas-phase velocity and groundwater saturation. However, these conditions are not usually met in most shallow subsurface environments where radon migration takes place under low gas phase velocities and low water saturation.

  16. On the air-filled effective porosity parameter of Rogers and Nielson's (1991) bulk radon diffusion coefficient in unsaturated soils.

    PubMed

    Saâdi, Zakaria

    2014-05-01

    The radon exhalation rate at the earth's surface from soil or rock with radium as its source is the main mechanism behind the radon activity concentrations observed in both indoor and outdoor environments. During the last two decades, many subsurface radon transport models have used Rogers and Nielson's formula for modeling the unsaturated soil bulk radon diffusion coefficient. This formula uses an "air-filled effective porosity" to account for radon adsorption and radon dissolution in the groundwater. This formula is reviewed here, and its hypotheses are examined for accuracy in dealing with subsurface radon transport problems. The author shows its limitations by comparing one dimensional steady-state analytical solutions of the two-phase (air/water) transport equation (Fick's law) with Rogers and Nielson's formula. For radon diffusion-dominated transport, the calculated Rogers and Nielson's radon exhalation rate is shown to be unrealistic as it is independent of the values of the radon adsorption and groundwater dissolution coefficients. For convective and diffusive transport, radon exhalation rates calculated using Fick's law and this formula agree only for high values of gas-phase velocity and groundwater saturation. However, these conditions are not usually met in most shallow subsurface environments where radon migration takes place under low gas phase velocities and low water saturation. PMID:24670909

  17. Interaction-driven fractional quantum Hall state of hard-core bosons on kagome lattice at one-third filling

    NASA Astrophysics Data System (ADS)

    Sheng, D. N.; Gong, S. S.; Zhu, W.

    There has been a growing interest in realizing topologically nontrivial states of matter in band insulators, where a quantum Hall effect can appear as an intrinsic property of the band structure. While the on-going progress is under way with a number of directions, the possibility of realizing novel interaction-generated topological phases, without the requirement of a nontrivial invariant encoded in single-particle wavefunction or band structure, can significantly extend the class of topological materials and is thus of great importance. Here, we show an interaction-driven topological phase emerging in an extended Bose-Hubbard model on kagome lattice, where the non-interacting band structure is topological trivial with zero Berry curvature in the Brillouin zone. By means of an unbiased state-of-the-art density-matrix renormalization group technique, we identify that the groundstate in a broad parameter region is equivalent to a bosonic fractional quantum Hall Laughlin state, based on the characterization of unverisal properties including groundstate degeneracy, edge excitations and anyonic quasiparticle statistics. Our work paves a way of finding interaction induced topological phase at the phase boundary of conventionally ordered solid phases. This research is supported by the DOE Grants No. DE-FG02-06ER46305, and the NSF Grant No. DMR-1408560.

  18. Interaction-driven fractional quantum Hall state of hard-core bosons on kagome lattice at one-third filling

    NASA Astrophysics Data System (ADS)

    Zhu, W.; Gong, S. S.; Sheng, D. N.

    2016-07-01

    There has been a growing interest in realizing topologically nontrivial states of matter in band insulators, where a quantum Hall effect can appear as an intrinsic property of the band structure. While ongoing progress is under way with a number of directions, the possibility of realizing novel interaction-generated topological phases, without the requirement of a nontrivial invariant encoded in single-particle wave function or band structure, can significantly extend the class of topological materials and is thus of great importance. Here, we show an interaction-driven topological phase emerging in an extended Bose-Hubbard model on a kagome lattice, where the noninteracting band structure is topological trivial with zero Berry curvature in the Brillouin zone. By means of an unbiased state-of-the-art density-matrix renormalization group technique, we identify that the ground state in a broad parameter region is equivalent to a bosonic fractional quantum Hall Laughlin state, based on the characterization of universal properties including ground-state degeneracy, edge excitations, and anyonic quasiparticle statistics. Our work paves a way to finding an interaction-induced topological phase at the phase boundary of conventionally ordered solid phases.

  19. Noble gas adsorption with and without mechanical stress: Not Martian signatures but fractionated air

    NASA Astrophysics Data System (ADS)

    Schwenzer, Susanne P.; Herrmann, Siegfried; Ott, Ulrich

    2012-06-01

    Sample preparation, involving physical and chemical methods, is an unavoidable step in geochemical analysis. From a noble gas perspective, the two important effects are loss of sample gas and/or incorporation of air, which are significant sources of analytical artifacts. This article reports on the effects of sample exposure to laboratory air without mechanical influence and during sample grinding. The experiments include pure adsorption on terrestrial analog materials (gibbsite and olivine) and grinding of Martian meteorites. A consistent observation is the presence of an elementally fractionated air component in the samples studied. This is a critical form of terrestrial contamination in meteorites as it often mimics the heavy noble gas signatures of known extra-terrestrial end-members that are the basis of important conclusions about the origin and evolution of a meteorite. Although the effects of such contamination can be minimized by avoiding elaborate sample preparation protocols, caution should be exercised in interpreting the elemental ratios (Ar/Xe, Kr/Xe), especially in the low-temperature step extractions. The experiments can also be transferred to the investigation of Martian meteorites with long terrestrial residence times, and to Mars, where the Mars Science Laboratory mission will be able to measure noble gas signatures in the current atmosphere and in rocks and soils collected on the surface in Gale crater.

  20. Small bowel necrosis as a consequence of spontaneous deflation and migration of an air-filled intragastric balloon – a potentially life-threatening complication

    PubMed Central

    Drozdowski, Robert; Wyleżoł, Mariusz; Frączek, Mariusz; Hevelke, Piotr; Sobański, Paweł

    2013-01-01

    Intragastric balloon placement is a common method of treatment of obesity and is often used by non-surgical teams in endoscopy departments. The likelihood of spontaneous intragastric balloon damage is a well-known phenomenon. We describe a patient who was disqualified from surgical obesity treatment and in whom intragastric fluid-filled balloons had already been inserted twice and removed due to their intolerance. Therefore we qualified this patient for placement of the air-filled balloon Heliosphere BAG. Two months after the planned check-up, he arrived at the surgery department complaining of nausea and vomiting and due to symptoms of ileus diagnosed with an X-ray and ultrasound examination we qualified him for emergency surgery. We would like to emphasise the following issues: the necessity of air-filled balloon removal according to the producer's instructions and multidisciplinary specialist team care along with appropriate diagnostic tools in every case of intragastric balloon insertion. PMID:25097704

  1. Limitations of quantitative oculoplethysmography and of directional Doppler ultrasonography in cerebrovascular diagnosis: assessment of an air-filled OPG system.

    PubMed

    Ginsberg, M D; Greenwood, S A; Goldberg, H I

    1981-01-01

    500 consecutive patients were evaluated for extracranial disease of the internal carotid arteries by an automated, air-filled, digital oculoplethysmographic system (OPG) of the Kartchner type (Zira) and by supraorbital (SO) and supratrochlear (ST) directional Doppler ultrasonography. Cerebral arteriograms were performed in 58 patients (110 vessels), and OPG timing criteria for detecting hemodynamically significant carotid artery stenosis (60% or greater diameter reduction) were ascertained. Optimal criteria were a delay of one ocular pulse, relative to the other, of greater than 12 msec; and a delay of an ocular pulse, relative to the earlier ear (external carotid) pulse, of greater than 36 msec. These criteria correctly identified 73% of vessels with 0 to 59% stenosis and 76% of vessels with 60 to 100% stenosis. However, in 26% of the vessels, OPG was either inconclusive or inaccurate. Correct diagnosis of bilateral hemodynamically significant carotid artery stenoses was made by OPG in 6 of 9 affected patients. SO Doppler was normal in 70% of vessels with 0-59% stenosis, and abnormal in 75% of vessels with 60-100% stenosis. Corresponding percentages for ST Doppler were 95% and 44%. Abnormal Doppler responses to compression of contralateral facial branches were predictive of intracranial cross-collateralization in only 25% of patients. These results suggest that both quantitative OPG in its present form and directional Doppler studies have serious limitations as non-invasive diagnostic methods.

  2. Intake fraction variability between air pollution emission sources inside an urban area.

    PubMed

    Tainio, Marko; Holnicki, Piotr; Loh, Miranda M; Nahorski, Zbigniew

    2014-11-01

    The cost-effective mitigation of adverse health effects caused by air pollution requires information on the contribution of different emission sources to exposure. In urban areas the exposure potential of different sources may vary significantly depending on emission height, population density, and other factors. In this study, we quantified this intraurban variability by predicting intake fraction (iF) for 3,066 emission sources in Warsaw, Poland. iF describes the fraction of the pollutant that is inhaled by people in the study area. We considered the following seven pollutants: particulate matter (PM), nitrogen oxides (NOx), sulfur dioxide (SO2), benzo[a] pyrene (BaP), nickel (Ni), cadmium (Cd), and lead (Pb). Emissions for these pollutants were grouped into four emission source categories (Mobile, Area, High Point, and Other Point sources). The dispersion of the pollutants was predicted with the CALPUFF dispersion model using the year 2005 emission rate data and meteorological records. The resulting annual average concentrations were combined with population data to predict the contribution of each individual source to population exposure. The iFs for different pollutant-source category combinations varied between 51 per million (PM from Mobile sources) and 0.013 per million (sulfate PM from High Point sources). The intraurban iF variability for Mobile sources primary PM emission was from 4 per million to 100 per million with the emission-weighted iF of 44 per million. These results propose that exposure due to intraurban air pollution emissions could be decreased more effectively by specifically targeting sources with high exposure potency rather than all sources.

  3. The unattached fraction of radon decay products: Potential effects of in-home air cleaners on lung cancer risk

    SciTech Connect

    Brady, P.A.

    1991-01-01

    Radon decay products are a factor in the development of lung cancer. Because of their efficient deposition within the lung, the fraction of decay products not attached to particulate (i.e., the unattached fraction) is very important in lung dosimetry. This study simulated the use of two in-home air cleaning devices to reduce airborne particulate concentrations, measure the effect on the unattached fraction, and estimate the radon lung cancer risk. Radon was released into a chamber having a volume-to-surface-area ratio similar to a small home. At radon-decay product equilibrium, radon and airborne particle concentrations were measured, and the concentration of the unattached fraction was estimated. The effect of particle concentration on the unattached fraction was then determined. The average unattached fractions corresponding to the particle concentration ranges expected for the air cleaning devices were used to calculate the annual alpha radiation dose and annual radon lung cancer for men, women and children at rest and under light activity. The annual doses and related risks were compared to those used in the models published by the Environmental Protection Agency. For particulate concentrations of a home with no particulate generating activities (e.g., smoking, cooking), the electronic air cleaner is predicted to reduce the unattached fraction from seven percent (the value used by the NCRP and confirmed in this study) to four percent. These conditions represent the maximum reduction in the unattached fraction. The decrease in the unattached fraction is tentatively attributed to an increase in plateout. Based on these results, a reduction of less than ten percent in the calculated annual lung cancer risk is found in all cases.

  4. Assessing changes in stratospheric mean age of air and fractional release using historical trace gas observations

    NASA Astrophysics Data System (ADS)

    Laube, Johannes; Bönisch, Harald; Engel, Andreas; Röckmann, Thomas; Sturges, William

    2014-05-01

    Large-scale stratospheric transport is pre-dominantly governed by the Brewer-Dobson circulation. Due to climatic change a long-term acceleration of this residual stratospheric circulation has been proposed (e.g. Austin et al.,2006). Observational evidence has revealed indications for temporary changes (e.g. Bönisch et al., 2011) but a confirmation of a significant long-term trend is missing so far (e.g. Engel et al., 2009). A different aspect is a possible long-term change in the break-down of chemically important species such as chlorofluorocarbons as proposed by Butchart et al. 2001. Recent studies show significant differences adding up to more than 20 % in the chlorine released from such compounds (Newman et al., 2007; Laube et al., 2013). We here use a data set of three long-lived trace gases, namely SF6, CF2Cl2, and N2O, as measured in whole-air samples collected during balloon and aircraft flights between 1975 and 2011, to assess changes in stratospheric transport and chemistry. For this purpose we utilise the mean stratospheric transit times (or mean ages of air) in combination with a measure of the chemical decomposition (i.e. fractional release factors). We also evaluate the influence of different trend correction methods on these quantities and explore their variability with latitude, altitude, and season. References Austin, J. & Li, F.: On the relationship between the strength of the Brewer-Dobson circulation and the age of stratospheric air, Geophys. Res. Lett., 33, L17807, 2006. Bönisch, H., Engel, A., Birner, Th., Hoor, P., Tarasick, D. W., and Ray, E. A.: On the structural changes in the Brewer-Dobson circulation after 2000, Atmos. Chem. Phys., 11, 3937-3948, 2011. Butchart, N. & Scaife, A. A. Removal of chlorofluorocarbons by increased mass exchange between the stratosphere and troposphere in a changing climate. Nature, 410, 799-802, 2001. Engel, A., Möbius, T., Bönisch, H., Schmidt, U., Heinz, R., Levin, I., Atlas, E., Aoki, S., Nakazawa, T

  5. Experimental study on the void fraction of air-water two-phase flow in a horizontal circular minichannel

    NASA Astrophysics Data System (ADS)

    Sudarja, Indarto, Deendarlianto, Haq, Aqli

    2016-06-01

    Void fraction is an important parameter in two-phase flow. In the present work, the adiabatic two-phase air-water flow void fraction in a horizontal minichannel has been studied experimentally. A transparent circular channel with 1.6 mm inner diameter was employed as the test section. Superficial gas and liquid velocities were varied in the range of 1.25 - 66.3 m/s and 0.033 - 4.935 m/s, respectively. Void fraction data were obtained by analyzing the flow images being captured by using a high-speed camera. Here, the homogeneous (β) and the measured void fractions (ɛ), respectively, were compared to the existing correlations. It was found that: (1) for the bubbly and slug flows, the void fractions increases with the increase of JG, (2) for churn, slug-annular, and annular flow patterns, there is no specific correlation between JG and void fraction was observed due to effect of the slip between gas and liquid, and (3) whilst for bubbly and slug flows the void fractions are close to homogeneous line, for churn, annular, and slug-annular flows are far below the homogeneous line. It indicates that the slip ratios for the second group of flow patterns are higher than unity.

  6. Enhancement of fill factor in air-processed inverted organic solar cells using self-assembled monolayer of fullerene catechol

    NASA Astrophysics Data System (ADS)

    Jeon, Il; Ogumi, Keisuke; Nakagawa, Takafumi; Matsuo, Yutaka

    2016-08-01

    [60]Fullerene catechol self-assembled monolayers were prepared and applied to inverted organic solar cells by an immersion method, and their energy conversion properties were measured. By introducing fullerenes at the surface, we improved the hole-blocking capability of electron-transporting metal oxide, as shown by the fill factor enhancement. The fullerene catechol-treated TiO x -containing device gave a power conversion efficiency (PCE) of 2.81% with a fill factor of 0.56 while the non treated device gave a PCE of 2.46% with a fill factor of 0.49. The solar cell efficiency improved by 13% compared with the non treated reference device.

  7. Air fractionation in plate-like inclusions within the EPICA-DML deep ice core

    NASA Astrophysics Data System (ADS)

    Nedelcu, A.; Faria, S. H.; Kipfstuhl, S.; Schmidt, B.; Kuhs, W. F.

    2009-04-01

    than this, they suggest that the diffusion of chemical traces in the ice matrix may not be negligible, at least locally, on a timescale of few years. These results could be important for the interpretation of ice-core paleoclimate records. Muguruma, J., S. Mae and A. Higashi, 1966. Void formation by non-basal glide in ice single crystals, Philos. Mag., 13(123), 625-629. Mae, S., 1968. Void formation during non-basal glide in ice single crystals under tension, Philos. Mag., 18(151), 101-114. Gow, A. J., 1971. Relaxation of ice in deep drill cores from Antarctica, J. Glaciol., 76(11), 2533-2541. Nedelcu, A. F., S. H. Faria and W. F. Kuhs, in press. Raman spectra of plate-like inclusions in the EPICA-DML ice core. J. Glaciol., 55(189) Nakahara, J., Y. Shigesato, A. Higashi, T. Hondoh and C.C. Langway, 1988. Raman spectra of natural clathrates in deep ice cores, Philos. Mag. B, 57(3), 421-430. Ikeda, T., H. Fukazawa, S. Mae, L. Pepin, P. Duval, B. Champagnon, V. Y. Lipenkov and T. Hondoh, 1999. Extreme fractionation of gases caused by formation of clathrate hydrates in Vostok Antarctic ice, Geophys. Res. Lett., 26(1), 91-94. Ikeda-Fukazawa, T., T. Hondoh, T. Fukumura, H. Fukazawa and S. Mae, 2001. Variation in N2/O2 ratio of occluded air in Dome Fuji antarctic ice, J. Geophys. Res., 106(D16), 17799-17810. Ikeda-Fukazawa, T., K. Fukumizu, K. Kawamura, S. Aoki, T. Nakazawa and T. Hondoh, 2005. Effects of molecular diffusion on trapped gas composition in polar ice cores, Earth Planet.Sci.Lett.,229(3-4),183-192. Severinghaus, J. P., and M. O. Battle, 2006. Fractionation of gases in polar ice during bubble close-off: new constraints from firn air, Ne, Kr and Xe observations, Earth Planet. Sci. Lett., 244(1-2), 474-500.

  8. A simple methodological validation of the gas/particle fractionation of polycyclic aromatic hydrocarbons in ambient air

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Hyun; Kim, Ki-Hyun

    2015-07-01

    The analysis of polycyclic aromatic hydrocarbons (PAH) in ambient air requires the tedious experimental steps of both sampling and pretreatment (e.g., extraction or clean-up). To replace pre-existing conventional methods, a simple, rapid, and novel technique was developed to measure gas-particle fractionation of PAH in ambient air based on ‘sorbent tube-thermal desorption-gas chromatograph-mass spectrometer (ST-TD-GC-MS)’. The separate collection and analysis of ambient PAHs were achieved independently by two serially connected STs. The basic quality assurance confirmed good linearity, precision, and high sensitivity to eliminate the need for complicated pretreatment procedures with the detection limit (16 PAHs: 13.1 ± 7.04 pg). The analysis of real ambient PAH samples showed a clear fractionation between gas (two-three ringed PAHs) and particulate phases (five-six ringed PAHs). In contrast, for intermediate (four ringed) PAHs (fluoranthene, pyrene, benz[a]anthracene, and chrysene), a highly systematic/gradual fractionation was established. It thus suggests a promising role of ST-TD-GC-MS as measurement system in acquiring a reliable database of airborne PAH.

  9. A simple methodological validation of the gas/particle fractionation of polycyclic aromatic hydrocarbons in ambient air

    PubMed Central

    Kim, Yong-Hyun; Kim, Ki-Hyun

    2015-01-01

    The analysis of polycyclic aromatic hydrocarbons (PAH) in ambient air requires the tedious experimental steps of both sampling and pretreatment (e.g., extraction or clean-up). To replace pre-existing conventional methods, a simple, rapid, and novel technique was developed to measure gas-particle fractionation of PAH in ambient air based on ‘sorbent tube-thermal desorption-gas chromatograph-mass spectrometer (ST-TD-GC-MS)’. The separate collection and analysis of ambient PAHs were achieved independently by two serially connected STs. The basic quality assurance confirmed good linearity, precision, and high sensitivity to eliminate the need for complicated pretreatment procedures with the detection limit (16 PAHs: 13.1 ± 7.04 pg). The analysis of real ambient PAH samples showed a clear fractionation between gas (two-three ringed PAHs) and particulate phases (five-six ringed PAHs). In contrast, for intermediate (four ringed) PAHs (fluoranthene, pyrene, benz[a]anthracene, and chrysene), a highly systematic/gradual fractionation was established. It thus suggests a promising role of ST-TD-GC-MS as measurement system in acquiring a reliable database of airborne PAH. PMID:26126962

  10. Performance of a hydrogen burner to simulate air entering scramjet combustors. [simulation of total temperature, total pressure, and volume fraction of oxygen of air at flight conditions

    NASA Technical Reports Server (NTRS)

    Russin, W. R.

    1974-01-01

    Tests were conducted to determine the performance of a hydrogen burner used to produce a test gas that simulates air entering a scramjet combustor at various flight conditions. The test gas simulates air in that it duplicates the total temperature, total pressure, and the volume fraction of oxygen of air at flight conditions. The main objective of the tests was to determine the performance of the burner as a function of the effective exhaust port area. The conclusions were: (1) pressure oscillations of the chugging type were reduced in amplitude to plus or minus 2 percent of the mean pressure level by proper sizing of hydrogen, oxygen, and air injector flow areas; (2) combustion efficiency remained essentially constant as the exhaust port area was increased by a factor of 3.4; (3) the mean total temperature determined from integrating the exit radial gas property profiles was within plus or minus 5 percent of the theoretical bulk total temperature; (4) the measured exit total temperature profile had a local peak temperature more than 30 percent greater than the theoretical bulk total temperature; and (5) measured heat transfer to the burner liner was 75 percent of that predicted by theory based on a flat radial temperature profile.

  11. FRACTIONAL AEROSOL FILTRATION EFFICIENCY OF IN-DUCT VENTILATION AIR CLEANERS

    EPA Science Inventory

    The filtration efficiency of ventilation air cleaners is highly particle-size dependent over the 0.01 to 3 μm diameter size range. Current standardized test methods, which determine only overall efficiencies for ambient aerosol or other test aerosols, provide data of limited util...

  12. Isotopic composition and fractionation of mercury in Great Lakes precipitation and ambient air.

    PubMed

    Gratz, Lynne E; Keeler, Gerald J; Blum, Joel D; Sherman, Laura S

    2010-10-15

    Atmospheric deposition is a primary pathway by which mercury (Hg) enters terrestrial and aquatic ecosystems; however, the chemical and meteorological processes that Hg undergoes from emission to deposition are not well understood. Hg stable isotope geochemistry is a growing field used to better understand Hg biogeochemical cycling. To examine the atmospheric Hg isotopic composition in the Great Lakes, precipitation and ambient vapor-phase Hg samples were collected in Chicago, IL, Holland, MI, and Dexter, MI, between April 2007 and September 2009. Precipitation samples were characterized by negative mass-dependent fractionation (MDF) (δ(202)Hg = -0.79‰ to 0.18‰), while most vapor-phase samples displayed positive MDF (δ(202)Hg = -0.59‰ to 0.43‰). Positive mass-independent fractionation (MIF) (Δ(199)Hg = 0.04‰ to 0.52‰) was observed in precipitation, whereas MIF was slightly negative in vapor-phase samples (Δ(199)Hg = -0.21‰ to 0.06‰). Significant positive MIF of (200)Hg up to 0.25‰ was also measured in precipitation. Such MIF of an even-mass Hg isotope has not been previously reported in natural samples. These results contrast with recent predictions of the isotopic composition of atmospheric Hg and suggest that, in addition to aqueous photoreduction, other atmospheric redox reactions and source-related processes may contribute to isotopic fractionation of atmospheric Hg.

  13. Evaluating the mutagenicity of the water-soluble fraction of air particulate matter: A comparison of two extraction strategies.

    PubMed

    Palacio, Isabel C; Oliveira, Ivo F; Franklin, Robson L; Barros, Silvia B M; Roubicek, Deborah A

    2016-09-01

    Many studies have focused on assessing the genotoxic potential of the organic fraction of airborne particulate matter. However, the determination of water-soluble compounds, and the evaluation of the toxic effects of these elements can also provide valuable information for the development of novel strategies to control atmospheric air pollution. To determine an appropriate extraction method for assessing the mutagenicity of the water-soluble fraction of PM, we performed microwave assisted (MW) and ultrasonic bath (US) extractions, using water as solvent, in eight different air samples (TSP and PM10). Mutagenicity and extraction performances were evaluated using the Salmonella/microsome assay with strains TA98 and TA100, followed by chemical determination of water-soluble metals. Additionally, we evaluated the chemical and biological stability of the extracts testing their mutagenic potential and chemically determining elements present in the samples along several periods after extraction. Reference material SRM 1648a was used. The comparison of MW and US extractions did not show differences on the metals concentrations, however positive mutagenic responses were detected with TA98 strain in all samples extracted using the MW method, but not with the US bath extraction. The recovery, using reference material was better in samples extracted with MW. We concluded that the MW extraction is more efficient to assess the mutagenic activity of the soluble fraction of airborne PM. We also observed that the extract freezing and storage over 60 days has a significant effect on the mutagenic and analytical results on PM samples, and should be avoided. PMID:27258903

  14. Evaluating the mutagenicity of the water-soluble fraction of air particulate matter: A comparison of two extraction strategies.

    PubMed

    Palacio, Isabel C; Oliveira, Ivo F; Franklin, Robson L; Barros, Silvia B M; Roubicek, Deborah A

    2016-09-01

    Many studies have focused on assessing the genotoxic potential of the organic fraction of airborne particulate matter. However, the determination of water-soluble compounds, and the evaluation of the toxic effects of these elements can also provide valuable information for the development of novel strategies to control atmospheric air pollution. To determine an appropriate extraction method for assessing the mutagenicity of the water-soluble fraction of PM, we performed microwave assisted (MW) and ultrasonic bath (US) extractions, using water as solvent, in eight different air samples (TSP and PM10). Mutagenicity and extraction performances were evaluated using the Salmonella/microsome assay with strains TA98 and TA100, followed by chemical determination of water-soluble metals. Additionally, we evaluated the chemical and biological stability of the extracts testing their mutagenic potential and chemically determining elements present in the samples along several periods after extraction. Reference material SRM 1648a was used. The comparison of MW and US extractions did not show differences on the metals concentrations, however positive mutagenic responses were detected with TA98 strain in all samples extracted using the MW method, but not with the US bath extraction. The recovery, using reference material was better in samples extracted with MW. We concluded that the MW extraction is more efficient to assess the mutagenic activity of the soluble fraction of airborne PM. We also observed that the extract freezing and storage over 60 days has a significant effect on the mutagenic and analytical results on PM samples, and should be avoided.

  15. Global Intraurban Intake Fractions for Primary Air Pollutants from Vehicles and Other Distributed Sources

    PubMed Central

    2012-01-01

    We model intraurban intake fraction (iF) values for distributed ground-level emissions in all 3646 global cities with more than 100 000 inhabitants, encompassing a total population of 2.0 billion. For conserved primary pollutants, population-weighted median, mean, and interquartile range iF values are 26, 39, and 14–52 ppm, respectively, where 1 ppm signifies 1 g inhaled/t emitted. The global mean urban iF reported here is roughly twice as large as previous estimates for cities in the United States and Europe. Intake fractions vary among cities owing to differences in population size, population density, and meteorology. Sorting by size, population-weighted mean iF values are 65, 35, and 15 ppm, respectively, for cities with populations larger than 3, 0.6–3, and 0.1–0.6 million. The 20 worldwide megacities (each >10 million people) have a population-weighted mean iF of 83 ppm. Mean intraurban iF values are greatest in Asia and lowest in land-rich high-income regions. Country-average iF values vary by a factor of 3 among the 10 nations with the largest urban populations. PMID:22332712

  16. Modelling the radiobiological effect of intraoperative X-ray brachytherapy for breast cancer using an air-filled spherical applicator

    PubMed Central

    Evans, Simon; Morgan, David

    2016-01-01

    Purpose We present a framework, in which we compare a conventional standard dose of 50 Gy in 25 fractions with accelerated partial breast irradiation (APBI) using electronic brachytherapy (eBT). We discuss how radiobiological modelling enables us to establish a framework, within which we can compare external beam radiotherapy (EBRT). This leads to a determination of the shell of isoeffect in breast tissue, at which very low kV eBT can be considered to be clinically equivalent to standard EBRT. Material and methods To estimate relative biological effectiveness (RBE) values as a function of dose and irradiation time, we used a modified linear quadratic (LQ) approach, taking into account the ability of this new device, to deliver 20 Gy at the surface of a 40 mm diameter rigid, hollow spherical applicator in less than 2 minutes. In this study, we considered the radiobiological effectiveness of the Papillon +™ X-ray brachytherapy device operating at 30 kV, 0.3 mA producing dose rates in excess of 14 Gy/min. Results Calculated clinical RBEs ranged from 1.154 at the surface of a 40 mm diameter applicator to 1.100 at 35 mm from the applicator surface for the Papillon+ device. The absolute physical dose D (abs) 30 kV ranged from 20.00 Gy at the applicator surface to 1.20 at 35 mm distant. The product of the isoeffective single dose of 60Co reference radiation – (RBE)60Co, and the RBE corrected standard 2 Gy equivalent dose fractions (EQD2) doses, EQD2(30 kV) * (RBE)60Co ranged from 98.62 Gy at the applicator surface to 1.13 at 35 mm. The ‘shell of isoeffect’, the value on the X-axis where the EQD2(30 kV) * (RBE)60Co line crosses the 50 Gy mark on the Y-axis, was found to be approximately 3.5 mm beyond the applicator surface. Conclusions The ‘shell of isoeffect’ can serve as a useful metric with which to compare the radiobiological effectiveness of low kV eBT with various regimes of conventional EBRT. PMID:27648085

  17. Modelling the radiobiological effect of intraoperative X-ray brachytherapy for breast cancer using an air-filled spherical applicator

    PubMed Central

    Evans, Simon; Morgan, David

    2016-01-01

    Purpose We present a framework, in which we compare a conventional standard dose of 50 Gy in 25 fractions with accelerated partial breast irradiation (APBI) using electronic brachytherapy (eBT). We discuss how radiobiological modelling enables us to establish a framework, within which we can compare external beam radiotherapy (EBRT). This leads to a determination of the shell of isoeffect in breast tissue, at which very low kV eBT can be considered to be clinically equivalent to standard EBRT. Material and methods To estimate relative biological effectiveness (RBE) values as a function of dose and irradiation time, we used a modified linear quadratic (LQ) approach, taking into account the ability of this new device, to deliver 20 Gy at the surface of a 40 mm diameter rigid, hollow spherical applicator in less than 2 minutes. In this study, we considered the radiobiological effectiveness of the Papillon +™ X-ray brachytherapy device operating at 30 kV, 0.3 mA producing dose rates in excess of 14 Gy/min. Results Calculated clinical RBEs ranged from 1.154 at the surface of a 40 mm diameter applicator to 1.100 at 35 mm from the applicator surface for the Papillon+ device. The absolute physical dose D (abs) 30 kV ranged from 20.00 Gy at the applicator surface to 1.20 at 35 mm distant. The product of the isoeffective single dose of 60Co reference radiation – (RBE)60Co, and the RBE corrected standard 2 Gy equivalent dose fractions (EQD2) doses, EQD2(30 kV) * (RBE)60Co ranged from 98.62 Gy at the applicator surface to 1.13 at 35 mm. The ‘shell of isoeffect’, the value on the X-axis where the EQD2(30 kV) * (RBE)60Co line crosses the 50 Gy mark on the Y-axis, was found to be approximately 3.5 mm beyond the applicator surface. Conclusions The ‘shell of isoeffect’ can serve as a useful metric with which to compare the radiobiological effectiveness of low kV eBT with various regimes of conventional EBRT.

  18. Associations between size-fractionated particulate air pollution and blood pressure in a panel of type II diabetes mellitus patients.

    PubMed

    Zhao, Ang; Chen, Renjie; Wang, Cuicui; Zhao, Zhuohui; Yang, Changyuan; Lu, Jianxiong; Chen, Xuan; Kan, Haidong

    2015-07-01

    Little is known regarding how the size distribution of particulate matter (PM) air pollution influences its effect on blood pressure (BP), especially among patients with diabetes. The objective of this study was to explore the short-term associations between size-fractionated PM and BP among diabetes patients. We scheduled 6 repeated BP examinations every 2 weeks from 13 April 2013 to 30 June 2013 in a panel of 35 type 2 diabetes mellitus patients recruited from an urban community in Shanghai, China. We measured real-time PM concentrations in the size range of 0.25 to 10 μm. We used linear mixed-effect models to examine the short-term association of size-fractionated PM and BP after controlling for individual characteristics, mean temperature, relative humidity, day of the week, years with diabetes and use of antihypertensive medication. The association with systolic BP and pulse pressure strengthened with decreasing diameter. The size fractions with the strongest associations were 0.25 to 0.40 μm for number concentrations and ≤ 2.5 μm for mass concentrations. Furthermore, these effects occurred immediately even after 0-2h and lasted for up to 48 h following exposure. An interquartile range increase in 24-h average number concentrations of PM0.25-0.40 was associated with increases of 3.61 mmHg in systolic BP and 2.96 mmHg in pulse pressure. Females, patients younger than 65 years of age and patients without antihypertensive treatment were more susceptible to these effects. Our results revealed important size and temporal patterns of PM in elevating BP among diabetes patients in China.

  19. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  20. Rechargeability of Li-air cathodes pre-filled with discharge products using an ether-based electrolyte solution: implications for cycle-life of Li-air cells.

    PubMed

    Meini, Stefano; Tsiouvaras, Nikolaos; Schwenke, K Uta; Piana, Michele; Beyer, Hans; Lange, Lukas; Gasteiger, Hubert A

    2013-07-21

    The instability of currently used electrolyte solutions and of the carbon support during charge-discharge in non-aqueous lithium-oxygen cells can lead to discharge products other than the desired Li2O2, such as Li2CO3, which is believed to reduce cycle-life. Similarly, discharge in an O2 atmosphere which contains H2O and CO2 impurities would lead to LiOH and Li2CO3 discharge products. In this work we therefore investigate the rechargeability of model cathodes pre-filled with four possible Li-air cell discharge products, namely Li2O2, Li2CO3, LiOH, and Li2O. Using Online Electrochemical Mass Spectrometry (OEMS), we determined the charge voltages and the gases evolved upon charge of pre-filled electrodes, thus determining the reversibility of the formation/electrooxidation reactions. We show that Li2O2 is the only reversible discharge product in ether-based electrolyte solutions, and that the formation of Li2CO3, LiOH, or Li2O is either irreversible and/or reacts with the electrolyte solution or the carbon during its oxidation.

  1. Rechargeability of Li-air cathodes pre-filled with discharge products using an ether-based electrolyte solution: implications for cycle-life of Li-air cells.

    PubMed

    Meini, Stefano; Tsiouvaras, Nikolaos; Schwenke, K Uta; Piana, Michele; Beyer, Hans; Lange, Lukas; Gasteiger, Hubert A

    2013-07-21

    The instability of currently used electrolyte solutions and of the carbon support during charge-discharge in non-aqueous lithium-oxygen cells can lead to discharge products other than the desired Li2O2, such as Li2CO3, which is believed to reduce cycle-life. Similarly, discharge in an O2 atmosphere which contains H2O and CO2 impurities would lead to LiOH and Li2CO3 discharge products. In this work we therefore investigate the rechargeability of model cathodes pre-filled with four possible Li-air cell discharge products, namely Li2O2, Li2CO3, LiOH, and Li2O. Using Online Electrochemical Mass Spectrometry (OEMS), we determined the charge voltages and the gases evolved upon charge of pre-filled electrodes, thus determining the reversibility of the formation/electrooxidation reactions. We show that Li2O2 is the only reversible discharge product in ether-based electrolyte solutions, and that the formation of Li2CO3, LiOH, or Li2O is either irreversible and/or reacts with the electrolyte solution or the carbon during its oxidation. PMID:23748698

  2. The Relationship Between Soil Air Filled Porosity and Soil Methane Oxidation is Almost Identical in Both Dry and Wet Temperate Eucalypt Forests

    NASA Astrophysics Data System (ADS)

    Fest, B. J.; Wardlaw, T.; Hinko-Najera, N.; Arndt, S. K.

    2015-12-01

    In order to gain a better understanding of the temporal variation in soil methane (CH4) exchange in temperate evergreen eucalypt forests in south-eastern Australia we measured soil CH4 exchange in high temporal resolution (every 2 hours or less) over two consecutive years (Wombat State Forest, Victoria, AUS) and over one year (Warra, Tasmania, AUS) in two temperate Eucalyptus obliqua (L. Her) forests with contrasting annual precipitation (Wombat State Forest = 870 mm yr-1, Warra = 1700 mm yr-1). Both forests were continuous CH4 sinks with the Victorian site having a sink strength of -1.79 kg CH4 ha-1 yr-1 and the Tasmanian site having a sink strength of -3.83 kg CH4 ha-1 yr-1. Our results show that CH4 uptake was strongly controlled by soil moisture at both sites and explained up to 90% of the temporal variability in CH4 uptake. Furthermore, when soil moisture was expressed as soil air filled porosity (AFP) we were able to predict the CH4 uptake of one site by the linear regression between AFP and CH4 uptake from the other site. Soil temperature only had an apparent control over seasonal variation in CH4 uptake during periods when soil moisture and soil temperature were closely correlated. The fluctuation of the generally low soil nitrogen levels did not influence soil CH4 uptake at either site.

  3. Rapid assessment of methanotrophic capacity of compost-based materials considering the effects of air-filled porosity, water content and dissolved organic carbon.

    PubMed

    Mancebo, Uriel; Hettiaratchi, J Patrick A

    2015-02-01

    Since the global warming potential of CH4 is 25 times that of CO2 on a 100-year time horizon, the development of methanotrophic applications for the conversion of CH4 to CO2 is emerging as an area of interest for researchers and practicing engineers. Compost exhibits most of the characteristics required for methanotroph growth media and has been used in several projects. This paper presents results from a study that was undertaken to assess the influence of physical and chemical characteristics of compost-based materials on the biological oxidation of CH4 when used in methane biofilters. The results showed that easily-measurable parameters, such as air filled porosity, water content and dissolved organic carbon, are correlated with maximum CH4 removal rates. The results obtained were used to develop an empirical relationship that could be regarded as a rapid assessment tool for the estimation of the performance of compost-based materials in engineered methanotrophic applications. PMID:25484123

  4. Nutrient digestibility of solvent-extracted Brassica napus and Brassica juncea canola meals and their air-classified fractions fed to ileal-cannulated grower pigs.

    PubMed

    Zhou, X; Zijlstra, R T; Beltranena, E

    2015-01-01

    Energy and nutrient digestibility of solvent-extracted canola meal (CM) is limited in pigs by its relatively high fiber content. The seed hull, which greatly contributes to the fiber content of CM, is denser than the oil-free cotyledon. By utilizing streams of air, air classification partially separates these seed components on the basis of their different sizes and densities to produce a low-fiber, light-particle fraction and a high-fiber, heavy-particle fraction. Compared with parent CM, ADF and NDF were reduced by 31.9% and 29.5% in the light-particle fraction and were enriched by 16.5% and 9.0% in the heavy-particle fraction (DM basis), respectively. Particle size was 638, 18.9, and 76.1 µm for the parent CM and light- and heavy-particle fractions, respectively. To determine the nutrient digestibility of CM and their air-classified fractions, Brassica napus and B. juncea CM and their 2 air-classified fractions were evaluated in a 2 × 3 factorial arrangement together with a basal diet and an N-free diet. The experiment was conducted as an 8 × 8 Latin square in which diets contained 40% B. napus or B. juncea CM or their air-classified fractions and 60% basal diet. Digesta data from pigs fed the N-free diet served to subtract basal endogenous AA losses. Eight ileal-cannulated barrows (32 kg initial BW) were fed the 8 diets at 2.7 times maintenance DE for eight 11-d periods. At the end of each period, feces were collected for 48 h, and ileal digesta were collected for two 12-h periods. The DE and calculated NE values and the apparent total tract digestibility (ATTD) of GE were 6.3%, 10.0%, and 7.8% greater (P < 0.001) for B. juncea CM than for B. napus CM; 6.1%, 10.8%, and 5.3% greater (P < 0.001) for the light-particle fraction than for parent CM; and 5.4%, 7.2%, and 3.8% lower (P < 0.001) for the heavy-particle fraction than for parent CM, respectively. The standardized ileal digestibilities (SID) of His, Ile, Val, Asp, and Tyr were greater (P < 0.05) for B

  5. Nutrient digestibility of solvent-extracted Brassica napus and Brassica juncea canola meals and their air-classified fractions fed to ileal-cannulated grower pigs.

    PubMed

    Zhou, X; Zijlstra, R T; Beltranena, E

    2015-01-01

    Energy and nutrient digestibility of solvent-extracted canola meal (CM) is limited in pigs by its relatively high fiber content. The seed hull, which greatly contributes to the fiber content of CM, is denser than the oil-free cotyledon. By utilizing streams of air, air classification partially separates these seed components on the basis of their different sizes and densities to produce a low-fiber, light-particle fraction and a high-fiber, heavy-particle fraction. Compared with parent CM, ADF and NDF were reduced by 31.9% and 29.5% in the light-particle fraction and were enriched by 16.5% and 9.0% in the heavy-particle fraction (DM basis), respectively. Particle size was 638, 18.9, and 76.1 µm for the parent CM and light- and heavy-particle fractions, respectively. To determine the nutrient digestibility of CM and their air-classified fractions, Brassica napus and B. juncea CM and their 2 air-classified fractions were evaluated in a 2 × 3 factorial arrangement together with a basal diet and an N-free diet. The experiment was conducted as an 8 × 8 Latin square in which diets contained 40% B. napus or B. juncea CM or their air-classified fractions and 60% basal diet. Digesta data from pigs fed the N-free diet served to subtract basal endogenous AA losses. Eight ileal-cannulated barrows (32 kg initial BW) were fed the 8 diets at 2.7 times maintenance DE for eight 11-d periods. At the end of each period, feces were collected for 48 h, and ileal digesta were collected for two 12-h periods. The DE and calculated NE values and the apparent total tract digestibility (ATTD) of GE were 6.3%, 10.0%, and 7.8% greater (P < 0.001) for B. juncea CM than for B. napus CM; 6.1%, 10.8%, and 5.3% greater (P < 0.001) for the light-particle fraction than for parent CM; and 5.4%, 7.2%, and 3.8% lower (P < 0.001) for the heavy-particle fraction than for parent CM, respectively. The standardized ileal digestibilities (SID) of His, Ile, Val, Asp, and Tyr were greater (P < 0.05) for B

  6. Air quality in the German-Czech border region: A focus on harmful fractions of PM and ultrafine particles

    NASA Astrophysics Data System (ADS)

    Schladitz, Alexander; Leníček, Jan; Beneš, Ivan; Kováč, Martin; Skorkovský, Jiří; Soukup, Aleš; Jandlová, Jana; Poulain, Laurent; Plachá, Helena; Löschau, Gunter; Wiedensohler, Alfred

    2015-12-01

    A comprehensive air quality study has been carried out at two urban background sites in Annaberg-Buchholz (Germany) and Ústí nad Labem (Czech Republic) in the German-Czech border region between January 2012 and June 2014. Special attention was paid to quantify harmful fractions of particulate matter (PM) and ultrafine particle number concentration (UFP) from solid fuel combustion and vehicular traffic. Source type contributions of UFP were quantified by using the daily concentration courses of UFP and nitrogen oxide. Two different source apportionment techniques were used to quantify relative and absolute mass contributions: positive matrix factorization for total PM2.5 and elemental carbon in PM2.5 and chemical mass balance for total PM1 and organic carbon in PM1. Contributions from solid fuel combustion strongly differed between the non-heating period (April-September) and the heating period (October-March). Major sources of solid fuel combustion in this study were wood and domestic coal combustion, while the proportion of industrial coal combustion was low (<3%). In Ústí nad Labem combustion of domestic brown coal was the most important source of organic carbon ranging from 34% to 43%. Wood combustion was an important source of organic carbon in Annaberg-Buchholz throughout the year. Heavy metals and less volatile polycyclic aromatic hydrocarbons (PAH) in the accumulation mode were related to solid fuel combustion with enhanced concentrations during the heating period. In contrast, vehicular PAH emissions were allocated to the Aitken mode. Only in Ústí nad Labem a significant contribution of photochemical new particle formation (e.g. from sulfur dioxide) to UFP of almost 50% was observed during noontime. UFPs from traffic emissions (nucleation particles) and primary emitted soot particles dominated at both sites during the rest of the day. The methodology of a combined source apportionment of UFP and PM can be adapted to other regions of the world with

  7. Fraction and composition of NOy transported in air masses lofted from the North American continental boundary layer

    NASA Astrophysics Data System (ADS)

    Parrish, D. D.; Ryerson, T. B.; Holloway, J. S.; Neuman, J. A.; Roberts, J. M.; Williams, J.; Stroud, C. A.; Frost, G. J.; Trainer, M.; Hübler, G.; Fehsenfeld, F. C.; Flocke, F.; Weinheimer, A. J.

    2004-05-01

    Five field studies have included research aircraft flights over the continental United States and the western North Atlantic Ocean from 1996 through 2000 in spring, summer, and fall seasons. The major source of NOx in this region is fossil fuel combustion, which is localized within the continental boundary layer (CBL). We use CO as a tracer of these anthropogenic emissions to estimate the fraction of the emitted NOx that is exported to the free troposphere (FT), either as NOx itself or as its oxidation products. This export was identified as plumes enhanced in CO above an estimated background by at least 30 ppbv, which account for 20-31% of the air parcels sampled in the FT during the five field studies. These plumes were encountered throughout the FT up to the 8 km ceiling of the aircraft but were primarily located just above the CBL with average altitudes of 3.0-4.1 km above ground level. In the summer over the continent, only 20 ± 5% of the originally emitted nitrogen oxides was transported in those plumes. This fraction is in reasonable accord with model results, but the models include only deep convection and not the shallow CBL venting mechanisms responsible for the observed plumes. During the two field studies in the early fall and in the spring over the western North Atlantic, we find that 9 ± 4% of the NOy was transported, although [2004] suggest that this is an underestimate and that 15 ± 11% is more accurate. Both of these numbers indicate that model results in the literature overestimate the amount of NOy transported from the CBL to the FT. In these five field studies, HNO3 generally accounted for one-half to two-thirds of the NOy, which is in contrast to the dominance by NOx and organic nitrates suggested by models. Over the North Atlantic, this difference is likely due to further photochemical processing of the NOy species within the FT and over the continent due to the different transport mechanism considered in the models.

  8. Benzo[a]pyrene-specific online high-performance liquid chromatography fractionation of air particulate extracts - a tool for evaluating biological interactions.

    PubMed

    Lim, Hwanmi; Bergvall, Christoffer; Jarvis, Ian; Mattsson, Åse; Dreij, Kristian; Stenius, Ulla; Westerholm, Roger

    2014-08-15

    Benzo[a]pyrene (B[a]P) is a known human carcinogen and is commonly used as a surrogate for assessing the carcinogenic risk posed by complex mixtures of polycyclic aromatic hydrocarbons (PAHs) present in air particulate matter (PM). However, studies have shown that using B[a]P as a surrogate may underestimate the carcinogenic potential of PAH mixtures, as the risk assessment approach does not consider interaction effects. Thus, toxicological studies using B[a]P to assess its carcinogenic potential in environmentally derived complex mixtures, as opposed to single compound experiments, could improve risk assessment. The intention of the present study was to develop an online HPLC fractionation system for the selective removal of B[a]P from air PM extracts. Two serial pyrenylethyl (PYE) columns enabled selective separation of B[a]P from its isomers and other PAHs as well as a short fractionation cycle of 30min. One run consisted of three collection steps: the first fraction contained PAHs eluting earlier than B[a]P, the second contained B[a]P and the last contained later-eluting PAHs. The selectivity and recovery of the system was investigated using extracts of Stockholm air PM samples. The overall recovery for all PAHs was approximately 80%, and the system proved to be selective, as it removed 94% of B[a]P and less than 3% of benzo[b]fluoranthene from the complex PAH mixture. Exposing human cells to blanks generated by the fractionation system did not induce cytotoxicity or DNA damage signalling. In conclusion, the online HPLC system was selective for B[a]P fractionation whilst minimising run-to-run variation and allowing repeated fractionations for larger samples due to its relatively short run time. PMID:24947883

  9. Filling agents.

    PubMed

    Glavas, Ioannis P

    2005-06-01

    Injectable fillers have become an important component of minimally invasive facial rejuvenation modalities. Their ease of use, effectiveness, low morbidity, and fast results with minimal downtime are factors that have made them popular among patients. Soft tissue augmentation has evolved to a unique combination of medicine and art. A wide selection of available agents and new products, each one with unique properties, may be used alone or in combination. The physician acquires the tools to rebalance facial characteristics not only by filling wrinkles but also by having the ability to shape the face and restore bony contours and lines. Careful selection of candidates, realistic expectations, and an understanding of the limitations of fillers are crucial for a successful result.

  10. Recent achievements in measurements of soot volume fraction and temperatures in a coflow, diffuse Ethylene-air flame by visible image processing

    NASA Astrophysics Data System (ADS)

    Zhou, Huai-Chun; Lou, Chun; Lu, Jing

    2009-02-01

    In this review paper, the recent achievements in measurements of soot volume fraction and temperatures in a coflow, diffuse Ethylene-air flame by visible image processing are briefly outlined. For the inverse analysis of the radiative properties and temperatures, different methods show different features. The least-squares method, a regularization method and a linear programming method are all suitable for this problem, and a linear programming method can give more reasonable results. The red, green and blue flame images, which can be captured by some colour CCD camera, can be taken approximately as monochromatic images, and can be used to reconstruct temperature and soot volume fraction. But more ideal is the true monochromatic images filtered by filters at certain wavelengths. Finally, the optically-thin assumption, which is adopted widely, will cause large errors, about 100 K for temperature and 50% for soot volume fraction, as the absorption of the flame medium is neglected.

  11. Storage stability of keratinocyte growth factor-2 in lyophilized formulations: effects of formulation physical properties and protein fraction at the solid-air interface.

    PubMed

    Devineni, Dilip; Gonschorek, Christoph; Cicerone, Marcus T; Xu, Yemin; Carpenter, John F; Randolph, Theodore W

    2014-10-01

    Lyophilized formulations of keratinocyte growth factor-2 (KGF-2) were prepared with a range of disaccharide (sucrose or trehalose) and hydroxyethyl starch (HES) mass ratios. Protein degradation was assessed as a function of time of storage of the dried formulations at 40, 50 and 60°C. Lyophilized and stored samples were rehydrated, and protein degradation was quantified by measuring loss of monomeric protein with size exclusion chromatography and by determining chemical degradation in the soluble fraction with reverse-phase chromatography. The secondary structure of the protein in the lyophilized formulations was studied with infrared spectroscopy. The magnitudes of degradation were compared the key physical properties of the formulations including retention of protein native secondary structure, glass transition temperature (Tg), inverse mean square displacements 〈u(2)〉(-1) for hydrogen atoms (fast β relaxation), and the relaxation time τ(β), which correlates with relaxation due to fast Johari-Goldstein motions in the glass (Xu et al., 2013) [1]. In addition, specific surface areas of the lyophilized formulations were determined by Brunauer-Emmet-Teller analysis of krypton adsorption isotherms and used to estimate the fraction of the KGF-2 molecules residing at the solid-air interface. KGF-2 degradation rates were highest in formulations wherein the protein's structure was most perturbed, and wherein β relaxations were fastest, but the dominant factor governing KGF-2 degradation in freeze-dried formulations was the fraction of the protein found at the glass solid-air interface. PMID:24859390

  12. Effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco

    PubMed Central

    2013-01-01

    This study aimed to evaluate the effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco in terms of internal temperature, produced gases quantity, organic matter conversion rate, and the quality of the final composts. For this purpose, in-vessel bioreactor was designed and used to evaluate both appropriate initial air pressure and appropriate initial moisture content for the composting process. Moreover, 5 experiments were carried out within initial moisture content of 55%, 65%, 70%, 75% and 85%. The initial air pressure and the initial moisture content of the mixture showed a significant effect on the aerobic composting. The experimental results demonstrated that for composting organic waste, relatively high moisture contents are better at achieving higher temperatures and retaining them for longer times. This study suggested that an initial moisture content of around 75%, under 0.6 bar, can be considered as being suitable for efficient composting of organic fraction of municipal solid waste. These last conditions, allowed maximum value of temperature and final composting product with good physicochemical properties as well as higher organic matter degradation and higher gas production. Moreover, final compost obtained showed good maturity levels and can be used for agricultural applications. PMID:23369502

  13. Effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco.

    PubMed

    Makan, Abdelhadi; Assobhei, Omar; Mountadar, Mohammed

    2013-01-03

    This study aimed to evaluate the effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco in terms of internal temperature, produced gases quantity, organic matter conversion rate, and the quality of the final composts.For this purpose, in-vessel bioreactor was designed and used to evaluate both appropriate initial air pressure and appropriate initial moisture content for the composting process. Moreover, 5 experiments were carried out within initial moisture content of 55%, 65%, 70%, 75% and 85%. The initial air pressure and the initial moisture content of the mixture showed a significant effect on the aerobic composting. The experimental results demonstrated that for composting organic waste, relatively high moisture contents are better at achieving higher temperatures and retaining them for longer times.This study suggested that an initial moisture content of around 75%, under 0.6 bar, can be considered as being suitable for efficient composting of organic fraction of municipal solid waste. These last conditions, allowed maximum value of temperature and final composting product with good physicochemical properties as well as higher organic matter degradation and higher gas production. Moreover, final compost obtained showed good maturity levels and can be used for agricultural applications.

  14. ORGANOCHLORINE PESTICIDE CONCENTRATIONS AND ENANTIOMER FRACTIONS FOR CHLORDANE IN INDOOR AIR FROM THE U.S. CORNBELT

    EPA Science Inventory

    Thirty-seven indoor air samples were collected and analyzed to determine if enantioselective degradation of past use organochlorine pesticides occurs indoors and to increase the available information on concentrations in homes. Samples were collected from homes in the U.S. cor...

  15. Polycyclic organic material (POM) in urban air. Fractionation, chemical analysis and genotoxicity of particulate and vapour phases in an industrial town in Finland

    NASA Astrophysics Data System (ADS)

    Pyysalo, Heikki; Tuominen, Jari; Wickström, Kim; Skyttä, Eija; Tikkanen, Leena; Salomaa, Sisko; Sorsa, Marja; Nurmela, Tuomo; Mattila, Tiina; Pohjola, Veijo

    Polycyclic organic material (POM) was collected by high-volume sampling on filter and on XAD-2 resin from the air of a small industrial town in Finland. Concurrent chemical analysis and the assays for genotoxic activity were performed on the particulate and the vapour phases of ambient air POM and their chemical fractions. Furthermore, correlations between seasonal meteorological parameters and POM concentrations were studied to reveal characteristic POM profiles for various emission sources. The range of total POM concentrations varied from 115 to 380 ng m -3 in late spring and from 17 to 83 ng m -3 in early winter. No direct correlation of ambient POM was seen with the temperature, but rather with the wind direction from various emission sources. Especially the low molecular weight compounds were associated with wind direction from industrial sources. Genotoxic activity, as detected by the Ames Salmonella/microsome test and the SCE assay in CHO cells, was found not only in the paniculate phase samples but also in the vapour phase. The polar fractions of some of the samples showed genotoxic activity, and also direct mutagenicity was observed with both the assay systems; these facts support the significance of compounds other than conventional polycyclic aromatic hydrocarbons (PAH) in the samples.

  16. COMPARISON OF 24H AVERAGE VOC MONITORING RESULTS FOR RESIDENTIAL INDOOR AND OUTDOOR AIR USING CARBOPACK X-FILLED DIFFUSIVE SAMPLERS AND ACTIVE SAMPLING - A PILOT STUDY

    EPA Science Inventory

    Analytical results obtained by thermal desorption GC/MS for 24h diffusive sampling of 11 volatile organic compounds (VOCs) are compared with results of time-averaged active sampling at a known constant flow rate. Air samples were collected with co-located duplicate diffusive samp...

  17. Brief exposure of air-filled guinea-pig isolated trachea to low levels of toluene diisocyanate (TDI) vapor in vitro increases reactivity to methacholine.

    PubMed

    Huang, J; Frazer, D G; Millecchia, L L; Fedan, J S

    1997-12-26

    Toluene diisocyanate (TDI) causes occupational asthma characterized by inflammation and hyperreactivity of airways to irritants and bronchoconstrictor drugs. We examined the non-immune, direct effect of TDI on airway reactivity in vitro in the absence of an inflammatory response using the guinea-pig isolated, perfused trachea preparation to measure reactivity to methacholine (MCh), and fixed point ion mobility spectrometry to measure moment to moment levels of TDI vapor in air that was delivered to the tracheal mucosa. MCh was added to the mucosal modified Krebs-Henseleit (MKH) perfusing solution to generate control concentration-response curves for contractile responses. The lumen was then emptied and perfused with air or air containing 5, 20 or 70 ppb TDI vapor, after which the trachea was perfused with MKH solution and reactivity to MCh was re-examined. After only 30 min of treatment, TDI vapor concentration-dependently increased reactivity of the trachea to MCh (2.4- and 2.9-fold, respectively, for 20 and 70 ppb TDI; 5 ppb TDI and air alone had no effect). In tracheas treated in vitro with 2 microM capsaicin to deplete tachykinins, TDI caused the same (4-fold) increase in reactivity to MCh that was observed in control tracheas. However, TDI vapor (70 ppb) no longer enhanced reactivity to MCh in tracheas from which the epithelium had been removed. Our results indicate that a direct, non-immune, non-inflammatory action of TDI on respiratory epithelium leads to hyperreactivity of airways in vitro. PMID:9457998

  18. Fractionally charged skyrmions in fractional quantum Hall effect

    NASA Astrophysics Data System (ADS)

    Balram, Ajit C.; Wurstbauer, U.; Wójs, A.; Pinczuk, A.; Jain, J. K.

    2015-11-01

    The fractional quantum Hall effect has inspired searches for exotic emergent topological particles, such as fractionally charged excitations, composite fermions, abelian and nonabelian anyons and Majorana fermions. Fractionally charged skyrmions, which support both topological charge and topological vortex-like spin structure, have also been predicted to occur in the vicinity of 1/3 filling of the lowest Landau level. The fractional skyrmions, however, are anticipated to be exceedingly fragile, suppressed by very small Zeeman energies. Here we show that, slightly away from 1/3 filling, the smallest manifestations of the fractional skyrmion exist in the excitation spectrum for a broad range of Zeeman energies, and appear in resonant inelastic light scattering experiments as well-defined resonances slightly below the long wavelength spin wave mode. The spectroscopy of these exotic bound states serves as a sensitive tool for investigating the residual interaction between composite fermions, responsible for delicate new fractional quantum Hall states in this filling factor region.

  19. Fractionally charged skyrmions in fractional quantum Hall effect.

    PubMed

    Balram, Ajit C; Wurstbauer, U; Wójs, A; Pinczuk, A; Jain, J K

    2015-01-01

    The fractional quantum Hall effect has inspired searches for exotic emergent topological particles, such as fractionally charged excitations, composite fermions, abelian and nonabelian anyons and Majorana fermions. Fractionally charged skyrmions, which support both topological charge and topological vortex-like spin structure, have also been predicted to occur in the vicinity of 1/3 filling of the lowest Landau level. The fractional skyrmions, however, are anticipated to be exceedingly fragile, suppressed by very small Zeeman energies. Here we show that, slightly away from 1/3 filling, the smallest manifestations of the fractional skyrmion exist in the excitation spectrum for a broad range of Zeeman energies, and appear in resonant inelastic light scattering experiments as well-defined resonances slightly below the long wavelength spin wave mode. The spectroscopy of these exotic bound states serves as a sensitive tool for investigating the residual interaction between composite fermions, responsible for delicate new fractional quantum Hall states in this filling factor region. PMID:26608906

  20. Fractionally charged skyrmions in fractional quantum Hall effect

    PubMed Central

    Balram, Ajit C.; Wurstbauer, U.; Wójs, A.; Pinczuk, A.; Jain, J. K.

    2015-01-01

    The fractional quantum Hall effect has inspired searches for exotic emergent topological particles, such as fractionally charged excitations, composite fermions, abelian and nonabelian anyons and Majorana fermions. Fractionally charged skyrmions, which support both topological charge and topological vortex-like spin structure, have also been predicted to occur in the vicinity of 1/3 filling of the lowest Landau level. The fractional skyrmions, however, are anticipated to be exceedingly fragile, suppressed by very small Zeeman energies. Here we show that, slightly away from 1/3 filling, the smallest manifestations of the fractional skyrmion exist in the excitation spectrum for a broad range of Zeeman energies, and appear in resonant inelastic light scattering experiments as well-defined resonances slightly below the long wavelength spin wave mode. The spectroscopy of these exotic bound states serves as a sensitive tool for investigating the residual interaction between composite fermions, responsible for delicate new fractional quantum Hall states in this filling factor region. PMID:26608906

  1. Fractionally charged skyrmions in fractional quantum Hall effect.

    PubMed

    Balram, Ajit C; Wurstbauer, U; Wójs, A; Pinczuk, A; Jain, J K

    2015-11-26

    The fractional quantum Hall effect has inspired searches for exotic emergent topological particles, such as fractionally charged excitations, composite fermions, abelian and nonabelian anyons and Majorana fermions. Fractionally charged skyrmions, which support both topological charge and topological vortex-like spin structure, have also been predicted to occur in the vicinity of 1/3 filling of the lowest Landau level. The fractional skyrmions, however, are anticipated to be exceedingly fragile, suppressed by very small Zeeman energies. Here we show that, slightly away from 1/3 filling, the smallest manifestations of the fractional skyrmion exist in the excitation spectrum for a broad range of Zeeman energies, and appear in resonant inelastic light scattering experiments as well-defined resonances slightly below the long wavelength spin wave mode. The spectroscopy of these exotic bound states serves as a sensitive tool for investigating the residual interaction between composite fermions, responsible for delicate new fractional quantum Hall states in this filling factor region.

  2. Fractionally charged skyrmions in fractional quantum Hall effect

    SciTech Connect

    Balram, Ajit C.; Wurstbauer, U.; Wójs, A.; Pinczuk, A.; Jain, J. K.

    2015-11-26

    The fractional quantum Hall effect has inspired searches for exotic emergent topological particles, such as fractionally charged excitations, composite fermions, abelian and nonabelian anyons and Majorana fermions. Fractionally charged skyrmions, which support both topological charge and topological vortex-like spin structure, have also been predicted to occur in the vicinity of 1/3 filling of the lowest Landau level. The fractional skyrmions, however, are anticipated to be exceedingly fragile, suppressed by very small Zeeman energies. Here we show that, slightly away from 1/3 filling, the smallest manifestations of the fractional skyrmion exist in the excitation spectrum for a broad range of Zeeman energies, and appear in resonant inelastic light scattering experiments as well-defined resonances slightly below the long wavelength spin wave mode. The spectroscopy of these exotic bound states serves as a sensitive tool for investigating the residual interaction between composite fermions, responsible for delicate new fractional quantum Hall states in this filling factor region.

  3. Comparison of 24 h averaged VOC monitoring results for residential indoor and outdoor air using Carbopack X-filled diffusive samplers and active sampling--a pilot study.

    PubMed

    McClenny, William A; Jacumin, Henry H; Oliver, Karen D; Daughtrey, E Hunter; Whitaker, Donald A

    2006-02-01

    Analytical results obtained by thermal desorption GC/MS for 24 h diffusive sampling of 11 volatile organic compounds (VOCs) are compared with results of time-averaged active sampling at a known constant flow rate. Air samples were collected with co-located duplicate diffusive sampling tubes and one passivated canister. A total of eight multiple-component sampling events took place at fixed positions inside and outside three private homes. Subsequently, a known amount of sample air was transferred from the canister to an adsorbent tube for analysis by thermal desorption GC/MS. Results for the 11 most prevalent compounds--Freon 11, 1,3-butadiene, benzene, toluene, tetrachloroethene, ethylbenzene, m,p-xylene, o-xylene, 4-ethyltoluene, 1,3,5-trimethylbenzene, and p-dichlorobenzene--show that the ratio of average study values (diffusive sampling to active sampling) is 0.92 with 0.70 and 1.14 extreme ratios. Absolute percent difference for duplicate samples using diffusive sampling was <10% for the four most prevalent compounds. Agreement between the two sampling approaches indicates that the prediction of approximately constant diffusive sampling rates based on previous laboratory studies is valid under the field conditions.

  4. Merging of OMI and AIRS Ozone Data

    NASA Technical Reports Server (NTRS)

    Labow, Gordon J.; Fisher, Bradford; Susskind, Joel

    2014-01-01

    The OMI Instrument measures ozone using the backscattered light in the UV part of the spectrum. In polar night there are no OMI measurements so we hope to incorporate the AIRS ozone data to fill in these missing regions. AIRS is on the Aqua platform and has been operating since May 2002. AIRS is a multi-detector array grating spectrometer containing 2378 IR channels between 650 per centimeter and 2760 per centimeter which measures atmospheric temperature, precipitable water, water vapor, CO, CH4, CO2 and ozone profiles and column amount. It can also measure effective cloud fraction and cloud top pressure for up to two cloud layers and sea-land skin temperature. Since 2008, OMI has had part of its aperture occulted with a piece of the thermal blanket resulting in several scan positions being unusable. We hope to use the AIRS data to fill in the missing ozone values for those missing scan positions.

  5. A hypothetical model of organic matter sea-to-air exchange processes based on stable carbon fractionation in the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Ceburnis, D.; Masalaite, A.; Garbaras, A.; Ovadnevaite, J.; Maenhaut, W.; Claeys, M.; Sciare, J.; O'Dowd, C. D. D.; Remeikis, V.

    2015-12-01

    Marine aerosol contributes significantly to the global aerosol loading and consequently has a significant impact on both the Earth's albedo and climate. Biological productivity in the global ocean is often resulting in significant amounts of primary organic matter in the aerosol phase. The North Atlantic Ocean is among the most productive oceanic regions and is the most studied ocean on Earth. The Southern Ocean, on the other hand, has been far less studied, even though similar organic matter enrichment patterns have been observed in marine aerosol. While numerous processes can contribute to organic matter in marine aerosols, carbon isotope analysis offers the most unambiguous estimates of the contributing sources. The stable carbon isotope ratios in marine aerosol samples collected during austral summer of 2007 at Amsterdam Island (Southern Indian Ocean) were examined. The measured δ13C values in the fine (Da <2.5µm) and coarse (Da >2.5µm) particle fractions were found to be evenly distributed between -28.2‰ and -20.0‰. These values are far lower than the previously reported ones as typical of unperturbed marine aerosol (-20‰). The δ13C values in the fine and coarse particle fractions were correlated with organic matter enrichment in sea spray. It was attempted to explain the variation of the δ13C values by the competition of the "fresh" and "old" organic matter pools in sea water during transfer into the aerosol phase, thereby implicating trophic level interactions. The hypothetical model suggests that fresh organic matter readily results in organic matter enrichment in sea spray particles and likely contains fresh colloidal and nanogel particulate matter, while the old organic matter is largely dissolved and unable to significantly enrich sea spray. Air mass back trajectory analysis suggests that the most productive regions, where sea spray particles are the most enriched in organic matter, are associated with low sea-water temperatures around the

  6. Pressurized gas filled tendons

    SciTech Connect

    Silcox, W. H.

    1985-06-04

    Pressurized gas filled tubular tendons provide a means for detecting leaks therein. Filling the tendon with a gaseous fluid provides increased buoyancy and reduces the weight supported by the buoyant structure. The use of a corrosion inhibiting gaseous fluid reduces the corrosion of the interior tendon wall.

  7. Getting a prescription filled

    MedlinePlus

    ... to get prescription filled; Pharmacy - mail order; Pharmacy - internet; Types of pharmacies ... stored at certain temperatures at a local pharmacy. INTERNET (ONLINE) PHARMACIES Internet pharmacies can be used for ...

  8. Pyrotechnic filled molding powder

    DOEpatents

    Hartzel, Lawrence W.; Kettling, George E.

    1978-01-01

    The disclosure relates to thermosetting molding compounds and more particularly to a pyrotechnic filled thermosetting compound comprising a blend of unfilled diallyl phthalate molding powder and a pyrotechnic mixture.

  9. Influence of entrapped air pockets on hydraulic transients in water pipelines

    SciTech Connect

    Zhou, Ling; Liu, Prof. Deyou; Karney, Professor Byran W.; Zhang, Qin Fen

    2011-01-01

    The pressure variations associated with a filling undulating pipeline containing an entrapped air pocket are investigated both experimentally and numerically. The influence of entrapped air on abnormal transient pressures is often ambiguous since the compressibility of the air pocket permits the liquid flow to accelerate but also partly cushions the system, with the balance of these tendencies being associated with the initial void fraction of the air pocket. Earlier experimental research involved systems with an initial void fraction greater than 5.8%; this paper focuses on initial void fractions ranging from 0% to 10%, in order to more completely characterize the transient response. Experimental results show that the maximum pressure increases and then decreases as the initial void fraction decreases. A simplified model is developed by neglecting the liquid inertia and energy loss of a short water column near the air-water interface. Comparisons of the calculated and observed results show the model is able to accurately predict peak pressures as a function of void fraction and filling conditions. Rigid water column models, however, perform poorly with small void fractions.

  10. Fractional randomness

    NASA Astrophysics Data System (ADS)

    Tapiero, Charles S.; Vallois, Pierre

    2016-11-01

    The premise of this paper is that a fractional probability distribution is based on fractional operators and the fractional (Hurst) index used that alters the classical setting of random variables. For example, a random variable defined by its density function might not have a fractional density function defined in its conventional sense. Practically, it implies that a distribution's granularity defined by a fractional kernel may have properties that differ due to the fractional index used and the fractional calculus applied to define it. The purpose of this paper is to consider an application of fractional calculus to define the fractional density function of a random variable. In addition, we provide and prove a number of results, defining the functional forms of these distributions as well as their existence. In particular, we define fractional probability distributions for increasing and decreasing functions that are right continuous. Examples are used to motivate the usefulness of a statistical approach to fractional calculus and its application to economic and financial problems. In conclusion, this paper is a preliminary attempt to construct statistical fractional models. Due to the breadth and the extent of such problems, this paper may be considered as an initial attempt to do so.

  11. Fractionally charged skyrmions in fractional quantum Hall effect

    DOE PAGES

    Balram, Ajit C.; Wurstbauer, U.; Wójs, A.; Pinczuk, A.; Jain, J. K.

    2015-11-26

    The fractional quantum Hall effect has inspired searches for exotic emergent topological particles, such as fractionally charged excitations, composite fermions, abelian and nonabelian anyons and Majorana fermions. Fractionally charged skyrmions, which support both topological charge and topological vortex-like spin structure, have also been predicted to occur in the vicinity of 1/3 filling of the lowest Landau level. The fractional skyrmions, however, are anticipated to be exceedingly fragile, suppressed by very small Zeeman energies. Here we show that, slightly away from 1/3 filling, the smallest manifestations of the fractional skyrmion exist in the excitation spectrum for a broad range of Zeemanmore » energies, and appear in resonant inelastic light scattering experiments as well-defined resonances slightly below the long wavelength spin wave mode. The spectroscopy of these exotic bound states serves as a sensitive tool for investigating the residual interaction between composite fermions, responsible for delicate new fractional quantum Hall states in this filling factor region.« less

  12. Building 930, oblique view to southeast from fill slope covering ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Building 930, oblique view to southeast from fill slope covering building 932, 135 mm lens. - Travis Air Force Base, Snack Bar, North of W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

  13. Loose-fill insulations

    SciTech Connect

    1995-05-01

    Whether you are increasing the insulation levels in your current home or selecting insulation for a new home, choosing the right insulation material can be challenging. Fibrous loose-fill insulations such as cellulose, fiberglass, and rock wool are options you may wish to consider. This publication will introduce you to these materials--what they are, how they are applied, how they compare with each other, and other considerations regarding their use--so that you can decide whether loose fills are right for your home.

  14. Reversibility of strontium sorption on fracture fillings

    SciTech Connect

    Cui, D.; Eriksen, T.E.

    1995-12-31

    Granite has been chosen by several countries as a major candidate for deep geologic disposal of radioactive waste. The authors have carried out a comparative study of sorption and desorption of strontium in groundwater on separated size and magnetic fractions of fracture fillings from deep granite. Complete reversibility of the sorption process was demonstrated by identical Freundlich isotherms, isotopic exchangeability and pH dependence of the distribution coefficient R{sub d}.

  15. Air-water centrifugal convection

    NASA Astrophysics Data System (ADS)

    Herrada, Miguel; Shtern, Vladimir

    2014-07-01

    A sealed cylindrical container is filled with air and water. The container rotation and the axial gradient of temperature induce the steady axisymmetric meridional circulation of both fluids due to the thermal buoyancy and surface-tension (Marangoni) effects. If the temperature gradient is small, the water circulation is one-cellular while the air circulation can be one- or two-cellular depending on water fraction Wf. The numerical simulations are performed for the cylinder length-to-radius ratio l = 1 and l = 4. The l = 4 results and the analytical solution for l → ∞ agree in the cylinder's middle part. As the temperature gradient increases, the water circulation becomes one-, two-, or three-cellular depending on Wf. The results are of fundamental interest and can be applied for bioreactors.

  16. Voids in Sonic Fill(TM) restorations compared to traditional incrementally-filled composite restorations

    NASA Astrophysics Data System (ADS)

    Abourezq, Ibraheem A.

    SonicFill(TM) is a new composite resin and delivery system designed to provide rapid filling of cavity preparations by decreasing viscosity through application of sonic energy. However, it may produce unwanted air voids in the final restoration due to the short filling time. Air voids compromise long-term performance by providing weak foci, discontinuity at cavosurface margins and at internal cavity walls, and potential crack propagation. This study assessed the locations, sizes, and numbers of voids in SonicFill restorations compared with traditional composite resin restorations in a set of extracted molars with mesio-occlusal-distal (MOD) cavity preparations. Fifty noncarious intact extracted third molars were collected randomly from a large collection of discarded anonymous tooth specimens. Standardized MOD cavity preparations were cut, and teeth were assigned randomly to one of two groups ( n = 25). The first group was restored with SonicFill composite in two steps. The second group was restored with Herculite Ultra(TM) using an multiple increment layering technique (1-2 mm per layer). Cross-sectional images of the filling were taken by digital microscope. A total of 196 voids were found in the 50 specimens: 97 in SonicFill restorations and 99 in conventional restorations. Mean number of voids in SonicFill restorations was 3.88 versus 3.96 for conventional restorations. Mean percentage of void area in SonicFill restorations was 0.588% versus 0.508% for conventional restorations. Unpaired t tests for these differences indicated no statistically significant differences (p =.931 and p =.629, respectively). One-way ANOVA tests for mean void count and mean void area percentage differences by three location zones for conventional and SonicFill restorations also indicated no significant differences among the groups. The bulk-fill SonicFill system does not result in increased or decreased numbers or ii area of voids within Class II MOD restorations compared with a

  17. Gas filled panel insulation

    DOEpatents

    Griffith, Brent T.; Arasteh, Dariush K.; Selkowitz, Stephen E.

    1993-01-01

    A structural or flexible highly insulative panel which may be translucent, is formed from multi-layer polymeric material in the form of an envelope surrounding a baffle. The baffle is designed so as to minimize heat transfer across the panel, by using material which forms substantially closed spaces to suppress convection of the low conductivity gas fill. At least a portion of the baffle carries a low emissivity surface for suppression of infrared radiation.

  18. Gas filled panel insulation

    DOEpatents

    Griffith, B.T.; Arasteh, D.K.; Selkowitz, S.E.

    1993-12-14

    A structural or flexible highly insulative panel which may be translucent, is formed from multi-layer polymeric material in the form of an envelope surrounding a baffle. The baffle is designed so as to minimize heat transfer across the panel, by using material which forms substantially closed spaces to suppress convection of the low conductivity gas fill. At least a portion of the baffle carries a low emissivity surface for suppression of infrared radiation. 18 figures.

  19. Release Fraction Evaluation

    SciTech Connect

    Bamberger, Judith A.; Glissmeyer, John A.

    2004-01-01

    This document presents results of experiments conducted to measure release fractions during certain tank retrieval processes. The tests were performed in a 1/4 scale model of a waste storage tank. The retrieval processes simulated were: (1) Discharging liquid or slurry from the mouth of a vertically oriented two-in. Schedule 40 pipe. The discharging material was in free-fall from the mouth of the pipe near the top of the tank into a liquid or slurry pool at the bottom of the tank. (2) The jet from a 9/16-in.-diameter nozzle transferring liquid or slurry waste from one side of the tank to the other. The discharging liquid was aimed at the opposite side of the tank from the nozzle and either impacted the tank wall or fell into a liquid or slurry pool in the bottom of the tank. (3) A high pressure fan jet of liquid striking a steel plate or simulated waste from a stand-off distance of a few inches. For each process, a water-soluble fluorescent dye was added to the liquid fraction as a tracer. Kaolin clay was used to represent the solids. The tank was covered and there was no forced ventilation in the tank during the tests. Six air samples were collected during each test. The air samples were collected at fixed positions in the tank. The air sample filters were dried and weighed to determine the solids collection. The fluorescent dye was then leached from each filter and quantified with a fluorometer to determine the collection of liquid. Samples of the slurry and liquid simulants were also collected to determine the quantities of simulant used in each test. To calculate the release fraction, the quantity collected on each air sample was adjusted for the fraction of the tank volume sampled and divided by the quantity of material exposed in the simulation. The method was not as sensitive for the solids content as it was for the liquid content, but in those instances where a solids release fraction was determined, it was in relatively good agreement with that of the

  20. Separation of empty and water-filled single-wall carbon nanotubes.

    PubMed

    Fagan, Jeffrey A; Huh, Ji Yeon; Simpson, Jeffrey R; Blackburn, Jeffrey L; Holt, Josh M; Larsen, Brian A; Walker, Angela R Hight

    2011-05-24

    The separation of empty and water-filled laser ablation and electric arc synthesized nanotubes is reported. Centrifugation of these large-diameter nanotubes dispersed with sodium deoxycholate using specific conditions produces isolated bands of empty and water-filled nanotubes without significant diameter selection. This separation is shown to be consistent across multiple nanotube populations dispersed from different source soots. Detailed spectroscopic characterization of the resulting empty and filled fractions reveals that water filling leads to systematic changes to the optical and vibrational properties. Furthermore, sequential separation of the resolved fractions using cosurfactants and density gradient ultracentrifugation reveals that water filling strongly influences the optimal conditions for metallic and semiconducting separation.

  1. Dye filled security seal

    DOEpatents

    Wilson, Dennis C. W.

    1982-04-27

    A security seal for providing an indication of unauthorized access to a sealed object includes an elongate member to be entwined in the object such that access is denied unless the member is removed. The elongate member has a hollow, pressurizable chamber extending throughout its length that is filled with a permanent dye under greater than atmospheric pressure. Attempts to cut the member and weld it together are revealed when dye flows through a rupture in the chamber wall and stains the outside surface of the member.

  2. Fluid Dynamics of Bottle Filling

    NASA Astrophysics Data System (ADS)

    McGough, Patrick; Gao, Haijing; Appathurai, Santosh; Basaran, Osman

    2011-11-01

    Filling of bottles is a widely practiced operation in a large number of industries. Well known examples include filling of ``large'' bottles with shampoos and cleaners in the household products and beauty care industries and filling of ``small'' bottles in the pharmaceutical industry. Some bottle filling operations have recently drawn much attention from the fluid mechanics community because of the occurrence of a multitude of complex flow regimes, transitions, and instabilities such as mounding and coiling that occur as a bottle is filled with a fluid. In this talk, we present a primarily computational study of the fluid dynamical challenges that can arise during the rapid filling of bottles. Given the diversity of fluids used in filling applications, we consider four representative classes of fluids that exhibit Newtonian, shear-thinning, viscoelastic, and yield-stress rheologies. The equations governing the dynamics of bottle filling are solved either in their full 3D but axisymmetric form or using the slender-jet approximation.

  3. Hydrogen Filling Station

    SciTech Connect

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    future. Project partners also conducted a workshop on hydrogen safety and permitting. This provided an opportunity for the various permitting agencies and end users to gather to share experiences and knowledge. As a result of this workshop, the permitting process for the hydrogen filling station on the Las Vegas Valley Water District’s land was done more efficiently and those who would be responsible for the operation were better educated on the safety and reliability of hydrogen production and storage. The lessons learned in permitting the filling station and conducting this workshop provided a basis for future hydrogen projects in the region. Continuing efforts to increase the working pressure of electrolysis and efficiency have been pursued. Research was also performed on improving the cost, efficiency and durability of Proton Exchange Membrane (PEM) hydrogen technology. Research elements focused upon PEM membranes, electrodes/catalysts, membrane-electrode assemblies, seals, bipolar plates, utilization of renewable power, reliability issues, scale, and advanced conversion topics. Additionally, direct solar-to-hydrogen conversion research to demonstrate stable and efficient photoelectrochemistry (PEC) hydrogen production systems based on a number of optional concepts was performed. Candidate PEC concepts included technical obstacles such as inefficient photocatalysis, inadequate photocurrent due to non-optimal material band gap energies, rapid electron-hole recombination, reduced hole mobility and diminished operational lifetimes of surface materials exposed to electrolytes. Project Objective 1: Design, build, operate hydrogen filling station Project Objective 2: Perform research and development for utilizing solar technologies on the hydrogen filling station and convert two utility vehicles for use by the station operators Project Objective 3: Increase capacity of hydrogen filling station; add additional vehicle; conduct safety workshop; develop a roadmap for

  4. Fraction Reduction through Continued Fractions

    ERIC Educational Resources Information Center

    Carley, Holly

    2011-01-01

    This article presents a method of reducing fractions without factoring. The ideas presented may be useful as a project for motivated students in an undergraduate number theory course. The discussion is related to the Euclidean Algorithm and its variations may lead to projects or early examples involving efficiency of an algorithm.

  5. Model Fractional Chern Insulators.

    PubMed

    Behrmann, Jörg; Liu, Zhao; Bergholtz, Emil J

    2016-05-27

    We devise local lattice models whose ground states are model fractional Chern insulators-Abelian and non-Abelian topologically ordered states characterized by exact ground state degeneracies at any finite size and infinite entanglement gaps. Most saliently, we construct exact parent Hamiltonians for two distinct families of bosonic lattice generalizations of the Z_{k} parafermion quantum Hall states: (i) color-entangled fractional Chern insulators at band filling fractions ν=k/(C+1) and (ii) nematic states at ν=k/2, where C is the Chern number of the lowest band. In spite of a fluctuating Berry curvature, our construction is partially frustration free: the ground states reside entirely within the lowest band and exactly minimize a local (k+1) body repulsion term by term. In addition to providing the first known models hosting intriguing states such as higher Chern number generalizations of the Fibonacci anyon quantum Hall states, the remarkable stability and finite-size properties make our models particularly well suited for the study of novel phenomena involving, e.g., twist defects and proximity induced superconductivity, as well as being a guide for designing experiments.

  6. Model Fractional Chern Insulators

    NASA Astrophysics Data System (ADS)

    Behrmann, Jörg; Liu, Zhao; Bergholtz, Emil J.

    2016-05-01

    We devise local lattice models whose ground states are model fractional Chern insulators—Abelian and non-Abelian topologically ordered states characterized by exact ground state degeneracies at any finite size and infinite entanglement gaps. Most saliently, we construct exact parent Hamiltonians for two distinct families of bosonic lattice generalizations of the Zk parafermion quantum Hall states: (i) color-entangled fractional Chern insulators at band filling fractions ν =k /(C +1 ) and (ii) nematic states at ν =k /2 , where C is the Chern number of the lowest band. In spite of a fluctuating Berry curvature, our construction is partially frustration free: the ground states reside entirely within the lowest band and exactly minimize a local (k +1 ) body repulsion term by term. In addition to providing the first known models hosting intriguing states such as higher Chern number generalizations of the Fibonacci anyon quantum Hall states, the remarkable stability and finite-size properties make our models particularly well suited for the study of novel phenomena involving, e.g., twist defects and proximity induced superconductivity, as well as being a guide for designing experiments.

  7. Model Fractional Chern Insulators.

    PubMed

    Behrmann, Jörg; Liu, Zhao; Bergholtz, Emil J

    2016-05-27

    We devise local lattice models whose ground states are model fractional Chern insulators-Abelian and non-Abelian topologically ordered states characterized by exact ground state degeneracies at any finite size and infinite entanglement gaps. Most saliently, we construct exact parent Hamiltonians for two distinct families of bosonic lattice generalizations of the Z_{k} parafermion quantum Hall states: (i) color-entangled fractional Chern insulators at band filling fractions ν=k/(C+1) and (ii) nematic states at ν=k/2, where C is the Chern number of the lowest band. In spite of a fluctuating Berry curvature, our construction is partially frustration free: the ground states reside entirely within the lowest band and exactly minimize a local (k+1) body repulsion term by term. In addition to providing the first known models hosting intriguing states such as higher Chern number generalizations of the Fibonacci anyon quantum Hall states, the remarkable stability and finite-size properties make our models particularly well suited for the study of novel phenomena involving, e.g., twist defects and proximity induced superconductivity, as well as being a guide for designing experiments. PMID:27284668

  8. Diffusivity fractionations of H2(16)O/H2(17)O and H2(16)O/H2(18)O in air and their implications for isotope hydrology.

    PubMed

    Barkan, Eugeni; Luz, Boaz

    2007-01-01

    We have determined the isotope effects of (17)O and (18)O substitution of (16)O in H(2)O on molecular diffusivities of water vapor in air by the use of evaporation experiments. The derived diffusion fractionation coefficients (17)alpha(diff) and (18)alpha(diff) are 1.0146 +/- 0.0002 and 1.0283 +/- 0.0003, respectively. We also determined, for the first time, the ratio ln((17)alpha(diff))/ln((18)alpha(diff)) as 0.5185 +/- 0.0002. This ratio, which is in excellent agreement with the theoretical value of 0.5184, is significantly smaller than the ratio in vapor-liquid equilibrium (0.529). We show how this new experimental information gives rise to (17)O excess in meteoric water, and how it can be applied in isotope hydrology.

  9. Two-dimensional photonic crystals from semiconductor material with polymer filled holes

    NASA Astrophysics Data System (ADS)

    van der Heijden, Rob; Kjellander, Charlotte; Carlström, Carl-Fredrik; Snijders, Juri; van der Heijden, Rob W.; Bastiaansen, Kees; Broer, Dick; Karouta, Fouad; Nötzel, Richard; van der Drift, Emile; Salemink, Huub W. M.

    2006-04-01

    Polymer filling of the air holes of indiumphosphide based two-dimensional photonic crystals is reported. The filling is performed by infiltration with a liquid monomer and solidification of the infill in situ by thermal polymerization. Complete hole filling is obtained with infiltration under ambient pressure. This conclusion is based both on cross-sectional scanning electron microscope inspection of the filled samples as well as on optical transmission measurements.

  10. Measurements of N2O and SF6 mole fraction between 1977 and 1998 in archived air samples from Cape Meares, Oregon

    NASA Astrophysics Data System (ADS)

    Rolfe, T.; Rice, A. L.; Radda, J.

    2015-12-01

    The quantification of greenhouse gas concentrations in the atmosphere is important for monitoring imbalances in their global budgets between sources and sinks and their changes in time. Nitrous oxide (N2O) is a strong radiative trace gas with a GWP of ~300 times CO2 over a 100 year period and an atmospheric lifetime of ~100 years. The preindustrial revolution background concentration of N2O was ~270 ppb. Today, the concentration is ~330 ppb. Sulfur hexafluoride (SF6) is another potent greenhouse gas with a long lifetime (800 to 3200 years) and very large GWP (~23000 times CO2 over a 100 year period). Its current atmospheric concentration is low (~8 ppt today). Direct measurements of N2O and SF6 in air prior to the mid-1990s are few. Over 200 archived atmospheric gas samples collected at Cape Meares, Oregon between 1977 and 1998 were analyzed for their N2O and SF6 concentrations using an Agilent (model 6890 N) gas chromatograph fitted with an electron capture detector using a two column "heart-cut" technique. Precision of measurement of N2O and SF6 is calculated at 0.13% (1σ) and 1.35% (1σ) respectively. N2O concentrations in the late 1970s and early 1980s average around 303 ppb, rising to 309 ppb in the early 1990s. Between 1980 and 1990, the increase in N2O concentrations is found to be ~0.5 ppb/yr. SF6 concentrations during the late 1970s and early 1980s average around 0.9 ppt and rise slowly, reaching 1.6 ppt in the 1990s. We find that the increase in SF6 between 1980 and 1990 to be ~0.07 ppt/yr. We also discuss sample integrity in storage and observed temporal trends of N2O and SF6.

  11. Effect of feeding low-fiber fraction of air-classified sunflower (Helianthus annus L.) meal on laying hen productive performance and egg yolk cholesterol.

    PubMed

    Laudadio, V; Ceci, E; Lastella, N M B; Tufarelli, V

    2014-11-01

    The present study was designed to determine the effect on laying performance and egg quality resulting from total substitution of soybean meal (SBM) with low-fiber sunflower meal (SFM; Helianthus annus L.) meal in diet of hens. ISA Brown layers, 28 wk of age, were randomly allocated to 2 dietary treatments and fed for 10 wk. The hens were kept in a free-range environment and fed 2 wheat middling-based diets consisting of a control diet, which contained SBM (153 g/kg of diet), and a test diet containing low-fiber SFM (160 g/kg of diet) as the main protein source. Each dietary treatment was replicated 4 times. Low-fiber SFM was obtained by a combination of sieving and air classification processes. Feed consumption was recorded daily and egg production was calculated on a hen-day basis; eggs from each group were collected weekly to evaluate egg components and quality. The total substitution of SBM with low-fiber SFM had no adverse effect on growth performance of laying hens. Egg production and none of egg quality traits examined were influenced by dietary treatment, except for yolk color (P < 0.05) and percentage of large-size eggs (P < 0.05) that were improved in hens fed the low-fiber SFM diet. Including low-fiber SFM decreased serum and egg yolk total cholesterol and low-density lipoprotein cholesterol concentrations (P < 0.001), and increased high-density lipoprotein cholesterol level. Our results suggest that the replacement of conventional soybean with low-fiber sunflower meal may be a valid alternative in diets for laying hens to improve egg quality and to develop low-cholesterol eggs.

  12. Defining filled and empty space: reassessing the filled space illusion for active touch and vision.

    PubMed

    Collier, Elizabeth S; Lawson, Rebecca

    2016-09-01

    In the filled space illusion, an extent filled with gratings is estimated as longer than an equivalent extent that is apparently empty. However, researchers do not seem to have carefully considered the terms filled and empty when describing this illusion. Specifically, for active touch, smooth, solid surfaces have typically been used to represent empty space. Thus, it is not known whether comparing gratings to truly empty space (air) during active exploration by touch elicits the same illusionary effect. In Experiments 1 and 2, gratings were estimated as longer if they were compared to smooth, solid surfaces rather than being compared to truly empty space. Consistent with this, Experiment 3 showed that empty space was perceived as longer than solid surfaces when the two were compared directly. Together these results are consistent with the hypothesis that, for touch, the standard filled space illusion only occurs if gratings are compared to smooth, solid surfaces and that it may reverse if gratings are compared to empty space. Finally, Experiment 4 showed that gratings were estimated as longer than both solid and empty extents in vision, so the direction of the filled space illusion in vision was not affected by the nature of the comparator. These results are discussed in relation to the dual nature of active touch.

  13. Defining filled and empty space: reassessing the filled space illusion for active touch and vision.

    PubMed

    Collier, Elizabeth S; Lawson, Rebecca

    2016-09-01

    In the filled space illusion, an extent filled with gratings is estimated as longer than an equivalent extent that is apparently empty. However, researchers do not seem to have carefully considered the terms filled and empty when describing this illusion. Specifically, for active touch, smooth, solid surfaces have typically been used to represent empty space. Thus, it is not known whether comparing gratings to truly empty space (air) during active exploration by touch elicits the same illusionary effect. In Experiments 1 and 2, gratings were estimated as longer if they were compared to smooth, solid surfaces rather than being compared to truly empty space. Consistent with this, Experiment 3 showed that empty space was perceived as longer than solid surfaces when the two were compared directly. Together these results are consistent with the hypothesis that, for touch, the standard filled space illusion only occurs if gratings are compared to smooth, solid surfaces and that it may reverse if gratings are compared to empty space. Finally, Experiment 4 showed that gratings were estimated as longer than both solid and empty extents in vision, so the direction of the filled space illusion in vision was not affected by the nature of the comparator. These results are discussed in relation to the dual nature of active touch. PMID:27233286

  14. Rigid-plug elastic-water model for transient pipe flow with entrapped air pocket

    SciTech Connect

    Zhou, Ling; Liu, Prof. Deyou; Karney, Professor Byran W.; Zhang, Qin Fen; OU, CHANGQI

    2011-01-01

    Pressure transients in a rapidly filling pipe with an entrapped air pocket are investigated analytically. A rigid-plug elastic water model is developed by applying elastic water hammer to the majority of the water column while applying rigid water analysis to a small portion near the air-water interface, which avoids effectively the interpolation error of previous approaches. Moreover, another two simplified models are introduced respectively based on constant water length and by neglecting water elasticity. Verification of the three models is confirmed by experimental results. Calculations show that the simplification of constant water length is feasible for small air pockets. The complete rigid water model is appropriate for cases with large initial air volume. The rigid-plug elastic model can predict all the essential features for the entire range of initial air fraction considered in this study, and it is the effective model for analysis of pressure transients of entrapped air.

  15. soil organic matter fractionation

    NASA Astrophysics Data System (ADS)

    Osat, Maryam; Heidari, Ahmad

    2010-05-01

    Carbon is essential for plant growth, due to its effects on other soil properties like aggregation. Knowledge of dynamics of organic matter in different locations in the soil matrix can provide valuable information which affects carbon sequestration and soil the other soil properties. Extraction of soil organic matter (SOM) fractions has been a long standing approach to elucidating the roles of soil organic matter in soil processes. Several kind fractionation methods are used and all provide information on soil organic matter function. Physical fractionation capture the effects on SOM dynamics of the spatial arrangement of primary and secondary organomineral particles in soil while chemical fractionation can not consider the spatial arrangement but their organic fractions are suitable for advanced chemical characterization. Three method of physical separation of soil have been used, sieving, sedimentation and densitometry. The distribution of organic matter within physical fractions of the soil can be assessed by sieving. Sieving separates soil particles based strictly on size. The study area is located on north central Iran, between 35° 41'- 36° 01' N and 50° 42'- 51° 14' E. Mean annual precipitation about 243.8 mm and mean annual air temperature is about 14.95 °C. The soil moisture and temperature regime vary between aridic-thermic in lower altitudes to xeric-mesic in upper altitudes. More than 36 surface soil samples (0-20 cm) were collected according to land-use map units. After preliminary analyzing of samples 10 samples were selected for further analyses in five size fractions and three different time intervals in September, January and April 2008. Fractionation carried out by dry sieving in five classes, 1-2 mm, 0.5-1 mm, 270 μm-0.5mm, 53-270 μm and <53 μm. Organic matter and C/N ratio were determined for all fractions at different time intervals. Chemical fractionation of organic matter also carried out according to Tan (2003), also Mineralogical

  16. The filling strategy of the Borexino experiment

    NASA Astrophysics Data System (ADS)

    Ianni, Andrea; Pallavicini, Marco

    2014-06-01

    The detection of solar neutrinos by means of a liquid scintillator requires very low levels of radioactivity throughout the whole active volume. The selection of clean detector materials and the purification of the scintillator are necessary, but not sufficient conditions. It is also crucial that during the filling operations the scintillator is not contaminated, either by air or by getting in contact with dirty surfaces. This paper describes the procedures which we adopted to minimize these risks and achieve very good levels of radio-purity which we finally got in Borexino.

  17. Filling an Unvented Cryogenic Tank

    NASA Technical Reports Server (NTRS)

    Beck, Phillip; Willen, Gary S.

    1987-01-01

    Slow-cooling technique enables tank lacking top vent to be filled with cryogenic liquid. New technique: pressure buildup prevented through condensation of accumulating gas resulting in condensate being added to bulk liquid. Filling method developed for vibration test on vacuum-insulated spherical tank containing liquid hydrogen.

  18. Fuel-air munition and device

    DOEpatents

    Carlson, Gary A.

    1976-01-01

    An aerially delivered fuel-air munition consisting of an impermeable tank filled with a pressurized liquid fuel and joined at its two opposite ends with a nose section and a tail assembly respectively to complete an aerodynamic shape. On impact the tank is explosively ruptured to permit dispersal of the fuel in the form of a fuel-air cloud which is detonated after a preselected time delay by means of high explosive initiators ejected from the tail assembly. The primary component in the fuel is methylacetylene, propadiene, or mixtures thereof to which is added a small mole fraction of a relatively high vapor pressure liquid diluent or a dissolved gas diluent having a low solubility in the primary component.

  19. No-vent fill pressurization tests using a cryogen simulant

    NASA Technical Reports Server (NTRS)

    Schmidt, G.; Carrigan, R.; Hahs, J.; Vaughan, D.; Foust, D.

    1992-01-01

    The results are described of an experimental program which studied the performance of various no-vent fill techniques for tank-to-tank liquid transfer. The tests were performed using a cryogen simulant (Freon-114) and a test bed consisting of a multiple tank/plumbing network that enabled studies of a variety of different inlet flow and active mixing regimes. Several results and conclusions were drawn from the 26 transfer experiments comprising the program. Most notable was the significant improvement in fill performance (i.e., minimized fill time and maximized fill fraction) with increased agitation of the liquid surface. Another was the close correlation between measured condensation rates and those predicted by recent theories which express condensation as a function of turbulent eddy effects on the liquid surface. In most cases, test data exhibited strong agreement with an analytical model which accounts for tank heat transfer and thermodynamics in a 1 g environment.

  20. No-vent fill pressurization tests using a cryogen simulant

    NASA Technical Reports Server (NTRS)

    Schmidt, G. R.; Carrigan, R. W.; Hahs, J. E.; Vaughan, D. A.; Foust, D. C.

    1991-01-01

    The results are described of an experimental program which studied the performance of various no-vent fill techniques for tank-to-tank liquid transfer. The tests were performed using a cryogen simulant (Freon-114) and a test bed consisting of a multiple tank/plumbing network that enabled studies of a variety of different inlet flow and active mixing regimes. Several results and conclusions were drawn from the 26 transfer experiments comprising the program. Most notable was the significant improvement in fill performance (i.e., minimized fill time and maximized fill fraction) with increased agitation of the liquid surface. Another was the close correlation between measured condensation rates and those predicted by recent theories which express condensation as a function of turbulent eddy effects on the liquid surface. In most cases, test data exhibited strong agreement with an analytical model which accounts for tank heat transfer and thermodynamics in a 1 g environment.

  1. The Characteristic of Porous Charges on a Base of a Water-Filled RDX Powder

    NASA Astrophysics Data System (ADS)

    Valiano, Georgy; Yankovskiy, Boris; Milyavskiy, Vladimir; Borodina, Tatiana

    2011-06-01

    A detonation velocity of a condensed RDX linearly depends on density at a range of 1,0-1,8 g/cm3. These charges are porous if the density of RDX monocrystal is 1,806 g/cm3. The state of porous charge can be characterized by the packing density. It can be rising, if RDX powder will be mixed with water for deciding technological problems. It is necessary to be able to predict characteristics of such charges. Charges on a base of a water-filled RDX powder with air inclusions can be described by three parameters: a density of a charge, packing density of RDX powder and RDX mass fraction. Last two parameters are independent parameters of a mix. We have designed a nomogram for definition of mutual communication of three quantities: velocity of a detonation, density of packing of RDX powder and its mass fraction in a mix. To check up correctness of a prelegends of a nomogram, we have carried out measurement of a detonation velocity of porous water-contained RDX charges. We prepared charges on a base of RDX powder which has consisted of particles with a size 80-220 mcm. We was changing RDX mass fraction of charges in a range 0,6-1,0 and a packing density of RDX powder in a range of 1,0-1,4 g/cm3. The disorder of experimental data concerning the nomogram data did not exceed basically of 3 percent.

  2. Maxillary Air Cyst

    PubMed Central

    Doucette-Preville, Stephane; Tamm, Alexander; Khetani, Justin; Wright, Erin; Emery, Derek

    2013-01-01

    Pathologic dilatation of the maxillary sinus by air is a rare condition with unclear etiology. We present a case of a 17 year old male with a maxillary air cyst diagnosed by computed tomography. The CT demonstrated air-filled expansion of the maxillary sinus beyond the normal anatomical limits with associated cortical bone thinning. The case report highlights the pathognomonic computed tomography findings of this rare entity and discusses the perplexing nomenclature, proposed etiologies and various treatment options. PMID:24421932

  3. Method and apparatus for filling thermal insulating systems

    DOEpatents

    Arasteh, Dariush K.

    1992-01-01

    A method for filling insulated glazing units is disclosed. The method utilizes a vacuum chamber in which the insulated glazing units are placed. The insulated glazing units and vacuum chamber are evacuated simultaneously. The units are then refilled with a low conductance gas such as Krypton while the chamber is simultaneously refilled with air.

  4. Method and apparatus for filling thermal insulating systems

    DOEpatents

    Arasteh, D.K.

    1992-01-14

    A method for filling insulated glazing units is disclosed. The method utilizes a vacuum chamber in which the insulated glazing units are placed. The insulated glazing units and vacuum chamber are evacuated simultaneously. The units are then refilled with a low conductance gas such as Krypton while the chamber is simultaneously refilled with air. 3 figs.

  5. Hierarchy of fillings for the FQHE in monolayer graphene

    PubMed Central

    Łydżba, Patrycja; Jacak, Lucjan; Jacak, Janusz

    2015-01-01

    In this paper, the commensurability conditions, which originated from the unique topology of two-dimensional systems, are applied to determine the quantum Hall effect hierarchy in the case of a monolayer graphene. The fundamental difference in a definition of a typical semiconductor and a monolayer graphene filling factor is pointed out. The calculations are undertaken for all spin-valley branches of two lowest Landau levels, since only they are currently experimentally accessible. The obtained filling factors are compared with the experimental data and a very good agreement is achieved. The work also introduces a concept of the single-loop fractional quantum Hall effect. PMID:26392385

  6. Pairing in half-filled Landau level

    SciTech Connect

    Wang, Zhiqiang; Mandal, Ipsita; Chung, Suk Bum; Chakravarty, Sudip

    2014-12-15

    Pairing of composite fermions in half-filled Landau level state is reexamined by solving the BCS gap equation with full frequency dependent current–current interactions. Our results show that there can be a continuous transition from the Halperin–Lee–Read state to a chiral odd angular momentum Cooper pair state for short-range contact interaction. This is at odds with the previously established conclusion of first order pairing transition, in which the low frequency effective interaction was assumed for the entire frequency range. We find that even if the low frequency effective interaction is repulsive, it is compensated by the high frequency regime, which is attractive. We construct the phase diagrams and show that ℓ=1 angular momentum channel is quite different from higher angular momenta ℓ≥3. Remarkably, the full frequency dependent analysis applied to the bilayer Hall system with a total filling fraction ν=1/2 +1/2 is quantitatively changed from the previously established results but not qualitatively.

  7. Paleovalley fills: Trunk vs. tributary

    USGS Publications Warehouse

    Kvale, E.P.; Archer, A.W.

    2007-01-01

    A late Mississippian-early Pennsylvanian eustatic sea level drop resulted in a complex lowstand drainage network being eroded across the Illinois Basin in the eastern United States. This drainage system was filled during the early part of the Pennsylvanian. Distinct differences can be recognized between the trunk and tributary paleovalley fills. Fills preserved within the trunk systems tend to be fluvially dominated and consist of bed-load deposits of coarse- to medium-grained sandstone and conglomerate. Conversely, the incised valleys of tributary systems tend to be filled with dark mudstone, thinly interbedded sandstones, and mudstones and siltstones. These finer grained facies exhibit marine influences manifested by tidal rhythmites, certain traces fossils, and macro- and microfauna. Examples of tributary and trunk systems, separated by no more than 7 km (4.3 mi) along strike, exhibit these styles of highly contrasting fills. Useful analogs for understanding this Pennsylvanian system include the Quaternary glacial sluiceways present in the lower Ohio, White, and Wabash river valleys of Indiana (United States) and the modern Amazon River (Brazil). Both the Amazon River and the Quaternary rivers of Indiana have (or had) trunk rivers that are (were) dominated by large quantities of bed load relative to their tributaries. The trunk valley systems of these analogs aggraded much more rapidly than their tributary valleys, which evolved into lakes because depositional rates along the trunk are (were) so high that the mouths of the tributaries have been dammed by bed-load deposits. These Holocene systems illustrate that sediment yields can significantly influence the nature of fill successions within incised valleys independent of rates of sea level changes or proximity to highstand coastlines. Copyright ?? 2007. The American Association of Petroleum Geologists. All rights reserved.

  8. Gas-Filled Capillary Model

    NASA Astrophysics Data System (ADS)

    Steinhauer, L. C.; Kimura, W. D.

    2006-11-01

    We have developed a 1-D, quasi-steady-state numerical model for a gas-filled capillary discharge that is designed to aid in selecting the optimum capillary radius in order to guide a laser beam with the required intensity through the capillary. The model also includes the option for an external solenoid B-field around the capillary, which increases the depth of the parabolic density channel in the capillary, thereby allowing for propagation of smaller laser beam waists. The model has been used to select the parameters for gas-filled capillaries to be utilized during the Staged Electron Laser Acceleration — Laser Wakefield (STELLA-LW) experiment.

  9. Weaving and bonding method to prevent warp and fill distortion

    NASA Technical Reports Server (NTRS)

    Farley, Gary L. (Inventor)

    1997-01-01

    A method to prevent fiber distortion in textile materials employed in a modified weaving process. In a first embodiment, a tacifier in powder form is applied to the yarn and melted while on the fabric. Cool air is then supplied after the tacifier has melted to expedite the solidification of the tacifier. In a second embodiment, a solution form of a tacifier is used by dissolving the tacifier into a solvent that has a high evaporation rate. The solution is then sprayed onto the fabric or fill yarn as each fill yarn is inserted into a shed of the fabric. A third embodiment applies the tacifier in a liquid form that has not been dissolved in a solvent. That is, the tacifier is melted and is sprayed as a liquid onto the fabric or fill yarn as it is being extracted from a fill yarn spool prior to the fill yarn being inserted into the shed of the fabric. A fourth embodiment employs adhesive yarns contained as an integral part of the warp or fill yarn. Additional tacifier material is not required because a matrix is used as the tacifier. The matrix is then locally melted using heating elements on clamping bars or take-up rollers, is cooled, if necessary, and solidified.

  10. Generation of slanted gas-filled icicles

    NASA Astrophysics Data System (ADS)

    Wäscher, Thomas

    1991-04-01

    A procedure for the generation of slanted gas-filled icicles by freezing, using a domestic refrigerator, is described. The freezing vessel was a plastic ice-cube tray, which was filled both with tap and deionized water and was frozen successively from the outer to the inner compartments of the tray. Icicles having slanted elevations grew out of the surface of the deionized water of the innermost compartments. The erection angle of the icicles to the horizontal lay between 30° and 60°, for the three longest and thinnest specimens it was almost exactly 30°. All icicles have gas inclusions. Their shape varies between an irregular distribution of circular bubbles and a nearly uninterrupted axial gas channel together with dendrite-like, radially distorted bubbles. If a cold (-18°C) specimen comes into contact with warm and humid room-air, then hoarfrost is observed at the bottom and the top of the icicle, while the area in between remains transparent.

  11. Air emissions from exposed contaminated sediments and dredged material

    SciTech Connect

    Valsaraj, K.T.; Ravikrishna, R.; Reible, D.D.; Thibodeaux, L.J.; Choy, B.; Price, C.B.; Brannon, J.M.; Myers, T.E.; Yost, S.

    1999-01-01

    The sediment-to-air fluxes of two polycyclic aromatic hydrocarbons (phenanthrene and pyrene) and a heterocyclic aromatic hydrocarbon (dibenzofuran) from a laboratory-contaminated sediment and those of three polycyclic aromatic hydrocarbons (naphthalene, phenanthrene, and pyrene) from three field sediments were investigated in experimental microcosms. The flux was dependent on the sediment moisture content, air-filled porosity, and the relative humidity of the air flowing over the sediment surface. The mathematical model predictions of flux from the laboratory-spiked sediment agreed with observed values. The fluxes of compounds with higher hydrophobicity were more air-side resistance controlled. Conspicuous differences were observed between the fluxes from the laboratory-spiked and two of the three field sediments. Two field sediments showed dramatic increases in mass-transfer resistances with increasing exposure time and had significant fractions of oil and grease. The proposed mathematical model was inadequate for predicting the flux from the latter field sediments. Sediment reworking enhanced the fluxes from the field sediments due to exposure of fresh solids to the air. Variations in flux from the lab-spiked sediment as a result of change in air relative humidity were due to differences in retardation of chemicals on a dry or wet surface sediment. High moisture in the air over the dry sediment increased the competition for sorption sites between water and contaminant and increased the contaminant flux.

  12. How is the ocean filled?

    NASA Astrophysics Data System (ADS)

    Gebbie, Geoffrey; Huybers, Peter

    2011-03-01

    The ocean surface rapidly exchanges heat, freshwater, and gases with the atmosphere, but once water sinks into the ocean interior, the inherited properties of seawater are closely conserved. Previous water-mass decompositions have described the oceanic interior as being filled by just a few different property combinations, or water masses. Here we apply a new inversion technique to climatological tracer distributions to find the pathways by which the ocean is filled from over 10,000 surface regions, based on the discretization of the ocean surface at 2° by 2° resolution. The volume of water originating from each surface location is quantified in a global framework, and can be summarized by the estimate that 15% of the surface area fills 85% of the ocean interior volume. Ranked from largest to smallest, the volume contributions scaled by surface area follow a power-law distribution with an exponent of -1.09 ± 0.03 that appears indicative of the advective-diffusive filling characteristics of the ocean circulation, as demonstrated using a simple model. This work quantifies the connection between the surface and interior ocean, allowing insight into ocean composition, atmosphere-ocean interaction, and the transient response of the ocean to a changing climate.

  13. Can-Filled Crash Barrier

    NASA Technical Reports Server (NTRS)

    Wilson, A. H.

    1983-01-01

    Crash barrier composed largely of used aluminum beverage cans protects occupants of cars in collisions with poles or trees. Lightweight, can-filled barrier very effective in softening impact of an automobile in head-on and off-angle collisions. Preliminary results indicate barrier is effective in collisions up to 40 mi/h (64 km/h).

  14. Space-filling polyhedral sorbents

    DOEpatents

    Haaland, Peter

    2016-06-21

    Solid sorbents, systems, and methods for pumping, storage, and purification of gases are disclosed. They derive from the dynamics of porous and free convection for specific gas/sorbent combinations and use space filling polyhedral microliths with facial aplanarities to produce sorbent arrays with interpenetrating interstitial manifolds of voids.

  15. Brain Responses to Filled Gaps

    ERIC Educational Resources Information Center

    Hestvik, Arild; Maxfield, Nathan; Schwartz, Richard G.; Shafer, Valerie

    2007-01-01

    An unresolved issue in the study of sentence comprehension is whether the process of gap-filling is mediated by the construction of empty categories (traces), or whether the parser relates fillers directly to the associated verb's argument structure. We conducted an event-related potentials (ERP) study that used the violation paradigm to examine…

  16. Matrix fractional systems

    NASA Astrophysics Data System (ADS)

    Tenreiro Machado, J. A.

    2015-08-01

    This paper addresses the matrix representation of dynamical systems in the perspective of fractional calculus. Fractional elements and fractional systems are interpreted under the light of the classical Cole-Cole, Davidson-Cole, and Havriliak-Negami heuristic models. Numerical simulations for an electrical circuit enlighten the results for matrix based models and high fractional orders. The conclusions clarify the distinction between fractional elements and fractional systems.

  17. Constitutive parameter de-embedding using inhomogeneously-filled rectangular waveguides with longitudinal section modes

    NASA Technical Reports Server (NTRS)

    Park, A.; Dominek, A. K.

    1990-01-01

    Constitutive parameter extraction from S parameter data using a rectangular waveguide whose cross section is partially filled with a material sample as opposed to being completely filled was examined. One reason for studying a partially filled geometry is to analyze the effect of air gaps between the sample and fixture for the extraction of constitutive parameters. Air gaps can occur in high temperature parameter measurements when the sample was prepared at room temperature. Single port and two port measurement approaches to parameter extraction are also discussed.

  18. [Long-lasting filling procedures].

    PubMed

    Môle, B

    2008-01-01

    A long-lasting filling product is accepted as such when, once the result has been obtained, no correction is required before the end of an arbitrary 2-year period. Other than silicone oil, which is not officially recognized for this indication in France, pure products can be distinguished from microparticle suspensions in a vector that will disappear in a short time. Flexible implants represent a totally separate entity and remain relatively little used since surgery is necessary for implantation. Our experience has led us to prefer monomolecular filling gels, in particular polyacrylamide hydrogels, with which we have had extensive experience, over gels with microparticles that we believe expose the patient to much greater inflammatory reactions that are sometimes difficult to overcome.

  19. Understanding the Relationship Between Filling Pattern and Part Quality in Die Casting

    SciTech Connect

    Jerald Brevick; R. Allen Miller

    2004-03-15

    The overall objective of this research project was to investigate phenomena involved in the filling of die cavities with molten alloy in the cold chamber die-casting process. It has long been recognized that the filling pattern of molten metal entering a die cavity influences the quality of die-cast parts. Filling pattern may be described as the progression of molten metal filling the die cavity geometry as a function of time. The location, size and geometric configuration of points of metal entry (gates), as well as the geometry of the casting cavity itself, have great influence on filling patterns. Knowledge of the anticipated filling patterns in die-castings is important for designers. Locating gates to avoid undesirable flow patterns that may entrap air in the casting is critical to casting quality - as locating vents to allow air to escape from the cavity (last places to fill). Casting quality attributes that are commonly flow related are non-fills, poor surface finish, internal porosity due to trapped air, cold shuts, cold laps, flow lines, casting skin delamination (flaking), and blistering during thermal treatment.

  20. Particle-filled microporous materials

    DOEpatents

    McAllister, J.W.; Kinzer, K.E.; Mrozinski, J.S.; Johnson, E.J.; Dyrud, J.F.

    1990-09-18

    A microporous particulate-filled thermoplastic polymeric article is provided. The article can be in the form of a film, a fiber, or a tube. The article has a thermoplastic polymeric structure having a plurality of interconnected passageways to provide a network of communicating pores. The microporous structure contains discrete submicron or low micron-sized particulate filler, the particulate filler being substantially non-agglomerated. 3 figs.

  1. Particle-filled microporous materials

    DOEpatents

    McAllister, Jerome W.; Kinzer, Kevin E.; Mrozinski, James S.; Johnson, Eric J.; Dyrud, James F.

    1990-01-01

    A microporous particulate-filled thermoplastic polymeric article is provided. The article can be in the form of a film, a fiber, or a tube. The article has a thermoplastic polymeric structure having a plurality of interconnected passageways to provide a network of communicating pores. The microporous structure contains discrete submicron or low micron-sized particulate filler, the particulate filler being substantially non-agglomerated.

  2. Particle-filled microporous materials

    DOEpatents

    McAllister, Jerome W.; Kinzer, Kevin E.; Mrozinski, James S.; Johnson, Eric J.

    1992-07-14

    A microporous particulate-filled thermoplastic polymeric article is provided. The article can be in the form of a film, a fiber, or a tube. The article has a thermoplastic polymeric structure having a plurality of interconnected passageways to provide a network of communicating pores. The microporous structure contains discrete submicron or low micron-sized particulate filler, the particulate filler being substantially non-agglomerated.

  3. Advances in Plasma-Filled Microwave Sources

    NASA Astrophysics Data System (ADS)

    Goebel, Dan M.

    1998-11-01

    Significant improvements in the performance of high power microwave tubes have been achieved in recent years by the introduction of plasma into the beam- coupling structures of the devices. Plasma has been credited with increasing the maximum electron beam current, frequency bandwidth, electrical efficiency and reducing or eliminating the need for guiding magnetic fields in microwave sources. These advances are critically important for the development of high power, frequency agile microwave systems where size and weight are important. Conversely, plasma has been blamed for causing noise, instabilities, power variations and pulse-length limitations in microwave tubes for many years. Recent experimental and theoretical studies have demonstrated that introducing the right amount of plasma in a controlled manner can be beneficial in the areas described above. Enhanced beam propagation at lower magnetic fields and higher beam current levels due to the space-charge neutralization by plasma can be realized provided that the neutralization fraction is fairly stable and maintained near a value of one for the duration of the desired pulse length. The generation of hybrid waves in plasma-filled slow-wave structures (SWS) operating near cutoff has resulted in an increased electric field on axis and improved coupling to solid beams in both helix and coupled-cavity SWS, and wider coupling-aperture pass-bands and frequency bandwidth in coupled-cavity devices. In the event of excess plasma generation in these TWTs or BWOs, the device structures rapidly approach cutoff or breakdown and the beam forms instabilities, which degrades the output power level and pulse length. Recent experimental and theoretical advances in this field including plasma implementation techniques in the gun and circuit will be presented, and the benefits and limitations of plasma filling of microwave sources will be shown and discussed.

  4. 24. BUILDING NO. 452, ORDNANCE FACILITY (BAG CHARGE FILLING PLANT), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. BUILDING NO. 452, ORDNANCE FACILITY (BAG CHARGE FILLING PLANT), INTERIOR VIEW LOOKING WEST AT NORTH END OF CENTRAL CORRIDOR (ROOM 3). STAIRWAY WORKBENCH WITH COMPRESSED-AIR POWERED CARTRIDGE LOADER. ARMORED PASS-THROUGH OF TRANSFER BOX FOR PASSING EXPLOSIVES MATERIALS THROUGH TO NEXT ROOM TO THE NORTH. - Picatinny Arsenal, 400 Area, Gun Bag Loading District, State Route 15 near I-80, Dover, Morris County, NJ

  5. 30 CFR 816.72 - Disposal of excess spoil: Valley fills/head-of-hollow fills.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-hollow fills. 816.72 Section 816.72 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-SURFACE MINING ACTIVITIES § 816.72 Disposal of excess spoil: Valley fills/head-of-hollow fills. Valley fills and head-of-hollow fills shall meet the requirements of § 816.71 and the...

  6. 30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-hollow fills. 817.72 Section 817.72 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.72 Disposal of excess spoil: Valley fill/head-of-hollow fills. Valley fills and head-of-hollow fills shall meet the requirements of § 817.71 and the...

  7. 30 CFR 816.72 - Disposal of excess spoil: Valley fills/head-of-hollow fills.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-hollow fills. 816.72 Section 816.72 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-SURFACE MINING ACTIVITIES § 816.72 Disposal of excess spoil: Valley fills/head-of-hollow fills. Valley fills and head-of-hollow fills shall meet the requirements of § 816.71 and the...

  8. 30 CFR 817.72 - Disposal of excess spoil: Valley fill/head-of-hollow fills.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-hollow fills. 817.72 Section 817.72 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.72 Disposal of excess spoil: Valley fill/head-of-hollow fills. Valley fills and head-of-hollow fills shall meet the requirements of § 817.71 and the...

  9. Opening carbon nanotubes with oxygen and implications for filling

    NASA Astrophysics Data System (ADS)

    Ajayan, P. M.; Ebbesen, T. W.; Ichihashi, T.; Iijima, S.; Tanigaki, K.; Hiura, H.

    1993-04-01

    CAPPED hollow carbon nanotubes1,2 can be modified into nanocomposite fibres by simultaneous opening of the caps (by heating in the presence of air and lead metal) and filling of the interior with an inorganic phase3. To generalize this approach, greater understanding is needed of the reaction mechanism between the tube caps and oxygen. Here we report that the oxidation of carbon nanotubes in air for short durations above about 700 °C results in the etching away of the tube caps and the thinning of tubes through layer-by-layer peeling of the outer layers, starting from the cap region. The oxidation reaction follows an Arrhenius-type relation with an activation energy barrier of about 225 kJ mol-1 in air. Heating of closed nanotubes with an oxide (Pb3O4) in an inert atmosphere lowers the activation barrier for the reaction and opening of the tubes occurs at lower temperatures. Contrary to intuition, however, open tubes are much more difficult to fill with inorganic materials than in the one-step filling of tubes reported previously3. But various other experiments might be possible in the inner nano-cavities of the open tubes such as studies of catalysis and of low-dimensional chemistry and physics.

  10. Initialized Fractional Calculus

    NASA Technical Reports Server (NTRS)

    Lorenzo, Carl F.; Hartley, Tom T.

    2000-01-01

    This paper demonstrates the need for a nonconstant initialization for the fractional calculus and establishes a basic definition set for the initialized fractional differintegral. This definition set allows the formalization of an initialized fractional calculus. Two basis calculi are considered; the Riemann-Liouville and the Grunwald fractional calculi. Two forms of initialization, terminal and side are developed.

  11. Tempered fractional calculus

    NASA Astrophysics Data System (ADS)

    Sabzikar, Farzad; Meerschaert, Mark M.; Chen, Jinghua

    2015-07-01

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  12. Tempered fractional calculus

    SciTech Connect

    Sabzikar, Farzad; Meerschaert, Mark M.; Chen, Jinghua

    2015-07-15

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  13. Fractional quantum Hall effect in the absence of Landau levels.

    PubMed

    Sheng, D N; Gu, Zheng-Cheng; Sun, Kai; Sheng, L

    2011-01-01

    It is well known that the topological phenomena with fractional excitations, the fractional quantum Hall effect, will emerge when electrons move in Landau levels. Here we show the theoretical discovery of the fractional quantum Hall effect in the absence of Landau levels in an interacting fermion model. The non-interacting part of our Hamiltonian is the recently proposed topologically non-trivial flat-band model on a checkerboard lattice. In the presence of nearest-neighbouring repulsion, we find that at 1/3 filling, the Fermi-liquid state is unstable towards the fractional quantum Hall effect. At 1/5 filling, however, a next-nearest-neighbouring repulsion is needed for the occurrence of the 1/5 fractional quantum Hall effect when nearest-neighbouring repulsion is not too strong. We demonstrate the characteristic features of these novel states and determine the corresponding phase diagram.

  14. TEMPERED FRACTIONAL CALCULUS

    PubMed Central

    MEERSCHAERT, MARK M.; SABZIKAR, FARZAD; CHEN, JINGHUA

    2014-01-01

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series. PMID:26085690

  15. Sound propagation in and low frequency noise absorption by helium-filled porous material.

    PubMed

    Choy, Y S; Huang, Lixi; Wang, Chunqi

    2009-12-01

    Low-frequency noise is difficult to deal with by traditional porous material due to its inherent high acoustic impedance. This study seeks to extend the effective range of sound absorption to lower frequencies by filling a low density gas, such as helium, in the porous material. Compared with conventional air-filled absorption material, the helium-filled porous material has a much reduced characteristic impedance; hence, a good impedance matching with pure air becomes more feasible at low frequencies. The acoustic properties of a series of helium-filled porous materials are investigated with a specially designed test rig. The characteristic of the sound propagation in a helium-filled porous material is established and validated experimentally. Based on the measured acoustic properties, the sound absorption performance of a helium-filled absorber (HA) of finite thickness is studied numerically as well as experimentally. For a random incidence field, the HA is found to perform much better than the air-filled absorber at low frequencies. The main advantage of HA lies in the middle range of oblique incidence angles where wave refraction in the absorber enhances sound absorption. The advantage of HA as duct lining is demonstrated both numerically and experimentally.

  16. 7 CFR 58.923 - Filling containers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Filling containers. 58.923 Section 58.923 Agriculture... Procedures § 58.923 Filling containers. (a) The filling of small containers with product shall be done in a sanitary manner. The containers shall not contaminate or detract from the quality of the product in any...

  17. Filling of carbon nanotubes and nanofibres

    PubMed Central

    Gately, Reece D

    2015-01-01

    Summary The reliable production of carbon nanotubes and nanofibres is a relatively new development, and due to their unique structure, there has been much interest in filling their hollow interiors. In this review, we provide an overview of the most common approaches for filling these carbon nanostructures. We highlight that filled carbon nanostructures are an emerging material for biomedical applications. PMID:25821693

  18. Experiments with Helium-Filled Balloons

    NASA Astrophysics Data System (ADS)

    Zable, Anthony C.

    2010-12-01

    The concepts of Newtonian mechanics, fluids, and ideal gas law physics are often treated as separate and isolated topics in the typical introductory college-level physics course, especially in the laboratory setting. To bridge these subjects, a simple experiment was developed that utilizes computer-based data acquisition sensors and a digital gram scale to estimate the molar mass of the gas in an inflated balloon. In this experiment, the comparable density of an inflated balloon to that of atmospheric air introduces a significant role for buoyancy that must be accounted for. The ideal gas law approximation is assumed for both the isolated gas mixture within the balloon and the surrounding air, which defines the relationship between the gas pressure, volume, temperature, and molar quantity. Analysis of the forces associated with the inflated balloon with the incorporation of Archimedes' principle and the ideal gas law into Newton's second law results in an experimental method for the measurement of the molar mass and mole fraction of a gas that is easy to implement yet academically challenging for students. The following narrative describes the basic setup of this experiment, along with a sample set of data as acquired and analyzed by a typical physics student from one of my classes.

  19. Comparing three gap filling methods for eddy covariance crop evapotranspiration measurements within a hilly agricultural catchment

    NASA Astrophysics Data System (ADS)

    Boudhina, Nissaf; Prévot, Laurent; Zitouna Chebbi, Rim; Mekki, Insaf; Jacob, Frédéric; Ben Mechlia, Netij; Masmoudi, Moncef

    2015-04-01

    Hilly watersheds are widespread throughout coastal areas around the Mediterranean Basin. They experience agricultural intensification since hilly topographies allow water-harvesting techniques that compensate for rainfall storage, water being a strong limiting factor for crop production. Their fragility is likely to increase with climate change and human pressure. Within semi-arid hilly watershed conditions, evapotranspiration (ETR) is a major term of both land surface energy and water balances. Several methods allow determining ETR, based either on direct measurements, or on estimations and forecast from weather and soil moisture data using simulation models. Among these methods, eddy covariance technique is based on high-frequency measurements of fluctuations of wind speed and air temperature / humidity, to directly determine the convective fluxes between land surface and atmosphere. In spite of experimental and instrumental progresses, datasets of eddy covariance measurements often experience large portions of missing data. The latter results from energy power failure, experimental maintenance, instrumental troubles such as krypton hygrometer malfunctioning because of air humidity, or quality assessment based filtering in relation to spatial homogeneity and temporal stationarity of turbulence within surface boundary layer. This last item is all the more important as hilly topography, when combined with strong winds, tends to increase turbulence within surface boundary layer. The main objective of this study is to establish gap-filling procedures to provide complete chronicles of eddy-covariance measurements of crop evapotranspiration (ETR) within a hilly agricultural watershed. We focus on the specific conditions induced by the combination of hilly topography and wind direction, by discriminating between upslope and downslope winds. The experiment was set for three field configurations within hilly conditions: two flux measurement stations (A, B) were installed

  20. Localized Memory Effect of Elastomers Filled with Nanoparticles

    NASA Astrophysics Data System (ADS)

    Li, Shoubo; Wang, Xiaorong

    When a filler-reinforced elastomer compound is oscillatory sheared or pressed at a small fixed strain (e.g., 2%) for a period of time, it can produce a localized memory perturbation in its dynamic spectrum. Typically, a localized memory appears near the applied strain amplitude in the loss modulus spectrum. Sequential holding the system at two strains can produce one or two holes depending on the deformation histories. While this discovery of localized memory effect seems to be significant and compelling, its generality in vulcanized elastomers containing various fillers has not yet been tested extensively. In this work, we intend to expand on our previous work of a colloidal silica-filled model system to carbon black-filled real rubbers. We also examine the effect of filler volume fraction in rubber compounds on the spectral memory phenomenon.

  1. Defect-enhanced void filling and novel filled phases of open-structure skutterudites

    DOE PAGES

    Xi, Lili; Qiu, Yuting; Zhang, Wenqing; Chen, Lidong; Singh, David J.; Yang, Jihui

    2015-05-14

    Here, we report the design of novel filled CoSb3 skutterudite phases based on a combination of filling and Sb-substituted Ga/In defects. Ga/In doped skutterudite phases with Li-, Nd-, and Sm-fillings can be formed via this strategy, which can have relatively wider ranges of carrier concentration than other conventional filled skutterudite phases.

  2. Defect-enhanced void filling and novel filled phases of open-structure skutterudites

    SciTech Connect

    Xi, Lili; Qiu, Yuting; Zhang, Wenqing; Chen, Lidong; Singh, David J.; Yang, Jihui

    2015-05-14

    Here, we report the design of novel filled CoSb3 skutterudite phases based on a combination of filling and Sb-substituted Ga/In defects. Ga/In doped skutterudite phases with Li-, Nd-, and Sm-fillings can be formed via this strategy, which can have relatively wider ranges of carrier concentration than other conventional filled skutterudite phases.

  3. Thermal Performance Evaluation of Walls with Gas Filled Panel Insulation

    SciTech Connect

    Shrestha, Som S.; Desjarlais, Andre Omer; Atchley, Jerald Allen

    2014-11-01

    Gas filled insulation panels (GFP) are very light weight and compact (when uninflated) advanced insulation products. GFPs consist of multiple layers of thin, low emittance (low-e) metalized aluminum. When expanded, the internal, low-e aluminum layers form a honeycomb structure. These baffled polymer chambers are enveloped by a sealed barrier and filled with either air or a low-conductivity gas. The sealed exterior aluminum foil barrier films provide thermal resistance, flammability protection, and properties to contain air or a low conductivity inert gas. This product was initially developed with a grant from the U.S. Department of Energy. The unexpanded product is nearly flat for easy storage and transport. Therefore, transportation volume and weight of the GFP to fill unit volume of wall cavity is much smaller compared to that of other conventional insulation products. This feature makes this product appealing to use at Army Contingency Basing, when transportation cost is significant compared to the cost of materials. The objective of this study is to evaluate thermal performance of walls, similar to those used at typical Barracks Hut (B-Hut) hard shelters, when GFPs are used in the wall cavities. Oak Ridge National Laboratory (ORNL) tested performance of the wall in the rotatable guarded hotbox (RGHB) according to the ASTM C 1363 standard test method.

  4. Wetting process of copper filling in through silicon vias

    NASA Astrophysics Data System (ADS)

    Zhang, Junhong; Luo, Wei; Li, Yi; Gao, Liming; Li, Ming

    2015-12-01

    In this paper, wetting process of copper filling in through silicon vias was investigated by agitation and vacuum pretreatment. Copper filling followed the pretreatment was fabricated in electrolyte with optimal additives concentration. By agitation pretreatment, a large void was observed at the bottom of the vias where the copper seed layer was clearly seen, which was attributed to the insufficient wetting of vias. In the blind vias with higher aspect ratio, the ambient gas phase was difficult to be completely removed from the vias by agitation. This resulted in electrolyte having better wettability does not reach all the places of the vias by capillarity. The vacuum pretreatment results suggested that the air inside the vias was almost completely evacuated. Hence, the deionized water used as wetting solution easily permeated the blind vias relying on atmospheric pressure. Consequently, the uniform, complete and void-free copper filling was achieved due to better wettability of 273 K deionized water. Nevertheless, deionized water with temperature higher than the critical vaporization temperature yielded a void formation at the bottom of the vias, which resulted from the insufficient wetting caused by the vaporization of deionized water. The conclusions drawn by the experimental results were employed in the through silicon vias, and void-free copper filling in the vias having aspect ratio as high as 16 was fabricated.

  5. Investigation and calculation of filling factor of SnO2 inverse opal

    NASA Astrophysics Data System (ADS)

    Wang, Jinquan; Wu, Shimin; Ji, Xiaoyuan; Li, Jinpeng; Zhang, Rong; Zhang, Ming

    2016-04-01

    In the process of preparing inverse opal, the structure of inverse opal is affected by many factors, and the filling factor of inverse opal is difficult to directly test. In this paper, SnO2 inverse opal was prepared with the sol-gel method by cooperative opal template. The repetition times of the infiltrating precursor into the opal templates were investigated in detail. The band-gap positions of SnO2 inverse opal were tested. In order to prepare perfect inverse opal structure, the filling quantity of the precursor is greater, as the diameter of the PS microsphere of opal is bigger. The filling factor of air in inverse opal can be calculated with a formula derived from Bragg’s law. For inverse opal, the filling factor of air in inverse opal gradually enlarges as the diameter of the void increases.

  6. System-level simulation of liquid filling in microfluidic chips.

    PubMed

    Song, Hongjun; Wang, Yi; Pant, Kapil

    2011-06-01

    Liquid filling in microfluidic channels is a complex process that depends on a variety of geometric, operating, and material parameters such as microchannel geometry, flow velocity∕pressure, liquid surface tension, and contact angle of channel surface. Accurate analysis of the filling process can provide key insights into the filling time, air bubble trapping, and dead zone formation, and help evaluate trade-offs among the various design parameters and lead to optimal chip design. However, efficient modeling of liquid filling in complex microfluidic networks continues to be a significant challenge. High-fidelity computational methods, such as the volume of fluid method, are prohibitively expensive from a computational standpoint. Analytical models, on the other hand, are primarily applicable to idealized geometries and, hence, are unable to accurately capture chip level behavior of complex microfluidic systems. This paper presents a parametrized dynamic model for the system-level analysis of liquid filling in three-dimensional (3D) microfluidic networks. In our approach, a complex microfluidic network is deconstructed into a set of commonly used components, such as reservoirs, microchannels, and junctions. The components are then assembled according to their spatial layout and operating rationale to achieve a rapid system-level model. A dynamic model based on the transient momentum equation is developed to track the liquid front in the microchannels. The principle of mass conservation at the junction is used to link the fluidic parameters in the microchannels emanating from the junction. Assembly of these component models yields a set of differential and algebraic equations, which upon integration provides temporal information of the liquid filling process, particularly liquid front propagation (i.e., the arrival time). The models are used to simulate the transient liquid filling process in a variety of microfluidic constructs and in a multiplexer, representing a

  7. System-level simulation of liquid filling in microfluidic chips.

    PubMed

    Song, Hongjun; Wang, Yi; Pant, Kapil

    2011-06-01

    Liquid filling in microfluidic channels is a complex process that depends on a variety of geometric, operating, and material parameters such as microchannel geometry, flow velocity∕pressure, liquid surface tension, and contact angle of channel surface. Accurate analysis of the filling process can provide key insights into the filling time, air bubble trapping, and dead zone formation, and help evaluate trade-offs among the various design parameters and lead to optimal chip design. However, efficient modeling of liquid filling in complex microfluidic networks continues to be a significant challenge. High-fidelity computational methods, such as the volume of fluid method, are prohibitively expensive from a computational standpoint. Analytical models, on the other hand, are primarily applicable to idealized geometries and, hence, are unable to accurately capture chip level behavior of complex microfluidic systems. This paper presents a parametrized dynamic model for the system-level analysis of liquid filling in three-dimensional (3D) microfluidic networks. In our approach, a complex microfluidic network is deconstructed into a set of commonly used components, such as reservoirs, microchannels, and junctions. The components are then assembled according to their spatial layout and operating rationale to achieve a rapid system-level model. A dynamic model based on the transient momentum equation is developed to track the liquid front in the microchannels. The principle of mass conservation at the junction is used to link the fluidic parameters in the microchannels emanating from the junction. Assembly of these component models yields a set of differential and algebraic equations, which upon integration provides temporal information of the liquid filling process, particularly liquid front propagation (i.e., the arrival time). The models are used to simulate the transient liquid filling process in a variety of microfluidic constructs and in a multiplexer, representing a

  8. Fractional quantum Hall states of Rydberg polaritons

    NASA Astrophysics Data System (ADS)

    Maghrebi, Mohammad F.; Yao, Norman Y.; Hafezi, Mohammad; Pohl, Thomas; Firstenberg, Ofer; Gorshkov, Alexey V.

    2015-03-01

    We propose a scheme for realizing fractional quantum Hall states of light. In our scheme, photons of two polarizations are coupled to different atomic Rydberg states to form two flavors of Rydberg polaritons that behave as an effective spin. An array of optical cavity modes overlapping with the atomic cloud enables the realization of an effective spin-1 /2 lattice. We show that the dipolar interaction between such polaritons, inherited from the Rydberg states, can be exploited to create a flat, topological band for a single spin-flip excitation. At half filling, this gives rise to a photonic (or polaritonic) fractional Chern insulator—a lattice-based, fractional quantum Hall state of light.

  9. Classification of munition fill using laser acoustics

    SciTech Connect

    Rodriguez, J.G.; Blackwood, L.G.

    1997-08-01

    Identification of a munition fill is easier if one can determine if there is fill material present (empty versus full), and if so, the phase (solid or liquid) of the fill. Previous munition inspection efforts by the Idaho National Engineering and Environmental Laboratory (INEEL) determined that resonance information could determine the fill. A portable, noncontacting laser-acoustic system was developed by INEEL that uses a low-power laser system to measure the container`s vibration characteristics in response to an acoustic excitation. These vibration characteristics were shown to be functions of the fill material and munition geometry. The laser acoustic system was used to characterize the fill of over one hundred 155-mm munitions. Additional research and development using this system is being performed for the Mobile Munitions Assessment System.

  10. Capillary filling dynamics of viscoelastic fluids

    NASA Astrophysics Data System (ADS)

    Bandopadhyay, Aditya; Ghosh, Uddipta; Chakraborty, Suman

    2014-05-01

    We consider the filling of a capillary by a viscoelastic fluid described by the Phan-Thien-Tanner (PTT) constitutive behavior. By considering both vertical capillary filling and horizontal capillary filling, we demarcate the role played by gravity and fluid rheology towards long-time oscillations in the capillary penetration depth. We also consider the isothermal filling of the capillary for a closed channel and thus bring out the fundamental differences in the nature of capillary filling for PTT and Newtonian fluids for closed channels in comparison to open channels. Through a scaling analysis, we highlight a distinct viscoelastic regime in the horizontal capillary filling which is in contrast to the Washburn scaling seen in the case of Newtonian fluids. Such an analysis with a very general constitutive behavior is therefore expected to shed light on many areas of microfluidics which focus on biofluids that are often well described by the PTT constitutive behavior.

  11. Filling of orbital fluid management systems

    NASA Technical Reports Server (NTRS)

    Merino, F.; Blatt, M. H.; Thies, N. C.

    1978-01-01

    A study was performed with three objectives: (1) analyze fluid management system fill under orbital conditions; (2) determine what experimentation is needed; and (3) develop an experimental program. The fluid management system was a 1.06m (41.7 in) diameter pressure vessel with screen channel device. Analyses were conducted using liquid hydrogen and N2O4. The influence of helium and autogenous pressurization systems was considered. Analyses showed that fluid management system fill will be more difficult with a cryogen than with an earth storable. The key to a successful fill with cryogens is in devising techniques for filling without vent liquid, and removing trapped vapor from the screen device at tank fill completion. This will be accomplished with prechill, fill, and vapor condensation processes. Refill will require a vent and purge process, to dilute the residual helium, prior to introducing liquid. Neither prechill, chill, nor purge processes will be required for earth storables.

  12. Mechanisms of tracheal filling in insects.

    PubMed

    Förster, Thomas D; Woods, H Arthur

    2013-02-01

    Insects exchange respiratory gases primarily using tracheal systems that are filled with gas. However, in different developmental and environmental circumstances, liquid can occupy the tracheal system, which can significantly impair its respiratory function. Insects therefore use a suite of mechanisms for tracheal filling, which is the process of replacing tracheal liquids with gas. We review these mechanisms for liquid removal and gas filling. By integrating recent molecular work with older physiological literature, we show that liquid removal likely involves active ion transport in the whole tracheal system. Gas filling reveals fascinating interactions between geometry, surface chemistry of the tracheal walls, the tracheal liquid, and dissolved gases. The temporal proximity to moulting allows for potentially complex interdependencies between gas filling, moult-associated hormone signaling, and cuticle sclerotization. We propose a mechanistic model for tracheal filling. However, because the composition of the liquid is unknown, it remains hypothetical. PMID:22616845

  13. Undercut and fill system for pitching coal. Open file report Aug 79-Jun 81

    SciTech Connect

    Mangolds, A.; Fisk, A.

    1981-06-01

    A study of the technical and economic feasibility of using a unique undercut and fill system developed by Bureau of Mines engineers to mine steeply pitching coal is discussed. The undercut and fill system combines hydraulic coal cutting with unassisted gravity fluming of the coal slurry. Mining occurs across strike and the extended entry is backfilled to provide uniform strata control and an impermeable water and air barrier. Subsequent mining occurs beneath the previously filled stope such that the roof consists of a solid, controlled back.

  14. A method to determine true air temperature fluctuations in clouds with liquid water fraction and estimate water droplet effect on the calculations of the spectral structure of turbulent heat fluxes in cumulus clouds based on aircraft data

    NASA Astrophysics Data System (ADS)

    Strunin, Alexander M.; Zhivoglotov, Dmitriy N.

    2014-03-01

    Liquid water droplets could distort aircraft temperature measurements in clouds, leading to errors in calculated heat fluxes and incorrect flux distribution pattern. The estimation of cloud droplet effect on the readings of the high-frequency aircraft thermometer employed at the Central Aerological Observatory (CAO) was based on an experimental study of the sensor in a wind tunnel, using an air flow containing liquid water droplets. Simultaneously, calculations of the distribution of speed and temperature in a flow through the sensitive element of the sensor were fulfilled. This permitted estimating the coefficient of water content effect on temperature readings. Another way of estimating cloud droplet effect was based on the analysis of data obtained during aircraft observations of cumulus clouds in a tropical zone (Cuba Island). As a result, a method of correcting air temperature and recovering true air temperature fluctuations inside clouds was developed. This method has provided consistent patterns of heat flux distribution in a cumulus area. Analysis of the results of aircraft observations of cumulus clouds with temperature correction fulfilled has permitted investigation of the spectral structure of the fields of air temperature and heat fluxes to be performed in cumulus zones based on wavelet transformation. It is shown that mesoscale eddies (over 500 m in length) were the main factor of heat exchange between a cloud and the ambient space. The role of turbulence only consisted in mixing inside the cloud.

  15. Dividing Fractions: A Pedagogical Technique

    ERIC Educational Resources Information Center

    Lewis, Robert

    2016-01-01

    When dividing one fraction by a second fraction, invert, that is, flip the second fraction, then multiply it by the first fraction. To multiply fractions, simply multiply across the denominators, and multiply across the numerators to get the resultant fraction. So by inverting the division of fractions it is turned into an easy multiplication of…

  16. Effective use of fly ash slurry as fill material.

    PubMed

    Horiuchi, S; Kawaguchi, M; Yasuhara, K

    2000-09-15

    A lot of effort has been put into increasing coal ash utilization; however, 50% of total amount is disposed of on land and in the sea. Several attempts have been reported recently concerning slurried coal fly ash use for civil engineering materials, such as for structural fill and backfill. The authors have studied this issue for more than 15 years and reported its potential for (1) underwater fills, (2) light weight backfills, and (3) light weight structural fills, through both laboratory tests and construction works. This paper is an overview of the results obtained for slurry, focusing on the following. (1) Coal fly ash reclaimed by slurry placement shows lower compressibility, higher ground density, and higher strength than by the other methods. This higher strength increases stability against liquefaction during earthquake. (2) Higher stability of the fly ash ground formed by slurry placement is caused by higher density and its self-hardening property. (3) Stability of fly ash reclaimed ground can be increased by increasing density and also by strength enhancement by cement addition. (4) Technical data obtained through a man-made island construction project shows the advantages of fly ash slurry in terms of mechanical properties such as higher stability against sliding failure, sufficient ground strength, and also in terms of cost saving. (5) Concentration in leachates from the placed slurry is lower than the Japanese environmental law. (6) In order to enlarge the fly ash slurry application toward a lightweight fill, mixtures of air foam, cement and fly ash were examined. Test results shows sufficient durability of this material against creep failure. This material was then used as lightweight structural fill around a high-rise building, and showed sufficient quality. From the above data, it can be concluded that coal fly ash slurry can be effectively utilized in civil engineering projects.

  17. Mekong Floods Fill Tonle Sap

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The monsoon season in Southeast Asia brings recurring, often devastating floods to countries in the region, but these floods also play a necessary role in the region's water cycle. These MODIS images centered on Cambodia reveal extensive flooding of the Mekong River, which comes in from Laos in the north, to the right of center in the images, and flows south through Cambodia and southeast through Vietnam to empty into the South China Sea. The true-color image shows the brownish, sediment-laden floodwaters filling the Mekong Delta in southern Cambodia and Vietnam on September 15, 2001. The false color image above has been enhanced to bring out the contrast between the floodwaters and the lands, with sediment-carrying floodwaters in purple. Sediment can be seen flowing into the South China Sea as well. This year's floods have affected over a million people, and 100 people have been killed in Vietnam alone. The monsoon floods bring not only devastation, but renewal. The large body of water just left of center in Cambodia is the Tonle Sap. This shallow lake plays a changing role in the regional water cycle. During the dry season, the stream-fed Tonle Sap drains via the Tonle Sab River into the Mekong River. During the wet season (June-November), flooding of the Mekong reverses the course of the Tonle Sab, roughly tripling the lake's size from about 3000 km2 to about 10,000. When the dry season returns, the lake once again begins to drain into the Mekong Delta, where it provides a flow of fresh water that balances the intrusion of salty seawater into the delta's agricultural lands. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  18. Laplace homotopy perturbation method for Burgers equation with space- and time-fractional order

    NASA Astrophysics Data System (ADS)

    Johnston, S. J.; Jafari, H.; Moshokoa, S. P.; Ariyan, V. M.; Baleanu, D.

    2016-07-01

    The fractional Burgers equation describes the physical processes of unidirectional propagation of weakly nonlinear acoustic waves through a gas-filled pipe. The Laplace homotopy perturbation method is discussed to obtain the approximate analytical solution of space-fractional and time-fractional Burgers equations. The method used combines the Laplace transform and the homotopy perturbation method. Numerical results show that the approach is easy to implement and accurate when applied to partial differential equations of fractional orders.

  19. ECO fill: automated fill modification to support late-stage design changes

    NASA Astrophysics Data System (ADS)

    Davis, Greg; Wilson, Jeff; Yu, J. J.; Chiu, Anderson; Chuang, Yao-Jen; Yang, Ricky

    2014-03-01

    One of the most critical factors in achieving a positive return for a design is ensuring the design not only meets performance specifications, but also produces sufficient yield to meet the market demand. The goal of design for manufacturability (DFM) technology is to enable designers to address manufacturing requirements during the design process. While new cell-based, DP-aware, and net-aware fill technologies have emerged to provide the designer with automated fill engines that support these new fill requirements, design changes that arrive late in the tapeout process (as engineering change orders, or ECOs) can have a disproportionate effect on tapeout schedules, due to the complexity of replacing fill. If not handled effectively, the impacts on file size, run time, and timing closure can significantly extend the tapeout process. In this paper, the authors examine changes to design flow methodology, supported by new fill technology, that enable efficient, fast, and accurate adjustments to metal fill late in the design process. We present an ECO fill methodology coupled with the support of advanced fill tools that can quickly locate the portion of the design affected by the change, remove and replace only the fill in that area, while maintaining the fill hierarchy. This new fill approach effectively reduces run time, contains fill file size, minimizes timing impact, and minimizes mask costs due to ECO-driven fill changes, all of which are critical factors to ensuring time-to-market schedules are maintained.

  20. Contaminants in ventilated filling boxes

    NASA Astrophysics Data System (ADS)

    Bolster, D. T.; Linden, P. F.

    While energy efficiency is important, the adoption of energy-efficient ventilation systems still requires the provision of acceptable indoor air quality. Many low-energy systems, such as displacement or natural ventilation, rely on temperature stratification within the interior environment, always extracting the warmest air from the top of the room. Understanding buoyancy-driven convection in a confined ventilated space is key to understanding the flow that develops with many of these modern low-energy ventilation schemes. In this work we study the transport of an initially uniformly distributed passive contaminant in a displacement-ventilated space. Representing a heat source as an ideal sourced of buoyancy, analytical and numerical models are developed that allow us to compare the average efficiency of contaminant removal between traditional mixing and modern low-energy systems. A set of small-scale analogue laboratory experiments was also conducted to further validate our analytical and numerical solutions.We find that on average traditional and low-energy ventilation methods are similar with regard to pollutant flushing efficiency. This is because the concentration being extracted from the system at any given time is approximately the same for both systems. However, very different vertical concentration gradients exist. For the low-energy system, a peak in contaminant concentration occurs at the temperature interface that is established within the space. This interface is typically designed to sit at some intermediate height in the space. Since this peak does not coincide with the extraction point, displacement ventilation does not offer the same benefits for pollutant flushing as it does for buoyancy removal.

  1. Recent progress in the theory of composite fermions near even-denominator filling factors

    NASA Astrophysics Data System (ADS)

    Read, N.

    1996-07-01

    Theories of compressible and incompressible states at filling factors v = 1/2, 1/4, 1/3, 2/5, ... in the fractional quantum Hall regime will be reviewed using mainly physical pictures. Our current understanding, and its relation to experiments, will be discussed.

  2. Critical temperature of noninteracting bosonic gases in cubic optical lattices at arbitrary integer fillings

    NASA Astrophysics Data System (ADS)

    Rakhimov, Abdulla; Askerzade, Iman N.

    2014-09-01

    We have shown that the critical temperature of a Bose-Einstein condensate to a normal phase transition of noninteracting bosons in cubic optical lattices has a linear dependence on the filling factor, especially at large densities. The condensed fraction exhibits a linear power law dependence on temperature in contrast to the case of ideal homogeneous Bose gases.

  3. Effect of particle size and density on the die fill of powders.

    PubMed

    Mills, L A; Sinka, I C

    2013-08-01

    The flow behaviour of powders during the process of die fill was examined. Gravity and suction fill experiments were carried out using a model shoe-die system. Five grades of microcrystalline cellulose were studied to identify the effect of particle size and density on flow. Flowability was quantified using the concept of critical velocity. Under gravity fill, the critical velocity was one order of magnitude higher for powders with large particle size compared to smaller particles. Under suction fill conditions, the critical velocity increased significantly compared to gravity fill, showed no consistent relationship with particle size, and the powders performed more similar to one another. Using high speed video, the gravity and suction fill mechanisms were discussed in the context of air flow and pressure build-up. The effect of shoe velocity, suction velocity and height of the powder in the shoe was explored in more detail. It was shown that one can identify individual contributions from material properties and process parameters to the flow behaviour during die fill; however, the flow performance depends on the inter-relationships between powder characteristics and process parameters. The die fill mechanisms described can be used to assist the optimisation of powder formulation and process design.

  4. Influence of template fill in graphoepitaxy DSA

    NASA Astrophysics Data System (ADS)

    Doise, Jan; Bekaert, Joost; Chan, Boon Teik; Hong, SungEun; Lin, Guanyang; Gronheid, Roel

    2016-03-01

    Directed self-assembly (DSA) of block copolymers (BCP) is considered a promising patterning approach for the 7 nm node and beyond. Specifically, a grapho-epitaxy process using a cylindrical phase BCP may offer an efficient solution for patterning randomly distributed contact holes with sub-resolution pitches, such as found in via and cut mask levels. In any grapho-epitaxy process, the pattern density impacts the template fill (local BCP thickness inside the template) and may cause defects due to respectively over- or underfilling of the template. In order to tackle this issue thoroughly, the parameters that determine template fill and the influence of template fill on the resulting pattern should be investigated. In this work, using three process flow variations (with different template surface energy), template fill is experimentally characterized as a function of pattern density and film thickness. The impact of these parameters on template fill is highly dependent on the process flow, and thus pre-pattern surface energy. Template fill has a considerable effect on the pattern transfer of the DSA contact holes into the underlying layer. Higher fill levels give rise to smaller contact holes and worse critical dimension uniformity. These results are important towards DSA-aware design and show that fill is a crucial parameter in grapho-epitaxy DSA.

  5. Air Pollution

    MedlinePlus

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's ...

  6. An Appetite for Fractions

    ERIC Educational Resources Information Center

    Wilkerson, Trena L.; Bryan, Tommy; Curry, Jane

    2012-01-01

    This article describes how using candy bars as models gives sixth-grade students a taste for learning to represent fractions whose denominators are factors of twelve. Using paper models of the candy bars, students explored and compared fractions. They noticed fewer different representations for one-third than for one-half. The authors conclude…

  7. (Carbon isotope fractionation inplants)

    SciTech Connect

    O'Leary, M.H.

    1990-01-01

    The objectives of this research are: To develop a theoretical and experimental framework for understanding isotope fractionations in plants; and to develop methods for using this isotope fractionation for understanding the dynamics of CO{sub 2} fixation in plants. Progress is described.

  8. The Future of Fractions

    ERIC Educational Resources Information Center

    Usiskin, Zalman P.

    2007-01-01

    In the 1970s, the movement to the metric system (which has still not completely occurred in the United States) and the advent of hand-held calculators led some to speculate that decimal representation of numbers would render fractions obsolete. This provocative proposition stimulated Zalman Usiskin to write "The Future of Fractions" in 1979. He…

  9. The polystyrene microsphere filling with hydrogen isotopes through the fill tube with consequent freezing

    NASA Astrophysics Data System (ADS)

    Izgorodin, V. M.; Solomatina, E. Y.; Pepelyaev, A. P.; Rogozhina, M. A.; Osetrov, E. I.

    2016-09-01

    Process of spherical polystyrene capsules filling with hydrogen isotopes through the fill tube for the purpose of a cryogenic target building is described. The scheme of the stand for researches and a technique of carrying out of experiments is represented. Results of capsules filling and subsequent freezing for protium, deuterium and protium- deuterium mixture are shown.

  10. Fractional quantum Hall effect in a tilted magnetic field

    NASA Astrophysics Data System (ADS)

    Papić, Z.

    2013-06-01

    We discuss the orbital effect of a tilted magnetic field on the quantum Hall effect in parabolic quantum wells. Many-body states realized at the fractional (1)/(3) and (1)/(2) filling of the second electronic subband are studied using finite-size exact diagonalization. In both cases, we obtain the phase diagram consisting of a fractional quantum Hall fluid phase that persists for moderate tilts, and eventually undergoes a direct transition to the stripe phase. It is shown that tilting of the field probes the geometrical degree of freedom of fractional quantum Hall fluids, and can be partly related to the effect of band-mass anisotropy.

  11. Droplet Measurement below Single-Layer Grid Fill

    NASA Astrophysics Data System (ADS)

    Vitkovic, Pavol

    2016-03-01

    The main part of the heat transfer in a cooling tower is in a fill zone. This one is consist of a cooling fill. For the cooling tower is used a film fill or grid fill or splash fill in the generally. The grid fill has lower heat transfer performance like film fill usually. But their advantage is high resistance to blockage of the fill. The grid fill is consisted with independent layers made from plastic usually. The layers consist of several bars connected to the different shapes. For experiment was used the rhombus shape. The drops diameter was measured above and below the Grid fill.

  12. Improved quantification of microbial CH4 oxidation efficiency in arctic wetland soils using carbon isotope fractionation

    NASA Astrophysics Data System (ADS)

    Preuss, I.; Knoblauch, C.; Gebert, J.; Pfeiffer, E.-M.

    2013-04-01

    Permafrost-affected tundra soils are significant sources of the climate-relevant trace gas methane (CH4). The observed accelerated warming of the arctic will cause deeper permafrost thawing, followed by increased carbon mineralization and CH4 formation in water-saturated tundra soils, thus creating a positive feedback to climate change. Aerobic CH4 oxidation is regarded as the key process reducing CH4 emissions from wetlands, but quantification of turnover rates has remained difficult so far. The application of carbon stable isotope fractionation enables the in situ quantification of CH4 oxidation efficiency in arctic wetland soils. The aim of the current study is to quantify CH4 oxidation efficiency in permafrost-affected tundra soils in Russia's Lena River delta based on stable isotope signatures of CH4. Therefore, depth profiles of CH4 concentrations and δ13CH4 signatures were measured and the fractionation factors for the processes of oxidation (αox) and diffusion (αdiff) were determined. Most previous studies employing stable isotope fractionation for the quantification of CH4 oxidation in soils of other habitats (such as landfill cover soils) have assumed a gas transport dominated by advection (αtrans = 1). In tundra soils, however, diffusion is the main gas transport mechanism and diffusive stable isotope fractionation should be considered alongside oxidative fractionation. For the first time, the stable isotope fractionation of CH4 diffusion through water-saturated soils was determined with an αdiff = 1.001 ± 0.000 (n = 3). CH4 stable isotope fractionation during diffusion through air-filled pores of the investigated polygonal tundra soils was αdiff = 1.013 ± 0.003 (n = 18). Furthermore, it was found that αox differs widely between sites and horizons (mean αox = 1.017 ± 0.009) and needs to be determined on a case by case basis. The impact of both fractionation factors on the quantification of CH4 oxidation was analyzed by considering both the

  13. Fractional calculus in bioengineering.

    PubMed

    Magin, Richard L

    2004-01-01

    Fractional calculus (integral and differential operations of noninteger order) is not often used to model biological systems. Although the basic mathematical ideas were developed long ago by the mathematicians Leibniz (1695), Liouville (1834), Riemann (1892), and others and brought to the attention of the engineering world by Oliver Heaviside in the 1890s, it was not until 1974 that the first book on the topic was published by Oldham and Spanier. Recent monographs and symposia proceedings have highlighted the application of fractional calculus in physics, continuum mechanics, signal processing, and electromagnetics, but with few examples of applications in bioengineering. This is surprising because the methods of fractional calculus, when defined as a Laplace or Fourier convolution product, are suitable for solving many problems in biomedical research. For example, early studies by Cole (1933) and Hodgkin (1946) of the electrical properties of nerve cell membranes and the propagation of electrical signals are well characterized by differential equations of fractional order. The solution involves a generalization of the exponential function to the Mittag-Leffler function, which provides a better fit to the observed cell membrane data. A parallel application of fractional derivatives to viscoelastic materials establishes, in a natural way, hereditary integrals and the power law (Nutting/Scott Blair) stress-strain relationship for modeling biomaterials. In this review, I will introduce the idea of fractional operations by following the original approach of Heaviside, demonstrate the basic operations of fractional calculus on well-behaved functions (step, ramp, pulse, sinusoid) of engineering interest, and give specific examples from electrochemistry, physics, bioengineering, and biophysics. The fractional derivative accurately describes natural phenomena that occur in such common engineering problems as heat transfer, electrode/electrolyte behavior, and sub

  14. Fractional calculus in bioengineering.

    PubMed

    Magin, Richard L

    2004-01-01

    Fractional calculus (integral and differential operations of noninteger order) is not often used to model biological systems. Although the basic mathematical ideas were developed long ago by the mathematicians Leibniz (1695), Liouville (1834), Riemann (1892), and others and brought to the attention of the engineering world by Oliver Heaviside in the 1890s, it was not until 1974 that the first book on the topic was published by Oldham and Spanier. Recent monographs and symposia proceedings have highlighted the application of fractional calculus in physics, continuum mechanics, signal processing, and electromagnetics, but with few examples of applications in bioengineering. This is surprising because the methods of fractional calculus, when defined as a Laplace or Fourier convolution product, are suitable for solving many problems in biomedical research. For example, early studies by Cole (1933) and Hodgkin (1946) of the electrical properties of nerve cell membranes and the propagation of electrical signals are well characterized by differential equations of fractional order. The solution involves a generalization of the exponential function to the Mittag-Leffler function, which provides a better fit to the observed cell membrane data. A parallel application of fractional derivatives to viscoelastic materials establishes, in a natural way, hereditary integrals and the power law (Nutting/Scott Blair) stress-strain relationship for modeling biomaterials. In this review, I will introduce the idea of fractional operations by following the original approach of Heaviside, demonstrate the basic operations of fractional calculus on well-behaved functions (step, ramp, pulse, sinusoid) of engineering interest, and give specific examples from electrochemistry, physics, bioengineering, and biophysics. The fractional derivative accurately describes natural phenomena that occur in such common engineering problems as heat transfer, electrode/electrolyte behavior, and sub

  15. Modelling of air pressure effects in casting moulds

    NASA Astrophysics Data System (ADS)

    Attar, E.; Homayonifar, P.; Babaei, R.; Asgari, K.; Davami, P.

    2005-09-01

    In the casting process, as a mould is filled with molten metal, air escapes through the vents. Air pressure in the mould cavity has serious effects upon the filling behaviour such as surface profile of the molten metal and filling time. In this project a computational model was developed for calculation of air pressure during the mould filling. A 3D single phase code based on the SOLA-VOF algorithm was used for the prediction of the fluid flow. The ideal gas assumption, conservation of mass equation and Bernoulli law were used for the calculation of air pressure. A new algorithm was developed to interpolate air pressure on the surface cells. The creation of air pressure was correlated with the sizes of the vents and their locations. An experimental test was designed to verify the modelling results. Comparison between the experimental data and simulation results has shown a good agreement.

  16. Post-flight Analysis of the Argon Filled Ion Chamber

    NASA Technical Reports Server (NTRS)

    Tai, H.; Goldhagen, P.; Jones, I. W.; Wilson, J. W.; Maiden, D. L.; Shinn, J. L.

    2003-01-01

    Atmospheric ionizing radiation is a complex mixture of primary galactic and solar cosmic rays and a multitude of secondary particles produced in collision with air nuclei. The first series of Atmospheric Ionizing Radiation (AIR) measurement flights on the NASA research aircraft ER-2 took place in June 1997. The ER-2 flight package consisted of fifteen instruments from six countries and were chosen to provide varying sensitivity to specific components. These AIR ER-2 flight measurements are to characterize the AIR environment during solar minimum to allow the continued development of environmental models of this complex mixture of ionizing radiation. This will enable scientists to study the ionizing radiation health hazard associated with the high-altitude operation of a commercial supersonic transport and to allow estimates of single event upsets for advanced avionics systems design. The argon filled ion chamber representing about 40 percent of the contributions to radiation risks are analyzed herein and model discrepancies for solar minimum environment are on the order of 5 percent and less. Other biologically significant components remain to be analyzed.

  17. Autocorrelation spectra of an air-fluidized granular system measured by NMR

    NASA Astrophysics Data System (ADS)

    Lasic, S.; Stepisnik, J.; Mohoric, A.; Sersa, I.; Planinsic, G.

    2006-09-01

    A novel insight into the dynamics of a fluidized granular system is given by a nuclear magnetic resonance method that yields the spin-echo attenuation proportional to the spectrum of the grain positional fluctuation. Measurements of the air-fluidized oil-filled spheres and mustard seeds at different degrees of fluidization and grain volume fractions provide the velocity autocorrelation that differs from the commonly anticipated exponential Enskog decay. An empiric formula, which corresponds to the model of grain caging at collisions with adjacent beads, fits well to the experimental data. Its parameters are the characteristic collision time, the free path between collisions and the cage-breaking rate or the diffusion-like constant, which decreases with increasing grain volume fraction. Mean-squared displacements calculated from the correlation spectrum clearly show transitions from ballistic, through sub-diffusion and into diffusion regimes of grain motion.

  18. Stable Chlorine Isotope Fractionation

    NASA Astrophysics Data System (ADS)

    Sharp, Z.

    2006-12-01

    Chlorine isotope partitioning between different phases is not well understood. Pore fluids can have δ37Cl values as low as -8‰, with neoform sediments having strongly positive values. Most strikingly, volcanic gases have δ37Cl values that cover a range in excess of 14‰ (Barnes et al., this meeting). The large range is difficult to explain in terms of equilibrium fractionation, which, although calculated to be very large for Cl in different oxidation states, should be less than 2‰ between chloride species (Schauble et al., 2003, GCA). To address the discrepancy between Nature and theory, we have measured Cl isotope fractionation for selected equilibrium and disequilibrium experiments in order to identify mechanisms that might lead to large fractionations. 1) NaCl (s,l) NaCl (v): NaCl was sealed in an evacuated silica tube and heated at one end, causing vaporization and reprecipitation of NaCl (v) at the cool end of the tube. The fractionation is 0.2‰ at 700°C (halite-vapor) and 0.7‰ at 800°C (liquid-vapor), respectively. The larger fractionation at higher temperature may be related to equilibrium fractionation between liquid and gas vs. `stripping' of the solid in the lower T experiments. 2) Sodalite NaCl(l): Nepheline and excess NaCl were sealed in a Pt crucible at 825°C for 48 hrs producing sodalite. The measured newly-formed sodalite-NaCl fractionation is -0.2‰. 3) Volatilization of HCl: Dry inert gas was bubbled through HCl solutions and the vapor was collected in a downstream water trap. There was no fractionation for 12.4M HCl (HCl fuming) vapor at 25°C. For a 1 M boiling HCl solution, the HCl-vapor fractionation was ~9‰. The difference is probably related to the degree of dissociation in the acid, with HCl dissolved in water for the highly acidic solutions, and dissociated H3O+ and Cl- for lower concentrations. The HCl volatilization experiments are in contrast to earlier vapor-liquid experiments in NaCl-H2O system, where fractionation was

  19. Intracellular Cadmium Isotope Fractionation

    NASA Astrophysics Data System (ADS)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  20. Chromatographic methods of fractionation.

    PubMed

    Friesen, A D

    1987-01-01

    Chromatography's functional versatility, separation efficiency, gentle non-denaturing separating process and ease of automation and scale-up make it attractive for industrial scale protein purification. The Winnipeg Rh Institute's new Plasma Fractionation facility is an example of the use of chromatography for the large scale purification of plasma protein fractions. The fractionation facility has a capacity to process 800 litres of plasma per batch into blood clotting factor VIII and IX, albumin and intravenous immune serum globulin (i.v. ISG). Albumin and i.v. ISG are purified using ion exchange columns of DEAE-Sepharose (230 litre size), DEAE-Biogel (150 litre size) and CM-Sepharose (150 litre size). The chromatographic process is automated using a Modicon 584 Programmable Logic Controller to regulate valves, pumps and sensors which control plasma flow during fractionation. The stainless steel tanks and piping are automatically cleaned-in-place. The high degree of automation and cleaning provides efficient operation and sanitary processing. Chromatographic methods (DEAE-Sepharose and metal chelation) are also being used at the pilot scale to purify the human blood products superoxide dismutase and hemoglobin from outdated red blood cells. Characterization of the protein fractions produced by chromatography has shown them to be of equal or higher quality than fractions produced by other techniques.

  1. Filling Squares: Variations on a Theme.

    ERIC Educational Resources Information Center

    Senteni, Alain

    1986-01-01

    Four methods of filling a square using programing with Logo are presented, with comments on children's solutions. Analysis of the mathematical or programing concepts underlying a few simple algorithms is the focus. (MNS)

  2. Foam-filled cushions for sliding trays

    NASA Technical Reports Server (NTRS)

    Nahin, S. B.; Robb, P. H.

    1980-01-01

    Polytetrafluoroethylene tube filled with polyurethane foam forms low friction sliding surface that cushions vibrations and absorbs manufacturing tolerances and misalignment. Possible uses include packaging of components for shipping and seals for doors in lockers, cars, and refrigerators.

  3. PERVAPORATION USING ADSORBENT-FILLED MEMBRANES

    EPA Science Inventory

    Membranes containing selective fillers, such as zeolites and activated carbon, can improve the separation by pervaporation. Applications of adsorbent-filled membranes in pervaporation have been demonstrated by a number of studies. These applications include removal of organic co...

  4. 5 CFR 362.303 - Filling positions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ....303 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PATHWAYS... to the Recent Graduates Program, pursuant to a Pathways MOU executed with the OPM, under Schedule D... fill. (v) Positions must have progressively more responsible duties that provide career...

  5. 5 CFR 362.303 - Filling positions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ....303 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PATHWAYS... to the Recent Graduates Program, pursuant to a Pathways MOU executed with the OPM, under Schedule D... fill. (v) Positions must have progressively more responsible duties that provide career...

  6. Contraction stresses of composite resin filling materials.

    PubMed

    Hegdahl, T; Gjerdet, N R

    1977-01-01

    The polymerization shrinkage of composite resin filling materials and the tensile stresses developed when the shrinkage is restrained were measured in an in vitro experiment. This allows an estimation to be made of the forces exerted upon the enamel walls of cavities filled with the resin in the acid etch technique. The results indicate that the stresses acting on the enamel are low compared to the tensile strength of the enamel.

  7. Drum silencer with shallow cavity filled with helium.

    PubMed

    Choy, Y S; Huang, Lixi

    2003-09-01

    The motivation of this study is twofold: (a) to produce a flow-through silencer with zero pressure loss for pressure-critical applications, and (b) to tackle low frequency noise with limited sideway space using cavities filled with helium. The work represents a further development of our recently conceived device of a drum-like silencer with conventional air cavity [Huang, J. Acoust. Soc. Am. 112, 2014-2025 (2002); Choy and Huang, ibid. 112, 2026-2035 (2002)]. Theoretical predictions are validated by experimental data. The new silencer consists of two highly tensioned membranes lining part of a duct, and each membrane is backed by a cavity filled with helium. For a typical configuration of a duct with height h, membrane length L = 7h, cavity depth h = 0.2h, and tension T = 0.52rho0c0(2)h2, where rho0 and c0 are the ambient density and speed of sound in air, respectively, the transmission loss has a continuous stop band of TL > 6.35 dB for frequency 0.03c0/h to 0.064c0/h, which is much better than traditional duct lining. In addition to the mechanisms at work for drum silencers with air cavity, the low density of helium reduces the masslike reactance of the cavity on the second in vacuo mode of membrane vibration. The reduction greatly enhances the membrane response at this mode, which is found to be critical for achieving a broadband performance in the low-frequency regime.

  8. Drum silencer with shallow cavity filled with helium

    NASA Astrophysics Data System (ADS)

    Choy, Y. S.; Huang, Lixi

    2003-09-01

    The motivation of this study is twofold: (a) to produce a flow-through silencer with zero pressure loss for pressure-critical applications, and (b) to tackle low frequency noise with limited sideway space using cavities filled with helium. The work represents a further development of our recently conceived device of a drum-like silencer with conventional air cavity [Huang, J. Acoust. Soc. Am. 112, 2014-2025 (2002); Choy and Huang, ibid. 112, 2026-2035 (2002)]. Theoretical predictions are validated by experimental data. The new silencer consists of two highly tensioned membranes lining part of a duct, and each membrane is backed by a cavity filled with helium. For a typical configuration of a duct with height h, membrane length L=7h, cavity depth hc=0.2h, and tension T=0.52ρ0c02h2, where ρ0 and c0 are the ambient density and speed of sound in air, respectively, the transmission loss has a continuous stop band of TL>6.35 dB for frequency 0.03c0/h to 0.064c0/h, which is much better than traditional duct lining. In addition to the mechanisms at work for drum silencers with air cavity, the low density of helium reduces the masslike reactance of the cavity on the second in vacuo mode of membrane vibration. The reduction greatly enhances the membrane response at this mode, which is found to be critical for achieving a broadband performance in the low-frequency regime.

  9. Left ventricular diastolic filling with an implantable ventricular assist device: beat to beat variability with overall improvement

    NASA Technical Reports Server (NTRS)

    Nakatani, S.; Thomas, J. D.; Vandervoort, P. M.; Zhou, J.; Greenberg, N. L.; Savage, R. M.; McCarthy, P. M.

    1997-01-01

    OBJECTIVES: We studied the effects of left ventricular (LV) unloading by an implantable ventricular assist device on LV diastolic filling. BACKGROUND: Although many investigators have reported reliable systemic and peripheral circulatory support with implantable LV assist devices, little is known about their effect on cardiac performance. METHODS: Peak velocities of early diastolic filling, late diastolic filling, late to early filling ratio, deceleration time of early filling, diastolic filling period and atrial filling fraction were measured by intraoperative transesophageal Doppler echocardiography before and after insertion of an LV assist device in eight patients. A numerical model was developed to simulate this situation. RESULTS: Before device insertion, all patients showed either a restrictive or a monophasic transmitral flow pattern. After device insertion, transmitral flow showed rapid beat to beat variation in each patient, from abnormal relaxation to restrictive patterns. However, when the average values obtained from 10 consecutive beats were considered, overall filling was significantly normalized from baseline, with early filling velocity falling from 87 +/- 31 to 64 +/- 26 cm/s (p < 0.01) and late filling velocity rising from 8 +/- 11 to 32 +/- 23 cm/s (p < 0.05), resulting in an increase in the late to early filling ratio from 0.13 +/- 0.18 to 0.59 +/- 0.38 (p < 0.01) and a rise in the atrial filling fraction from 8 +/- 10% to 26 +/- 17% (p < 0.01). The deceleration time (from 112 +/- 40 to 160 +/- 44 ms, p < 0.05) and the filling period corrected by the RR interval (from 39 +/- 8% to 54 +/- 10%, p < 0.005) were also significantly prolonged. In the computer model, asynchronous LV assistance produced significant beat to beat variation in filling indexes, but overall a normalization of deceleration time as well as other variables. CONCLUSIONS: With LV assistance, transmitral flow showed rapidly varying patterns beat by beat in each patient, but

  10. Fractional Noether Theorem Based on Extended Exponentially Fractional Integral

    NASA Astrophysics Data System (ADS)

    Long, Zi-Xuan; Zhang, Yi

    2013-10-01

    Based on the new type of fractional integral definition, namely extended exponentially fractional integral introduced by EI-Nabulsi, we study the fractional Noether symmetries and conserved quantities for both holonomic system and nonholonomic system. First, the fractional variational problem under the sense of extended exponentially fractional integral is established, the fractional d'Alembert-Lagrange principle is deduced, then the fractional Euler-Lagrange equations of holonomic system and the fractional Routh equations of nonholonomic system are given; secondly, the invariance of fractional Hamilton action under infinitesimal transformations of group is also discussed, the corresponding definitions and criteria of fractional Noether symmetric transformations and quasi-symmetric transformations are established; finally, the fractional Noether theorems for both holonomic system and nonholonomic system are explored. What's more, the relationship between the fractional Noether symmetry and conserved quantity are revealed.

  11. Fractional quantum Hall effect on the two-sphere: A matrix model proposal

    SciTech Connect

    Morariu, Bogdan; Polychronakos, Alexios P.

    2005-12-15

    We present a Chern-Simons matrix model describing the fractional quantum Hall effect on the two sphere. We demonstrate the equivalence of our proposal to particular restrictions of the Calogero-Sutherland model, reproduce the quantum states and filling fraction and show the compatibility of our result with the Haldane spherical wave functions.

  12. Charge filling factors in clean and disordered arrays of tunnel junctions

    PubMed Central

    Walker, Kelly A.; Vogt, Nicolas; Cole, Jared H.

    2015-01-01

    We simulate one-dimensional arrays of tunnel junctions using the kinetic Monte Carlo method to study charge filling behaviour in the large charging energy limit. By applying a small fixed voltage bias and varying the offset voltage, we investigate this behaviour in clean and disordered arrays (both weak and strong disorder effects). The offset voltage dependent modulation of the current is highly sensitive to background charge disorder and exhibits substantial variation depending on the strength of the disorder. We show that while small fractional charge filling factors are likely to be washed out in experimental devices due to strong background charge disorder, larger factors may be observable. PMID:26627327

  13. Charge filling factors in clean and disordered arrays of tunnel junctions.

    PubMed

    Walker, Kelly A; Vogt, Nicolas; Cole, Jared H

    2015-12-02

    We simulate one-dimensional arrays of tunnel junctions using the kinetic Monte Carlo method to study charge filling behaviour in the large charging energy limit. By applying a small fixed voltage bias and varying the offset voltage, we investigate this behaviour in clean and disordered arrays (both weak and strong disorder effects). The offset voltage dependent modulation of the current is highly sensitive to background charge disorder and exhibits substantial variation depending on the strength of the disorder. We show that while small fractional charge filling factors are likely to be washed out in experimental devices due to strong background charge disorder, larger factors may be observable.

  14. Improved quantification of microbial CH4 oxidation efficiency in Arctic wetland soils using carbon isotope fractionation

    NASA Astrophysics Data System (ADS)

    Preuss, I.; Knoblauch, C.; Gebert, J.; Pfeiffer, E.-M.

    2012-12-01

    Permafrost-affected tundra soils are significant sources of the climate-relevant trace gas methane (CH4). The observed accelerated warming of the Arctic will cause a deeper permafrost thawing followed by increased carbon mineralization and CH4 formation in water saturated tundra soils which might cause a positive feedback to climate change. Aerobic CH4 oxidation is regarded as the key process reducing CH4 emissions from wetlands, but quantification of turnover rates has remained difficult so far. The application of carbon stable isotope fractionation enables the in situ quantification of CH4 oxidation efficiency in arctic wetland soils. The aim of the current study is to quantify CH4 oxidation efficiency in permafrost-affected tundra soils in Russia's Lena River Delta based on stable isotope signatures of CH4. Therefore, depth profiles of CH4 concentrations and δ13CH4-signatures were measured and the fractionation factors for the processes of oxidation (αox) and diffusion (αdiff) were determined. Most previous studies employing stable isotope fractionation for the quantification of CH4 oxidation in soils of other habitats (e.g. landfill cover soils) have assumed a gas transport dominated by advection (αtrans = 1). In tundra soils, however, diffusion is the main gas transport mechanism, aside from ebullition. Hence, diffusive stable isotope fractionation has to be considered. For the first time, the stable isotope fractionation of CH4 diffusion through water-saturated soils was determined with an αdiff = 1.001 ± 0.000 (n = 3). CH4 stable isotope fractionation during diffusion through air-filled pores of the investigated polygonal tundra soils was αdiff = 1.013 ± 0.003 (n = 18). Furthermore, it was found that αox differs widely between sites and horizons (mean αox, = 1.017 ± 0.009) and needs to be determined individually. The impact of both fractionation factors on the quantification of CH4 oxidation was analyzed by considering both the potential diffusion

  15. Air Abrasion

    MedlinePlus

    ... delivered directly to your desktop! more... What Is Air Abrasion? Article Chapters What Is Air Abrasion? What Happens? The Pros and Cons Will I Feel Anything? Is Air Abrasion for Everyone? print full article print this ...

  16. Polystyrene Foam Products Equation of State as a Function of Porosity and Fill Gas

    NASA Astrophysics Data System (ADS)

    Mulford, R. N.; Swift, D. C.

    2009-12-01

    An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam. Differences between air-filled, Ar-blown, and CO2-blown foams are investigated, to estimate the importance of allowing air to react with products of polystyrene decomposition. O2-blown foams are included in some comparisons, to amplify any consequences of reaction with oxygen in air. He-blown foams are included in some comparisons, to provide an extremum of density. Product pressures are slightly higher for oxygen-containing fill gases than for non-oxygen-containing fill gases. Examination of product species indicates that CO2 decomposes at high temperatures.

  17. Polystyrene foam products equation of state as a function of porosity and fill gas

    SciTech Connect

    Mulford, Roberta N; Swift, Damian C

    2009-01-01

    An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam. Differences between air-filled, Ar-blown, and CO{sub 2}-blown foams are investigated, to estimate the importance of allowing air to react with products of polystyrene decomposition. O{sub 2}-blown foams are included in some comparisons, to amplify any consequences of reaction with oxygen in air. He-blown foams are included in some comparisons, to provide an extremum of density. Product pressures are slightly higher for oxygen-containing fill gases than for non-oxygen-containing fill gases. Examination of product species indicates that CO{sub 2} decomposes at high temperatures.

  18. Study of two-dimensional photonic crystal microcavities filled with polymer

    NASA Astrophysics Data System (ADS)

    Benmerkhi, A.; Bouchemat, M.; Bouchemat, T.; Paraire, N.

    2010-11-01

    We present numerical study of microcavity biosensor in photonic crystal (PC) with triangular lattice of air holes patterned perpendicularly to an InP-based confining heterostructure. The microcavity is formed by varying the radius of one air hole. The 2D finite difference time domain (FDTD) method algorithm (fullwave simulator) is used to compute the light transmission efficiency and the quality factor (Q) when the refractive index (RI) filled in the air holes of water and polymer. The detected spectrum has a Lorentzian line shape, and the peak occurs when the PC cavity is at resonance. The resonance wavelength of this cavity will shift accordingly due to the variation of RI. The polymer filling of photonic crystal holes can be used to measure gas, fluids, biolayers, or bound chemical.

  19. Partition noise and statistics in the fractional quantum hall effect.

    PubMed

    Safi, I; Devillard, P; Martin, T

    2001-05-14

    A microscopic theory of current partition in fractional quantum Hall liquids, described by chiral Luttinger liquids, is developed to compute the noise correlations, using the Keldysh technique. In this Hanbury-Brown and Twiss geometry, at Laughlin filling factors nu = 1/3, the real time noise correlator exhibits oscillations which persist over larger time scales than that of an uncorrelated Hall fluid. The zero frequency noise correlations are negative at filling factor 1/3 as for bare electrons (antibunching), but are strongly reduced in amplitude. These correlations become positive (bunching) for nu < or = 1/5, suggesting a tendency towards bosonic behavior.

  20. FRACTIONAL CRYSTALLIZATION FEED ENVELOPE

    SciTech Connect

    HERTING DL

    2008-03-19

    Laboratory work was completed on a set of evaporation tests designed to establish a feed envelope for the fractional crystallization process. The feed envelope defines chemical concentration limits within which the process can be operated successfully. All 38 runs in the half-factorial design matrix were completed successfully, based on the qualitative definition of success. There is no feed composition likely to be derived from saltcake dissolution that would cause the fractional crystallization process to not meet acceptable performance requirements. However, some compositions clearly would provide more successful operation than other compositions.

  1. Soft tissue augmentation with ArteFill.

    PubMed

    Hilinski, John M; Cohen, Steven R

    2009-05-01

    ArteFill is a novel, third-generation polymethylmethacrylate (PMMA) injectable filler with unique properties. When compared with predecessor materials, ArteFill demonstrates improved biocompatibility as a result of more uniform PMMA microsphere size and shape. This translates into less adverse events after placement. ArteFill can provide a permanent volume enhancement by stimulation of fibroblasts that encapsulate nonabsorbable microspheres with collagen deposition. Currently, ArteFill is FDA approved for permanent augmentation of moderately deep nasolabial folds. It is also commonly used off-label for augmentation of other skin creases and regional areas of volume deficiency, such as the tear trough-malar and marionette line-prejowl sulcus regions. The key to success with ArteFill is a conservative approach with avoidance of overcorrection. Proper technique includes deep dermal to subcutaneous placement with full correction achieved gradually over several treatments. Complications are mostly limited to nodule formation, which is easily managed in most cases with conservative intervention.

  2. Gap Filling as Exact Path Length Problem.

    PubMed

    Salmela, Leena; Sahlin, Kristoffer; Mäkinen, Veli; Tomescu, Alexandru I

    2016-05-01

    One of the last steps in a genome assembly project is filling the gaps between consecutive contigs in the scaffolds. This problem can be naturally stated as finding an s-t path in a directed graph whose sum of arc costs belongs to a given range (the estimate on the gap length). Here s and t are any two contigs flanking a gap. This problem is known to be NP-hard in general. Here we derive a simpler dynamic programming solution than already known, pseudo-polynomial in the maximum value of the input range. We implemented various practical optimizations to it, and compared our exact gap-filling solution experimentally to popular gap-filling tools. Summing over all the bacterial assemblies considered in our experiments, we can in total fill 76% more gaps than the best previous tool, and the gaps filled by our method span 136% more sequence. Furthermore, the error level of the newly introduced sequence is comparable to that of the previous tools. The experiments also show that our exact approach does not easily scale to larger genomes, where the problem is in general difficult for all tools. PMID:26959081

  3. Momentum fractionation on superstrata

    DOE PAGES

    Bena, Iosif; Martinec, Emil; Turton, David; Warner, Nicholas P.

    2016-05-11

    Superstrata are bound states in string theory that carry D1, D5, and momentum charges, and whose supergravity descriptions are parameterized by arbitrary functions of (at least) two variables. In the D1-D5 CFT, typical three-charge states reside in highdegree twisted sectors, and their momentum charge is carried by modes that individually have fractional momentum. Understanding this momentum fractionation holographically is crucial for understanding typical black-hole microstates in this system. We use solution-generating techniques to add momentum to a multi-wound supertube and thereby construct the first examples of asymptotically-flat superstrata. The resulting supergravity solutions are horizonless and smooth up to well-understood orbifoldmore » singularities. Upon taking the AdS3 decoupling limit, our solutions are dual to CFT states with momentum fractionation. We give a precise proposal for these dual CFT states. Lastly, our construction establishes the very nontrivial fact that large classes of CFT states with momentum fractionation can be realized in the bulk as smooth horizonless supergravity solutions.« less

  4. Understanding Fraction Multiplication.

    ERIC Educational Resources Information Center

    Bezuk, Nadine S.; Armstrong, Barbara E.

    1992-01-01

    Presents five activities to help students construct meaning for multiplying fractions through real-world problem contexts, physical or pictorial models, the recognition of patterns, and the use of calculators. In the context of a garden plot, worksheets examine various aspects of parts of plots, patterns in plots, and a maximization problem.…

  5. Fractions through Fruit Salad.

    ERIC Educational Resources Information Center

    Lincoln, Lisa

    1987-01-01

    The mathematics concept of fractions was taught to a group of learning disabled, dyslexic, and multiply handicapped students (15-20 years old) by preparing a fruit salad. Enthusiastic student participation and enhanced knowledge illustrated the effectiveness of employing several sensory modes in learning activities. (CB)

  6. Field-Flow Fractionation.

    ERIC Educational Resources Information Center

    Caldwell, Karin D.

    1988-01-01

    Describes a technique for separating samples that range over 15 orders of magnitude in molecular weight. Discusses theory, apparatus, and sample preparation techniques. Lists several types of field-flow fractionation (FFF) and their uses: sedimentation FFF, thermal FFF, flow FFF, electrical FFF, and steric FFF. (ML)

  7. Avoidance of Fractions.

    ERIC Educational Resources Information Center

    Hart, Kathleen; Kerslake, Daphne

    The Concepts in Secondary Mathematics and Science (CSMS) and Strategies and Errors in Secondary Mathematics (SESM) research projects based at Chelsa College, England, have shown the marked reluctance of secondary school students to use fractions when solving mathematical problems, even though they have been taught the topic for a number of years.…

  8. Sweet Work with Fractions

    ERIC Educational Resources Information Center

    Vinogradova, Natalya; Blaine, Larry

    2013-01-01

    Almost everyone loves chocolate. However, the same cannot be said about fractions, which are loved by markedly fewer. Middle school students tend to view them with wary respect, but little affection. The authors attempt to sweeten the subject by describing a type of game involving division of chocolate bars. The activity they describe provides a…

  9. Videodisc Instruction in Fractions.

    ERIC Educational Resources Information Center

    Carnine, Douglas; And Others

    1987-01-01

    How laser videodisc technology can be used to improve mathematics instruction is described, with note of the development of a videodisc curriculum on mastering fractions. Relevant research is reviewed, as well as how teachers can use the technology. The instructional design is described, and field-testing and revision reported. (MNS)

  10. Momentum fractionation on superstrata

    NASA Astrophysics Data System (ADS)

    Bena, Iosif; Martinec, Emil; Turton, David; Warner, Nicholas P.

    2016-05-01

    Superstrata are bound states in string theory that carry D1, D5, and momentum charges, and whose supergravity descriptions are parameterized by arbitrary functions of (at least) two variables. In the D1-D5 CFT, typical three-charge states reside in high-degree twisted sectors, and their momentum charge is carried by modes that individually have fractional momentum. Understanding this momentum fractionation holographically is crucial for understanding typical black-hole microstates in this system. We use solution-generating techniques to add momentum to a multi-wound supertube and thereby construct the first examples of asymptotically-flat superstrata. The resulting supergravity solutions are horizonless and smooth up to well-understood orbifold singularities. Upon taking the AdS3 decoupling limit, our solutions are dual to CFT states with momentum fractionation. We give a precise proposal for these dual CFT states. Our construction establishes the very nontrivial fact that large classes of CFT states with momentum fractionation can be realized in the bulk as smooth horizonless supergravity solutions.

  11. Slotted Polyimide-Aerogel-Filled-Waveguide Arrays

    NASA Technical Reports Server (NTRS)

    Rodriguez-Solis, Rafael A.; Pacheco, Hector L.; Miranda, Felix A.; Meador, Mary Ann B.

    2013-01-01

    Polyimide aerogels were considered to serve as a filling for millimeter-wave waveguides. While these waveguides present a slightly higher loss than hollow waveguides, they have less losses than Duroid substrate integrated waveguides (less than 0.15 dB at Ka-band, in a 20 mm section), and exhibit an order of magnitude of mass reduction when compared to commercial waveguides. A Ka-band slotted aerogel-filled-waveguide array was designed, which provided the same gain (9 dBi) as its standard waveguide counterpart, and a slotted aerogel-filled-waveguide array using folded-slots was designed for comparison, obtaining a gain of 9 dB and a bandwidth of 590 MHz.

  12. Experimental study on capillary filling in nanochannels

    NASA Astrophysics Data System (ADS)

    Yang, Min; Cao, Bing-Yang; Wang, Wei; Yun, He-Ming; Chen, Bao-Ming

    2016-10-01

    We investigated the capillary filling kinetics of deionized water in nanochannels with heights of 50-120 nm. The measured position of the moving meniscus was proportional to the square root of time, as predicted by the LW equation. However, the extracted slopes were significantly smaller than the predictions based on the bulk properties. This unusual behavior was found to be mainly caused by the electro-viscous effect and dynamic contact angle, which was significantly larger than the static angle. In addition, when the filling distance reached about 600 μm, bubbles tended to be formed, leading to the main meniscus was almost immobile.

  13. [Coronal filling biomaterials. Criteria for selection].

    PubMed

    Degrange, M

    1990-01-01

    The aim of this paper is to assess filling biomaterials according to specification criteria, the foremost of which is the respective ability of each to form a tight seal along cavity walls. Their direct or indirect (cementing or bonding) adhesive potential is the determining factor in their durability and the biocompatibility of the restoration achieved. Gold inlay alloys and amalgams appear as yet to be the most reliable and well-tolerated biomaterials for posterior restorations. For filling small cavities in the anterior sector, microfilled composites are clearly indicated; bonded porcelain, while not yet validated over time, would seem to be a good alternative for more extensive restorations.

  14. Alkaline earth filled nickel skutterudite antimonide thermoelectrics

    DOEpatents

    Singh, David Joseph

    2013-07-16

    A thermoelectric material including a body centered cubic filled skutterudite having the formula A.sub.xFe.sub.yNi.sub.zSb.sub.12, where A is an alkaline earth element, x is no more than approximately 1.0, and the sum of y and z is approximately equal to 4.0. The alkaline earth element includes guest atoms selected from the group consisting of Be, Mb, Ca, Sr, Ba, Ra and combinations thereof. The filled skutterudite is shown to have properties suitable for a wide variety of thermoelectric applications.

  15. Polarization splitter based on dual core liquid crystal-filled holey fiber

    NASA Astrophysics Data System (ADS)

    Wang, Er-Lei; Jiang, Hai-Ming; Xie, Kang; Chen, Chun; Hu, Zhi-Jia

    2016-09-01

    Through filling the liquid crystal into the air holes of a dual-core holey fiber with a simple structure, the transmission mechanism of the fiber is changed from total internal reflection to photonic bandgap (PBG), and a polarization splitter based on the liquid crystal-filled dual-core PBG holey fiber is investigated. The results demonstrate that, by setting appropriate geometrical parameters, the polarization splitter possesses a short length of 890.5 μm, and its wide bandwidth of ˜150 nm almost covers all the S, C, and L communication bands. Besides, it has an excellent electro-interference-resistance property and certain sensitivity to temperature.

  16. Coupled discrete element and smoothed particle hydrodynamics simulations of the die filling process

    NASA Astrophysics Data System (ADS)

    Breinlinger, Thomas; Kraft, Torsten

    2015-08-01

    Die filling is an important part of the powder compaction process chain, where defects in the final part can be introduced—or prevented. Simulation of this process is therefore a goal for many part producers and has been studied by some researchers already. In this work, we focus on the influence of the surrounding air on the powder flow. We demonstrate the implementing and coupling of the discrete element method for the granular powder and the smoothed particle hydrodynamics method for the gas flow. Application of the method to the die filling process is demonstrated.

  17. Coupled discrete element and smoothed particle hydrodynamics simulations of the die filling process

    NASA Astrophysics Data System (ADS)

    Breinlinger, Thomas; Kraft, Torsten

    2016-11-01

    Die filling is an important part of the powder compaction process chain, where defects in the final part can be introduced—or prevented. Simulation of this process is therefore a goal for many part producers and has been studied by some researchers already. In this work, we focus on the influence of the surrounding air on the powder flow. We demonstrate the implementing and coupling of the discrete element method for the granular powder and the smoothed particle hydrodynamics method for the gas flow. Application of the method to the die filling process is demonstrated.

  18. 62. VIEW LOOKING NORTHWEST AT THE OIL FILLED CIRCUIT BREAKER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. VIEW LOOKING NORTHWEST AT THE OIL FILLED CIRCUIT BREAKER FOR GENERATOR NUMBER 1. CIRCUIT BREAKERS ARE AUTOMATED SWITCHES WHICH DISCONNECT THE GENERATORS FROM THE LINE WHEN SHORT CIRCUITS OCCUR. WHEN CIRCUITS INVOLVING HIGH CURRENTS AND VOLTAGES ARE BROKEN, THE AIR SURROUNDING MECHANICAL PARTS OF THE SWITCH BECOMES IONIZED AND CONTINUES TO CONDUCT ELECTRIC POWER ACROSS ANY GAP IN THE SWITCH CONTACTS. TO PREVENT THIS AND INSURE A POSITIVE INTERRUPTION OF CURRENT, THE SWITCH CONTACTS ARE IMMERSED IN A CONTAINER OF OIL. THE OIL DOES NOT SUPPORT THE FORMATION OF AN ARC AND EFFECTIVELY CUTS OFF THE CURRENT WHEN THE SWITCH CONTACTS ARE OPENED. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  19. Ag-Air Service

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Econ, Inc.'s agricultural aerial application, "ag-air," involves more than 10,000 aircraft spreading insecticides, herbicides, fertilizer, seed and other materials over millions of acres of farmland. Difficult for an operator to estimate costs accurately and decide what to charge or which airplane can handle which assignment most efficiently. Computerized service was designed to improve business efficiency in choice of aircraft and determination of charge rates based on realistic operating cost data. Each subscriber fills out a detailed form which pertains to his needs and then receives a custom-tailored computer printout best suited to his particular business mix.

  20. Experimental verification of enhanced sound transmission from water to air at low frequencies.

    PubMed

    Calvo, David C; Nicholas, Michael; Orris, Gregory J

    2013-11-01

    Laboratory measurements of enhanced sound transmission from water to air at low frequencies are presented. The pressure at a monitoring hydrophone is found to decrease for shallow source depths in agreement with the classical theory of a monopole source in proximity to a pressure release interface. On the other hand, for source depths below 1/10 of an acoustic wavelength in water, the radiation pattern in the air measured by two microphones becomes progressively omnidirectional in contrast to the classical geometrical acoustics picture in which sound is contained within a cone of 13.4° half angle. The measured directivities agree with wavenumber integration results for a point source over a range of frequencies and source depths. The wider radiation pattern owes itself to the conversion of evanescent waves in the water into propagating waves in the air that fill the angular space outside the cone. A ratio of pressure measurements made using an on-axis microphone and a near-axis hydrophone are also reported and compared with theory. Collectively, these pressure measurements are consistent with the theory of anomalous transparency of the water-air interface in which a large fraction of acoustic power emitted by a shallow source is radiated into the air.

  1. Disorder-induced heating of ultracold neutral plasmas created from atoms in partially filled optical lattices

    NASA Astrophysics Data System (ADS)

    Murphy, D.; Sparkes, B. M.

    2016-08-01

    We quantify the disorder-induced heating (DIH) of ultracold neutral plasmas (UCNPs) created from cold atoms in optical lattices with partial filling fractions, using a conservation of energy model involving the spatial correlations of the initial state and the equation of state in thermal equilibrium for a one-component plasma. We show, for experimentally achievable filling fractions, that the ionic Coulomb coupling parameter could be increased to a degree comparable to other proposed DIH-mitigation schemes. Molecular dynamics simulations were performed with compensation for finite-size and periodic boundary effects, which agree with calculations using the model. Reduction of DIH using optical lattices will allow for the study of strongly coupled plasma physics using low-density, low-temperature, laboratory-based plasmas, and lead to improved brightness in UCNP-based cold electron and ion beams, where DIH is otherwise a fundamental limitation to beam focal sizes and diffraction imaging capability.

  2. Disorder-induced heating of ultracold neutral plasmas created from atoms in partially filled optical lattices.

    PubMed

    Murphy, D; Sparkes, B M

    2016-08-01

    We quantify the disorder-induced heating (DIH) of ultracold neutral plasmas (UCNPs) created from cold atoms in optical lattices with partial filling fractions, using a conservation of energy model involving the spatial correlations of the initial state and the equation of state in thermal equilibrium for a one-component plasma. We show, for experimentally achievable filling fractions, that the ionic Coulomb coupling parameter could be increased to a degree comparable to other proposed DIH-mitigation schemes. Molecular dynamics simulations were performed with compensation for finite-size and periodic boundary effects, which agree with calculations using the model. Reduction of DIH using optical lattices will allow for the study of strongly coupled plasma physics using low-density, low-temperature, laboratory-based plasmas, and lead to improved brightness in UCNP-based cold electron and ion beams, where DIH is otherwise a fundamental limitation to beam focal sizes and diffraction imaging capability. PMID:27627236

  3. SEM evaluation of the interface between filling and root-end filling materials.

    PubMed

    Rosa, R A; Santini, M F; Heiden, K; Só, B B; Kuga, M C; Pereira, J R; Só, M V R

    2014-01-01

    The aim of this ex vivo study was to evaluate, by scanning electron microscopy (SEM), the presence of gaps at the interface between filling material and three root-end filling materials. Thirty human upper molars disto-buccal roots were instrumented and filled with gutta-percha and eugenol-based sealer. The apicoectomy was performed 2 mm from the apex and retrograde cavities were prepared with ultrasonic points (3 mm in deep). The samples were divided into three experimental groups (n = 10): Group I-white mineral trioxide aggregate (MTA); Group II-Super EBA; and Group III-Portland cement. The root-end filling materials were inserted into the retocavities using a MTA carrier. After 48 h, the roots were transversally sectioned in order to obtain the apical 5 mm. Next, each specimen was prepared longitudinally with crescent granulation of abrasives water-wet sandpapers in order to expose the filling and root-end filling materials. Then, the specimens were subjected to slow dehydration with silica gel, mounted onto specific stubs and coated with paladium coverage for SEM analysis of the interface between filling and root-end filling materials. The percentage of gaps at the interfacial area was calculated by using Image Tool 3.0 software. Super EBA presented the higher percentage of gaps (1.5 ± 0.67%), whereas MTA presented the lowest values (0.33 ± 0.20%; p = 0.0004). Despite the statistical differences observed between Super EBA and MTA, all the root-end filling materials presented great adaptation to the filling material, presenting small amount of gaps. PMID:23733414

  4. Preoperative saline-filled computed tomography thoracography for awake video-assisted thoracic surgery: report of three cases.

    PubMed

    Watanabe, Tatsuaki; Noda, Masafumi; Okazaki, Toshimasa; Tsukidate, Hisakatsu; Sato, Kota; Notsuda, Hirotsugu; Niikawa, Hiromichi; Okada, Yoshinori; Matsumura, Yuji; Kondo, Takashi

    2015-12-01

    Awake video-assisted thoracic surgery (VATS) is a therapeutic option for patients with intractable secondary spontaneous pneumothorax (SSP) complicated by impaired pulmonary function. The preoperative identification of air leak points is one of the keys to the success of this procedure. We describe how we performed saline-filled computed tomography (CT) thoracography to detect pleural fistulae in three patients with intractable SSP. Saline-filled CT thoracography showed bubble signs in two patients and an air-water level in bulla in one patient. The preoperative identification of air leak points resulted in successful awake VATS for all three patients. Our experience demonstrates that saline-filled CT thoracography is a useful diagnostic tool for SSP, especially when used in preparation for awake VATS when minimally invasive procedures are desirable. PMID:26070908

  5. An Introduction to Continued Fractions.

    ERIC Educational Resources Information Center

    Moore, Charles G.

    Provided is an introduction to the properties of continued fractions for the intellectually curious high school student. Among the topics included are (1) Expansion of Rational Numbers into Simple Continued Fractions, (2) Convergents, (3) Continued Fractions and Linear Diophantine Equations of the Type am + bn = c, (4) Continued Fractions and…

  6. Effect of Drying on Heavy Metal Fraction Distribution in Rice Paddy Soil

    PubMed Central

    Qi, Yanbing; Huang, Biao; Darilek, Jeremy Landon

    2014-01-01

    An understanding of how redox conditions affect soil heavy metal fractions in rice paddies is important due to its implications for heavy metal mobility and plant uptake. Rice paddy soil samples routinely undergo oxidation prior to heavy metal analysis. Fraction distribution of Cu, Pb, Ni, and Cd from paddy soil with a wide pH range was investigated. Samples were both dried according to standard protocols and also preserved under anaerobic conditions through the sampling and analysis process and heavy metals were then sequentially extracted for the exchangeable and carbonate bound fraction (acid soluble fraction), iron and manganese oxide bound fraction (reducible fraction), organic bound fraction (oxidizable fraction), and residual fraction. Fractions were affected by redox conditions across all pH ranges. Drying decreased reducible fraction of all heavy metals. Curesidual fraction, Pboxidizable fraction, Cdresidual fraction, and Niresidual fraction increased by 25%, 33%, 35%, and >60%, respectively. Pbresidual fraction, Niacid soluble fraction, and Cdoxidizable fraction decreased 33%, 25%, and 15%, respectively. Drying paddy soil prior to heavy metal analysis overestimated Pb and underestimated Cu, Ni, and Cd. In future studies, samples should be stored after injecting N2 gas to maintain the redox potential of soil prior to heavy metal analysis, and investigate the correlation between heavy metal fraction distribution under field conditions and air-dried samples. PMID:24823670

  7. Enigmatic 12/5 fractional quantum Hall effect

    NASA Astrophysics Data System (ADS)

    Pakrouski, Kiryl; Troyer, Matthias; Wu, Yang-Le; Das Sarma, Sankar; Peterson, Michael R.

    2016-08-01

    We numerically study the fractional quantum Hall effect at filling factors ν =12 /5 and 13/5 (the particle-hole conjugate of 12/5) in high-quality two-dimensional GaAs heterostructures via exact diagonalization including finite well width and Landau-level mixing. We find that Landau-level mixing suppresses the ν =13 /5 fractional quantum Hall effect relative to ν =12 /5 . By contrast, we find both ν =2 /5 and (its particle-hole conjugate) ν =3 /5 fractional quantum Hall effects in the lowest Landau level to be robust under Landau-level mixing and finite well-width corrections. Our results provide a possible explanation for the experimental absence of the 13/5 fractional quantum Hall state as caused by Landau-level mixing effects.

  8. SOIL AND FILL LABORATORY SUPPORT - 1991

    EPA Science Inventory

    The report gives results of soil analysis laboratory work by the University of Florida in Support of the Florida Radon Research Program (FRRP). Analyses were performed on soil and fill samples collected during 1991 by the FRRP Research House program and the New House Evaluation P...

  9. A dental cloud over a silver filling

    SciTech Connect

    Van Pelt, D.

    1990-10-01

    For 150 years, silver fillings have been used for cavities. Now some dentists are urging their colleagues to stop using the mixture because it includes mercury, which they say poses health risks. While a small group of dentists have complied, the mainstream profession says the claims are unsubstantiated.

  10. Irregularly Shaped Space-Filling Truncated Octahedra

    ERIC Educational Resources Information Center

    Hanson, John Robert

    2008-01-01

    For any parent tetrahedron ABCD, centroids of selected sub-tetrahedra form the vertices of an irregularly shaped space-filling truncated octahedron. To reflect these properties, such a figure will be called an ISTO. Each edge of the ISTO is parallel to and one-eighth the length of one of the edges of tetrahedron ABCD and the volume of the ISTO is…

  11. Banach spaces that realize minimal fillings

    SciTech Connect

    Bednov, B. B.; Borodin, P. A. E-mail: pborodin@inbox.ru

    2014-04-30

    It is proved that a real Banach space realizes minimal fillings for all its finite subsets (a shortest network spanning a fixed finite subset always exists and has the minimum possible length) if and only if it is a predual of L{sub 1}. The spaces L{sub 1} are characterized in terms of Steiner points (medians). Bibliography: 25 titles. (paper)

  12. New Skeletal-Space-Filling Models

    ERIC Educational Resources Information Center

    Clarke, Frank H.

    1977-01-01

    Describes plastic, skeletal molecular models that are color-coded and can illustrate both the conformation and overall shape of small molecules. They can also be converted to space-filling counterparts by the additions of color-coded polystyrene spheres. (MLH)

  13. The Chemistry of Modern Dental Filling Materials.

    ERIC Educational Resources Information Center

    Nicholson, John W.; Anstice, H. Mary

    1999-01-01

    Discusses materials used by dentists to restore teeth after decay has been removed. Shows how dental-material science is an interdisciplinary field in which chemistry plays a major part. Reviews the many developments polymer chemistry has contributed to the field of dental fillings. (CCM)

  14. 5 CFR 362.203 - Filling positions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... PROGRAMS Internship Program § 362.203 Filling positions. (a) Announcement. (1) When an agency accepts... opportunities to participate in the agency's Internship Program. For the purposes of this paragraph (a), “agency... Internship opportunities; and (iv) Any other information OPM considers appropriate. (2) OPM will...

  15. 5 CFR 362.203 - Filling positions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... PROGRAMS Internship Program § 362.203 Filling positions. (a) Announcement. (1) When an agency accepts... opportunities to participate in the agency's Internship Program. For the purposes of this paragraph (a), “agency... Internship opportunities; and (iv) Any other information OPM considers appropriate. (2) OPM will...

  16. Cotton-Fiber-Filled Rubber Insulation

    NASA Technical Reports Server (NTRS)

    Anderson, Floyd A.

    1987-01-01

    Carbonization of fibers at high temperatures improves strength and erosion resistance. Cotton linters tested as replacement for asbestos filler currently used in rubber insulation in solid rocket motors. Cotton-filled rubber insulation has industrial uses; in some kinds of chemical- or metal-processing equipment, hoses, and protective clothing.

  17. Postscript: Filling-in Models of Completion

    ERIC Educational Resources Information Center

    Anderson, Barton L.

    2007-01-01

    Presents some additional comments from the current author regarding his original article "Filling-in models of completion: Rejoinder to Kellman, Garrigan, Shipley, and Keane (2007) and Albert (2007)." Despite repeated assertions by Kellman et al., I have never claimed that luminance constraints block modal completion; rather, they merely weaken…

  18. Biomineral nanoparticles are space-filling

    NASA Astrophysics Data System (ADS)

    Yang, Li; Killian, Christopher E.; Kunz, Martin; Tamura, Nobumichi; Gilbert, P. U. P. A.

    2011-02-01

    Sea urchin biominerals have been shown to form from aggregating nanoparticles of amorphous calcium carbonate (ACC), which then crystallize into macroscopic single crystals of calcite. Here we measure the surface areas of these biominerals and find them to be comparable to those of space-filling macroscopic geologic calcite crystals. These biominerals differ from synthetic mesocrystals, which are invariably porous. We propose that space-filling ACC is the structural precursor for echinoderm biominerals.Sea urchin biominerals have been shown to form from aggregating nanoparticles of amorphous calcium carbonate (ACC), which then crystallize into macroscopic single crystals of calcite. Here we measure the surface areas of these biominerals and find them to be comparable to those of space-filling macroscopic geologic calcite crystals. These biominerals differ from synthetic mesocrystals, which are invariably porous. We propose that space-filling ACC is the structural precursor for echinoderm biominerals. This article was submitted as part of a Themed Issue on Crystallization and Formation Mechanisms of Nanostructures. Other papers on this topic can be found in issue 11 of vol. 2 (2010). This issue can be found from the Nanoscale homepage [http://www.rsc.org/nanoscale

  19. How to fill key leadership positions strategically.

    PubMed

    Sanford, Kathleen D

    2011-06-01

    To fill strategic positions in their organizations with top talent, nursing and finance leaders can: Start by determining which jobs are truly "mission critical". Align the individuals in these positions on strategic teams Strengthen partnerships between key clinical leaders, such as the CMO and CNO PMID:21692375

  20. Experimental and numerical study of water-filled vessel impacted by flat projectiles

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Ren, Peng; Huang, Wei; Gao, Yu Bo

    2014-05-01

    To understand the failure modes and impact resistance of double-layer plates separated by water, a flat-nosed projectile was accelerated by a two-stage light gas gun against a water-filled vessel which was placed in an air-filled tank. Targets consisted of a tank made of two flat 5A06 aluminum alloy plates held by a high strength steel frame. The penetration process was recorded by a digital high-speed camera. The same projectile-target system was also used to fire the targets placed directly in air for comparison. Parallel numerical tests were also carried out. The result indicated that experimental and numerical results were in good agreement. Numerical simulations were able to capture the main physical behavior. It was also found that the impact resistance of double layer plates separated by water was lager than that of the target plates in air. Tearing was the main failure models of the water-filled vessel targets which was different from that of the target plates in air where the shear plugging was in dominate.

  1. Testing fractional action cosmology

    NASA Astrophysics Data System (ADS)

    Shchigolev, V. K.

    2016-08-01

    The present work deals with a combined test of the so-called Fractional Action Cosmology (FAC) on the example of a specific model obtained by the author earlier. In this model, the effective cosmological term is proportional to the Hubble parameter squared through the so-called kinematic induction. The reason of studying this cosmological model could be explained by its ability to describe two periods of accelerated expansion, that is in agreement with the recent observations and the cosmological inflation paradigm. First of all, we put our model through the theoretical tests, which gives a general conception of the influence of the model parameters on its behavior. Then, we obtain some restrictions on the principal parameters of the model, including the fractional index, by means of the observational data. Finally, the cosmography parameters and the observational data compared to the theoretical predictions are presented both analytically and graphically.

  2. [Fractionated P-bilirubins].

    PubMed

    Schou, C S; Mortensen, H

    1989-08-14

    A diazo-based dry film technique for the estimation of different bilirubins in plasma is now available. This procedure separates bilirubins from icteric sera into three separate fractions: bilirubin (unconjugated), bilirubin-glucuronides (mono + diglucuronide) and bilirubin-albumin. In newborns with prolonged jaundice classification of hyperbilirubinemia is of importance for choice of treatment. While binding of bilirubin and bilirubin-glucuronides to albumin is non covalent, reversible, bilirubin-albumin appears to be firmly associated with albumin by covalent bonds. This causes delayed clearance of this bilirubin fraction from plasma as the half-life of albumin is approximately 18 days. Hence the substance concentration of bilirubin-albumin will decrease at a slower rate than will bilirubin and bilirubin-glucuronide, despite hepatobiliary recovery. Bilirubin-albumin may therefore prove of value in the differentiation between different clinical entities with hyperbilirubinemia. PMID:2773134

  3. New Dry Fractionation Methods

    NASA Technical Reports Server (NTRS)

    McKay, David S.; Cooper, Bonnie L.

    2010-01-01

    This slide presentation describes new fractionation methods that are used to create dust that is respirable for testing the effects of inhalation of lunar dust in preparation for future manned lunar exploration. Because lunar dust is a very limited commodity, a method that does not result in loss of the material had to be developed. The dust separation system that is described incorporates some traditional methods, while preventing the dust from being contaminated or changed in reactivity properties while also limiting losses.

  4. Fractional Galilean symmetries

    NASA Astrophysics Data System (ADS)

    Hosseiny, Ali; Rouhani, Shahin

    2016-09-01

    We generalize the differential representation of the operators of the Galilean algebras to include fractional derivatives. As a result a whole new class of scale invariant Galilean algebras are obtained. The first member of this class has dynamical index z = 2 similar to the Schrödinger algebra. The second member of the class has dynamical index z = 3 / 2, which happens to be the dynamical index Kardar-Parisi-Zhang equation.

  5. Effective Field Theory of Fractional Quantized Hall Nematics

    SciTech Connect

    Mulligan, Michael; Nayak, Chetan; Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC

    2012-06-06

    We present a Landau-Ginzburg theory for a fractional quantized Hall nematic state and the transition to it from an isotropic fractional quantum Hall state. This justifies Lifshitz-Chern-Simons theory - which is shown to be its dual - on a more microscopic basis and enables us to compute a ground state wave function in the symmetry-broken phase. In such a state of matter, the Hall resistance remains quantized while the longitudinal DC resistivity due to thermally-excited quasiparticles is anisotropic. We interpret recent experiments at Landau level filling factor {nu} = 7/3 in terms of our theory.

  6. Numerical recipes for mold filling simulation

    SciTech Connect

    Kothe, D.; Juric, D.; Lam, K.; Lally, B.

    1998-07-01

    Has the ability to simulate the filling of a mold progressed to a point where an appropriate numerical recipe achieves the desired results? If results are defined to be topological robustness, computational efficiency, quantitative accuracy, and predictability, all within a computational domain that faithfully represents complex three-dimensional foundry molds, then the answer unfortunately remains no. Significant interfacial flow algorithm developments have occurred over the last decade, however, that could bring this answer closer to maybe. These developments have been both evolutionary and revolutionary, will continue to transpire for the near future. Might they become useful numerical recipes for mold filling simulations? Quite possibly. Recent progress in algorithms for interface kinematics and dynamics, linear solution methods, computer science issues such as parallelization and object-oriented programming, high resolution Navier-Stokes (NS) solution methods, and unstructured mesh techniques, must all be pursued as possible paths toward higher fidelity mold filling simulations. A detailed exposition of these algorithmic developments is beyond the scope of this paper, hence the authors choose to focus here exclusively on algorithms for interface kinematics. These interface tracking algorithms are designed to model the movement of interfaces relative to a reference frame such as a fixed mesh. Current interface tracking algorithm choices are numerous, so is any one best suited for mold filling simulation? Although a clear winner is not (yet) apparent, pros and cons are given in the following brief, critical review. Highlighted are those outstanding interface tracking algorithm issues the authors feel can hamper the reliable modeling of today`s foundry mold filling processes.

  7. Protective supplied-breathing-air garment

    DOEpatents

    Childers, E.L.; von Hortenau, E.F.

    1982-05-28

    A breathing-air garment for isolating a wearer from hostile environments containing toxins or irritants is disclosed. The garment includes a suit and a separate head-protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air-delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air-delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit sealed with an adhesive sealing flap.

  8. Laser-filamentation-induced water condensation and snow formation in a cloud chamber filled with different ambient gases.

    PubMed

    Liu, Yonghong; Sun, Haiyi; Liu, Jiansheng; Liang, Hong; Ju, Jingjing; Wang, Tiejun; Tian, Ye; Wang, Cheng; Liu, Yi; Chin, See Leang; Li, Ruxin

    2016-04-01

    We investigated femtosecond laser-filamentation-induced airflow, water condensation and snow formation in a cloud chamber filled respectively with air, argon and helium. The mass of snow induced by laser filaments was found being the maximum when the chamber was filled with argon, followed by air and being the minimum with helium. We also discussed the mechanisms of water condensation in different gases. The results show that filaments with higher laser absorption efficiency, which result in higher plasma density, are beneficial for triggering intense airflow and thus more water condensation and precipitation.

  9. Laser-filamentation-induced water condensation and snow formation in a cloud chamber filled with different ambient gases.

    PubMed

    Liu, Yonghong; Sun, Haiyi; Liu, Jiansheng; Liang, Hong; Ju, Jingjing; Wang, Tiejun; Tian, Ye; Wang, Cheng; Liu, Yi; Chin, See Leang; Li, Ruxin

    2016-04-01

    We investigated femtosecond laser-filamentation-induced airflow, water condensation and snow formation in a cloud chamber filled respectively with air, argon and helium. The mass of snow induced by laser filaments was found being the maximum when the chamber was filled with argon, followed by air and being the minimum with helium. We also discussed the mechanisms of water condensation in different gases. The results show that filaments with higher laser absorption efficiency, which result in higher plasma density, are beneficial for triggering intense airflow and thus more water condensation and precipitation. PMID:27137026

  10. Grapefruit Fiber Filled with Silver Nanowires Surface Plasmon Resonance Sensor in Aqueous Environments

    PubMed Central

    Lu, Ying; Hao, Cong-Jing; Wu, Bao-Qun; Huang, Xiao-Hui; Wen, Wu-Qi; Fu, Xiang-Yong; Yao, Jian-Quan

    2012-01-01

    A kind of surface plasmon resonance sensor based on grapefruit photonic crystal fiber (PCF) filled with different numbers of silver nanowires has been studied in this paper. The surface plasmon resonance modes and the sensing properties are investigated comprehensively using the finite element method (FEM). The simulation results show that the intensity sensitivity is related to nanowire numbers and the distance between two nanowires. The optimum value obtained is 2,400 nm/RIU, corresponding to a resolution of 4.51 × 10−5 RIU with a maximum distance of 2 μm. To a certain extent, the PCF filled with more nanowires is better than with just one. Furthermore, the air holes of grapefruit PCF are large enough to operate in practice. Moreover, the irregularity of the filled nanowires has no effect on sensitivity, which will be very convenient for the implementation of experiments. PMID:23112697

  11. Numerical study of sidewall filling for gas-fed pulse detonation engines

    NASA Astrophysics Data System (ADS)

    Rongrat, Wunnarat

    Pulse detonation engines for aerospace propulsion are required to operate at 50-100 Hz meaning that each pulse is 10-20 ms long. Filling of the engine and the related purging process become dominant due to their long duration compared to ignition and detonation wave propagation. This study uses ANSYS FLUENT to investigate the filling of a 1 m long tube with an internal diameter of 100 mm. Six different configurations were investigated with an endwall port and various sidewall arrangements, including stagger and inclination. A stoichiometric mixture of gaseous octane and air at STP was used to fill the tube at injection rates of 40, 150 and 250 m/s. Phase injection was also investigated and it showed performance improvements such as reduced lling time and reduced propellant escape from the exit.

  12. SEMICONDUCTOR TECHNOLOGY Dummy fill effect on CMP planarity

    NASA Astrophysics Data System (ADS)

    Junxiong, Zhou; Lan, Chen; Wenbiao, Ruan; Zhigang, Li; Weixiang, Shen; Tianchun, Ye

    2010-10-01

    With the use of a chemical-mechanical polishing (CMP) simulator verified by testing data from a foundry, the effect of dummy fill characteristics, such as fill size, fill density and fill shape, on CMP planarity is analyzed. The results indicate that dummy density has a significant impact on oxide erosion, and copper dishing is in proportion to dummy size. We also demonstrate that cross shape dummy fill can have the best dishing performance at the same density.

  13. Air resources

    SciTech Connect

    1995-10-01

    This section describes the ambient (surrounding) air quality of the TVA region, discusses TVA emission contributions to ambient air quality, and identifies air quality impacts to human health and welfare. Volume 2 Technical Document 2, Environmental Consequences, describes how changes in TVA emissions could affect regional air quality, human health, environmental resources, and materials. The primary region of the affected environment is broadly defined as the state of Tennessee, as well as southern Kentucky, western Virginia, southern West Virginia, western North Carolina, and northern Georgia, Alabama, and Mississippi. This area represents the watershed of the Tennessee River and the 201 counties of the greater TVA service area. Emissions from outside the Tennessee Valley region contribute to air quality in the Valley. Also, TVA emissions are transported outside the Valley and have some impact on air quality beyond the primary study area. Although the study area experiences a number of air quality problems, overall air quality is good.

  14. Mechanisms of reduced left ventricular filling rate in coronary artery disease.

    PubMed Central

    Hui, W K; Gibson, D G

    1983-01-01

    To identify mechanisms underlying slow left ventricular filling in coronary artery disease, left ventriculograms from 93 patients and 18 normal subjects were digitised frame by frame and global and regional function analysed. In 54 patients peak normalised filling rates were above the lower 95% confidence limit of normal (2 X 9s-1) and in 39 they were below. Patients with slow filling had a lower ejection fraction, a higher end systolic volume, and less overall shape index change, although a larger percentage occurred during isovolumic relaxation owing to asynchronous relaxation. Stroke volume was not significantly different. Slow outward wall motion was associated with increased cavity volume and systolic hypokinesis. Wall motion was also appreciably asynchronous, with wide spreads in the times of peak outward velocity and termination of rapid outward movement between regions. Early outward movement usually started in the anterior region, with peak velocity occurring before mitral valve opening, and significantly earlier than that in the apex or the inferior region. Ventricular oscillations occurred during filling in 23 patients. This asynchronous wall movement was unrelated to the distribution of coronary artery disease, systolic hypokinesis, or Q waves on electrocardiograms but was similar to that occurring in mitral stenosis. The main causes of slow left ventricular filling in patients with coronary artery disease appear to be (a) failure to achieve a normal low end systolic volume, with associated loss of physiological changes in left ventricular cavity shape, and (b) incoordinate wall motion during isovolumic relaxation which dissipates energy normally coupled to rapid ventricular filling. The resulting slow and asynchronous wall motion may have clinical implications especially when the time available for left ventricular filling is short. PMID:6626399

  15. Left atrial strain: a new parameter for assessment of left ventricular filling pressure.

    PubMed

    Cameli, Matteo; Mandoli, Giulia Elena; Loiacono, Ferdinando; Dini, Frank Lloyd; Henein, Michael; Mondillo, Sergio

    2016-01-01

    In order to obtain accurate diagnosis, treatment and prognostication in many cardiac conditions, there is a need for assessment of left ventricular (LV) filling pressure. While systole depends on ejection function of LV, diastole and its disturbances influence filling function and pressures. The commonest condition that represents the latter is heart failure with preserved ejection fraction in which LV ejection is maintained, but diastole is disturbed and hence filling pressures are raised. Significant diastolic dysfunction results in raised LV end-diastolic pressure, mean left atrial (LA) pressure and pulmonary capillary wedge pressure, all referred to as LV filling pressures. Left and right heart catheterization has traditionally been used as the gold standard investigation for assessing these pressures. More recently, Doppler echocardiography has taken over such application because of its noninvasive nature and for being patient friendly. A number of indices are used to achieve accurate assessment of filling pressures including: LV pulsed-wave filling velocities (E/A ratio, E wave deceleration time), pulmonary venous flow (S wave and D wave), tissue Doppler imaging (E' wave and E/E' ratio) and LA volume index. LA longitudinal strain derived from speckle tracking echocardiography (STE) is also sensitive in estimating intracavitary pressures. It is angle-independent, thus overcomes Doppler limitations and provides highly reproducible measures of LA deformation. This review examines the application of various Doppler echocardiographic techniques in assessing LV filling pressures, in particular the emerging role of STE in assessing LA pressures in various conditions, e.g., HF, arterial hypertension and atrial fibrillation.

  16. [Ablative and fractional lasers].

    PubMed

    Beylot, C; Grognard, C; Michaud, T

    2009-10-01

    The use of pulsed or scanning Carbon Dioxide, and pulsed Erbium-YAG lasers allows the programmable and reproducible photocoagulation of thin layers of the epidermis and superficial dermis. Thermal damage depends on the type of laser and is greater with CO(2) lasers. The degree of neocollagenesis is proportional to the thermal damage and is better with CO(2) lasers. Their main indication is the correction of photoaged facial skin but they can also be used for corrective dermatology, e.g. for scars and genodermatosis. Results are highly satisfactory but the technique is invasive and the patient experiences a social hindrance of around two weeks. Fractionated techniques treat 25% of the defective skin area at each session in noncontiguous microzones; four sessions are therefore necessary to treat the entire cutaneous surface. The treatment is given under topical anesthesia and is much less invasive, particularly with nonablative fractional laser treatment in which photothermolysis does not penetrate below the epidermis and/or the effects are slight, with no or very little social isolation. However, the results are much less satisfactory than the results of ablative laser and there is no firming effect. Other zones than the face can be treated. With the fractional CO(2) and Erbium ablative lasers, which have multiplied over the past 2 years, the much wider impacts cause perforation of the epidermis and there is a zone of ablation by laser photovaporization, with a zone of thermal damage below. The results are better in correcting photoaging of the face, without, however, achieving the efficacy of ablative lasers, which remain the reference technique. However, the effects are not insignificant, requiring at least 5 days of social isolation.

  17. Water Tank with Capillary Air/Liquid Separation

    NASA Technical Reports Server (NTRS)

    Ungar, Eugene K.; Smith, Frederick; Edeen, Gregg; Almlie, Jay C.

    2010-01-01

    A bladderless water tank (see figure) has been developed that contains capillary devices that allow it to be filled and emptied, as needed, in microgravity. When filled with water, the tank shields human occupants of a spacecraft against cosmic radiation. A membrane that is permeable by air but is hydrophobic (neither wettable nor permeable by liquid water) covers one inside surface of the tank. Grooves between the surface and the membrane allow air to flow through vent holes in the surface as the tank is filled or drained. A margin of wettable surface surrounds the edges of the membrane, and all the other inside tank surfaces are also wettable. A fill/drain port is located in one corner of the tank and is covered with a hydrophilic membrane. As filling begins, water runs from the hydrophilic membrane into the corner fillets of the tank walls. Continued filling in the absence of gravity will result in a single contiguous air bubble that will be vented through the hydrophobic membrane. The bubble will be reduced in size until it becomes spherical and smaller than the tank thickness. Draining the tank reverses the process. Air is introduced through the hydrophobic membrane, and liquid continuity is maintained with the fill/drain port through the corner fillets. Even after the tank is emptied, as long as the suction pressure on the hydrophilic membrane does not exceed its bubble point, no air will be drawn into the liquid line.

  18. Fractional channel multichannel analyzer

    DOEpatents

    Brackenbush, Larry W.; Anderson, Gordon A.

    1994-01-01

    A multichannel analyzer incorporating the features of the present invention obtains the effect of fractional channels thus greatly reducing the number of actual channels necessary to record complex line spectra. This is accomplished by using an analog-to-digital converter in the asynscronous mode, i.e., the gate pulse from the pulse height-to-pulse width converter is not synchronized with the signal from a clock oscillator. This saves power and reduces the number of components required on the board to achieve the effect of radically expanding the number of channels without changing the circuit board.

  19. Air Pollution.

    ERIC Educational Resources Information Center

    Gilpin, Alan

    A summary of one of our most pressing environmental problems, air pollution, is offered in this book by the Director of Air Pollution Control for the Queensland (Australia) State Government. Discussion of the subject is not restricted to Queensland or Australian problems and policies, however, but includes analysis of air pollution the world over.…

  20. Rubber elasticity: From topology to filled elastomers

    SciTech Connect

    Heinrich, G.; Vilgis, T.A.

    1993-12-31

    Various new aspects in the elasticity of rubbers and statistics of unfilled and filled elastomers, together with various consequences for practical application are discussed. It is shown that the role of network topology is crucial in the statistics of rubbers. This is seen mostly on the influence of heterogeneities of crosslink density which determine the elastic modulus, ultimate properties as well as the dynamical behavior. The filler effects, entanglements in filled rubbers, and the filler/bound rubber/mobile rubber problem are discussed from a novel point of view. A localization model is adopted, where it can be shown that on a rough (filler) surface more polymer can be adsorbed compared to a flat surface with similar energetic properties. The role of carbon black networking and fractal properties of the filler are discussed in relation to the dynamic-mechanical properties of the elastomer.

  1. Ultrafast carriers dynamics in filled-skutterudites

    NASA Astrophysics Data System (ADS)

    Guo, Liang; Xu, Xianfan; Salvador, James R.

    2015-06-01

    Carrier dynamics of filled-skutterudites, an important class of thermoelectric materials, is investigated using ultrafast optical spectroscopy. By tuning the wavelength of the probe laser, charge transfers at different electronic energy levels are interrogated. Analysis based on the Kramers-Kronig relation explains the complex spectroscopy data, which is mainly due to band filling caused by photo-excited carriers and free carrier absorption. The relaxation time of hot carriers is found to be about 0.4-0.6 ps, depending on the electronic energy level, and the characteristic time for carrier-phonon equilibrium is about 0.95 ps. These studies of carrier dynamics, which fundamentally determines the transport properties of thermoelectric material, can provide guidance for the design of materials.

  2. Ultrafast carriers dynamics in filled-skutterudites

    SciTech Connect

    Guo, Liang; Xu, Xianfan; Salvador, James R.

    2015-06-08

    Carrier dynamics of filled-skutterudites, an important class of thermoelectric materials, is investigated using ultrafast optical spectroscopy. By tuning the wavelength of the probe laser, charge transfers at different electronic energy levels are interrogated. Analysis based on the Kramers-Kronig relation explains the complex spectroscopy data, which is mainly due to band filling caused by photo-excited carriers and free carrier absorption. The relaxation time of hot carriers is found to be about 0.4–0.6 ps, depending on the electronic energy level, and the characteristic time for carrier-phonon equilibrium is about 0.95 ps. These studies of carrier dynamics, which fundamentally determines the transport properties of thermoelectric material, can provide guidance for the design of materials.

  3. Moon - 'Ghost' craters formed during Mare filling.

    NASA Technical Reports Server (NTRS)

    Cruikshank, D. P.; Hartmann, W. K.; Wood, C. A.

    1973-01-01

    This paper discusses formation of 'pathological' cases of crater morphology due to interaction of craters with molten lavas. Terrestrial observations of such a process are discussed. In lunar maria, a number of small impact craters (D less than 10 km) may have been covered by thin layers of fluid lavas, or formed in molten lava. Some specific lunar examples are discussed, including unusual shallow rings resembling experimental craters deformed by isostatic filling.

  4. Microscopic justification of the equal filling approximation

    SciTech Connect

    Perez-Martin, Sara; Robledo, L. M.

    2008-07-15

    The equal filling approximation, a procedure widely used in mean-field calculations to treat the dynamics of odd nuclei in a time-reversal invariant way, is justified as the consequence of a variational principle over an average energy functional. The ideas of statistical quantum mechanics are employed in the justification. As an illustration of the method, the ground and lowest-lying states of some octupole deformed radium isotopes are computed.

  5. Complex networks from space-filling bearings.

    PubMed

    Kranz, J J; Araújo, N A M; Andrade, J S; Herrmann, H J

    2015-07-01

    Two-dimensional space-filling bearings are dense packings of disks that can rotate without slip. We consider the entire first family of bearings for loops of four disks and propose a hierarchical construction of their contact network. We provide analytic expressions for the clustering coefficient and degree distribution, revealing bipartite scale-free behavior with a tunable degree exponent depending on the bearing parameters. We also analyze their average shortest path and percolation properties.

  6. Slotted Polyimide-Aerogel-Filled-Waveguide Arrays

    NASA Technical Reports Server (NTRS)

    Rodriguez-Solis, Rafael A.; Pacheco, Hector L.; Miranda, Felix A.; Meador, Mary Ann B.

    2013-01-01

    This presentation discussed the potential advantages of developing Slotted Waveguide Arrays using polyimide aerogels. Polyimide (PI) aerogels offer great promise as an enabling technology for lightweight aerospace antenna systems. PI aerogels are highly porous solids possessing low density and low dielectric permittivity combined with good mechanical properties. For slotted waveguide array applications, there are significant advantages in mass that more than compensate for the slightly higher loss of the aerogel filled waveguide when compared to state of practice commercial waveguide.

  7. Abandoned Channel Fill Sequences in Tidal Estuaries

    NASA Astrophysics Data System (ADS)

    Gray, A. B.; Pasternack, G. B.; Goni, M. A.; Watson, E. B.

    2014-12-01

    This study proposes a modification of the current model for abandoned channel fill stratigraphy produced in unidirectional flow river reaches to incorporate seasonal tidal deposition. Evidence supporting this concept came from a study of two consecutive channel abandonment sequences in Ropers Slough of the lower Eel River Estuary in northern California. Aerial photographs showed that Ropers Slough was abandoned around 1943, reoccupied after the 1964 flood, and abandoned again in 1974 with fill continuing to the present. Planform geomorphic characteristics derived from these images were used in conjunction with sub-cm resolution stratigraphic analyses to describe the depositional environment processes and their resultant sedimentary deposits. Results showed that both abandonment sequences recorded quasi-annual scale fluvial/tidal deposition couplets. In both cases tidal deposits contained very little sand, and were higher in organic and inorganic carbon content than the sandier fluvial through-flow deposits. However, the two abandonment fills differed significantly in terms of the temporal progression of channel narrowing and fluvial sediment deposition characteristics. The first abandonment sequence led to a more rapid narrowing of Ropers Slough and produced deposits with a positive relationship between grain size/deposit thickness and discharge. The second abandonment resulted in a much slower narrowing of Ropers Slough and generally thinner fluvial deposits with no clear relationship between grain size/deposit thickness and discharge. The δ13C values and organic nitrogen to organic carbon ratios of deposits from the first phase overlapped with Eel River suspended sediment characteristics found for low flows (1-5 times mean discharge), while those of the second phase were consistent suspended sediment from higher flows (7-10 times mean discharge). The abandoned channel fill sequences appeared to differ due to the topographic steering of bed sediment transport and

  8. Xenon Filled Silicon Germanium Thermoelectric Generators

    NASA Technical Reports Server (NTRS)

    Dewinter, F.

    1972-01-01

    An analysis is presented that shows the desirability and feasibility of using a xenon fill in the initial stages of operation of a silicon-germanium radioisotope thermoelectric generator to be used in outer-planetary exploration. The xenon cover gas offers protection against oxidation and against material sublimation, and allows the generator to deliver required power throughout the prelaunch and launch phases. The protective mechanisms afforded by the xenon cover gas and the mechanization of a xenon supply system are also discussed.

  9. The partially filled viscous ring damper.

    NASA Technical Reports Server (NTRS)

    Alfriend, K. T.

    1973-01-01

    The problem of a spinning satellite with a partially filled viscous ring damper is investigated. It is shown that there are two distinct modes of motion, the nutation-synchronous mode and spin-synchronous mode. From an approximate solution of the equations of motion a time constant is obtained for each mode. From a consideration of the fluid dynamics several methods are developed for determining the damping constant.

  10. Flow in a torsionally oscillating filled cylinder

    NASA Technical Reports Server (NTRS)

    Schafer, C. F.

    1983-01-01

    The flow of a liquid in a completely filled cylinder undergoing torsional oscillations about its longitudinal symmetry axis was studied analytically and experimentally. The objective of the studies was to determine the efficacy of the torsional oscillations in mixing the confined liquid. Flow was found to be confined primarily to toroidal cells at the ends of the cylinder. Cell thickness was about equal to the cylinder radius. The use of baffles at the end walls was shown to enhance the mixing process.

  11. Statistical evaluation of metal fill widths for emulated metal fill in parasitic extraction methodology

    NASA Astrophysics Data System (ADS)

    J-Me, Teh; Noh, Norlaili Mohd.; Aziz, Zalina Abdul

    2015-05-01

    In the chip industry today, the key goal of a chip development organization is to develop and market chips within a short time frame to gain foothold on market share. This paper proposes a design flow around the area of parasitic extraction to improve the design cycle time. The proposed design flow utilizes the usage of metal fill emulation as opposed to the current flow which performs metal fill insertion directly. By replacing metal fill structures with an emulation methodology in earlier iterations of the design flow, this is targeted to help reduce runtime in fill insertion stage. Statistical design of experiments methodology utilizing the randomized complete block design was used to select an appropriate emulated metal fill width to improve emulation accuracy. The experiment was conducted on test cases of different sizes, ranging from 1000 gates to 21000 gates. The metal width was varied from 1 x minimum metal width to 6 x minimum metal width. Two-way analysis of variance and Fisher's least significant difference test were used to analyze the interconnect net capacitance values of the different test cases. This paper presents the results of the statistical analysis for the 45 nm process technology. The recommended emulated metal fill width was found to be 4 x the minimum metal width.

  12. In Brief: Air pollution app

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2010-10-01

    A new smartphone application takes advantage of various technological capabilities and sensors to help users monitor air quality. Tapping into smartphone cameras, Global Positioning System (GPS) sensors, compasses, and accelerometers, computer scientists with the University of Southern California's (USC) Viterbi School of Engineering have developed a new application, provisionally entitled “Visibility.” Currently available for the Android telephone operating system, the application is available for free download at http://robotics.usc.edu/˜mobilesensing/Projects/AirVisibilityMonitoring. An iPhone application may be introduced soon. Smartphone users can take a picture of the sky and then compare it with models of sky luminance to estimate visibility. While conventional air pollution monitors are costly and thinly deployed in some areas, the smartphone application potentially could help fill in some blanks in existing air pollution maps, according to USC computer science professor Gaurav Sukhatme.

  13. Lithium isotope fractionation during uptake by gibbsite

    NASA Astrophysics Data System (ADS)

    Wimpenny, Josh; Colla, Christopher A.; Yu, Ping; Yin, Qing-Zhu; Rustad, James R.; Casey, William H.

    2015-11-01

    The intercalation of lithium from solution into the six-membered μ2-oxo rings on the basal planes of gibbsite is well-constrained chemically. The product is a lithiated layered-double hydroxide solid that forms via in situ phase change. The reaction has well established kinetics and is associated with a distinct swelling of the gibbsite as counter ions enter the interlayer to balance the charge of lithiation. Lithium reacts to fill a fixed and well identifiable crystallographic site and has no solvation waters. Our lithium-isotope data shows that 6Li is favored during this intercalation and that the solid-solution fractionation depends on temperature, electrolyte concentration and counter ion identity (whether Cl-, NO3- or ClO4-). We find that the amount of isotopic fractionation between solid and solution (ΔLisolid-solution) varies with the amount of lithium taken up into the gibbsite structure, which itself depends upon the extent of conversion and also varies with electrolyte concentration and in the counter ion in the order: ClO4- < NO3- < Cl-. Higher electrolyte concentrations cause more rapid expansion of the gibbsite interlayer and some counter ions, such as Cl-, are more easily taken up than others, probably because they ease diffusion. The relationship between lithium loading and ΔLisolid-solution indicates two stages: (1) uptake into the crystallographic sites that favors light lithium, in parallel with adsorption of solvated cations, and (2) continued uptake of solvated cations after all available octahedral vacancies are filled; this second stage has no isotopic preference. The two-step reaction progress is supported by solid-state NMR spectra that clearly resolve a second reservoir of lithium in addition to the expected layered double-hydroxide phase.

  14. A Performance Map for Ideal Air Breathing Pulse Detonation Engines

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E.

    2001-01-01

    The performance of an ideal, air breathing Pulse Detonation Engine is described in a manner that is useful for application studies (e.g., as a stand-alone, propulsion system, in combined cycles, or in hybrid turbomachinery cycles). It is shown that the Pulse Detonation Engine may be characterized by an averaged total pressure ratio, which is a unique function of the inlet temperature, the fraction of the inlet flow containing a reacting mixture, and the stoichiometry of the mixture. The inlet temperature and stoichiometry (equivalence ratio) may in turn be combined to form a nondimensional heat addition parameter. For each value of this parameter, the average total enthalpy ratio and total pressure ratio across the device are functions of only the reactant fill fraction. Performance over the entire operating envelope can thus be presented on a single plot of total pressure ratio versus total enthalpy ratio for families of the heat addition parameter. Total pressure ratios are derived from thrust calculations obtained from an experimentally validated, reactive Euler code capable of computing complete Pulse Detonation Engine limit cycles. Results are presented which demonstrate the utility of the described method for assessing performance of the Pulse Detonation Engine in several potential applications. Limitations and assumptions of the analysis are discussed. Details of the particular detonative cycle used for the computations are described.

  15. Isolation and characterization of three endosomal fractions from the liver of estradiol-treated rats

    SciTech Connect

    Belcher, J.D.; Hamilton, R.L.; Brady, S.E.; Hornick, C.A.; Jaeckle, S.; Schneider, W.J.; Havel, R.J.

    1987-10-01

    Three distinct endosomal fractions were isolated in high purity from livers of estradiol-treated rats. Each fraction had characteristic physical and ultrastructural properties, but the lipid composition and major proteins of their membranes were similar and differed from those derived from the Golgi apparatus. Injected radioiodinated low density lipoproteins accumulated first in the fraction of intermediate density and later in the low density fraction. The latter was composed almost exclusively of lipoprotein-filled multivesicular bodies, most of which had a single membranous appendage. The fraction of intermediate density was composed of lipoprotein-filled vesicles that were smaller than multivesicular bodies and also had membranous appendages. The high density fraction was composed of membranes resembling the appendages of the two vesicular fractions. All three fractions were enriched in receptors for low density lipoproteins and asialoglycoproteins, but receptor concentrations were considerably reduced in multivesicular bodies. The fraction of intermediate density may represent the compartment of uncoupling of receptor and ligand (CURL) described by Geuze et al. CURL vesicles may lose some of their appendages as multivesicular bodies are formed. The high density fraction than may represent a receptor-recycling compartment.

  16. Polystyrene Foam EOS as a Function of Porosity and Fill Gas

    NASA Astrophysics Data System (ADS)

    Mulford, Roberta; Swift, Damian

    2009-06-01

    An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam, Differences between air-filled, nitrogen-blown, and CO2-blown foams are investigated, to estimate the importance of allowing air to react with plastic products during decomposition. Results differ somewhat from the conventional EOS, which are generated from values for plastic extrapolated to low densities.

  17. Grid fill algorithm for vector graphics render on mobile devices

    NASA Astrophysics Data System (ADS)

    Zhang, Jixian; Yue, Kun; Yuan, Guowu; Zhang, Binbin

    2015-12-01

    The performance of vector graphics render has always been one of the key elements in mobile devices and the most important step to improve the performance is to enhance the efficiency of polygon fill algorithms. In this paper, we proposed a new and more efficient polygon fill algorithm based on the scan line algorithm and Grid Fill Algorithm (GFA). First, we elaborated the GFA through solid fill. Second, we described the techniques for implementing antialiasing and self-intersection polygon fill with GFA. Then, we discussed the implementation of GFA based on the gradient fill. Generally, compared to other fill algorithms, GFA has better performance and achieves faster fill speed, which is specifically consistent with the inherent characteristics of mobile devices. Experimental results show that better fill effects can be achieved by using GFA.

  18. Protective supplied breathing air garment

    DOEpatents

    Childers, E.L.; Hortenau, E.F. von.

    1984-07-10

    A breathing air garment is disclosed for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap. 17 figs.

  19. Protective supplied breathing air garment

    DOEpatents

    Childers, Edward L.; von Hortenau, Erik F.

    1984-07-10

    A breathing air garment for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap.

  20. What is a fractional derivative?

    NASA Astrophysics Data System (ADS)

    Ortigueira, Manuel D.; Tenreiro Machado, J. A.

    2015-07-01

    This paper discusses the concepts underlying the formulation of operators capable of being interpreted as fractional derivatives or fractional integrals. Two criteria for required by a fractional operator are formulated. The Grünwald-Letnikov, Riemann-Liouville and Caputo fractional derivatives and the Riesz potential are accessed in the light of the proposed criteria. A Leibniz rule is also obtained for the Riesz potential.

  1. Positive fractional linear electrical circuits

    NASA Astrophysics Data System (ADS)

    Kaczorek, Tadeusz

    2013-10-01

    The positive fractional linear systems and electrical circuits are addressed. New classes of fractional asymptotically stable and unstable electrical circuits are introduced. The Caputo and Riemann-Liouville definitions of fractional derivatives are used to analysis of the positive electrical circuits composed of resistors, capacitors, coils and voltage (current) sources. The positive fractional electrical and specially unstable different types electrical circuits are analyzed. Some open problems are formulated.

  2. Experimental observation of fractional echoes

    NASA Astrophysics Data System (ADS)

    Karras, G.; Hertz, E.; Billard, F.; Lavorel, B.; Siour, G.; Hartmann, J.-M.; Faucher, O.; Gershnabel, Erez; Prior, Yehiam; Averbukh, Ilya Sh.

    2016-09-01

    We report the observation of fractional echoes in a double-pulse excited nonlinear system. Unlike standard echoes, which appear periodically at delays which are integer multiples of the delay between the two exciting pulses, the fractional echoes appear at rational fractions of this delay. We discuss the mechanism leading to this phenomenon, and provide experimental demonstration of fractional echoes by measuring third harmonic generation in a thermal gas of CO2 molecules excited by a pair of femtosecond laser pulses.

  3. Fractional diffusion on bounded domains

    SciTech Connect

    Defterli, Ozlem; D'Elia, Marta; Du, Qiang; Gunzburger, Max Donald; Lehoucq, Richard B.; Meerschaert, Mark M.

    2015-03-13

    We found that the mathematically correct specification of a fractional differential equation on a bounded domain requires specification of appropriate boundary conditions, or their fractional analogue. In this paper we discuss the application of nonlocal diffusion theory to specify well-posed fractional diffusion equations on bounded domains.

  4. Effects of verapamil and propranolol on left ventricular systolic function and diastolic filling in patients with coronary artery disease: radionuclide angiographic studies at rest and during exercise

    SciTech Connect

    Bonow, R.O.; Leon, M.B.; Rosing, D.R.; Kent, K.M.; Lipson, L.C.; Bacharach, S.L.; Green, M.V.; Epstein, S.E.

    1982-06-01

    To determine the effects of verapamil on left ventricular (LV) systolic function and diastolic filling in patients with coronary artery disease (CAD), researchers performed gated radionuclide angiography at rest and during exercise in 16 symptomatic patients before and during oral verapamil therapy (480 mg/day). Twelve patients were also studied during oral propranolol. LV ejection fraction at rest was normal in 13 patients, but abnormal diastolic filling at rest, defined as peak filling rate (PFR) less than 2.5 end-diastolic volumes (EDV)/sec or time to PFR greater than 180 msec, was present in 15. During verapamil, resting ejection fraction decreased, but resting diastolic filling improved: PFR increased and time to PFR decreased. Exercise ejection fraction did not change during verapamil, but exercise PFR increased, and exercise time to PFR decreased. In contrast, propranolol did not alter ejection fraction, PFR, or time to PFR at rest or during exercise. Thus, LV ejection fraction is decreased by verapamil at rest but is unchanged during exercise. While LV systolic function is not improved by verapamil, LV diastolic filling is enhanced by verapamil, both at rest and during exercise. These mechanisms may account in part for the symptomatic improvement in many patients during verapamil therapy.

  5. Electrical conductivity modeling and research of polypropylene composites filled with carbon black

    NASA Astrophysics Data System (ADS)

    Stepashkina, A. S.; Tsobkallo, E. S.; Alyoshin, A. N.

    2014-12-01

    Composites of polypropylene filled with carbon black (PP/CB composite) at different concentrations were prepared by melt mixing followed by compression molding. The dependence of electrical resistance on the filler mass fraction was experimentally received. It was shown that the received dependence had the threshold character. The composite kept dielectric properties at the filler concentration below the threshold and at the concentration above the threshold the electrical resistance decreased more than on 8-10 orders. The theoretical description of electrical conductivity of the composite was offered. Experimental data of the dependence between electrical resistance and the filler mass fraction agreed with the theoretical. The process of conductivity in the PP/CB composite was simulated by means of the Monte-Carlo method for threshold mass fraction estimation.

  6. Fractionation of Subcellular Organelles.

    PubMed

    Graham, John M

    2015-01-01

    This unit provides both a theoretical and a practical background to all the techniques associated with the application of differential and density gradient centrifugation for the analysis of subcellular membranes. The density gradient information focuses on the use of the modern gradient solute iodixanol, chosen for its ease of use, versatility, and compatibility with biological particles. Its use in both pre-formed discontinuous and continuous gradients and in self-generated gradients is discussed. Considerable emphasis is given to selection of the appropriate centrifuge rotors and tubes and their influence on the methods used for creation, fractionation, and analysis of density gradients. Without proper consideration of these critical ancillary procedures, the resolving power of the gradient can be easily compromised. PMID:26621372

  7. Fractionation of Subcellular Organelles.

    PubMed

    Graham, John M

    2015-12-01

    This unit provides both a theoretical and a practical background to all the techniques associated with the application of differential and density gradient centrifugation for the analysis of subcellular membranes. The density gradient information focuses on the use of the modern gradient solute iodixanol, chosen for its ease of use, versatility, and compatibility with biological particles. Its use in both pre-formed discontinuous and continuous gradients and in self-generated gradients is discussed. Considerable emphasis is given to selection of the appropriate centrifuge rotors and tubes and their influence on the methods used for creation, fractionation, and analysis of density gradients. Without proper consideration of these critical ancillary procedures, the resolving power of the gradient can be easily compromised.

  8. Soot Volume Fraction Imaging

    NASA Technical Reports Server (NTRS)

    Greenberg, Paul S.; Ku, Jerry C.

    1994-01-01

    A new technique is described for the full-field determination of soot volume fractions via laser extinction measurements. This technique differs from previously reported point-wise methods in that a two-dimensional array (i.e., image) of data is acquired simultaneously. In this fashion, the net data rate is increased, allowing the study of time-dependent phenomena and the investigation of spatial and temporal correlations. A telecentric imaging configuration is employed to provide depth-invariant magnification and to permit the specification of the collection angle for scattered light. To improve the threshold measurement sensitivity, a method is employed to suppress undesirable coherent imaging effects. A discussion of the tomographic inversion process is provided, including the results obtained from numerical simulation. Results obtained with this method from an ethylene diffusion flame are shown to be in close agreement with those previously obtained by sequential point-wise interrogation.

  9. Pressure distribution evaluation of different filling methods for deposition of powders in dies: Measurement and modeling

    NASA Astrophysics Data System (ADS)

    Sayyar Roudsari, Saed

    The aim of this research was to measure, analyze, and model the pressure distribution characteristics of powder deposition into rectangular and circular shallow dies using four filling methods. The feed shoe, the rotational rainy, the point feed, and the pneumatic filling methods were used to investigate the deposition characteristics into shallow dies. In order to evaluate the pressure distribution during filling of shallow dies, factors influencing powder deposition were studied. The factors included particle size and shape, particle size distribution, feed shoe speed, and tube cross-section (in case of feed shoe filling) and deposition rates (in case of rotational rainy, point feed, and pneumatic filling). A battery powder mixture (BPM) and microcrystalline cellulose (Avicel PH102) with median size of 84 and 600mum, respectively, were used to fill a shallow rectangular die 32x30 mm and 6.5 mm deep and a shallow circular die 35 mm in diameter and 6.5 mm deep. The second generation of pressure deposition tester (PDT-II) with circular and square feed shoe tube cross-sections was used to measure the two powders' pressure distribution characteristics. An innovative rotational rainy filling device was designed and fabricated. This versatile device can be used to measure filling characteristics at different rotational speeds (1-10 rpm) for various powders. The point feed (funnel fill) method with a funnel of 30 mm inlet diameter and 4.2 mm outlet diameter opening was used to fill the rectangular and circular shallow dies. The pneumatic filling method was designed and fabricated to fill the die using air as the conveying medium in a rectangular cross-section tube. The pneumatic filling device was limited to using only the BPM powder, since the Avicel powder generated substantial quantity of airborne dust during the test. Symmetry analysis, variance metrics, and uniformity analysis were used to quantify the deposition characteristics. The results showed that: (1) filled

  10. AGU member running to fill congressional seat

    NASA Astrophysics Data System (ADS)

    Crum, Emily

    John F Mink, an AGU member (Hydrology) for 50 years, and husband of the late Representative Patsy T. Mink (D-Hawaii), will run in a special election on 30 November to fill the remainder of his wife's unexpired congressional term. Patsy Mink, who represented the 2nd Congressional District of Hawaii, passed away on 28 September after battling pneumonia.Her name will appear on the 5 November election ballot as a candidate for Hawaii's 2nd District in the 108th Congress. If she is elected posthumously, the state of Hawaii will hold a special election in January to select an official to serve the full two-year term.

  11. Multiple scattering theory for space filling potentials

    SciTech Connect

    Butler, W.H. ); Brown, R.G. . Dept. of Physics); Nesbet, R.K. . Almaden Research Center)

    1990-01-01

    Multiple scattering theory (MST) provides an efficient technique for solving the wave equation for the special case of muffin-tin potentials. Here MST is extended to treat space filling non-muffin tin potentials and its validity, accuracy and efficiency are tested by application of the two dimensional empty lattice test. For this test it is found that the traditional formulation of MST does not coverage as the number of partial waves is increased. A simple modification of MST, however, allows this problem to be solved exactly and efficiently. 15 refs., 3 tabs.

  12. Liquid-Filled Piping System Analysis

    1993-07-07

    WHAM6 is used to calculate pressure and velocity transients in liquid-filled piping networks. It can be applied to multiloop complex piping networks consisting of dead ends, elbows, orifices, multiple-branch tees, changes of flow passage cross section, check valves, pumps, pressurizers or tanks, and exit valves or breaks. Hydraulic losses are considered. Transients can be initiated either by closure or opening of one or more exit valves (equivalent to system ruptures) or by a prescribed gasmore » pressure history in a pressurizer tank.« less

  13. 21 CFR 872.3820 - Root canal filling resin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification... for use during endodontic therapy to fill the root canal of a tooth. (b) Classification. (1) Class...

  14. 21 CFR 1306.06 - Persons entitled to fill prescriptions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... substance may only be filled by a pharmacist, acting in the usual course of his professional practice and either registered individually or employed in a registered pharmacy, a registered central fill...

  15. 21 CFR 1306.06 - Persons entitled to fill prescriptions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... substance may only be filled by a pharmacist, acting in the usual course of his professional practice and either registered individually or employed in a registered pharmacy, a registered central fill...

  16. Intraventricular filling under increasing left ventricular wall stiffness and heart rates

    NASA Astrophysics Data System (ADS)

    Samaee, Milad; Lai, Hong Kuan; Schovanec, Joseph; Santhanakrishnan, Arvind; Nagueh, Sherif

    2015-11-01

    Heart failure with normal ejection fraction (HFNEF) is a clinical syndrome that is prevalent in over 50% of heart failure patients. HFNEF patients show increased left ventricle (LV) wall stiffness and clinical diagnosis is difficult using ejection fraction (EF) measurements. We hypothesized that filling vortex circulation strength would decrease with increasing LV stiffness irrespective of heart rate (HR). 2D PIV and hemodynamic measurements were acquired on LV physical models of varying wall stiffness under resting and exercise HRs. The LV models were comparatively tested in an in vitro flow circuit consisting of a two-element Windkessel model driven by a piston pump. The stiffer LV models were tested in comparison with the least stiff baseline model without changing pump amplitude, circuit compliance and resistance. Increasing stiffness at resting HR resulted in diminishing cardiac output without lowering EF below 50% as in HFNEF. Increasing HR to 110 bpm in addition to stiffness resulted in lowering EF to less than 50%. The circulation strength of the intraventricular filling vortex diminished with increasing stiffness and HR. The results suggest that filling vortex circulation strength could be potentially used as a surrogate measure of LV stiffness. This research was supported by the Oklahoma Center for Advancement of Science and Technology (HR14-022).

  17. 40 CFR 1065.365 - Nonmethane cutter penetration fractions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Nonmethane cutter penetration...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calibrations and Verifications Hydrocarbon Measurements § 1065.365 Nonmethane cutter penetration fractions. (a) Scope and frequency. If you use a...

  18. 40 CFR 1065.365 - Nonmethane cutter penetration fractions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Nonmethane cutter penetration...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calibrations and Verifications Hydrocarbon Measurements § 1065.365 Nonmethane cutter penetration fractions. (a) Scope and frequency. If you use a...

  19. 40 CFR 1065.365 - Nonmethane cutter penetration fractions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Nonmethane cutter penetration...) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Calibrations and Verifications Hydrocarbon Measurements § 1065.365 Nonmethane cutter penetration fractions. (a) Scope and frequency. If you use a...

  20. Kinetic Modeling of Sunflower Grain Filling and Fatty Acid Biosynthesis.

    PubMed

    Durruty, Ignacio; Aguirrezábal, Luis A N; Echarte, María M

    2016-01-01

    Grain growth and oil biosynthesis are complex processes that involve various enzymes placed in different sub-cellular compartments of the grain. In order to understand the mechanisms controlling grain weight and composition, we need mathematical models capable of simulating the dynamic behavior of the main components of the grain during the grain filling stage. In this paper, we present a non-structured mechanistic kinetic model developed for sunflower grains. The model was first calibrated for sunflower hybrid ACA855. The calibrated model was able to predict the theoretical amount of carbohydrate equivalents allocated to the grain, grain growth and the dynamics of the oil and non-oil fraction, while considering maintenance requirements and leaf senescence. Incorporating into the model the serial-parallel nature of fatty acid biosynthesis permitted a good representation of the kinetics of palmitic, stearic, oleic, and linoleic acids production. A sensitivity analysis showed that the relative influence of input parameters changed along grain development. Grain growth was mostly affected by the specific growth parameter (μ') while fatty acid composition strongly depended on their own maximum specific rate parameters. The model was successfully applied to two additional hybrids (MG2 and DK3820). The proposed model can be the first building block toward the development of a more sophisticated model, capable of predicting the effects of environmental conditions on grain weight and composition, in a comprehensive and quantitative way.

  1. Mullins effect in a filled elastomer under uniaxial tension.

    PubMed

    Maiti, A; Small, W; Gee, R H; Weisgraber, T H; Chinn, S C; Wilson, T S; Maxwell, R S

    2014-01-01

    Modulus softening and permanent set in filled polymeric materials due to cyclic loading and unloading, commonly known as the Mullins effect, can have a significant impact on their use as support cushions. A quantitative analysis of such behavior is essential to ensure the effectiveness of such materials in long-term deployment. In this work we combine existing ideas of filler-induced modulus enhancement, strain amplification, and irreversible deformation within a simple non-Gaussian constitutive model to quantitatively interpret recent measurements on a relevant PDMS-based elastomeric cushion. We find that the experimental stress-strain data is consistent with the picture that during stretching (loading) two effects take place simultaneously: (1) the physical constraints (entanglements) initially present in the polymer network get disentangled, thus leading to a gradual decrease in the effective cross-link density, and (2) the effective filler volume fraction gradually decreases with increasing strain due to the irreversible pulling out of an initially occluded volume of the soft polymer domain. PMID:24580250

  2. Mullins effect in a filled elastomer under uniaxial tension

    NASA Astrophysics Data System (ADS)

    Maiti, A.; Small, W.; Gee, R. H.; Weisgraber, T. H.; Chinn, S. C.; Wilson, T. S.; Maxwell, R. S.

    2014-01-01

    Modulus softening and permanent set in filled polymeric materials due to cyclic loading and unloading, commonly known as the Mullins effect, can have a significant impact on their use as support cushions. A quantitative analysis of such behavior is essential to ensure the effectiveness of such materials in long-term deployment. In this work we combine existing ideas of filler-induced modulus enhancement, strain amplification, and irreversible deformation within a simple non-Gaussian constitutive model to quantitatively interpret recent measurements on a relevant PDMS-based elastomeric cushion. We find that the experimental stress-strain data is consistent with the picture that during stretching (loading) two effects take place simultaneously: (1) the physical constraints (entanglements) initially present in the polymer network get disentangled, thus leading to a gradual decrease in the effective cross-link density, and (2) the effective filler volume fraction gradually decreases with increasing strain due to the irreversible pulling out of an initially occluded volume of the soft polymer domain.

  3. Mullins effect in a filled elastomer under uniaxial tension

    DOE PAGES

    Maiti, A.; Small, W.; Gee, R. H.; Weisgraber, T. H.; Chinn, S. C.; Wilson, T. S.; Maxwell, R. S.

    2014-01-16

    Modulus softening and permanent set in filled polymeric materials due to cyclic loading and unloading, commonly known as the Mullins effect, can have a significant impact on their use as support cushions. The quantitative analysis of such behavior is essential to ensure the effectiveness of such materials in long-term deployment. In this work we combine existing ideas of filler-induced modulus enhancement, strain amplification, and irreversible deformation within a simple non-Gaussian constitutive model to quantitatively interpret recent measurements on a relevant PDMS-based elastomeric cushion. Also, we find that the experimental stress-strain data is consistent with the picture that during stretching (loading)more » two effects take place simultaneously: (1) the physical constraints (entanglements) initially present in the polymer network get disentangled, thus leading to a gradual decrease in the effective cross-link density, and (2) the effective filler volume fraction gradually decreases with increasing strain due to the irreversible pulling out of an initially occluded volume of the soft polymer domain.« less

  4. Mullins effect in a filled elastomer under uniaxial tension

    SciTech Connect

    Maiti, A.; Small, W.; Gee, R. H.; Weisgraber, T. H.; Chinn, S. C.; Wilson, T. S.; Maxwell, R. S.

    2014-01-16

    Modulus softening and permanent set in filled polymeric materials due to cyclic loading and unloading, commonly known as the Mullins effect, can have a significant impact on their use as support cushions. The quantitative analysis of such behavior is essential to ensure the effectiveness of such materials in long-term deployment. In this work we combine existing ideas of filler-induced modulus enhancement, strain amplification, and irreversible deformation within a simple non-Gaussian constitutive model to quantitatively interpret recent measurements on a relevant PDMS-based elastomeric cushion. Also, we find that the experimental stress-strain data is consistent with the picture that during stretching (loading) two effects take place simultaneously: (1) the physical constraints (entanglements) initially present in the polymer network get disentangled, thus leading to a gradual decrease in the effective cross-link density, and (2) the effective filler volume fraction gradually decreases with increasing strain due to the irreversible pulling out of an initially occluded volume of the soft polymer domain.

  5. Kinetic Modeling of Sunflower Grain Filling and Fatty Acid Biosynthesis

    PubMed Central

    Durruty, Ignacio; Aguirrezábal, Luis A. N.; Echarte, María M.

    2016-01-01

    Grain growth and oil biosynthesis are complex processes that involve various enzymes placed in different sub-cellular compartments of the grain. In order to understand the mechanisms controlling grain weight and composition, we need mathematical models capable of simulating the dynamic behavior of the main components of the grain during the grain filling stage. In this paper, we present a non-structured mechanistic kinetic model developed for sunflower grains. The model was first calibrated for sunflower hybrid ACA855. The calibrated model was able to predict the theoretical amount of carbohydrate equivalents allocated to the grain, grain growth and the dynamics of the oil and non-oil fraction, while considering maintenance requirements and leaf senescence. Incorporating into the model the serial-parallel nature of fatty acid biosynthesis permitted a good representation of the kinetics of palmitic, stearic, oleic, and linoleic acids production. A sensitivity analysis showed that the relative influence of input parameters changed along grain development. Grain growth was mostly affected by the specific growth parameter (μ′) while fatty acid composition strongly depended on their own maximum specific rate parameters. The model was successfully applied to two additional hybrids (MG2 and DK3820). The proposed model can be the first building block toward the development of a more sophisticated model, capable of predicting the effects of environmental conditions on grain weight and composition, in a comprehensive and quantitative way. PMID:27242809

  6. Microcomputed tomographic comparison of posterior composite resin restorative techniques: sonicated bulk fill versus incremental fill.

    PubMed

    Jarisch, Justin; Lien, Wen; Guevara, Peter H; Greenwood, William J; Dunn, William J

    2016-01-01

    Sonication technology has recently been touted to decrease composite viscosity during delivery and may allow better cavity preparation adaptation and minimize voids. The purpose of this investigation was to evaluate the difference between conventional, hand-placed, incremental application of a standard hybrid resin-based composite (RBC) and sonicated application of a bulk-fill RBC in box-type and cylindrical cavity preparations. Experimental restorations were fabricated using molds of box-type or cylindrical preparations. For bulk-filled specimens, a single compule of bulk-fill composite was dispensed with a sonic handpiece. The conventional hybrid material was placed in 3 increments (2 mm, 2 mm, and 1 mm). Microfocus x-ray computed tomography was used to analyze voids for percentage and total volume porosity as well as number of actual pores. An analysis of variance indicated that RBC restorations that were applied to cylindrical cavities using a sonicated bulk-filled application method exhibited significantly less porosity (1.42%; P < 0.001) than incrementally placed cylindrical restorations (2.87%); sonicated bulk-filled, cube-shaped restorations (3.12%); and incrementally placed cube-shaped restorations (5.16%). When the groups were subcategorized into the specific characteristics of shape (cube vs cylinder) and application method (bulk vs incremental), the cylindrical group, which included both bulk-filled and incrementally placed specimens, demonstrated significantly less porosity (2.00%; P < 0.001) than other groups. Restorations that were incrementally placed into cube-shaped cavities produced the largest amount of porosity. PMID:27599276

  7. Distribution of 1-Butyl-3-methylimidazolium Bistrifluoromethylsulfonimide in Mesoporous Silica as a Function of Pore Filling

    SciTech Connect

    Han, Kee Sung; Wang, Xiqing; Hagaman, Edward {Ed} W; Dai, Sheng

    2013-01-01

    Rotational dynamics of the ionic liquid (IL) 1-butyl-3-methlyimidazolium bistrifluoromethylsulfonimide, [C4mim][Tf2N], 1, as a neat liquid and confined in mesoporous silica were investigated by 1H spin-spin (T2) and spin-lattice (T1) relaxation measurements and 13C NMR spectroscopy. Translational dynamics (self-diffusion) were monitored via the diffusion coefficient, D, obtained with 1H pulsed field gradient NMR measurements. These data were used to determine the distribution of 1 in the pores of KIT-6, a mesoporous silica with a bicontinuous gyroid pore structure, as a function of filling fraction. Relaxation studies performed as a function of filling factor and temperature, reveal a dynamic heterogeneity in both translational and rotational motions for 1 at filling factors, f, = 0.2-1.0 (f = 1 corresponds to fully filled pores). Spin-lattice and spin-spin relaxation times reveal the motion of 1 in silica mesopores conform to that expected for a two-dimensional relaxation model. The relaxation dynamics are interpreted using a two-state, fast exchange model for all motions; a slow rotation (and translation) of molecules in contact with the surface and a faster motion approximated by the values for bulk relaxation and diffusion. 1 retains liquid like behavior at all filling factors and temperatures that extend to ca. 50 degrees below the bulk melting point. Translational motion in these systems, interpreted with MD-simulated diffusivity limits, confirms the high propensity of 1 to form a monolayer film on the silica surface at low filling factors.. The attractive interaction of 1 with the surface is greater than that for self-association of 1. The trends in diffusion data at short and long diffusion time suggest that the population of surface-bound 1 is in intimate contact with 1 in the pores. This condition is most easily met at higher filling fractions with successive additions of 1 increasing the layer thickness built up on the surface layer.

  8. Aerodynamical sealing by air curtains

    NASA Astrophysics Data System (ADS)

    Frank, Daria; Linden, Paul

    2015-11-01

    Air curtains are artificial high-velocity plane turbulent jets which are installed in a doorway in order to reduce the heat and the mass exchange between two environments. The performance of an air curtain is assessed in terms of the sealing effectiveness E, the fraction of the exchange flow prevented by the air curtain compared to the open-door situation. The main controlling parameter for air curtain dynamics is the deflection modulus Dm representing the ratio of the momentum flux of the air curtain and the transverse forces acting on it due to the stack effect. In this talk, we examine the influence of two factors on the performance of an air curtain: the presence of an additional ventilation pathway in the room, such as a small top opening, and the effects of an opposing buoyancy force which for example arises if a downwards blowing air curtain is heated. Small-scale experiments were conducted to investigate the E (Dm) -curve of an air curtain in both situations. We present both experimental results and theoretical explanations for our observations. We also briefly illustrate how simplified models developed for air curtains can be used for more complex phenomena such as the effects of wind blowing around a model building on the ventilation rates through the openings.

  9. Filled liquid silicone rubbers: possibilities and challenges

    NASA Astrophysics Data System (ADS)

    Yu, Liyun; Vudayagiri, Sindhu; Zakaria, Shamsul; Benslimane, Mohamed Y.; Skov, Anne L.

    2014-03-01

    Liquid silicone rubbers (LSRs) have been shown to possess very favorable properties as dielectric electroactive polymers due to their very high breakdown strengths (up to 170 V/μm) combined with their fast response, relatively high tear strength, acceptable Young's modulus as well as they can be filled with permittivity enhancing fillers. However, LSRs possess large viscosity, especially when additional fillers are added. Therefore both mixing and coating of the required thin films become difficult. The solution so far has been to use solvent to dilute the reaction mixture in order both to ensure better particle dispersion as well as allowing for film formation properties. We show that the mechanical properties of the films as well as the electrical breakdown strength can be affected, and that the control of the amount of solvent throughout the coating process is essential for solvent borne processes. Another problem encountered when adding solvent to the highly filled reaction mixture is the loss of tension in the material upon large deformations. These losses are shown to be irreversible and happen within the first large-strain cycle.

  10. Liquid crystal filled surface plasmon resonance thermometer.

    PubMed

    Lu, Mengdi; Zhang, Xinpu; Liang, Yuzhang; Li, Lixia; Masson, Jean-Francois; Peng, Wei

    2016-05-16

    A novel surface plasmon resonance (SPR) thermometer based on liquid crystal (LC) filled hollow fiber is demonstrated in this paper. A hollow fiber was internally coated with silver and then filled with LC. The SPR response to temperature was studied using modeling and verified experimentally. The results demonstrated that the refractive index of LC decreases with the increasing temperature and the variation can be detected by the resonance wavelength shift of the plasmon resonance. The temperature sensitivities were 4.72 nm/°C in the temperature range of 20 to 34.5 °C and 0.55 nm/°C in the temperature range of 36 to 50 °C, At the phase transition temperature between nematic and isotropic phases of the LC, the temperature sensitivity increased by one order of magnitude and a shift of more than 46 nm was observed with only a 1.5 °C temperature change. This sensor can be used for temperature monitoring and alarming, and can be extended for other physical parameter measurement. PMID:27409911

  11. Fractional telegrapher's equation from fractional persistent random walks

    NASA Astrophysics Data System (ADS)

    Masoliver, Jaume

    2016-05-01

    We generalize the telegrapher's equation to allow for anomalous transport. We derive the space-time fractional telegrapher's equation using the formalism of the persistent random walk in continuous time. We also obtain the characteristic function of the space-time fractional process and study some particular cases and asymptotic approximations. Similarly to the ordinary telegrapher's equation, the time-fractional equation also presents distinct behaviors for different time scales. Specifically, transitions between different subdiffusive regimes or from superdiffusion to subdiffusion are shown by the fractional equation as time progresses.

  12. Fractional telegrapher's equation from fractional persistent random walks.

    PubMed

    Masoliver, Jaume

    2016-05-01

    We generalize the telegrapher's equation to allow for anomalous transport. We derive the space-time fractional telegrapher's equation using the formalism of the persistent random walk in continuous time. We also obtain the characteristic function of the space-time fractional process and study some particular cases and asymptotic approximations. Similarly to the ordinary telegrapher's equation, the time-fractional equation also presents distinct behaviors for different time scales. Specifically, transitions between different subdiffusive regimes or from superdiffusion to subdiffusion are shown by the fractional equation as time progresses. PMID:27300830

  13. 21 CFR 872.3820 - Root canal filling resin.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate,...

  14. 21 CFR 872.3820 - Root canal filling resin.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate,...

  15. 21 CFR 872.3820 - Root canal filling resin.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate,...

  16. 21 CFR 872.3820 - Root canal filling resin.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate,...

  17. 7 CFR 52.774 - Fill of container.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... United States Standards for Grades of Canned Red Tart Pitted Cherries 1 Fill of Container § 52.774 Fill of container. (a) FDA requirements. Canned red tart pitted cherries shall meet the fill of container requirements as set forth in the regulations of the Food and Drug Administration (21 CFR 145.125(c))....

  18. 7 CFR 52.774 - Fill of container.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... United States Standards for Grades of Canned Red Tart Pitted Cherries 1 Fill of Container § 52.774 Fill of container. (a) FDA requirements. Canned red tart pitted cherries shall meet the fill of container requirements as set forth in the regulations of the Food and Drug Administration (21 CFR 145.125(c))....

  19. 21 CFR 872.3310 - Coating material for resin fillings.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to the... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Coating material for resin fillings....

  20. 21 CFR 872.3310 - Coating material for resin fillings.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to the... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Coating material for resin fillings....

  1. 21 CFR 872.3310 - Coating material for resin fillings.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to the... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Coating material for resin fillings....

  2. 27 CFR 19.410 - Age and fill date.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Age and fill date. 19.410... Spirits from Customs Custody § 19.410 Age and fill date. For purposes of this part, the age and fill date for spirits imported or brought into the United States will be: (a) The claimed age, as shown on...

  3. 27 CFR 19.410 - Age and fill date.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Age and fill date. 19.410... Spirits from Customs Custody § 19.410 Age and fill date. For purposes of this part, the age and fill date for spirits imported or brought into the United States will be: (a) The claimed age, as shown on...

  4. 27 CFR 19.410 - Age and fill date.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Age and fill date. 19.410... Spirits from Customs Custody § 19.410 Age and fill date. For purposes of this part, the age and fill date for spirits imported or brought into the United States will be: (a) The claimed age, as shown on...

  5. 27 CFR 19.410 - Age and fill date.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Age and fill date. 19.410... Spirits from Customs Custody § 19.410 Age and fill date. For purposes of this part, the age and fill date for spirits imported or brought into the United States will be: (a) The claimed age, as shown on...

  6. 21 CFR 872.3310 - Coating material for resin fillings.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Coating material for resin fillings. 872.3310... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3310 Coating material for resin fillings. (a) Identification. A coating material for resin fillings is a device intended to be applied to...

  7. 19 CFR 132.22 - When quota is filled.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false When quota is filled. 132.22 Section 132.22... TREASURY QUOTAS Mail Importation of Absolute Quota Merchandise § 132.22 When quota is filled. Any packages containing merchandise subject to an absolute quota which is filled shall be returned to the postmaster...

  8. 19 CFR 132.22 - When quota is filled.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false When quota is filled. 132.22 Section 132.22... TREASURY QUOTAS Mail Importation of Absolute Quota Merchandise § 132.22 When quota is filled. Any packages containing merchandise subject to an absolute quota which is filled shall be returned to the postmaster...

  9. 19 CFR 132.22 - When quota is filled.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false When quota is filled. 132.22 Section 132.22... TREASURY QUOTAS Mail Importation of Absolute Quota Merchandise § 132.22 When quota is filled. Any packages containing merchandise subject to an absolute quota which is filled shall be returned to the postmaster...

  10. Teaching Science: Air Pressure "Eggs-periments."

    ERIC Educational Resources Information Center

    Leyden, Michael B.

    1994-01-01

    Discusses how teachers can introduce students to various scientific concept concerning motion, air composition, and heat by conducting an experiment: A peeled, hard-boiled egg is sucked into a bottle neck slightly smaller than the egg, after the bottle has been filled and emptied of hot water. Also discusses how students' understanding of the…

  11. Air Pollution.

    ERIC Educational Resources Information Center

    Fox, Donald L.

    1989-01-01

    Materials related to air pollution are reviewed for the period January 1987, to October 1988. The topics are pollution monitoring, air pollution, and environmental chemistry. The organization consists of two major analytical divisions: (1) gaseous methods; and (2) aerosol and particulate methods. (MVL)

  12. Air Pollution.

    EPA Science Inventory

    Air quality is affected by many types of pollutants that are emitted from various sources, including stationary and mobile. These sources release both criteria and hazardous air pollutants, which cause health effects, ecological harm, and material damage. They are generally categ...

  13. Method development for VOST Fractionator

    SciTech Connect

    St. Germain Wickham, M.E.; Cummins, S.B.; Radolovich, G. )

    1994-01-01

    A VOST Fractionator was designed and tested to fractionate an original VOST sample into two samples: one large and one small sample. The device allows for quantitation of high levels of compounds in the small fraction and trace levels in the large fraction. Several preliminary validation samples were prepared, split, and analyzed to test the feasibility of the VOST Fractionator. These validation samples contained 40,000 ng of three terpene compounds and 100 ng of 42 other volatile target analytes. Analyte recoveries ranged from 70 to 130 percent, except for five water-soluble compounds. Recovery for the terpene compounds was 110 to 118 percent. Precision for triplicate spiked samples was less than 30 percent relative standard deviation (%RSD) for most compounds. Results indicate that the VOST Fractionator accurately splits the sample and allows quantitation of extremely high levels of compounds without sacrificing sensitivity for trace compounds. 3 refs., 1 fig., 3 tabs.

  14. Partially-Filled Macropores in Swelling and Nonswelling Media: Flow Modes Requiring Supplementation of Darcy's Law

    NASA Astrophysics Data System (ADS)

    Nimmo, J. R.; Perkins, K. S.; Gaten-Slahor, L.

    2015-12-01

    A traditional assumption for unsaturated flow is that the pores are either water-filled and conducting or empty and nonconducting. Evidence from lab and field investigations, however, shows that substantial preferential flow can occur in macropores that are partially filled. Such flow can transmit large fluxes of water. Rates of transport can exceed the saturated hydraulic conductivity, because of possible reductions of friction and buoyancy effects. These conditions reduce the influence of capillarity on energy state, driving force, and the configuration of water-filled space. Influences such as gravity, inertia, and chaotic liquid-phase irregularities then take on increased importance. Perhaps most important is that with partial filling, the flux of water entering the pore is a determining influence on the configuration of air and water phases. Hence the incoming flux itself influences the pore's conductance, and Darcy's law cannot be expected to apply. Flow through partially-filled macropores thus requires new or revised concepts of flow pathways in unsaturated soil, and new ways of quantifying their effect. Flow modes can include free-surface films, rivulets that are not fully confined by capillarity, pulse flow, and sliding drops. Gravity dominates the driving force. Because capillarity does not establish complete geometrical confinement for these modes of flow, the mathematical relation between flux and force is not the direct Darcian proportionality, but rather a mode-specific relation involving incoming flux and flow-stream dimensions. In swelling soils there is the further complication that flow may switch from one mode to another because macropore size, shape, and connectedness vary dynamically with changing water content. This presentation evaluates commonalities and divergences among different partially-filled flow modes and compares them with commonly-assumed Poiseuille flow modes. Mathematical relations for the physical processes of these flow modes

  15. Nonbiological fractionation of iron isotopes

    NASA Technical Reports Server (NTRS)

    Anbar, A. D.; Roe, J. E.; Barling, J.; Nealson, K. H.

    2000-01-01

    Laboratory experiments demonstrate that iron isotopes can be chemically fractionated in the absence of biology. Isotopic variations comparable to those seen during microbially mediated reduction of ferrihydrite are observed. Fractionation may occur in aqueous solution during equilibration between inorganic iron complexes. These findings provide insight into the mechanisms of iron isotope fractionation and suggest that nonbiological processes may contribute to iron isotope variations observed in sediments.

  16. Tensile and fracture toughness properties of alumina trihydrate filled epoxy resins

    SciTech Connect

    Pritchard, G.; Wainwright, R.

    1993-12-31

    Certain non-halogen fire retardants such as alumina trihydrate (ATH) are effective in organic matrix composite materials only when they constitute a very high volume fraction of the total material and therefore have major effects on mechanical properties. ATH particles have weak cleavage planes and are easily fractured; their effects are rather different from those of stronger fillers. This paper is concerned with the importance of various particle characteristics, especially size distribution, in ATH filled epoxy resin castings. Tensile strength, modulus, and elongation were measured, and fracture parameters were also determined as a function of filler volume fraction for various grades. Surface treatment reduced the modulus of filled resins, except for ATH particles produced by a precipitation process. The changes were nevertheless broadly consistent with those predicted by published equations such as the Nielsen equation. The size of the largest particles had a major effect on strength and elongation. The strength typically fell to 35% of the strength of the unfilled epoxy resin, for volume fractions of 0.45 approximately, as predicted by Nicolais and Schrager equations.

  17. Prediction of changes in important physical parameters during composting of separated animal slurry solid fractions.

    PubMed

    Chowdhury, Md Albarune; de Neergaard, Andreas; Jensen, Lars Stoumann

    2014-01-01

    Solid-liquid separation of animal slurry, with solid fractions used for composting, has gained interest recently. However, efficient composting of separated animal slurry solid fractions (SSFs) requires a better understanding of the process dynamics in terms of important physical parameters and their interacting physical relationships in the composting matrix. Here we monitored moisture content, bulk density, particle density and air-filled porosity (AFP) during composting of SSF collected from four commercially available solid-liquid separators. Composting was performed in laboratory-scale reactors for 30 days (d) under forced aeration and measurements were conducted on the solid samples at the beginning of composting and at 10-d intervals during composting. The results suggest that differences in initial physical properties of SSF influence the development of compost maximum temperatures (40-70 degreeC). Depending on SSF, total wet mass and volume losses (expressed as % of initial value) were up to 37% and 34%, respectively. After 30 d of composting, relative losses of total solids varied from 17.9% to 21.7% and of volatile solids (VS) from 21.3% to 27.5%, depending on SSF. VS losses in all composts showed different dynamics as described by the first-order kinetic equation. The estimated component particle density of 1441 kg m-3 for VS and 2625 kg m-3 for fixed solids can be used to improve estimates of AFP for SSF within the range tested. The linear relationship between wet bulk density and AFP reported by previous researchers held true for SSF.

  18. Increasing Polymer Solar Cell Fill Factor by Trap-Filling with F4-TCNQ at Parts Per Thousand Concentration.

    PubMed

    Yan, Han; Manion, Joseph G; Yuan, Mingjian; García de Arquer, F Pelayo; McKeown, George R; Beaupré, Serge; Leclerc, Mario; Sargent, Edward H; Seferos, Dwight S

    2016-08-01

    Intrinsic traps in organic semiconductors can be eliminated by trap-filling with F4-TCNQ. Photovoltaic tests show that devices with F4-TCNQ at parts per thousand concentration outperform control devices due to an improved fill factor. Further studies confirm the trap-filling pathway and demonstrate the general nature of this finding.

  19. Trigonometric Integrals via Partial Fractions

    ERIC Educational Resources Information Center

    Chen, H.; Fulford, M.

    2005-01-01

    Parametric differentiation is used to derive the partial fractions decompositions of certain rational functions. Those decompositions enable us to integrate some new combinations of trigonometric functions.

  20. Holocene alluvial fills in the South Loup Valley, Nebraska

    NASA Astrophysics Data System (ADS)

    May, David W.

    1989-07-01

    Four Holocene alluvial fills are present in Nebraska's South Loup River valley. Fill IV, the oldest and thickest, was deposited between 10,200 and 4800 14C yr B.P.; Fill III has an age of about 3000 14C yr B.P.; Fill II is younger than 2100 and older than 900 14C yr B.P.; and Fill I is younger than 900 14C yr B.P. Regional contemporaneity of valley alluviation in the eastcentral Great Plains suggests that climate has controlled long-term sediment storage in the South Loup River valley.

  1. Rheology and microstructure of filled polymer melts

    NASA Astrophysics Data System (ADS)

    Anderson, Benjamin John

    The states of particle dispersion in polymer nanocomposite melts are studied through rheological characterization of nanocomposite melt mechanical properties and small angle X-ray scattering measurement of the particle microstructure. The particle microstructure probed with scattering is related to bulk flow mechanics to determine the origin of slow dynamics in these complex dispersions: whether a gel or glass transition or a slowing down of dispersing phase dynamics. These studies were conducted to understand polymer mediated particle-particle interactions and potential particle-polymer phase separation. The phase behavior of the dispersion will be governed by enthalpic and entropic contributions. A variety of phases are expected: homogeneous fluid, phase separated, or non-equilibrium gel. The effects of dispersion control parameters, namely particle volume fraction, polymer molecular weight, and polymer-particle surface affinity, on the phase behavior of 44 nm silica dispersions are studied in low molecular weight polyethylene oxide (PEO), polyethylene oxide dimethylether (PEODME), and polytetrahydrofuran (PTHF). Scattering measurements of the particle second virial coefficient in PEO melts indicates repulsive particles by a value slightly greater than unity. In PEO nanocomposites, dispersion dynamics slow down witnessed by a plateau in the elastic modulus as the particle separation approaches the length scale of the polymer radius of gyration. As the polymer molecular weight is increased, the transition shifts to lower particle volume fractions. Below polymer entanglement, the slow dynamics mimics that of a colloidal glass by the appearance of two relaxation times in the viscous modulus that display power law scaling with volume fraction. Above entanglement, the slow dynamics is qualitatively different resembling the behavior of a gelled suspension yet lacking any sign of scattering from particle agglomerates. As polymer molecular weight is increased at a fixed

  2. Method of filling a microchannel separation column

    DOEpatents

    Arnold, Don W.

    2002-01-01

    A method for packing a stationary phase into a small diameter fluid passageway or flow channel. Capillary action is employed to distribute a stationary phase uniformly along both the length and diameter of the flow channel. The method disclosed here: 1) eliminates the need for high pressure pumps and fittings and the safety hazards associated therewith; 2) allows the use of readily available commercial microparticles, either coated or uncoated, as the stationary phase; 3) provides for different types of particles, different particle sizes, and different particle size distributions to be packed in sequence, or simultaneously; 4) eliminates the need for plugging the flow channel prior to adding the stationary phase to retain the packing particles; and 5) many capillaries can be filled simultaneously.

  3. Single-pole ladder at quarter filling

    NASA Astrophysics Data System (ADS)

    Aristov, D. N.; Kiselev, M. N.; Kikoin, K.

    2007-06-01

    We study the ground state and excitation spectrum of a quasi-one-dimensional system consisting of a pole and rungs oriented in opposite directions (“centipede ladder,” CL) at quarter filling. The spin and charge excitation spectra are found in the limits of small and large longitudinal hoppings t‖ compared to the on-rung hopping rate t⊥ and exchange coupling I⊥ . At small t‖ , the system with ferromagnetic on-rung exchange demonstrates instability against dimerization. Coherent propagation of charge-transfer excitons is possible in this limit. At large t‖ , CL behaves like two-orbital Hubbard chain, but the gap opens in the charge excitation spectrum, thus reducing the symmetry from SU(4) to SU(2). The spin excitations are always gapless and their dispersion changes from quadratic magnonlike for ferromagnetic on-rung exchange to linear spinonlike for antiferromagnetic on-rung exchange in weak longitudinal hopping limit.

  4. Constrained ceramic-filled polymer armor

    DOEpatents

    Sandstrom, Donald J.; Calkins, Noel C.; Gac, Frank D.

    1990-01-01

    An armor system in which a plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material, which is a ceramic material in particulate form dispersed in a polymeric matrix.

  5. Boron-Filled Hybrid Carbon Nanotubes.

    PubMed

    Patel, Rajen B; Chou, Tsengming; Kanwal, Alokik; Apigo, David J; Lefebvre, Joseph; Owens, Frank; Iqbal, Zafar

    2016-07-27

    A unique nanoheterostructure, a boron-filled hybrid carbon nanotube (BHCNT), has been synthesized using a one-step chemical vapor deposition process. The BHCNTs can be considered to be a novel form of boron carbide consisting of boron doped, distorted multiwalled carbon nanotubes (MWCNTs) encapsulating boron nanowires. These MWCNTs were found to be insulating in spite of their graphitic layered outer structures. While conventional MWCNTs have great axial strength, they have weak radial compressive strength, and do not bond well to one another or to other materials. In contrast, BHCNTs are shown to be up to 31% stiffer and 233% stronger than conventional MWCNTs in radial compression and have excellent mechanical properties at elevated temperatures. The corrugated surface of BHCNTs enables them to bond easily to themselves and other materials, in contrast to carbon nanotubes (CNTs). BHCNTs can, therefore, be used to make nanocomposites, nanopaper sheets, and bundles that are stronger than those made with CNTs.

  6. Boron-Filled Hybrid Carbon Nanotubes

    PubMed Central

    Patel, Rajen B.; Chou, Tsengming; Kanwal, Alokik; Apigo, David J.; Lefebvre, Joseph; Owens, Frank; Iqbal, Zafar

    2016-01-01

    A unique nanoheterostructure, a boron-filled hybrid carbon nanotube (BHCNT), has been synthesized using a one-step chemical vapor deposition process. The BHCNTs can be considered to be a novel form of boron carbide consisting of boron doped, distorted multiwalled carbon nanotubes (MWCNTs) encapsulating boron nanowires. These MWCNTs were found to be insulating in spite of their graphitic layered outer structures. While conventional MWCNTs have great axial strength, they have weak radial compressive strength, and do not bond well to one another or to other materials. In contrast, BHCNTs are shown to be up to 31% stiffer and 233% stronger than conventional MWCNTs in radial compression and have excellent mechanical properties at elevated temperatures. The corrugated surface of BHCNTs enables them to bond easily to themselves and other materials, in contrast to carbon nanotubes (CNTs). BHCNTs can, therefore, be used to make nanocomposites, nanopaper sheets, and bundles that are stronger than those made with CNTs. PMID:27460526

  7. Boron-Filled Hybrid Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Patel, Rajen B.; Chou, Tsengming; Kanwal, Alokik; Apigo, David J.; Lefebvre, Joseph; Owens, Frank; Iqbal, Zafar

    2016-07-01

    A unique nanoheterostructure, a boron-filled hybrid carbon nanotube (BHCNT), has been synthesized using a one-step chemical vapor deposition process. The BHCNTs can be considered to be a novel form of boron carbide consisting of boron doped, distorted multiwalled carbon nanotubes (MWCNTs) encapsulating boron nanowires. These MWCNTs were found to be insulating in spite of their graphitic layered outer structures. While conventional MWCNTs have great axial strength, they have weak radial compressive strength, and do not bond well to one another or to other materials. In contrast, BHCNTs are shown to be up to 31% stiffer and 233% stronger than conventional MWCNTs in radial compression and have excellent mechanical properties at elevated temperatures. The corrugated surface of BHCNTs enables them to bond easily to themselves and other materials, in contrast to carbon nanotubes (CNTs). BHCNTs can, therefore, be used to make nanocomposites, nanopaper sheets, and bundles that are stronger than those made with CNTs.

  8. Aging Studies of Filled and Unfilled VCE

    SciTech Connect

    Letant, S; Herberg, J; Alviso, C; Small, W; Mulcahy, H; Pearson, M; Wilson, T; Chinn, S; Maxwell, R

    2009-11-10

    This report presents data on the effects of temperature and gamma radiation on the chemical and structural properties of both filled and unfilled VCE material produced by the Kansas City Plant using WR-qualified processes. Thermal effects up to 300 C and gamma irradiation doses of 1 MRad and 25 MRad were investigated under atmospheric conditions. Characterization techniques used in the study comprise Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), Tensile Testing, Solid Phase MicroExtraction - Gas Chromatography/Mass Spectrometry (SPME-GC/MS), phenol extraction followed by HPLC, and various Nuclear Magnetic Resonance (NMR) techniques including: {sup 13}C, {sup 13}C {l_brace}{sup 1}H{r_brace} cross polarization (CP), {sup 1}H magic angle spinning (MAS), 13C{l_brace}{sup 1}H{r_brace} Wide-line-Separation (2D-WISE) and development of Center band-Only Detection of Exchange (CODEX).

  9. Neutron transmission measurements on hydrogen filled microspheres

    NASA Astrophysics Data System (ADS)

    Dyrnjaja, Eva; Hummel, Stefan; Keding, Marcus; Smolle, Marie-Theres; Gerger, Joachim; Zawisky, Michael

    2014-01-01

    Hollow microspheres are promising candidates for future hydrogen storage technologies. Although the physical process for hydrogen diffusion through glass is well understood, measurements of static quantities (e.q. hydrogen pressure inside the spheres) as well as dynamic properties (e.g. diffusion rate of hydrogen through glass) are still difficult to handle due to the small size of the spheres (d≈15μm). For diffusion rate measurements, the long-term stability of the experiment is also mandatory due to the relatively slow diffusion rate. In this work, we present an accurate and long-term stable measurement technique for static and dynamic properties, using neutron radiography. Furthermore, possible applications for hydrogen filled microspheres within the scope of radiation issues are discussed.

  10. Constrained ceramic-filled polymer armor

    SciTech Connect

    Sandstrom, D.J.; Calkins, N.C.; Gac, F.D.

    1990-11-13

    An armor system is disclosed in which a plurality of constraint cells are mounted on a surface of a substrate, which is metal armor plate or a similar tough material, such that the cells almost completely cover the surface of the substrate. Each constraint cell has a projectile-receiving wall parallel to the substrate surface and has sides which are perpendicular to and surround the perimeter of the receiving wall. The cells are mounted such that, in one embodiment, the substrate surface serves as a sixth side or closure for each cell. Each cell has inside of it a plate, termed the front plate, which is parallel to and in contact with substantially all of the inside surface of the receiving wall. The balance of each cell is completely filled with a projectile-abrading material, which is a ceramic material in particulate form dispersed in a polymeric matrix. 5 figs.

  11. Boron-Filled Hybrid Carbon Nanotubes.

    PubMed

    Patel, Rajen B; Chou, Tsengming; Kanwal, Alokik; Apigo, David J; Lefebvre, Joseph; Owens, Frank; Iqbal, Zafar

    2016-01-01

    A unique nanoheterostructure, a boron-filled hybrid carbon nanotube (BHCNT), has been synthesized using a one-step chemical vapor deposition process. The BHCNTs can be considered to be a novel form of boron carbide consisting of boron doped, distorted multiwalled carbon nanotubes (MWCNTs) encapsulating boron nanowires. These MWCNTs were found to be insulating in spite of their graphitic layered outer structures. While conventional MWCNTs have great axial strength, they have weak radial compressive strength, and do not bond well to one another or to other materials. In contrast, BHCNTs are shown to be up to 31% stiffer and 233% stronger than conventional MWCNTs in radial compression and have excellent mechanical properties at elevated temperatures. The corrugated surface of BHCNTs enables them to bond easily to themselves and other materials, in contrast to carbon nanotubes (CNTs). BHCNTs can, therefore, be used to make nanocomposites, nanopaper sheets, and bundles that are stronger than those made with CNTs. PMID:27460526

  12. USE OF BIOCERAMICS IN FILLING BONE DEFECTS

    PubMed Central

    Garrido, Carlos Antõnio; Sampaio, Tania Clarete Fonseca Vieira Sales

    2015-01-01

    Objective: To present the results from using biological ceramics for filling bone defects resulting from post-traumatic or orthopedic injuries. Methods: Thirty-six patients with bone defects caused by trauma or orthopedic injury were evaluated. Nineteen patients were male (52.8%) and 17 were female (47.2%). Their ages ranged from 19 to 84 years, with a mean of 45.7 years and median of 37 years. Only patients with defects that required at least five grams of biological ceramic were included. Eighteen cases were classified as orthopedic: bone defects were observed in 11 cases of total hip arthroplasty; one case of primary total hip arthroplasty, due to coxarthrosis; five cases of femoral or tibial open wedge osteotomy; and one case of tarsal arthrodesis. There were 18 cases of trauma-related defects; uninfected pseudarthrosis, eight cases; recent fractures of the tibial plateau with compression of the spongy bone, three cases; and exposed fractures treated with external fixators, seven cases. The surgical technique consisted of curetting and debriding the injury until bone suitable for grafting was found. Biological ceramic was then used to fill the defect and some kind of fixation was applied. Results: Among the 36 patients evaluated, it was seen that 35 (97.2%) presented integration of the biological ceramic, while one case of open fracture treated with external fixation had poor integration of the biological ceramic. Conclusion: Treatment of bone defects of orthopedic or post-traumatic etiology using a phosphocalcium ceramic composed of hydroxyapatite was shown to be a practical, effective and safe method. PMID:27022576

  13. Two variants of minimum discarded fill ordering

    SciTech Connect

    D'Azevedo, E.F. ); Forsyth, P.A.; Tang, Wei-Pai . Dept. of Computer Science)

    1991-01-01

    It is well known that the ordering of the unknowns can have a significant effect on the convergence of Preconditioned Conjugate Gradient (PCG) methods. There has been considerable experimental work on the effects of ordering for regular finite difference problems. In many cases, good results have been obtained with preconditioners based on diagonal, spiral or natural row orderings. However, for finite element problems having unstructured grids or grids generated by a local refinement approach, it is difficult to define many of the orderings for more regular problems. A recently proposed Minimum Discarded Fill (MDF) ordering technique is effective in finding high quality Incomplete LU (ILU) preconditioners, especially for problems arising from unstructured finite element grids. Testing indicates this algorithm can identify a rather complicated physical structure in an anisotropic problem and orders the unknowns in the preferred'' direction. The MDF technique may be viewed as the numerical analogue of the minimum deficiency algorithm in sparse matrix technology. At any stage of the partial elimination, the MDF technique chooses the next pivot node so as to minimize the amount of discarded fill. In this work, two efficient variants of the MDF technique are explored to produce cost-effective high-order ILU preconditioners. The Threshold MDF orderings combine MDF ideas with drop tolerance techniques to identify the sparsity pattern in the ILU preconditioners. These techniques identify an ordering that encourages fast decay of the entries in the ILU factorization. The Minimum Update Matrix (MUM) ordering technique is a simplification of the MDF ordering and is closely related to the minimum degree algorithm. The MUM ordering is especially for large problems arising from Navier-Stokes problems. Some interesting pictures of the orderings are presented using a visualization tool. 22 refs., 4 figs., 7 tabs.

  14. A magnetic resonance study of pore filling processes during spontaneous imbibition in Berea sandstone

    NASA Astrophysics Data System (ADS)

    Chen, Quan; Gingras, Murray K.; Balcom, Bruce J.

    2003-11-01

    A new magnetic resonance technique, DDIF (the decay of magnetization due to diffusion in the internal field), was combined with mercury porosimetry to investigate pore geometry, including pore- and throat-size distribution, and pore connectivity for porous media. A comparison of DDIF spectra for a fully water saturated Berea sandstone, with the partially saturated sample by centrifugation in air, indicated that DDIF can be used for the measurement of water filled pore size distribution in partially saturated porous media. Dynamic water imbibition into air-filled Berea sandstone was studied using the DDIF technique. Simultaneously, in situ three-dimensional saturation and capillary driven water penetration were monitored using Conical-SPRITE, which is a rapid, centric scanning, spin-density weighted single point three-dimensional magnetic resonance imaging technique. These measurements provide direct evidence for differences in the pore filling mechanisms for co-current imbibition and counter-current imbibition in Berea sandstone. During co-current imbibition, water flows through the pores and connected throats with a piston-type mechanism. Air is displaced from the sample by the leading edge of the waterfront, resulting in a macroscopic piston-like flow through the entire sample. During counter-current imbibition, water flows through the pores and connected throats with a film-like structure along the corners and surfaces of the pore space. Air escapes from the sample by flowing through the center of the pores and pore throats, in the opposite direction. Once the penetrating waterfronts meet, at the sample center, there is a global, uniform increase in water content.

  15. Thermal resistance of attic loose-fill insulations decreases under simulated winter conditions

    SciTech Connect

    Graves, R.S.; Wilkes, K.E.; McElroy, D.L.

    1994-05-01

    Two absolute techniques were used to measure the thermal resistance of attic loose-fill insulations: the Large Scale Climate Simulator (LSCS) and the Unguarded Thin-Heater Apparatus (UTHA). Two types of attic loose-fill insulations (unbonded and bonded/cubed) were tested under simulated winter conditions. To simulate winter conditions for an attic insulation, the specimens were tested with heat flow up, large temperature differences, and an air gap. The specimens were tested either with a constant mean temperature (30 or 21{degrees}C) and an increasing temperature difference or with a constant base temperature (21{degrees}C) and an increasing temperature difference (i.e., a decreasing mean temperature). The UTHA test specimens had a nominal thickness of 0.2 m of loose-fill insulation. The LSCS test specimens had a nominal thickness of 0.3 m of loose-fill insulation contained in a 4.2 by 5 m attic test module with a gypsum board base. The module had a gabled attic with a 5 in 12 slope roof. The tests yielded the surface-to-surface thermal resistance, R, which includes the thermal resistance due to gypsum, insulation, and any wood joists. Tests with and without an air gap were conducted in the UTHA. Surface-to-surface thermal resistance results from the LSCS and the UTHA show similar trends for these two types of loose-fill insulation when tested under simulated winter conditions. Tests with no air gap gave values of R that agreed with the bag label R-value for the insulations; R increased with lower mean temperatures. These no-gap values of R were 2 to 5% greater than the values of R obtained with an air gap for temperature differences of less than 22{degrees}C. For larger temperature differences R decreased, and at temperature differences of over 40{degrees}C, the R values were 50% less than those at small temperature differences.

  16. Experimental and Numerical Study of Water-Filled Vessel Impacted by Flat Projectiles

    NASA Astrophysics Data System (ADS)

    Ren, Peng; Zhang, Wei; Guo, Zitao; Wei, Gang

    2011-06-01

    To understand the failure patterns and impact resistance of watertight vessel, a flat-nosed projectile was accelerated by a two-stage light gas gun against a vessel filled with water which was placed in an air-filled tank. The targets were the 5A06 aluminum which were installed on two opposite sides of the vessel. The penetration process was recorded by a digital high-speed camera. In order to compare, numerical simulations for the vessel with and without water impacted by projectiles were conducted by AUTODYN-3D. The material parameters of targets and projectiles used in the simulation were obtained from several previous studies. The result indicated that experimental and numerical results were in good agreement. Numerical simulations were capable to capture the main physical behavior. It was also found that the impact resistance of targets in the water-filled vessel was lager than that of the empty vessel. Tearing was the main failure models of the water-filled vessel targets which was different from that of the empty vessel where the shear plugging was in dominate.

  17. Experimental and Numerical Study of Water-Filled Vessel Impacted by Flat Projectiles

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Ren, Peng; Huang, Wei; Gao, Yubo

    2013-06-01

    To understand the failure patterns and impact resistance of watertight vessel, a flat-nosed projectile was accelerated by a two-stage light gas gun against a vessel filled with water which was placed in an air-filled tank. The targets were the 5A06 aluminum which were installed on two opposite sides of the vessel. The penetration process was recorded by a digital high-speed camera. In order to compare, numerical simulations for the vessel with and without water impacted by projectiles were conducted by AUTODYN-3D. The material parameters of targets and projectiles used in the simulation were obtained from several previous studies. The result indicated that experimental and numerical results were in good agreement. Numerical simulations were capable to capture the main physical behavior. It was also found that the impact resistance of targets in the water-filled vessel was lager than that of the empty vessel. Tearing was the main failure models of the water-filled vessel targets which was different from that of the empty vessel where the shear plugging was in dominate. National Natural Science Foundation of China (NO.:11072072).

  18. Separation of the metallic and non-metallic fraction from printed circuit boards employing green technology.

    PubMed

    Estrada-Ruiz, R H; Flores-Campos, R; Gámez-Altamirano, H A; Velarde-Sánchez, E J

    2016-07-01

    The generation of electrical and electronic waste is increasing day by day; recycling is attractive because of the metallic fraction containing these. Nevertheless, conventional techniques are highly polluting. The comminution of the printed circuit boards followed by an inverse flotation process is a clean technique that allows one to separate the metallic fraction from the non-metallic fraction. It was found that particle size and superficial air velocity are the main variables in the separation of the different fractions. In this way an efficient separation is achieved by avoiding the environmental contamination coupled with the possible utilization of the different fractions obtained. PMID:26963241

  19. The Origin of Stratospheric Air

    NASA Astrophysics Data System (ADS)

    Schoeberl, M. R.; Dessler, A. E.; Wang, T.

    2012-12-01

    The domain-filling, forward trajectory calculation model developed by Schoeberl and Dessler [2011] is used to investigate the origin of air that enters the stratosphere, and the origin of the driest and wettest air parcels. We compare results from NASA's MERRA, NCEP's CFSR, and ECMWF's ERAi reanalyses in a non-convection simulation. The stratospheric air parcel origin is related to but distinct from the location of final dehydration zones. Final dehydration zones control stratospheric water vapor, but stratospheric air origin tells about the origin of non-water soluble constituents such as HCN or CO. The models broadly agree that stratospheric air parcel origins follow the ITCZ in winter with maxima over the tropical west Pacific and South America. The origins are more broadly dispersed in summer. Somewhat surprisingly, the seasonal cycle for the origins is small with most of the air parcels entering the stratosphere from 360K originate in non-DJF months. The origin of the wettest and driest parcels shows that the driest parcels (1-3 ppmv) originate in the tropical West Pacific while the wettest (6-10 ppmv) parcels originate in the East Pacific/ Central America.

  20. Commensurability condition and hierarchy of fillings for FQHE in higher Landau levels in conventional 2DEG systems and in graphene—monolayer and bilayer

    NASA Astrophysics Data System (ADS)

    Jacak, Janusz; Jacak, Lucjan

    2016-01-01

    The structure of the filling rate hierarchy referred to as the fractional quantum Hall effect is studied in higher Landau levels using the commensurability condition. The hierarchy of fillings that are derived in this manner is consistent with the experimental observations of the first three Landau levels in conventional semiconductor Hall systems. The relative poverty of the fractional structure in higher Landau levels compared with the lowest Landau level is explained using commensurability topological arguments. The commensurability criterion for correlated states for higher Landau levels (with n≥slant 1) including the paired states at half fillings of the spin-subbands of these levels is formulated. The commensurability condition is applied to determine the hierarchy of the fractional fillings of Landau levels in the monolayer and bilayer graphene. Good agreement with current experimental observations of fractional quantum Hall effect in the graphene monolayer and bilayer is achieved. The presence of even denominator rates in the hierarchy for fractional quantum Hall effect in the bilayer graphene is also explained.

  1. Confined combustion of TNT explosion products in air

    SciTech Connect

    Chandler, J; Ferguson, R E; Forbes, J; Kuhl, A L; Oppenheim, A K; Spektor, R

    1998-08-31

    Effects of turbulent combustion induced by explosion of a 0.8 kg cylindrical charge of TNT in a 17 m3 chamber filled with air, are investigated. The detonation wave in the charge transforms the solid explosive (C7H5N3O6) to gaseous products, rich (~20% each) in carbon dust and carbon monoxide. The detonation pressure (~210 kb) thereby engendered causes the products to expand rapidly, driving a blast wave into the surrounding air. The interface between the products and air, being essentially unstable as a consequence of strong acceleration to which it is subjected within the blast wave, evolves into a turbulent mixing layer-a process enhanced by shock reflections from the walls. Under such circumstances rapid combustion takes place where the expanded detonation products play the role of fuel. Its dynamic effect is manifested by the experimental measurement of ~3 bar pressure increase in the chamber, in contrast to ~1bar attained by a corresponding TNT explosion in nitrogen. The experiments were modeled as a turbulent combustion in an unmixed system at infinite Reynolds, Peclet and DamkGhler numbers. The CFD solution was obtained by a high-order Godunov scheme using an AMR (Adaptive Mesh Refinement) to trace the turbulent mixing on the computational grid in as much detail as possible. The evolution of the mass fraction of fuel consumed by combustion thus determined exhibited the properties of an exponential decay following a sharp initiation. The results reveal all the dynamic features of the exothermic process of combustion controlled by fluid mechanic transport in a highly turbulent field, in contrast to those elucidated by the conventional reaction-diffusion model.

  2. Rational Exponentials and Continued Fractions

    ERIC Educational Resources Information Center

    Denny, J. K.

    2012-01-01

    Using continued fraction expansions, we can approximate constants, such as pi and e, using an appropriate integer n raised to the power x[superscript 1/x], x a suitable rational. We review continued fractions and give an algorithm for producing these approximations.

  3. Multiple fractional Fourier transform holography

    NASA Astrophysics Data System (ADS)

    Zeng, Yangsu; Zhang, Yixiao; Gao, Feng; Gao, Fuhua; Huang, Xiaoyang; Guo, Yongkang

    2002-04-01

    In this paper, we introduce the recording and reconstruction theories of the multiple fractional Fourier transform hologram (M-FRTH). We fabricated a multiple fractional Fourier transform hologram, and obtained satisfying reconstruction results. The experimental result shows that the M-FRTH has a high anti-counterfeiting capacity and can be used in the fabrication of the trademark, ID, and the notes.

  4. Fractionation process for petroleum wax

    SciTech Connect

    Jones, R.L.; Mitchael, M.R.; Krenowicz, R.A.; Southard, W.M.

    1991-07-16

    This patent describes a process which comprises separating a petroleum wax into a lower boiling wax fraction of a narrow melting range and a higher boiling wax fraction of wider melting range by subjecting the petroleum wax to distillation in a wiped film evaporator.

  5. Understanding Magnitudes to Understand Fractions

    ERIC Educational Resources Information Center

    Gabriel, Florence

    2016-01-01

    Fractions are known to be difficult to learn and difficult to teach, yet they are vital for students to have access to further mathematical concepts. This article uses evidence to support teachers employing teaching methods that focus on the conceptual understanding of the magnitude of fractions.

  6. Investigations on Multiplication of Fractions.

    ERIC Educational Resources Information Center

    Sai, Khoo Phon; Inder, Walter R. D.

    1984-01-01

    Three different models with continuous materials, discontinuous materials, and number lines were used to study the operation concept in six investigations on multiplication with fractions with pupils aged 11-12 in a Penang International School. All approaches could be understood by pupils, but they preferred the area and fractional models. (MNS)

  7. Radiating subdispersive fractional optical solitons

    SciTech Connect

    Fujioka, J. Espinosa, A.; Rodríguez, R. F.; Malomed, B. A.

    2014-09-01

    It was recently found [Fujioka et al., Phys. Lett. A 374, 1126 (2010)] that the propagation of solitary waves can be described by a fractional extension of the nonlinear Schrödinger (NLS) equation which involves a temporal fractional derivative (TFD) of order α > 2. In the present paper, we show that there is also another fractional extension of the NLS equation which contains a TFD with α < 2, and in this case, the new equation describes the propagation of radiating solitons. We show that the emission of the radiation (when α < 2) is explained by resonances at various frequencies between the pulses and the linear modes of the system. It is found that the new fractional NLS equation can be derived from a suitable Lagrangian density, and a fractional Noether's theorem can be applied to it, thus predicting the conservation of the Hamiltonian, momentum and energy.

  8. Determination of degradation rates of organic substances in the unsaturated soil zone depending on the grain size fractions of various soil types

    NASA Astrophysics Data System (ADS)

    Fichtner, Thomas; Stefan, Catalin; Goersmeyer, Nora

    2015-04-01

    Rate and extent of the biological degradation of organic substances during transport through the unsaturated soil zone is decisively influenced by the chemical and physical properties of the pollutants such as water solubility, toxicity and molecular structure. Furthermore microbial degradation processes are also influenced by soil-specific properties. An important parameter is the soil grain size distribution on which the pore volume and the pore size depends. Changes lead to changes in air and water circulation as well as preferred flow paths. Transport capacity of water inclusive nutrients is lower in existing bad-drainable fine pores in soils with small grain size fractions than in well-drainable coarse pores in a soil with bigger grain size fractions. Because fine pores are saturated with water for a longer time than the coarse pores and oxygen diffusion in water is ten thousand times slower than in air, oxygen is replenished much slower in soils with small grain size fractions. As a result life and growth conditions of the microorganisms are negatively affected. This leads to less biological activity, restricted degradation/mineralization of pollutants or altered microbial processes. The aim of conducted laboratory column experiments was to study the correlation between the grain size fractions respectively pore sizes, the oxygen content and the biodegradation rate of infiltrated organic substances. Therefore two columns (active + sterile control) were filled with different grain size fractions (0,063-0,125 mm, 0,2-0,63 mm and 1-2 mm) of soils. The sterile soil was inoculated with a defined amount of a special bacteria culture (sphingobium yanoikuae). A solution with organic substances glucose, oxalic acid, sinaphylic alcohol and nutrients was infiltrated from the top in intervals. The degradation of organic substances was controlled by the measurement of dissolved organic carbon in the in- and outflow of the column. The control of different pore volumes

  9. Air Pollution

    MedlinePlus

    ... tobacco smoke. How is air pollution linked to climate change? While climate change is a global process, it ... ozone levels are also a concern. Impacts of Climate Change on Human Health in the United States: A ...

  10. Air Apparent.

    ERIC Educational Resources Information Center

    Harbster, David A.

    1988-01-01

    Explains the principle upon which a barometer operates. Describes how to construct two barometric devices for use in the classroom that show air's changing pressure. Cites some conditions for predicting weather. (RT)

  11. Microstructure-property relationships in alumina trihydrate filled poly (methyl methacrylate) composite materials

    NASA Astrophysics Data System (ADS)

    Zhang, Ruoyu

    2015-07-01

    The mechanical properties (Young's modulus and fracture toughness) of composite made from a poly (methyl methacrylate) (PMMA) matrix filled with alumina trihydrate(ATH) are reported. The experiments were performed using flexural tests and single edge notched bend (SENB) tests. The composites samples were tested at a range of filler volume fractions (34.7%, 39.4% and 44.4%) and mean filler diameters (8 pm, 15 pm and 25 pm). The data of Young's modulus agreed well with the results of Lielens model and finite element analysis (FEA) model.

  12. Urban air

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Air pollution and the risk of potential health effects are not sufficiently convincing reasons for people to stop driving their cars, according to a study by the Population Reference Bureau (PRB) released on November 18.While sufficient levels of suspended particulate matter, carbon monoxide, and lead can present health concerns, the study found that many people surveyed for the study were not convinced of the clear linkage between air pollution and health.

  13. Channel fill characteristics in submarine fans and deltas

    SciTech Connect

    Bouma, A.H.; Goddard, D. )

    1993-02-01

    Excellent data sources may not answer all pertinent questions and multifold seismic data usually cannot resolve internal characteristics of channel fills, even when it can detect the channel. Well log correlations can be wrong, especially when dealing with thin channel fills and outcrops are seldom sufficiently large to reveal a complete channel fill. In the final analysis, integration of all these types of data is necessary. Although not well understood, a lot of similarities exist between the channel fills from submarine fans and those from deltas. It is definitely beneficial to compare data from both environments. Channels and their fills can be: (1) primarily the result of major erosion forming an incisement that becomes gradually filled; (2) primarily the result of deposition, maintaining a channel, gradually filling it and simultaneously building its levees; (3) massive fill; (4) a bedded fill with or without an upward and/or lateral thinning or fining; or (5) a combination of thick bedded and thin bedded. Many channels alternate between erosional and depositional activities. Often an erosional cut is lined with shale, reducing fluid flow between channel sandstones and those of the levees. Also, a thorough knowledge of all of these varied processes is essential for the understanding of why [open quotes]massive[close quotes] channel fills can be wet and [open quotes]thin-bedded levees[close quotes] deposits oil prone.

  14. Vision-based level control for beverage-filling processes

    NASA Astrophysics Data System (ADS)

    Ley, Dietmar; Braune, Ingolf

    1994-11-01

    This paper presents a vision-based on-line level control system which is used in beverage filling machines. Motivation for the development of this sensor system was the need for an intelligent filling valve, which can provide constant filling levels for all container/product combinations (i.e. juice, milk, beer, water, etc. in glass or PET bottles with various transparency and shape) by using a non-tactile and completely sterile measurement method. The sensor concept being presented in this paper is based on several CCD-cameras imaging the moving containers from the outside. The stationary lighting system illuminating the bottles is located within the filler circle. The field of view covers between 5 and 8 bottles depending on the bottle diameter and the filler partitioning. Each filling element's number is identified by the signals of an angular encoder. The electro-pneumatic filling valves can be opened and closed by computer control The cameras continuously monitor the final stages of the filling process, i.e. after the filling height has reached the upper half of the bottle. The sensor system measures the current filling height and derives the filling speed. Based on static a priori- knowledge and dynamic process knowledge the sensor system generates a best estimate of the particular time when the single valve is to be closed. After every new level measurement the system updates the closing time. The measurement process continues until the result of the next level calculation would be available after the estimated closing time would have been passed. The vision-based filling valve control enables the filling machine to adapt the filling time of each valve to the individual bottle shape. Herewith a standard deviation between 2 and 4 mm (depending on the slew rate in the bottle neck) can be accomplished, even at filling speed > 70.000 bottles per hour. 0

  15. Intake fraction of nonreactive vehicle emissions in US urban areas

    NASA Astrophysics Data System (ADS)

    Marshall, Julian D.; Teoh, Soon-Kay; Nazaroff, William W.

    Intake fraction, which is the fraction of emissions that are inhaled by people, quantifies the "exposure efficiency" of an emission source. We use three methods to estimate intake fractions for vehicle emissions in US urban areas. First, we use a one-compartment steady-state mass-balance model, incorporating meteorological and demographic data. Second, we use an empirical emissions-to-concentration relationship for vehicle carbon monoxide developed for 15 US urban areas. Third, we analyze model results for benzene and diesel particulate matter from the US Environmental Protection Agency's National-scale Air Toxics Assessment (NATA). The population-weighted mean intraurban intake fraction for nonreactive gaseous vehicle emissions in US urban areas is estimated to be in the range 7-21 per million, with a best estimate of 14 per million. The intake fraction for diesel particles is 4 per million, based on NATA results. An intake fraction of 4 per million means that 4 mg of pollution are inhaled per kg emitted. Intake fraction values for urban vehicle emissions are usually higher in winter than in summer because of seasonal variability in the atmospheric mixing height. The results presented in this work can be used in health risk assessments, cost-benefit analyses, and other investigations that require a summary of the emission-to-intake relationship.

  16. Acoustic attenuation, phase and group velocities in liquid-filled pipes III: nonaxisymmetric propagation and circumferential modes in lossless conditions.

    PubMed

    Baik, Kyungmin; Jiang, Jian; Leighton, Timothy G

    2013-03-01

    Equations for the nonaxisymmetric modes that are axially and circumferentially propagating in a liquid-filled tube with elastic walls surrounded by air/vacuum are presented using exact elasticity theory. Dispersion curves for the axially propagating modes are obtained and verified through comparison with measurements. The resulting theory is applied to the circumferential modes, and the pressures and the stresses in the liquid-filled pipe are calculated under external forced oscillation by an acoustic source. This provides the theoretical foundation for the narrow band acoustic bubble detector that was subsequently deployed at the Target Test Facility (TTF) of the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL), TN.

  17. Two-octave supercontinuum generation in a water-filled photonic crystal fiber.

    PubMed

    Bethge, J; Husakou, A; Mitschke, F; Noack, F; Griebner, U; Steinmeyer, G; Herrmann, J

    2010-03-15

    Supercontinuum generation in a water-filled photonic crystal fiber is reported. By only filling the central hollow core of this fiber with water, the fiber properties are changed such that the air cladding provides broadband guiding. Using a pump wavelength of 1200 nm and few-microjoule pump pulses, the generation of supercontinua with two-octave spectral coverage from 410 to 1640 nm is experimentally demonstrated. Numerical simulations confirm these results, revealing a transition from a soliton-induced mechanism to self-phase modulation dominated spectral broadening with increasing pump power. Compared to supercontinua generated in glass core photonic fibers, the liquid core supercontinua show a higher degree of coherence, and the larger mode field area and the higher damage threshold of the water core enable significantly higher pulse energies of the white light pulses, ranging up to 0.39microJ. PMID:20389646

  18. Whole-body imaging of the distribution of mercury released from dental fillings into monkey tissues

    SciTech Connect

    Hahn, L.J.; Kloiber, R.; Leininger, R.W.; Vimy, M.J.; Lorscheider, F.L. )

    1990-11-01

    The fate of mercury (Hg) released from dental silver amalgam tooth fillings into human mouth air is uncertain. A previous report about sheep revealed uptake routes and distribution of amalgam Hg among body tissues. The present investigation demonstrates the bodily distribution of amalgam Hg in a monkey whose dentition, diet, feeding regimen, and chewing pattern closely resemble those of humans. When amalgam fillings, which normally contain 50% Hg, are made with a tracer of radioactive {sup 203}Hg and then placed into monkey teeth, the isotope appears in high concentration in various organs and tissues within 4 wk. Whole-body images of the monkey revealed that the highest levels of Hg were located in the kidney, gastrointestinal tract, and jaw. The dental profession's advocacy of silver amalgam as a stable tooth restorative material is not supported by these findings.

  19. Development of a 3D Filling Model of Low-Pressure Die-Cast Aluminum Alloy Wheels

    NASA Astrophysics Data System (ADS)

    Duan, Jianglan; Maijer, Daan; Cockcroft, Steve; Reilly, Carl

    2013-12-01

    A two-phase computational fluid dynamics model of the low-pressure die-cast process for the production of A356 aluminum alloy wheels has been developed to predict the flow conditions during die filling. The filling model represents a 36-deg section of a production wheel, and was developed within the commercial finite-volume package, ANSYS CFX, assuming isothermal conditions. To fully understand the behavior of the free surface, a novel technique was developed to approximate the vent resistances as they impact on the development of a backpressure within the die cavity. The filling model was first validated against experimental data, and then was used to investigate the effects of venting conditions and pressure curves during die filling. It was found that vent resistance and vent location strongly affected die filling time, free surface topography, and air entrainment for a given pressure fill-curve. With regard to the pressure curve, the model revealed a strong relation between the pressure curve and the flow behavior in the hub, which is an area prone to defect formation.

  20. On the Filling Process Forming Silicic Segregations

    NASA Astrophysics Data System (ADS)

    Zavala, K.; Marsh, B. D.

    2001-05-01

    Interdigitating silicic lenses are particularly well developed and well exposed in the Ferrar Dolerites of the McMurdo Dry Valleys, Antarctica. Silicic segregations are texturally splotchy, have sharp upper contacts, and diffuse lower contacts that grade into normal dolerite. What is unusual about these 1- 2 m lenses is that the background sill shows very little compositional variation and yet the silicic segregations show wide compositional variation. In particular, silica content varies between 47 and 68%, and thus produces for the sill overall a bimodal composition. We have analyzed over 100 segregation samples in order to investigate the nature of the filling process. Previous work (Zavala & Marsh, 1999) has shown that segregations have compositions that correspond to interstitial liquid present at crystallinities between 59 and 63 % and temperatures between 1135° and 1115° . Additionally, it was noted that the large segregation lenses are not homogeneous and exhibit cyclic variations in silica content. This observation lead to the current study, in which new samples from the Peneplain Sill (235 to 241) show remarkable correlations between segregation texture, stratigraphic position and silica enrichment. Incompatibles like Zr indicate relatively low 35 to 40% concentrations of melt at the point of segregation extraction, which supports the notion that segregations formed by withdrawal of interstitial melt into tears as the solidification front (SF) became gravitationally unstable. The details of the filling process can also be gauged using chemical profiles normalized to segregation thickness. One group shows distinct multiple smaller cycles of silica enrichment versus depth, which suggests successive stages of opening. The other group shows a strong enrichment in silica followed by a steady decay to the base. The general form of this latter pattern measures the gradient in melt composition immediately below the segregation at the time of infilling. From

  1. Estimation of bottle filling counts for conventional pharmaceutical tablets and capsules.

    PubMed

    Mullarney, Matthew P; Hutchins, Allan; Taylor, Graeme

    2015-04-01

    A method has been developed using commonly available data for estimating the number of tablets or hard shell capsules that can be filled into bottles. The single unit volumes of conventional pharmaceutical biconvex tablets and capsules can be calculated from simple geometric relationships, which then can be used to determine the packing fraction of the units in bottles. The packing fractions of capsules and tablets studied in this work ranged from 0.53 to 0.63 and 0.56 to 0.62, respectively, and were dependent on bottle size and shape. This method can be used to assess a variety of packaging configurations computationally during drug product development. PMID:24592891

  2. Direct measurements of fractional quantum Hall effect gaps.

    PubMed

    Khrapai, V S; Shashkin, A A; Trokina, M G; Dolgopolov, V T; Pellegrini, V; Beltram, F; Biasiol, G; Sorba, L

    2007-08-24

    We measure the chemical potential jump across the fractional gap in the low-temperature limit in the two-dimensional electron system of GaAs/AlGaAs single heterojunctions. In the fully spin-polarized regime, the gap for filling factor nu=1/3 increases linearly with the magnetic field and is coincident with that for nu=2/3, reflecting the electron-hole symmetry in the spin-split Landau level. In low magnetic fields, at the ground-state spin transition for nu=2/3, a correlated behavior of the nu=1/3 and nu=2/3 gaps is observed.

  3. Laser-plasma interactions in large gas-filled hohlraums

    SciTech Connect

    Turner, R.E.; Powers, L.V.; Berger, R.L.

    1996-06-01

    Indirect-drive targets planned for the National Ignition Facility (NIF) laser consist of spherical fuel capsules enclosed in cylindrical Au hohlraums. Laser beams, arranged in cylindrical rings, heat the inside of the Au wall to produce x rays that in turn heat and implode the capsule to produce fusion conditions in the fuel. Detailed calculations show that adequate implosion symmetry can be maintained by filling the hohlraum interior with low-density, low-Z gases. The plasma produced from the heated gas provides sufficient pressure to keep the radiating Au surface from expanding excessively. As the laser heats this gas, the gas becomes a relatively uniform plasma with small gradients in velocity and density. Such long-scale-length plasmas can be ideal mediums for stimulated Brillouin Scattering (SBS). SBS can reflect a large fraction of the incident laser light before it is absorbed by the hohlraum; therefore, it is undesirable in an inertial confinement fusion target. To examine the importance of SBS in NIF targets, the authors used Nova to measure SBS from hohlraums with plasma conditions similar to those predicted for high-gain NIF targets. The plasmas differ from the more familiar exploding foil or solid targets as follows: they are hot (3 keV); they have high electron densities (n{sub e}=10{sup 21}cm{sup {minus}3}); and they are nearly stationary, confined within an Au cylinder, and uniform over large distances (>2 mm). These hohlraums have <3% peak SBS backscatter for an interaction beam with intensities of 1-4 x 10{sup 15} W/cm{sup 2}, a laser wavelength of 0.351{micro}m, f/4 or f/8 focusing optics, and a variety of beam smoothing implementations. Based on these conditions the authors conclude that SBS does not appear to be a problem for NIF targets.

  4. Fatigue behaviour of mineral filled polyamide 6-6

    SciTech Connect

    Trotignon, J.P.; Demdoum, L.; Verdu, J.

    1993-12-31

    The flexural fatigue at 10Hz, 23 {+-} 2{degree}C and various deformation amplitudes ({var_epsilon} = 1.4, 2.2 and 3.1%) was studied for various PA 66 samples containing mineral fillers in low (<5%) weight fraction. The fillers were talc, mica and wollastonite having a very different granulometry and aspect ratio. A preliminary DSC investigation showed that all these minerals display a nucleation effect of PA 66 crystallization, their efficiency being in the order talc>mica>wollastonite. Stress recording during the fatigue testing allows to detect the rupture, which occurs generally in a brittle (sudden) mode. When fatigue testing is made in dry state, the sample compliance remains constant during the whole test duration, for low stress levels. For high stress levels, in the case of unfilled and mica filled samples, the stress decreases rapidly in the first 10% of the lifetime and reaches a plateau value corresponding to about 50% of the initial stress amplitude. In situ measurements of the surface temperature show that the initial stress decrease is due to self heating above the glass transition temperature (60{degree}C) of the polymer. In all the cases, the presence of a filler-despite its very low concentration-reduces significantly the lifetime. Similar tests were made in wet state (2,5 % absorbed water). In this case, the behavior observed only for high stress levels in mica and unfilled samples in dry state appears in all the cases here, which is obviously linked to the lower Tg value due to plasticization of PA 66 by water. The role of fillers in fatigue damage and rupture will be discussed on the basis of the above results and complementary SEM observations.

  5. Surface Patterning Using Diazonium Ink Filled Nanopipette.

    PubMed

    Zhou, Min; Yu, Yun; Blanchard, Pierre-Yves; Mirkin, Michael V

    2015-11-01

    Molecular grafting of diazonium is a widely employed surface modification technique. Local electrografting of this species is a promising approach to surface doping and related properties tailoring. The instability of diazonium cation complicates this process, so that this species was generated in situ in many reported studies. In this Article, we report the egress transfer of aryl diazonium cation across the liquid/liquid interface supported at the nanopipette tip that can be used for controlled delivery this species to the external aqueous phase for local substrate patterning. An aryl diazonium salt was prepared with weakly coordinating and lipophilic tetrakis(pentafluorophenyl)borate anion stable as a solid and soluble in low polarity media. The chemically stable solution of this salt in 1,2-dichloroethane can be used as "diazonium ink". The ink-filled nanopipette was employed as a tip in the scanning electrochemical microscope (SECM) for surface patterning with the spatial resolution controlled by the pipette orifice radius and a few nanometers film thickness. The submicrometer-size grafted spots produced on the HOPG surface were located and imaged with the atomic force microscope (AFM). PMID:26456795

  6. Liquid-filled tunable lenticular lens

    NASA Astrophysics Data System (ADS)

    Iimura, Yoshinobu; Onoe, Hiroaki; Teshima, Tetsuhiko; Heo, Yun Jung; Yoshida, Shotaro; Morimoto, Yuya; Takeuchi, Shoji

    2015-03-01

    This paper describes a liquid-filled tunable lenticular lens for switching between two-dimensional (2D) and three-dimensional (3D) images in naked-eye 3D displays. Compared with previous 2D/3D switchable displays, this tunable lenticular lens that is directly attached to a smartphone display can project both a 2D image with the original resolution of the smartphone display and a 3D image with high brightness. This lens is simply composed of transparent poly(dimethylsiloxane) (PDMS) microchannels. While the thin top membrane on the microchannels is normally flat to transmit light without deflection for displaying 2D images, applying pressure to the microchannel deforms the membrane to acquire characteristics of lenticular lenses for 3D images. We successfully demonstrate the switching between the 2D and 3D modes. We believe that our lens can be applied as a part of a portable 2D/3D naked-eye 3D display.

  7. Handbook for Gas Filled RF Cavity Aficionados'

    SciTech Connect

    Tollestrup, A.V.; Chung, Moses; Yonehara, Katsuya; /Fermilab

    2009-05-01

    The use of hydrogen gas filled RF cavities in muon cooling channels has been proposed by Rolland Johnson. Impressive results have been obtained toward attaining high voltage gradients and rapid training in preliminary tests done at the FNAL MTA facility. However, so far it has not been possible to test them under conditions where they were subject to the transversal of a high intensity particle beam. This note is an attempt to bring together a description of some of the pertinent physical processes that take place in the dilute plasma that is generated in the hydrogen gas by the beam. Two effects dominate. The first is that the free electrons generated can load down the cavity and transfer its energy to heating the gas. The second is a question of what happens to the plasma in the longer term. There is an enormous literature on the subject of the subject of dilute hydrogen plasmas and we can tap into this information in order to understand and predict the behavior of the cavity.

  8. The Performance of Gas Filled Multilayer Insulation

    NASA Astrophysics Data System (ADS)

    Mills, G. L.; Zeller, C. M.

    2008-03-01

    The NASA Exploration Program is currently planning to use liquid oxygen, methane and hydrogen for propulsion in future spacecraft for the human exploration of the Moon and Mars. This will require the efficient long term, on-orbit storage of these cryogens. Multilayer insulation (MLI) will be critical to achieving the required thermal performance since it has much lower heat transfer than any other insulation when used in a vacuum. However, the size and mass constraints of these propulsion systems will not allow a structural shell to be used to provide vacuum for the MLI during ground hold and launch. One approach is to purge the MLI during ground hold with an inert gas which is then vented during launch ascent and on-orbit. In this paper, we report on experimental tests and modeling that we have done on MLI used to insulate a cryogenic tank. These include measurements of the heat transfer of gas filled insulation, evacuated insulation and during the transition in between.

  9. Fill tube bore inspection with machine vision

    SciTech Connect

    Pechersky, M.J.; Mosley, W.C.; Dickerson, R.K.

    1992-01-01

    A semi-automated technique for bore inspection of small diameter tubes is presented. The inspections are performed to insure that the bore surfaces are free of contaminants or defects. The image collectionscheme uses a borescope which is stepped along the length of the tube. An image is acquired at each step and portions from each image are combined to yield a planar image. Color analysis classifies the oxidation levels in the bore of the fill tubes. The analysis is performed by taking the image's mean values of the red, green, and blue intensities and computing a figure of merit which is then used to estimate the relative amount of oxidation. This estimation scheme was shown to have a high level of correlation with the tube oxidation levels and the quality of the subsequent welds as determined by metallographic evaluation.Surface imperfections are detected by a series of digital filtering steps followed by a statistical analysis of the resulting binary image. The frequency parameter of the Poisson distribution for the total image and image segments are computed. A statistical significance test is performed by comparing the frequency parameter of each segment to the global statistics of the image. Fine longitudinal scratches were detected with this method.

  10. Fill tube bore inspection with machine vision

    SciTech Connect

    Pechersky, M.J.; Mosley, W.C.; Dickerson, R.K.

    1992-12-31

    A semi-automated technique for bore inspection of small diameter tubes is presented. The inspections are performed to insure that the bore surfaces are free of contaminants or defects. The image collectionscheme uses a borescope which is stepped along the length of the tube. An image is acquired at each step and portions from each image are combined to yield a planar image. Color analysis classifies the oxidation levels in the bore of the fill tubes. The analysis is performed by taking the image`s mean values of the red, green, and blue intensities and computing a figure of merit which is then used to estimate the relative amount of oxidation. This estimation scheme was shown to have a high level of correlation with the tube oxidation levels and the quality of the subsequent welds as determined by metallographic evaluation.Surface imperfections are detected by a series of digital filtering steps followed by a statistical analysis of the resulting binary image. The frequency parameter of the Poisson distribution for the total image and image segments are computed. A statistical significance test is performed by comparing the frequency parameter of each segment to the global statistics of the image. Fine longitudinal scratches were detected with this method.

  11. An in vitro model to investigate filling of lateral canals.

    PubMed

    Venturi, Mauro; Di Lenarda, Roberto; Prati, Carlo; Breschi, Lorenzo

    2005-12-01

    Aims of this work were to examine lateral canals in extracted teeth, to propose a new technique to produce artificial lateral canals, and to compare two obturation techniques. Cleared roots were examined to record measure and shape of lateral canals. Artificial lateral canals were prepared on human demineralized teeth before final clearing. Specimens were divided in two groups: canals of group 1 were filled with Schilder's technique, canals of group 2 were filled with vertical compaction with apical backfilling. Stereomicroscopic analysis of lateral canal filling revealed lower filling rates in apical canals compared to coronal ones and higher filling rates with "vertical compaction with apical backfilling" compared to Schilder's group. The tested procedure appears to be a reliable technique to obtain standardized lateral canals and to compare filling procedures.

  12. Relationship between fractional calculus and fractional Fourier transform

    NASA Astrophysics Data System (ADS)

    Zhang, Yanshan; Zhang, Feng; Lu, Mingfeng

    2015-09-01

    The fractional calculus (FC) deals with integrals and derivatives of arbitrary (i.e., non-integer) order, and shares its origins with classical integral and differential calculus. The fractional Fourier transform (FRFT), which has been found having many applications in optics and other areas, is a generalization of the usual Fourier transform. The FC and the FRFT are two of the most interesting and useful fractional areas. In recent years, it appears many papers on the FC and FRFT, however, few of them discuss the connection of the two fractional areas. We study their relationship. The relational expression between them is deduced. The expectation of interdisciplinary cross fertilization is our motivation. For example, we can use the properties of the FC (non-locality, etc.) to solve the problem which is difficult to be solved by the FRFT in optical engineering; we can also through the physical meaning of the FRFT optical implementation to explain the physical meaning of the FC. The FC and FRFT approaches can be transposed each other in the two fractional areas. It makes that the success of the fractional methodology is unquestionable with a lot of applications, namely in nonlinear and complex system dynamics and image processing.

  13. Fractional trajectories: Decorrelation versus friction

    NASA Astrophysics Data System (ADS)

    Svenkeson, A.; Beig, M. T.; Turalska, M.; West, B. J.; Grigolini, P.

    2013-11-01

    The fundamental connection between fractional calculus and subordination processes is explored and affords a physical interpretation of a fractional trajectory, that being an average over an ensemble of stochastic trajectories. Heretofore what has been interpreted as intrinsic friction, a form of non-Markovian dissipation that automatically arises from adopting the fractional calculus, is shown to be a manifestation of decorrelations between trajectories. We apply the general theory developed herein to the Lotka-Volterra ecological model, providing new insight into the final equilibrium state. The relaxation time to achieve this state is also considered.

  14. ARE PLANETARY SYSTEMS FILLED TO CAPACITY? A STUDY BASED ON KEPLER RESULTS

    SciTech Connect

    Fang, Julia; Margot, Jean-Luc

    2013-04-20

    We used a sample of Kepler candidate planets with orbital periods less than 200 days and radii between 1.5 and 30 Earth radii (R{sub Circled-Plus }) to determine the typical dynamical spacing of neighboring planets. To derive the intrinsic (i.e., free of observational bias) dynamical spacing of neighboring planets, we generated populations of planetary systems following various dynamical spacing distributions, subjected them to synthetic observations by the Kepler spacecraft, and compared the properties of observed planets in our simulations with actual Kepler detections. We found that, on average, neighboring planets are spaced 21.7 mutual Hill radii apart with a standard deviation of 9.5. This dynamical spacing distribution is consistent with that of adjacent planets in the solar system. To test the packed planetary systems hypothesis, the idea that all planetary systems are dynamically packed or filled to capacity, we determined the fraction of systems that are dynamically packed by performing long-term (10{sup 8} years) numerical simulations. In each simulation, we integrated a system with planets spaced according to our best-fit dynamical spacing distribution but containing an additional planet on an intermediate orbit. The fraction of simulations exhibiting signs of instability provides an approximate lower bound on the fraction of systems that are dynamically packed; we found that {>=}31%, {>=}35%, and {>=}45% of two-planet, three-planet, and four-planet systems are dynamically packed, respectively. Such sizeable fractions suggest that many planetary systems are indeed filled to capacity. This feature of planetary systems is another profound constraint that formation and evolution models must satisfy.

  15. 46 CFR 98.25-65 - Filling density.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Filling density. 98.25-65 Section 98.25-65 Shipping... § 98.25-65 Filling density. (a) The filling density, or the percent ratio of the liquefied gas that may be loaded in the tank to the weight of the water the tank will hold at 60 °F., shall not exceed...

  16. 46 CFR 98.25-65 - Filling density.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Filling density. 98.25-65 Section 98.25-65 Shipping... § 98.25-65 Filling density. (a) The filling density, or the percent ratio of the liquefied gas that may be loaded in the tank to the weight of the water the tank will hold at 60 °F., shall not exceed...

  17. 46 CFR 98.25-65 - Filling density.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Filling density. 98.25-65 Section 98.25-65 Shipping... § 98.25-65 Filling density. (a) The filling density, or the percent ratio of the liquefied gas that may be loaded in the tank to the weight of the water the tank will hold at 60 °F., shall not exceed...

  18. 46 CFR 98.25-65 - Filling density.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Filling density. 98.25-65 Section 98.25-65 Shipping... § 98.25-65 Filling density. (a) The filling density, or the percent ratio of the liquefied gas that may be loaded in the tank to the weight of the water the tank will hold at 60 °F., shall not exceed...

  19. 46 CFR 98.25-65 - Filling density.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Filling density. 98.25-65 Section 98.25-65 Shipping... § 98.25-65 Filling density. (a) The filling density, or the percent ratio of the liquefied gas that may be loaded in the tank to the weight of the water the tank will hold at 60 °F., shall not exceed...

  20. Laser absorption, power transfer, and radiation symmetry during the first shock of inertial confinement fusion gas-filled hohlraum experiments

    NASA Astrophysics Data System (ADS)

    Pak, A.; Dewald, E. L.; Landen, O. L.; Milovich, J.; Strozzi, D. J.; Berzak Hopkins, L. F.; Bradley, D. K.; Divol, L.; Ho, D. D.; MacKinnon, A. J.; Meezan, N. B.; Michel, P.; Moody, J. D.; Moore, A. S.; Schneider, M. B.; Town, R. P. J.; Hsing, W. W.; Edwards, M. J.

    2015-12-01

    Temporally resolved measurements of the hohlraum radiation flux asymmetry incident onto a bismuth coated surrogate capsule have been made over the first two nanoseconds of ignition relevant laser pulses. Specifically, we study the P2 asymmetry of the incoming flux as a function of cone fraction, defined as the inner-to-total laser beam power ratio, for a variety of hohlraums with different scales and gas fills. This work was performed to understand the relevance of recent experiments, conducted in new reduced-scale neopentane gas filled hohlraums, to full scale helium filled ignition targets. Experimental measurements, matched by 3D view factor calculations, are used to infer differences in symmetry, relative beam absorption, and cross beam energy transfer (CBET), employing an analytic model. Despite differences in hohlraum dimensions and gas fill, as well as in laser beam pointing and power, we find that laser absorption, CBET, and the cone fraction, at which a symmetric flux is achieved, are similar to within 25% between experiments conducted in the reduced and full scale hohlraums. This work demonstrates a close surrogacy in the dynamics during the first shock between reduced-scale and full scale implosion experiments and is an important step in enabling the increased rate of study for physics associated with inertial confinement fusion.

  1. Laser absorption, power transfer, and radiation symmetry during the first shock of inertial confinement fusion gas-filled hohlraum experiments

    SciTech Connect

    Pak, A.; Dewald, E. L.; Landen, O. L.; Milovich, J.; Strozzi, D. J.; Berzak Hopkins, L. F.; Bradley, D. K.; Divol, L.; Ho, D. D.; MacKinnon, A. J.; Meezan, N. B.; Michel, P.; Moody, J. D.; Moore, A. S.; Schneider, M. B.; Town, R. P. J.; Hsing, W. W.; Edwards, M. J.

    2015-12-15

    Temporally resolved measurements of the hohlraum radiation flux asymmetry incident onto a bismuth coated surrogate capsule have been made over the first two nanoseconds of ignition relevant laser pulses. Specifically, we study the P2 asymmetry of the incoming flux as a function of cone fraction, defined as the inner-to-total laser beam power ratio, for a variety of hohlraums with different scales and gas fills. This work was performed to understand the relevance of recent experiments, conducted in new reduced-scale neopentane gas filled hohlraums, to full scale helium filled ignition targets. Experimental measurements, matched by 3D view factor calculations, are used to infer differences in symmetry, relative beam absorption, and cross beam energy transfer (CBET), employing an analytic model. Despite differences in hohlraum dimensions and gas fill, as well as in laser beam pointing and power, we find that laser absorption, CBET, and the cone fraction, at which a symmetric flux is achieved, are similar to within 25% between experiments conducted in the reduced and full scale hohlraums. This work demonstrates a close surrogacy in the dynamics during the first shock between reduced-scale and full scale implosion experiments and is an important step in enabling the increased rate of study for physics associated with inertial confinement fusion.

  2. Dynamics of exogenous nitrogen partitioning and nitrogen remobilization from vegetative organs in pea revealed by 15N in vivo labeling throughout seed filling.

    PubMed

    Schiltz, Séverine; Munier-Jolain, Nathalie; Jeudy, Christian; Burstin, Judith; Salon, Christophe

    2005-04-01

    The fluxes of (1) exogenous nitrogen (N) assimilation and (2) remobilization of endogenous N from vegetative plant compartments were measured by 15N labeling during the seed-filling period in pea (Pisum sativum L. cv Cameor), to better understand the mechanism of N remobilization. While the majority (86%) of exogenous N was allocated to the vegetative organs before the beginning of seed filling, this fraction decreased to 45% at the onset of seed filling, the remainder being directed to seeds. Nitrogen remobilization from vegetative parts contributed to 71% of the total N in mature seeds borne on the first two nodes (first stratum). The contribution of remobilized N to total seed N varied, with the highest proportion at the beginning of filling; it was independent of the developmental stage of each stratum of seeds, suggesting that remobilized N forms a unique pool, managed at the whole-plant level and supplied to all filling seeds whatever their position on the plant. Once seed filling starts, N is remobilized from all vegetative organs: 30% of the total N accumulated in seeds was remobilized from leaves, 20% from pod walls, 11% from roots, and 10% from stems. The rate of N remobilization was maximal when seeds of all the different strata were filling, consistent with regulation according to the N demand of seeds. At later stages of seed filling, the rate of remobilization decreases and may become controlled by the amount of residual N in vegetative tissues.

  3. Application of the TEMPEST computer code to canister-filling heat transfer problems

    SciTech Connect

    Farnsworth, R.K.; Faletti, D.W.; Budden, M.J.

    1988-03-01

    Pacific Northwest Laboratory (PNL) researchers used the TEMPEST computer code to simulate thermal cooldown behavior of nuclear waste glass after it was poured into steel canisters for long-term storage. The objective of this work was to determine the accuracy and applicability of the TEMPEST code when used to compute canister thermal histories. First, experimental data were obtained to provide the basis for comparing TEMPEST-generated predictions. Five canisters were instrumented with appropriately located radial and axial thermocouples. The canister were filled using the pilot-scale ceramic melter (PSCM) at PNL. Each canister was filled in either a continous or a batch filling mode. One of the canisters was also filled within a turntable simulant (a group of cylindrical shells with heat transfer resistances similar to those in an actual melter turntable). This was necessary to provide a basis for assessing the ability of the TEMPEST code to also model the transient cooling of canisters in a melter turntable. The continous-fill model, Version M, was found to predict temperatures with more accuracy. The turntable simulant experiment demonstrated that TEMPEST can adequately model the asymmetric temperature field caused by the turntable geometry. Further, TEMPEST can acceptably predict the canister cooling history within a turntable, despite code limitations in computing simultaneous radiation and convection heat transfer between shells, along with uncertainty in stainless-steel surface emissivities. Based on the successful performance of TEMPEST Version M, development was initiated to incorporate 1) full viscous glass convection, 2) a dynamically adaptive grid that automatically follows the glass/air interface throughout the transient, and 3) a full enclosure radiation model to allow radiation heat transfer to non-nearest neighbor cells. 5 refs., 47 figs., 17 tabs.

  4. Gas-Filled Panels: An update on applications in the building thermal envelope

    SciTech Connect

    Griffith, B.T.; Arasteh, D.; Tuerler, D.

    1995-10-01

    This paper discusses the application of Gas-Filled Panels to the building thermal envelope. Gas-Filled Panels, or GFPs, are thermal insulating devices that retain a high concentration of a low- conductivity gas, at atmospheric pressure, within a multilayer infrared reflective baffle. The thermal performance of the panel depends on the type of gas fill and the baffle configuration. Heat- flow meter apparatus measurements have shown effective apparent thermal conductivities of 0.194 Btu{center_dot}in/h{center_dot}ft{sup 2}{center_dot}{degree}F with air as the gas fill, 0.138 Btu{center_dot}in/h{center_dot}ft{sup 2}{center_dot}{degree}F with argon, and 0.081 Btu{center_dot}in/h{center_dot}ft{sup 2}{center_dot}{degree}F with krypton. Calorimetric measurements have also shown total resistance levels of about R-12.6 h{center_dot}ft{sup 2}{center_dot}{degree}F/Btu for a 1.0-inch thick krypton panel, R-25.7 h{center_dot}ft{sup 2}{center_dot}{degree}F/Btu for a 2.0-inch krypton panel, and R-18.4 f{center_dot}ft{sup 2}{center_dot}{degree}F/Btu for a 10-inch xenon panel. GFPs are flexible, self-supporting and can be made in a variety of shapes and sizes to thoroughly fill most types of cavities in building walls and roofs, although the modular nature of the panels can lead to complications in installing them, especially for irregularly shaped cavities. We present computer simulation results showing the improvement in thermal resistance resulting from using an argon-GFP in place of glass fiber batt insulation in wood-frame construction. This report also presents estimates of the quantity and cost of material components needed to manufacture GFPs using current prototype designs.

  5. Filling defects in the pancreatic duct on endoscopic retrograde pancreatography.

    PubMed

    Taylor, A J; Carmody, T J; Schmalz, M J; Wiedmeyer, D A; Stewart, E T

    1992-12-01

    Filling defects in the pancreatic duct are a frequent finding during endoscopic retrograde pancreatography (ERP) and have a variety of causes. Some filling defects may be artifactual or related to technical factors and, once their origin is recognized, can be disregarded. Others may be due to acute changes of pancreatitis and should prompt more careful injection of contrast material into the duct. Intraluminal masses may represent calculi or a neoplasm, either of which may require surgery or endoscopic intervention. The exact nature of these filling defects may not be apparent on radiographs, and other studies may be needed. This article reviews our approach to the evaluation of filling defects in the pancreatic duct.

  6. Chemical method of filling carbon nanotubes with magnetic material

    NASA Astrophysics Data System (ADS)

    Seifu, Dereje; Hijji, Yousef; Hirsch, Gary; Karna, Shashi P.

    A versatile chemical method is used to fill multi-wall carbon nanotubes (MWCNTs) with magnetic material. The process appears to open up tips of 100% of MWCNTs that are observed but the filling yield is rather low. The filling yield improved greatly by introducing metal chelating polymer, chitosan, in the nanotubes. Mössbauer measurements of the filled MWCNTs suggest the presence of magnetic and non-magnetic phases of Fe nanoparticles. The hyperfine magnetic field of the magnetic phase increased from its room temperature value of 182-251 kOe at 20 K.

  7. 26. VIEW, LOOKING NORTHWEST INSIDE TRANSFORMER ROOM, SHOWING OIL FILLED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. VIEW, LOOKING NORTHWEST INSIDE TRANSFORMER ROOM, SHOWING OIL- FILLED TRANSFORMER POTS - Sacramento River Bridge, Spanning Sacramento River at California State Highway 275, Sacramento, Sacramento County, CA

  8. Evidence for a fractional fractal quantum Hall effect in graphene superlattices.

    PubMed

    Wang, Lei; Gao, Yuanda; Wen, Bo; Han, Zheng; Taniguchi, Takashi; Watanabe, Kenji; Koshino, Mikito; Hone, James; Dean, Cory R

    2015-12-01

    The Hofstadter energy spectrum provides a uniquely tunable system to study emergent topological order in the regime of strong interactions. Previous experiments, however, have been limited to low Bloch band fillings where only the Landau level index plays a role. We report measurements of high-mobility graphene superlattices where the complete unit cell of the Hofstadter spectrum is accessible. We observed coexistence of conventional fractional quantum Hall effect (QHE) states together with the integer QHE states associated with the fractal Hofstadter spectrum. At large magnetic field, we observed signatures of another series of states, which appeared at fractional Bloch filling index. These fractional Bloch band QHE states are not anticipated by existing theoretical pictures and point toward a distinct type of many-body state.

  9. Evidence for a fractional fractal quantum Hall effect in graphene superlattices.

    PubMed

    Wang, Lei; Gao, Yuanda; Wen, Bo; Han, Zheng; Taniguchi, Takashi; Watanabe, Kenji; Koshino, Mikito; Hone, James; Dean, Cory R

    2015-12-01

    The Hofstadter energy spectrum provides a uniquely tunable system to study emergent topological order in the regime of strong interactions. Previous experiments, however, have been limited to low Bloch band fillings where only the Landau level index plays a role. We report measurements of high-mobility graphene superlattices where the complete unit cell of the Hofstadter spectrum is accessible. We observed coexistence of conventional fractional quantum Hall effect (QHE) states together with the integer QHE states associated with the fractal Hofstadter spectrum. At large magnetic field, we observed signatures of another series of states, which appeared at fractional Bloch filling index. These fractional Bloch band QHE states are not anticipated by existing theoretical pictures and point toward a distinct type of many-body state. PMID:26785484

  10. Observation of fractional Bloch band quantum Hall states in graphene/h-BN superlattices

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Gao, Yuanda; Wen, Bo; Hone, James; Dean, Cory

    The Hofstadter energy spectrum provides a uniquely tunable system to study emergent topological order in the regime of strong interactions. Previous experiments, however, have been limited to low Bloch band fillings where only the Landau level index plays a role. Here we report measurements of high mobility graphene superlattices where the complete unit cell of the Hofstadter spectrum is accessible. We observe coexistence of conventional fractional quantum Hall effect (QHE) states together with the integer QHE states associated with the fractal Hofstadter spectrum. At large magnetic field, we observe signatures of another series of states, which appears at fractional Bloch filling index. These fractional Bloch band QHE states are not anticipated by existing theoretical pictures and point towards a distinct type of many-body state.

  11. Evidence for a fractional fractal quantum Hall effect in graphene superlattices

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Gao, Yuanda; Wen, Bo; Han, Zheng; Taniguchi, Takashi; Watanabe, Kenji; Koshino, Mikito; Hone, James; Dean, Cory R.

    2015-12-01

    The Hofstadter energy spectrum provides a uniquely tunable system to study emergent topological order in the regime of strong interactions. Previous experiments, however, have been limited to low Bloch band fillings where only the Landau level index plays a role. We report measurements of high-mobility graphene superlattices where the complete unit cell of the Hofstadter spectrum is accessible. We observed coexistence of conventional fractional quantum Hall effect (QHE) states together with the integer QHE states associated with the fractal Hofstadter spectrum. At large magnetic field, we observed signatures of another series of states, which appeared at fractional Bloch filling index. These fractional Bloch band QHE states are not anticipated by existing theoretical pictures and point toward a distinct type of many-body state.

  12. Use of Air2Air Technology to Recover Fresh-Water from the Normal Evaporative Cooling Loss at Coal-Based Thermoelectric Power Plants

    SciTech Connect

    Ken Mortensen

    2009-06-30

    This program was undertaken to build and operate the first Air2Air{trademark} Water Conservation Cooling Tower at a power plant, giving a validated basis and capability for water conservation by this method. Air2Air{trademark} water conservation technology recovers a portion of the traditional cooling tower evaporate. The Condensing Module provides an air-to-air heat exchanger above the wet fill media, extracting the heat from the hot saturated moist air leaving in the cooling tower and condensing water. The rate of evaporate water recovery is typically 10%-25% annually, depending on the cooling tower location (climate).

  13. Australia's Next Top Fraction Model

    ERIC Educational Resources Information Center

    Gould, Peter

    2013-01-01

    Peter Gould suggests Australia's next top fraction model should be a linear model rather than an area model. He provides a convincing argument and gives examples of ways to introduce a linear model in primary classrooms.

  14. Ejection Fraction Heart Failure Measurement

    MedlinePlus

    ... 70. You can have a normal ejection fraction reading and still have heart failure (called HFpEF or ... to be made. Here we delve into the importance of shared decision making. HF Resources For Life ...

  15. Air surveillance

    SciTech Connect

    Patton, G.W.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the air surveillance and monitoring programs currently in operation at that Hanford Site. Atmospheric releases of pollutants from Hanford to the surrounding region are a potential source of human exposure. For that reason, both radioactive and nonradioactive materials in air are monitored at a number of locations. The influence of Hanford emissions on local radionuclide concentrations was evaluated by comparing concentrations measured at distant locations within the region to concentrations measured at the Site perimeter. This section discusses sample collection, analytical methods, and the results of the Hanford air surveillance program. A complete listing of all analytical results summarized in this section is reported separately by Bisping (1995).

  16. Air-Operated Sump Pump

    NASA Technical Reports Server (NTRS)

    Nolt, Gary D.

    1988-01-01

    Pump removes liquid seepage from small, restricted area and against large pressure head. Developed for moving small amounts of water and oil from sump pit 85 ft (25.91 m) deep. Fits in space only 6 1/2 in. (16.5 cm) in diameter and 18 in. (45.7 cm) long. In discharge part of pumping cycle, air forces liquid out of pump chamber through pipe. During filling part of pumping cycle, water enters pump chamber from sump pit. Float in chamber next to pump chamber controls pressurization through timer and solenoid valve.

  17. Commercial SNF Accident Release Fractions

    SciTech Connect

    J. Schulz

    2004-11-05

    The purpose of this analysis is to specify and document the total and respirable fractions for radioactive materials that could be potentially released from an accident at the repository involving commercial spent nuclear fuel (SNF) in a dry environment. The total and respirable release fractions are used to support the preclosure licensing basis for the repository. The total release fraction is defined as the fraction of total commercial SNF assembly inventory, typically expressed as an activity inventory (e.g., curies), of a given radionuclide that is released to the environment from a waste form. Radionuclides are released from the inside of breached fuel rods (or pins) and from the detachment of radioactive material (crud) from the outside surfaces of fuel rods and other components of fuel assemblies. The total release fraction accounts for several mechanisms that tend to retain, retard, or diminish the amount of radionuclides that are available for transport to dose receptors or otherwise can be shown to reduce exposure of receptors to radiological releases. The total release fraction includes a fraction of airborne material that is respirable and could result in inhalation doses; this subset of the total release fraction is referred to as the respirable release fraction. Accidents may involve waste forms characterized as: (1) bare unconfined intact fuel assemblies, (2) confined intact fuel assemblies, or (3) canistered failed commercial SNF. Confined intact commercial SNF assemblies at the repository are contained in shipping casks, canisters, or waste packages. Four categories of failed commercial SNF are identified: (1) mechanically and cladding-penetration damaged commercial SNF, (2) consolidated/reconstituted assemblies, (3) fuel rods, pieces, and debris, and (4) nonfuel components. It is assumed that failed commercial SNF is placed into waste packages with a mesh screen at each end (CRWMS M&O 1999). In contrast to bare unconfined fuel assemblies, the

  18. Right ventricular filling in dilated cardiomyopathy.

    PubMed Central

    Fujimoto, S.; Parker, K. H.; Gibson, D. G.

    1995-01-01

    PURPOSE--To assess right ventricular filling in dilated cardiomyopathy. PATIENTS--32 patients with dilated cardiomyopathy and 24 healthy controls. METHODS--Stroke distances were measured by pulsed Doppler echocardiography at left ventricular outflow and left and right ventricular inflow. The inflow tract dimensions of both ventricles and the outflow tract dimension of the left ventricle were measured from two dimensional images. Right and left sided atrioventricular (AV) ring excursions were measured by M mode echocardiography at the tricuspid and mitral rings. Stroke volume was derived as stroke distance multiplied by left ventricular outflow tract area. Total stroke distances were calculated as the sum of AV valve Doppler stroke distances and ring excursion. The effective orifice areas of the two AV valves were thus defined as stroke volumes divided by total stroke distance. RESULTS--Total tricuspid stroke distance was normally less than mitral (6.0 (1.7) v 7.6 (1.7) cm, P < 0.05), implying that effective orifice area of the tricuspid valve was consistently greater (6.6 (1.6) v 4.5 (0.8) cm2, P < 0.01). Total tricuspid ring excursion was normally more than mitral (2.30 (0.30) v 1.62 (0.22) cm, P < 0.01). Total tricuspid stroke distance in dilated cardiomyopathy was also less than mitral (7.8 (2.4) v 9.7 (2.8) cm, P < 0.05). Tricuspid stroke distance was significantly increased in patients with dilated cardiomyopathy compared with that in healthy controls (P < 0.05 v controls), though stroke volume was much smaller (26 (10) v 63 (11) ml, P < 0.01) so that tricuspid effective orifice area was reduced to less than half normal (2.7 (1.2) cm2, P < 0.01). Total tricuspid ring long axis excursion was more than mitral (1.37 (0.6) v 0.74 (0.21) cm, P < 0.01). Right ventricular end diastolic inflow dimension was increased compared with that in healthy controls (3.9 (0.7) v 2.8 (0.5) cm, P < 0.01), correlating inversely with tricuspid effective orifice area (r = -0.71, P

  19. Estimating the change of porosity in the saturated zone during air sparging.

    PubMed

    Tsai, Yih-jin; Kuo, Yu-chia; Chen, Tsu-chi; Chou, Feng-chih

    2006-01-01

    Air sparging is a remedial method for groundwater. The remedial region is similar to the air flow region in the saturated zone. If soil particles are transported during air sparging, the porosity distributions in the saturated zone change, which may alter the flow path of the air. To understand better the particle movement, this study performed a sandbox test to estimate the soil porosity change during air sparging. A clear fracture was formed and the phenomenon of particle movement was observed when the air injection was started. The moved sand filled the porous around the fracture and the reparked sand filled the fracture, reducing the porosity around the fracture. The results obtained from the photographs of the sandbox, the current measurements and the direct sand sample measurements were close to each other and are credible. Therefore, air injection during air sparging causes sand particle movement of sand, altering the characteristic of the sand matrix and the air distribution.

  20. Xenon fractionation in porous planetesimals

    NASA Technical Reports Server (NTRS)

    Zahnle, Kevin; Pollack, James B.; Kasting, James F.

    1990-01-01

    The distinctively fractionated Xe on Mars and earth may have its root in a common source from which both planets accreted. Beginning with Ozima and Nakazawa's (1980) hypothesis that terrestrial Xe fractionation was caused by gravitational separation of adsorbed solar nebular gases inside large porous planetesimals, it is pointed out that Xe would have been trapped as the planetesimal grew and pores were squeezed shut by lithostatic pressure. It is shown that enough fractionated Xe to supply the earth could have been trapped this way. The degree of fractionation is controlled by the lithostatic pressure at the pore-closing front and so would have been roughly the same for all large planetesimals. The predicted degree of fractionation agrees well with that preserved in terrestrial and Martian Xe. Relative to Xe, this source is strongly depleted in other noble gases. In contrast to the original Ozima and Nakazawa hypothesis, the present hypothesis predicts the observed fractionation, and it allows planetary accretion to occur after the dissipation of the solar nebula.

  1. Xenon fractionation in porous planetesimals.

    PubMed

    Zahnle, K; Pollack, J B; Kasting, J F

    1990-01-01

    The distinctively fractionated Xe on Mars and Earth may have its root in a common source from which both planets accreted. We begin with Ozima and Nakazawa's hypothesis that terrestrial Xe fractionation was caused by gravitational separation of adsorbed solar nebular gases inside large porous planetesimals. We point out that Xe would have been trapped as the planetesimal grew and pores were squeezed shut by lithostatic pressure. We show that enough fractionated Xe to supply the Earth could have been trapped this way. The degree of fractionation is controlled by the lithostatic pressure at the pore-closing front and so would have been roughly the same for all large planetesimals. The predicted degree of fractionation agrees well with that preserved in terrestrial and martian Xe. Relative to Xe, this source is strongly depleted in other noble gases. In contrast to the original Ozima and Nakazawa hypothesis, our hypothesis predicts the observed fractionation, and it allows planetary accretion to occur after the dissipation of the solar nebula. The required planetesimals are large, representing a class of object now extinct in the solar system.

  2. Xenon fractionation in porous planetesimals.

    PubMed

    Zahnle, K; Pollack, J B; Kasting, J F

    1990-01-01

    The distinctively fractionated Xe on Mars and Earth may have its root in a common source from which both planets accreted. We begin with Ozima and Nakazawa's hypothesis that terrestrial Xe fractionation was caused by gravitational separation of adsorbed solar nebular gases inside large porous planetesimals. We point out that Xe would have been trapped as the planetesimal grew and pores were squeezed shut by lithostatic pressure. We show that enough fractionated Xe to supply the Earth could have been trapped this way. The degree of fractionation is controlled by the lithostatic pressure at the pore-closing front and so would have been roughly the same for all large planetesimals. The predicted degree of fractionation agrees well with that preserved in terrestrial and martian Xe. Relative to Xe, this source is strongly depleted in other noble gases. In contrast to the original Ozima and Nakazawa hypothesis, our hypothesis predicts the observed fractionation, and it allows planetary accretion to occur after the dissipation of the solar nebula. The required planetesimals are large, representing a class of object now extinct in the solar system. PMID:11537194

  3. Modified spontaneous emission of organic molecules in-filled in inverse opals.

    PubMed

    Deng, Lier; Wang, Yongsheng; He, Dawei

    2011-11-01

    Inverse opals were prepared by replication of colloidal crystal templates made from silica spheres 298 nm in diameter. The air between the silica spheres was filled with the mixture of the monomer poly(methyl methacrylate) (PMMA) and the organic molecule Alq3 that can be subsequently polymerized. After removing the silica sphere templates, the photonic bandgap effect on the spontaneous emission of Alq3 were investigated. The dip in the fluorescence spectrum was interpreted in terms of redistribution of the photon density of states in the photonic crystal. PMID:22413286

  4. Electrical breakdown of a bubble in a water-filled capillary

    SciTech Connect

    Bruggeman, P.J.; Leys, C.A.; Vierendeels, J. A.

    2006-06-01

    In this Communication, the electrical breakdown of a static bubble in a water-filled capillary generated in a dc electrical field is studied. We present experimental results which indicate that the liquid layer between capillary and bubble wall can have an important influence on the breakdown mechanism of the bubble. The breakdown electrical field (atmospheric pressure) without a liquid layer in a (vapor) bubble is 18 kV/cm. When a liquid layer is present, the electrical breakdown of an air bubble is observed at electrical fields typically two times smaller. Local plasma formation is observed in this case possibly due to bubble deformation.

  5. A giant gas-filled abdominal mass in an elderly female: a case report.

    PubMed

    Chong, Hoi Man Deon; Lee, Fung Yee Janet; Lo, Anthony; Li, Chak Man Jimmy

    2011-08-21

    We report an extremely rare case of gas-filled abdominal mass caused by an ovarian teratoma fistulating to the sigmoid colon. The patient was an 85-year-old female, who presented with severe abdominal distension. Urgent computed tomography scan showed a huge abdominal mass with air fluid level and fecal matter inside. Communication between the mass and the sigmoid colon was suspected. She underwent emergency laparotomy. The mass was resected with the involved segment of colon. Pathology confirmed squamous cell carcinoma arising from mature cystic teratoma of the ovary.

  6. Design and Use of a Novel Apparatus for Measuring Capsule Fill Hole Conductance

    SciTech Connect

    Seugling, R M; Nederbragt, W W; Klingmann, J L; Edson, S; Reynolds, J; Cook, R

    2006-11-27

    Description and results of a novel apparatus for determining the flow conductance through a laser drilled hole in a spherical shell for inertial confinement fusion experiments are described. The instrument monitors the pressure of an enclosed volume containing the laser pressure drilled capsule as air bleeds through the hole into the shell. From these measurements one obtains the conductance of the fill hole. This system has proven to be a valuable tool for verifying the conduct conductance into the capsule in a timely and nondestructive manner.

  7. Solar energy storage via liquid filled cans - Test data and analysis

    NASA Technical Reports Server (NTRS)

    Saha, H.

    1978-01-01

    This paper describes the design of a solar thermal storage test facility with water-filled metal cans as heat storage medium and also presents some preliminary tests results and analysis. This combination of solid and liquid mediums shows unique heat transfer and heat contents characteristics and will be well suited for use with solar air systems for space and hot water heating. The trends of the test results acquired thus far are representative of the test bed characteristics while operating in the various modes.

  8. Modified spontaneous emission of organic molecules in-filled in inverse opals.

    PubMed

    Deng, Lier; Wang, Yongsheng; He, Dawei

    2011-11-01

    Inverse opals were prepared by replication of colloidal crystal templates made from silica spheres 298 nm in diameter. The air between the silica spheres was filled with the mixture of the monomer poly(methyl methacrylate) (PMMA) and the organic molecule Alq3 that can be subsequently polymerized. After removing the silica sphere templates, the photonic bandgap effect on the spontaneous emission of Alq3 were investigated. The dip in the fluorescence spectrum was interpreted in terms of redistribution of the photon density of states in the photonic crystal.

  9. Properties and testing of loose-fill cellulosic insulation

    SciTech Connect

    Yarbrough, D.W.; McElroy, D.L.; Harris, W.W.

    1982-02-01

    New methods for measuring thermal resistance, permeability to air, settled density, and compressibility of loose-fill cellulosic insulation (LFCI) are described. The resultant property measurements are discussed. Chemical analyses were completed on the LFCI in the sampling. The results represent a first attempt to assess the variability of products and fire-retardant formulations. Chemical characteristics have been compared with test performance. Compounds present in the insulations tested were not identified directly but were deduced from elemental analyses. The amount of water-soluble fire retardant in LFCI products were found to vary from 14 to 36 wt %. Formulations containing from one to five separate compounds were identified. It was observed that products containing above 20 wt % fire-retardant chemicals had the highest acceptance (pass) rate for the combustion tests specified by federal specification HH-I-515D. The overall performance of the LFCI materials tested was poor as measured by HH-I-515D methods. Results for the important smoldering-combustion test yielded passing rates from 30.6 to 62.7%. Seventy-five percent of the LFCI specimens passed the radiant panel test. The percentage of the sample that passed both the smoldering-combustion and the radiant panel test ranged from 42 to 50%. The blower-cyclone-shaker (BCS) test for settled density has been subjected to continued interlaboratory evaluation.Laboratory results have been compared with field measurements to determine the applicability of the test as a predictor. The average of the results of the BCS Test compares very closely (<1%) with field data from four cities. Individual materials, however, can show differences between field and laboratory results of up to 20%.

  10. Field measurements of isotope fractionation during evaporation

    NASA Astrophysics Data System (ADS)

    Smith, R. B.; Williams, J. K.; Lee, X.

    2004-12-01

    The isotopic fractionation associated with evaporation from bodies of water is an important process for the interpretation of isotope data from the atmosphere and in the development of ice core climate records. Existing theories include the resistance model of Craig and Gordon [1965] summarized by Gat [1996], and the exchange model of Merlivat and Jouzel [1979, MJ79]. The MJ79 model was recently extended by He and Smith [1999, HS99] to include a limited exchange between the liquid at depth and the air-liquid interface. These theories are relatively complex as they must include not only equilibrium fractionation but also the kinetic effects of diffusion and the influence of the "back-flux" of water vapor to the surface. Laboratory experiments by Craig et al. (1963), Merlivat and Coantic [1975], Merlivat [1978] and Cappa et al. (2003) have added new insight and generated proposals for parameterizations. Field testing of these theories and parametrizations has received little attention however. The primary difficulty to be overcome is that water vapor collected near the liquid interface is not representative of the evaporative flux, as it contains a significant proportion of vapor from the free atmosphere above. We overcome this problem using a two-level sampling technique developed by Keeling [1960] for carbon isotopes and applied to water vapor by Yakir and Wang [1996], Gat [2000], and He and Smith [2003] among others. Vapor collections were carried out over the Hudson River in the summer 2003 at altitudes of 12 and 190 centimeters. Samples from the two levels showed systematic differences in specific humidity and isotope ratio, allowing the isotope ratio in the net flux to be determined. In general, flux isotope ratios were significantly lighter than the collected vapor. Furthermore, the flux ratios are significantly lighter than that in equilibrium with river water samples. This small data set provides an opportunity to evaluate existing theories of isotope

  11. The effectiveness of a heated air curtain

    NASA Astrophysics Data System (ADS)

    Frank, Daria

    2014-11-01

    Air curtains are high-velocity plane turbulent jets which are installed in the doorway in order to reduce the heat and the mass exchange between two environments. The air curtain effectiveness E is defined as the fraction of the exchange flow prevented by the air curtain compared to the open-door situation. In the present study, we investigate the effects of an opposing buoyancy force on the air curtain effectiveness. Such an opposing buoyancy force arises for example if a downwards blowing air curtain is heated. We conducted small-scale experiments using water as the working fluid with density differences created by salt and sugar. The effectiveness of a downwards blowing air curtain was measured for situations in which the initial density of the air curtain was less than both the indoor and the outdoor fluid density, which corresponds to the case of a heated air curtain. We compare the effectiveness of the heated air curtain to the case of the neutrally buoyant air curtain. It is found that the effectiveness starts to decrease if the air curtain is heated beyond a critical temperature. Furthermore, we propose a theoretical model to describe the dynamics of the buoyant air curtain. Numerical results obtained from solving this model corroborate our experimental findings.

  12. Fractional characteristic times and dissipated energy in fractional linear viscoelasticity

    NASA Astrophysics Data System (ADS)

    Colinas-Armijo, Natalia; Di Paola, Mario; Pinnola, Francesco P.

    2016-08-01

    In fractional viscoelasticity the stress-strain relation is a differential equation with non-integer operators (derivative or integral). Such constitutive law is able to describe the mechanical behavior of several materials, but when fractional operators appear, the elastic and the viscous contribution are inseparable and the characteristic times (relaxation and retardation time) cannot be defined. This paper aims to provide an approach to separate the elastic and the viscous phase in the fractional stress-strain relation with the aid of an equivalent classical model (Kelvin-Voigt or Maxwell). For such equivalent model the parameters are selected by an optimization procedure. Once the parameters of the equivalent model are defined, characteristic times of fractional viscoelasticity are readily defined as ratio between viscosity and stiffness. In the numerical applications, three kinds of different excitations are considered, that is, harmonic, periodic, and pseudo-stochastic. It is shown that, for any periodic excitation, the equivalent models have some important features: (i) the dissipated energy per cycle at steady-state coincides with the Staverman-Schwarzl formulation of the fractional model, (ii) the elastic and the viscous coefficients of the equivalent model are strictly related to the storage and the loss modulus, respectively.

  13. Shockley-Read-Hall recombination in pre-filled and photo-filled intermediate band solar cells

    SciTech Connect

    Mayani, Maryam Gholami; Reenaas, Turid Worren

    2014-08-18

    In this work, we study how Shockley-Read-Hall (SRH) recombination via energy levels in the bandgap, caused by defects or impurities, affects the performance of both photo-filled and pre-filled intermediate band solar cells (IBSCs). For a pre-filled cell, the IB is half-filled in equilibrium, while it is empty for the photo-filled cell in equilibrium. The energy level, density, and capture cross-sections of the defects/impurities are varied systematically. We find that the photo-filled cells are, in general, less efficient than pre-filled cells, except when the defect level is between the conduction band and the IB. In that case, for a range of light intensities, the photo-filled cell performs better than the pre-filled. When the defect level is at the same energy as the IB, the efficiency is above 82% of the defect-free case, when less than 50% of the states at the IB lead to SRH recombination. This shows that even if SRH recombination via the IB takes place, high efficiencies can be achieved. We also show that band gap optimization can be used to reduce the SRH recombination.

  14. Thermal Conductivity of Humid Air

    NASA Astrophysics Data System (ADS)

    Beirão, S. G. S.; Ribeiro, A. P. C.; Lourenço, M. J. V.; Santos, F. J. V.; Nieto de Castro, C. A.

    2012-09-01

    In this article, measurements of the thermal conductivity of humid air as a function of pressure, temperature, and mole fraction of water, for pressures up to 5 MPa and temperatures up to 430 K, for different water contents (up to 10 % vapor mole fraction) are reported. Measurements were performed using a transient hot-wire apparatus capable of obtaining data with an uncertainty of 0.8 % for gases. However, as moist air becomes corrosive above 373 K and at pressures >5 MPa, the apparatus, namely, the pressure vessel and the cells had to be modified, by coating all stainless-steel parts with a titanium nitride thin film coating, about 4 μm thick, obtained by physical vapor deposition. The expanded uncertainty (coverage factor k = 2) of the present experimental thermal conductivity data is 1.7 %, while the uncertainty in the mole fraction is estimated to be better than 0.0006. Experimental details regarding the preparation of the samples, the precautions taken to avoid condensation in the tubes connected to the measuring cell, and the method developed for obtaining reliable values of the water content for the gas mixtures are discussed. A preliminary analysis of the application of the kinetic theory of transport properties in reacting mixtures to interpret the complex dependence of the thermal conductivity of humid air on water composition is addressed.

  15. Featureless and nonfractionalized Mott insulators on the honeycomb lattice at 1/2 site filling

    PubMed Central

    Kimchi, Itamar; Parameswaran, S. A.; Turner, Ari M.; Wang, Fa; Vishwanath, Ashvin

    2013-01-01

    Within the Landau paradigm, phases of matter are distinguished by spontaneous symmetry breaking. Implicit here is the assumption that a completely symmetric state exists: a paramagnet. At zero temperature such quantum featureless insulators may be forbidden, triggering either conventional order or topological order with fractionalized excitations. Such is the case for interacting particles when the particle number per unit cell, f, is not an integer. However, can lattice symmetries forbid featureless insulators even at integer f? An especially relevant case is the honeycomb (graphene) lattice—where free spinless fermions at (the two sites per unit cell mean is half-filling per site) are always metallic. Here we present wave functions for bosons, and a related spin-singlet wave function for spinful electrons, on the honeycomb lattice and demonstrate via quantum to classical mappings that they do form featureless Mott insulators. The construction generalizes to symmorphic lattices at integer f in any dimension. Our results explicitly demonstrate that in this case, despite the absence of a noninteracting insulator at the same filling, lack of order at zero temperature does not imply fractionalization.

  16. Determinants of global left ventricular peak diastolic filling rate during rest and exercise in normal volunteers

    SciTech Connect

    Filiberti, A.W.; Bianco, J.A.; Baker, S.P.; Doherty; Nalivaika, L.A.; King, M.A.; Alpert, J.S.

    1984-01-01

    Early peak diastolic filling rate (PFR) of the left ventricle (LV) is said to be a sensitive index of LV dysfunction in patients with coronary disease, hypertension and hypertrophic cardiomyopathy. Radionuclide (RN0 multigated PFR was measured in 20 normal volunteers (13 males, 7 females, mean age 31 yrs., range 20-43) at rest and during supine bicycle exercise conducted to a symptomatic end-point. At rest, RN PFR was 3.4 +- SD 0.4 end-diastolic vols./sec (range 3.1 - 3.6). During exercise all normal volunteers had a progressive and numerically and statistically significant increase in PFR. Stepwise multiple linear regression (BMPD2R) was applied to the rest and exercise PFR data to develop a linear model describing the main determinants of the RN PFR. The potential independent variables which were included in the model were heart rate (HR), ejection fraction (EF), systolic arterial pressure, systolic ejection rate and exercise stage. Ranking of variables for prediction of RN PFR, and exclusion of less important variables, was done by F value criteria. The final multivariate equation was: LVPFR = -3.84437 + 0.03834 HR + 0.07537 LVEF. The model fit was highly significant (p<0.001), and accounted for 89 per cent of variability in the PFR. The authors conclude that the left ventricular peak filling rate is critically determined by heart rate and by ejection fraction at rest and during exercise.

  17. Isotope fractionation studies of molybdenum

    NASA Astrophysics Data System (ADS)

    Wieser, M. E.; de Laeter, J. R.; Varner, M. D.

    2007-08-01

    Mass spectrometric studies of the isotopic composition of molybdenum have become an active area of research in stable isotope geochemistry, biogeochemistry and cosmochemistry. The redox chemistry of Mo, together with its proclivity for covalent bonding, indicates its importance in isotope fractionation studies such as palaeoceanography. The measurement of the magnitude of isotope fractionation of Mo in natural systems is a challenging task, in that natural fractionation has to be carefully distinguished from chemical and instrumental isotope fractionation. An ion exchange chemical separation procedure has been developed with high efficiency and low blank, to ensure that the isobaric elements Zr and Ru are removed from the samples before mass spectrometric analysis. The isotope fractionation resulting from this procedure is 0.14[per mille sign] per u. The isotopic composition of Mo of a Laboratory Standard has been measured by positive and negative thermal ionization mass spectrometry (P-TIMS and N-TIMS, respectively), to give an isotope fractionation of 6.4[per mille sign] and 0.5[per mille sign] per u, respectively, with respect to the absolute isotope abundances of Mo. In both cases the lighter isotopes are enhanced with respect to the heavier isotopes. An ascorbic acid activator has enabled the sensitivity of P-TIMS to be improved as compared to traditional methods. The same experiment was repeated using a multiple collector-inductively coupled plasma-mass spectrometer (MC-ICP-MS) to give an isotope fractionation of approximately 17.0[per mille sign] per u. In this case the heavier isotopes are enhanced with respect to the lighter isotopes. The strengths and weaknesses of these three mass spectrometric techniques are evaluated. We conclude that MC-ICP-MS is the optimum mass spectrometric method for accurately measuring the isotope fractionation of Mo in natural materials, provided chemical and instrumental isotope fractionation can be resolved from naturally

  18. Laboratory Characterization of Cemented Rock Fill for Underhand Cut and Fill Method of Mining

    NASA Astrophysics Data System (ADS)

    Kumar, Dinesh; Singh, Upendra Kumar; Singh, Gauri Shankar Prasad

    2015-08-01

    Backfilling with controlled specifications is employed for improved ground support and pillar recovery in underground metalliferous mine workings. This paper reports the results of a laboratory study to characterise various mechanical properties of cemented rock fill (CRF) formulations for different compaction levels and cement content percentage for use in underhand cut and fill method of mining. Laboratory test set ups and procedures have been described for conducting compressive and bending tests of CRF block samples. A three dimensional numerical modelling study has also been carried out to overcome the limitations arising due to non-standard dimension of test blocks used in flexural loading test and the test setup devised for this purpose. Based on these studies, specific relations have been established between the compressive and the flexural properties of the CRF. The flexural strength of the wire mesh reinforced CRF is also correlated with its residual strength and the Young's modulus of elasticity under flexural loading condition. The test results of flexural strength, residual flexural strength and modulus show almost linear relations with cement content in CRF. The compressive strength of the CRF block samples is estimated as seven times the flexural strength whereas the compressive modulus is four times the flexural modulus. It has been found that the strengths of CRF of low compaction and no compaction are 75 and 60 % respectively to that of the medium compaction CRF. The relation between the strength and the unit weight of CRF as obtained in this study is significantly important for design and quality control of CRF during its large scale application in underhand cut and fill stopes.

  19. Air Pollution.

    ERIC Educational Resources Information Center

    Scorer, Richard S.

    The purpose of this book is to describe the basic mechanisms whereby pollution is transported and diffused in the atmosphere. It is designed to give practitioners an understanding of basic mechanics and physics so they may have a correct basis on which to formulate their decisions related to practical air pollution control problems. Since many…

  20. Air Pollution

    PubMed Central

    Clifton, Marjorie

    1964-01-01

    Dr Marjorie Clifton describes the classification of gaseous and nongaseous constituents of air pollution and then outlines the methods of measuring these. The National Survey embraced 150 towns of all sizes throughout England and Wales and provided data on smoke and sulphur dioxide in relation to climate, topography, industrialization, population density, fuel utilization and urban development. Dr W C Turner discusses the relationship between air pollution and mortality from respiratory conditions, and particularly the incidence of chronic bronchitis. He postulates a theory that such respiratory conditions arise as an allergy to the spores of certain moulds, spore formation being encouraged by the air humidity in Greatv Britain and overcrowded and damp living conditions. He describes the results of a twenty-week study undertaken in 1962-3, showing associations between respiratory disease and levels of air pollution. Dr Stuart Carne undertook a survey in general practice to plot the patterns of respiratory illness in London during the winter of 1962-3. There were two peaks of respiratory illnesses coinciding with the fog at the beginning of December and the freeze-up from the end of December until the beginning of March. PMID:14178955

  1. The development of an instrumented tamp-filling capsule machine I. Instrumentation Of a Bosch GKF 400S machine and feasibility study.

    PubMed

    Podczeck, F

    2000-01-01

    The instrumentation of capsule filling machines operating by the tamp-filling principle has been described only once, using strain gauges. In the present paper the instrumentation of a Bosch GKF 400S tamp-filling machine has been described using a prototype of a pneumatic tamping head equipped with a piezoelectric force transducer. The pneumatic system replaces the conventional springs situated between tamping pins and upper part of the tamping head. Via a feedback switch valve, the air pressure inside the pneumatic chamber can be regulated. This provides a potential mechanism for feedback control of capsule fill weight during continuous capsule filling. It was found that the use of the pneumatic tamping head is limited to the control of fill weight during tamping. Major adjustments of fill weight at the set-up stage of the machine should be made by alteration of the tamping pin and powder bed height settings. The principles of capsule fill weight control by continuous monitoring of tamping forces have been established, but the transfer of the system to full industrial use requires further development of the prototype by the machine manufacturer. PMID:10838016

  2. Forced air heat sink apparatus

    NASA Technical Reports Server (NTRS)

    Rippel, Wally E. (Inventor)

    1989-01-01

    A high efficiency forced air heat sink assembly employs a split feed transverse flow configuration to minimize the length of the air flow path through at least two separated fin structures. Different embodiments use different fin structure material configurations including honeycomb, corrugated and serpentine. Each such embodiment uses a thermally conductive plate having opposed exterior surfaces; one for receiving a component to be cooled and one for receiving the fin structures. The serpentine structured fin embodiment employs a plurality of fin supports extending from the plate and forming a plurality of channels for receiving the fin structures. A high thermal conductivity bondant, such as metal-filled epoxy, may be used to bond the fin structures to either the plate or the fin supports. Dip brazing and soldering may also be employed depending upon the materials selected.

  3. Using Habit Reversal to Decrease Filled Pauses in Public Speaking

    ERIC Educational Resources Information Center

    Mancuso, Carolyn; Miltenberger, Raymond G.

    2016-01-01

    This study evaluated the effectiveness of simplified habit reversal in reducing filled pauses that occur during public speaking. Filled pauses consist of "uh," "um," or "er"; clicking sounds; and misuse of the word "like." After baseline, participants received habit reversal training that consisted of…

  4. 21 CFR 1305.22 - Procedure for filling electronic orders.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Procedure for filling electronic orders. 1305.22... I AND II CONTROLLED SUBSTANCES Electronic Orders § 1305.22 Procedure for filling electronic orders... digital certificate has not expired. (3) Check the validity of the certificate holder's certificate...

  5. Long fluid filled bags suspended by line forces

    NASA Technical Reports Server (NTRS)

    Mullins, M. L.; Duncan, J. L.

    1975-01-01

    A previous analysis of fluid filled storage bags is extended to the case of a long fluid filled cylindrical membrane supported by uniform line loads. Cross-sectional shape, stiffness of the support system and stress resultants in the membrane are determined. The application of the numerical results to problems arising in the design of nonrigid airships is discussed.

  6. MALLEABLE CHARGE BUCKET, SITTING ON A ROTATING TRACK, IS FILLED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MALLEABLE CHARGE BUCKET, SITTING ON A ROTATING TRACK, IS FILLED WITH IRON, COKE AND LIMESTONE FROM A SKIP HOIST LOADED IN THE YARD BELOW. THE FILLED CHARGE BUCKET TIPS, TOPPLING ITS LOAD INTO EITHER OF THE TWO MALLEABLE CUPOLAS IN THE MALLEABLE FOUNDRY. - Stockham Pipe & Fittings Company, Malleable Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  7. 27 CFR 26.312 - Standards of fill.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Liquor Bottles § 26.312 Standards of fill. Distilled spirits brought into the United States from Puerto... bottles, including liquor bottles of less than 200 ml capacity, which conform to the applicable standards of fill provided in § 5.47 or § 5.47a of this chapter. Empty liquor bottles, including liquor...

  8. 27 CFR 26.312 - Standards of fill.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Liquor Bottles § 26.312 Standards of fill. Distilled spirits brought into the United States from Puerto... bottles, including liquor bottles of less than 200 ml capacity, which conform to the applicable standards of fill provided in § 5.47 or § 5.47a of this chapter. Empty liquor bottles, including liquor...

  9. Cavernous hemangioma. Why is peripheral filling at scintigraphy so rare

    SciTech Connect

    Drane, W.E.; Weatherby, E. III

    1987-10-01

    Peripheral filling at dynamic CT occurs frequently with cavernous hemangiomas, yet this phenomenon is a rare finding on Tc-99m RBC imaging. A case of peripheral filling of a cavernous hemangioma with scintigraphy is reported and the rationale for its infrequent occurrence is discussed.

  10. 7 CFR 52.774 - Fill of container.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Canned Red Tart Pitted Cherries 1 Fill of Container § 52.774 Fill of container. (a) FDA requirements. Canned red tart pitted... Administration (21 CFR 145.125(c)). (b) Recommended minimum drained weights—(1) General. The minimum...

  11. 7 CFR 52.774 - Fill of container.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Canned Red Tart Pitted Cherries 1 Fill of Container § 52.774 Fill of container. (a) FDA requirements. Canned red tart pitted... Administration (21 CFR 145.125(c)). (b) Recommended minimum drained weights—(1) General. The minimum...

  12. Investigating Diffusion and Entropy with Carbon Dioxide-Filled Balloons

    ERIC Educational Resources Information Center

    Jadrich, James; Bruxvoort, Crystal

    2010-01-01

    Fill an ordinary latex balloon with helium gas and you know what to expect. Over the next day or two the volume will decrease noticeably as helium escapes from the balloon. So what happens when a latex balloon is filled with carbon dioxide gas? Surprisingly, carbon dioxide balloons deflate at rates as much as an order of magnitude faster than…

  13. 46 CFR 153.282 - Cargo filling lines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo filling lines. 153.282 Section 153.282 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING... and Cargo Handling Equipment § 153.282 Cargo filling lines. The discharge point of a cargo...

  14. 46 CFR 153.282 - Cargo filling lines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Cargo filling lines. 153.282 Section 153.282 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING... and Cargo Handling Equipment § 153.282 Cargo filling lines. The discharge point of a cargo...

  15. 7 CFR 2902.20 - Fluid-filled transformers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...-conducting) fluid to provide insulating and cooling properties. (2) Vegetable oil-based fluid-filled transformers. Electric power transformers that are designed to utilize a vegetable oil-based dielectric (non... transformers—66 percent. (2) Vegetable oil-based fluid-filled transformers—95 percent. (c)...

  16. 7 CFR 2902.20 - Fluid-filled transformers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...-conducting) fluid to provide insulating and cooling properties. (2) Vegetable oil-based fluid-filled transformers. Electric power transformers that are designed to utilize a vegetable oil-based dielectric (non... transformers—66 percent. (2) Vegetable oil-based fluid-filled transformers—95 percent. (c)...

  17. 7 CFR 3201.20 - Fluid-filled transformers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...-conducting) fluid to provide insulating and cooling properties. (2) Vegetable oil-based fluid-filled transformers. Electric power transformers that are designed to utilize a vegetable oil-based dielectric (non... transformers—66 percent. (2) Vegetable oil-based fluid-filled transformers—95 percent. (c)...

  18. 7 CFR 3201.20 - Fluid-filled transformers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...-conducting) fluid to provide insulating and cooling properties. (2) Vegetable oil-based fluid-filled transformers. Electric power transformers that are designed to utilize a vegetable oil-based dielectric (non... transformers—66 percent. (2) Vegetable oil-based fluid-filled transformers—95 percent. (c)...

  19. 7 CFR 3201.20 - Fluid-filled transformers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...-conducting) fluid to provide insulating and cooling properties. (2) Vegetable oil-based fluid-filled transformers. Electric power transformers that are designed to utilize a vegetable oil-based dielectric (non... transformers—66 percent. (2) Vegetable oil-based fluid-filled transformers—95 percent. (c)...

  20. A new taxonomy for perceptual filling-in

    PubMed Central

    Weil, Rimona S.; Rees, Geraint

    2011-01-01

    Perceptual filling-in occurs when structures of the visual system interpolate information across regions of visual space where that information is physically absent. It is a ubiquitous and heterogeneous phenomenon, which takes place in different forms almost every time we view the world around us, such as when objects are occluded by other objects or when they fall behind the blind spot. Yet, to date, there is no clear framework for relating these various forms of perceptual filling-in. Similarly, whether these and other forms of filling-in share common mechanisms is not yet known. Here we present a new taxonomy to categorize the different forms of perceptual filling-in. We then examine experimental evidence for the processes involved in each type of perceptual filling-in. Finally, we use established theories of general surface perception to show how contextualizing filling-in using this framework broadens our understanding of the possible shared mechanisms underlying perceptual filling-in. In particular, we consider the importance of the presence of boundaries in determining the phenomenal experience of perceptual filling-in. PMID:21059374