Sample records for average phase factor

  1. The Albedo of Kepler's Small Worlds

    NASA Astrophysics Data System (ADS)

    Jansen, Tiffany; Kipping, David

    2018-01-01

    The study of exoplanet phase curves has been established as a powerful tool for measuring the atmospheric properties of other worlds. To first order, phase curves have the same amplitude as occultations, yet far greater temporal baselines enabling substantial improvements in sensitivity. Even so, only a relatively small fraction of Kepler planets have detectable phase curves, leading to a population dominated by hot-Jupiters. One way to boost sensitivity further is to stack different planets of similar types together, giving rise to an average phase curve for a specific ensemble. In this work, we measure the average albedo, thermal redistribution efficiency, and greenhouse boosting factor from the average phase curves of 115 Neptunian and 50 Terran (solid) worlds. We construct ensemble phase curve models for both samples accounting for the reflection and thermal components and regress our models assuming a global albedo, redistribution factor and greenhouse factor in a Bayesian framework. We find modest evidence for a detected phase curve in the Neptunian sample, although the albedo and thermal properties are somewhat degenerate meaning we can only place an upper limit on the albedo of Ag < 0.23 and greenhouse factor of f < 1.40 to 95% confidence. As predicted theoretically, this confirms hot-Neptunes are darker than Neptune and Uranus. Additionally, we place a constraint on the albedo of solid, Terran worlds of Ag < 0.42 and f < 1.60 to 95% confidence, compatible with a dark Lunar-like surface.

  2. [Spectrum simulation based on data derived from red tide].

    PubMed

    Liu, Zhen-Yu; Cui, Ting-Wei; Yue, Jie; Jiang, Tao; Cao, Wen-Xi; Ma, Yi

    2011-11-01

    The present paper utilizes the absorption data of red tide water measured during the growing and dying course to retrieve imaginary part of the index of refraction based on Mie theory, carries out the simulation and analysis of average absorption efficiency factors, average backscattering efficiency factors and scattering phase function. The analysis of the simulation shows that Mie theory can be used to reproduce the absorption property of Chaetoceros socialis with an average error of 11%; the average backscattering efficiency factors depend on the value of absorption whose maximum value corresponds to the wavelength range from 400 to 700 nanometer; the average backscattering efficiency factors showed a maximum value on 17th with a low value during the outbreak of red tide and the minimum on 21th; the total scattering, weakly depending on the absorption, is proportional to the size parameters which represent the relative size of cell diameter with respect to the wavelength, while the angle scattering intensity is inversely proportional to wavelength.

  3. Evaluation of gastrointestinal solubilization of petroleum hydrocarbon residues in soil using an in vitro physiologically based model.

    PubMed

    Holman, Hoi-Ying N; Goth-Goldstein, Regine; Aston, David; Yun, Mao; Kengsoontra, Jenny

    2002-03-15

    Petroleum hydrocarbon residues in weathered soils may pose risks to humans through the ingestion pathway. To understand the factors controlling their gastrointestinal (GI) absorption, a newly developed experimental extraction protocol was used to model the GI solubility of total petroleum hydrocarbon (TPH) residues in highly weathered soils from different sites. The GI solubility of TPH residues was significantly higher for soil contaminated with diesel than with crude oil. Compared to the solubility of TPH residues during fasted state,the solubility of TPH residues during fat digestion was much greater. Diesel solubility increased from an average of 8% during the "gallbladder empty" phase of fasting (and less than 0.2% during the otherfasting phase) to an average of 16% during fat digestion. For crude oil, the solubility increased from an average of 1.2% during the gallbladder empty phase of fasting (and undetectable during the other fasting phase) to an average of 4.5% during fat digestion. Increasing the concentration of bile salts also increased GI solubility. GI solubility was reduced by soil organic carbon but enhanced by the TPH content.

  4. Estimating the population size and colony boundary of subterranean termites by using the density functions of directionally averaged capture probability.

    PubMed

    Su, Nan-Yao; Lee, Sang-Hee

    2008-04-01

    Marked termites were released in a linear-connected foraging arena, and the spatial heterogeneity of their capture probabilities was averaged for both directions at distance r from release point to obtain a symmetrical distribution, from which the density function of directionally averaged capture probability P(x) was derived. We hypothesized that as marked termites move into the population and given sufficient time, the directionally averaged capture probability may reach an equilibrium P(e) over the distance r and thus satisfy the equal mixing assumption of the mark-recapture protocol. The equilibrium capture probability P(e) was used to estimate the population size N. The hypothesis was tested in a 50-m extended foraging arena to simulate the distance factor of field colonies of subterranean termites. Over the 42-d test period, the density functions of directionally averaged capture probability P(x) exhibited four phases: exponential decline phase, linear decline phase, equilibrium phase, and postequilibrium phase. The equilibrium capture probability P(e), derived as the intercept of the linear regression during the equilibrium phase, correctly projected N estimates that were not significantly different from the known number of workers in the arena. Because the area beneath the probability density function is a constant (50% in this study), preequilibrium regression parameters and P(e) were used to estimate the population boundary distance 1, which is the distance between the release point and the boundary beyond which the population is absent.

  5. Submicron particle mass concentrations and sources in the Amazonian wet season (AMAZE-08)

    NASA Astrophysics Data System (ADS)

    Chen, Q.; Farmer, D. K.; Rizzo, L. V.; Pauliquevis, T.; Kuwata, M.; Karl, T. G.; Guenther, A.; Allan, J. D.; Coe, H.; Andreae, M. O.; Pöschl, U.; Jimenez, J. L.; Artaxo, P.; Martin, S. T.

    2015-04-01

    Real-time mass spectra of the non-refractory species in submicron aerosol particles were recorded in a tropical rainforest in the central Amazon Basin during the wet season from February to March 2008, as a part of the Amazonian Aerosol Characterization Experiment (AMAZE-08). Organic material accounted on average for more than 80% of the non-refractory submicron particle mass concentrations during the period of measurements. There was insufficient ammonium to neutralize sulfate. In this acidic, isoprene-rich, HO2-dominant environment, positive-matrix factorization of the time series of particle mass spectra identified four statistical factors to account for the 99% of the variance in the signal intensities of the organic constituents. The first factor was identified as associated with regional and local pollution and labeled "HOA" for its hydrocarbon-like characteristics. A second factor was associated with long-range transport and labeled "OOA-1" for its oxygenated characteristics. A third factor, labeled "OOA-2," was implicated as associated with the reactive uptake of isoprene oxidation products, especially of epoxydiols to acidic haze, fog, or cloud droplets. A fourth factor, labeled "OOA-3," was consistent with an association with the fresh production of secondary organic material (SOM) by the mechanism of gas-phase oxidation of biogenic volatile organic precursors followed by gas-to-particle conversion of the oxidation products. The suffixes 1, 2, and 3 on the OOA labels signify ordinal ranking with respect to the extent of oxidation represented by the factor. The process of aqueous-phase oxidation of water-soluble products of gas-phase photochemistry might also have been associated to some extent with the OOA-2 factor. The campaign-average factor loadings had a ratio of 1.4:1 for OOA-2 : OOA-3, suggesting the comparable importance of particle-phase compared to gas-phase pathways for the production of SOM during the study period.

  6. Unity power factor switching regulator

    NASA Technical Reports Server (NTRS)

    Rippel, Wally E. (Inventor)

    1983-01-01

    A single or multiphase boost chopper regulator operating with unity power factor, for use such as to charge a battery is comprised of a power section for converting single or multiphase line energy into recharge energy including a rectifier (10), one inductor (L.sub.1) and one chopper (Q.sub.1) for each chopper phase for presenting a load (battery) with a current output, and duty cycle control means (16) for each chopper to control the average inductor current over each period of the chopper, and a sensing and control section including means (20) for sensing at least one load parameter, means (22) for producing a current command signal as a function of said parameter, means (26) for producing a feedback signal as a function of said current command signal and the average rectifier voltage output over each period of the chopper, means (28) for sensing current through said inductor, means (18) for comparing said feedback signal with said sensed current to produce, in response to a difference, a control signal applied to the duty cycle control means, whereby the average inductor current is proportionate to the average rectifier voltage output over each period of the chopper, and instantaneous line current is thereby maintained proportionate to the instantaneous line voltage, thus achieving a unity power factor. The boost chopper is comprised of a plurality of converters connected in parallel and operated in staggered phase. For optimal harmonic suppression, the duty cycles of the switching converters are evenly spaced, and by negative coupling between pairs 180.degree. out-of-phase, peak currents through the switches can be reduced while reducing the inductor size and mass.

  7. Decomposition of Atmospheric Aerosol Phase Function by Particle Size and Morphology via Single Particle Scattering Measurements

    NASA Astrophysics Data System (ADS)

    Aptowicz, K. B.; Pan, Y.; Martin, S.; Fernandez, E.; Chang, R.; Pinnick, R. G.

    2013-12-01

    We report upon an experimental approach that provides insight into how particle size and shape affect the scattering phase function of atmospheric aerosol particles. Central to our approach is the design of an apparatus that measures the forward and backward scattering hemispheres (scattering patterns) of individual atmospheric aerosol particles in the coarse mode range. The size and shape of each particle is discerned from the corresponding scattering pattern. In particular, autocorrelation analysis is used to differentiate between spherical and non-spherical particles, the calculated asphericity factor is used to characterize the morphology of non-spherical particles, and the integrated irradiance is used for particle sizing. We found the fraction of spherical particles decays exponentially with particle size, decreasing from 11% for particles on the order of 1 micrometer to less than 1% for particles over 5 micrometer. The average phase functions of subpopulations of particles, grouped by size and morphology, are determined by averaging their corresponding scattering patterns. The phase functions of spherical and non-spherical atmospheric particles are shown to diverge with increasing size. In addition, the phase function of non-spherical particles is found to vary little as a function of the asphericity factor.

  8. Induction of a shorter compression phase is correlated with a deeper chest compression during metronome-guided cardiopulmonary resuscitation: a manikin study.

    PubMed

    Chung, Tae Nyoung; Bae, Jinkun; Kim, Eui Chung; Cho, Yun Kyung; You, Je Sung; Choi, Sung Wook; Kim, Ok Jun

    2013-07-01

    Recent studies have shown that there may be an interaction between duty cycle and other factors related to the quality of chest compression. Duty cycle represents the fraction of compression phase. We aimed to investigate the effect of shorter compression phase on average chest compression depth during metronome-guided cardiopulmonary resuscitation. Senior medical students performed 12 sets of chest compressions following the guiding sounds, with three down-stroke patterns (normal, fast and very fast) and four rates (80, 100, 120 and 140 compressions/min) in random sequence. Repeated-measures analysis of variance was used to compare the average chest compression depth and duty cycle among the trials. The average chest compression depth increased and the duty cycle decreased in a linear fashion as the down-stroke pattern shifted from normal to very fast (p<0.001 for both). Linear increase of average chest compression depth following the increase of the rate of chest compression was observed only with normal down-stroke pattern (p=0.004). Induction of a shorter compression phase is correlated with a deeper chest compression during metronome-guided cardiopulmonary resuscitation.

  9. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Akkelin, S.V.; Sinyukov, Yu.M.

    A method allowing analysis of the overpopulation of phase space in heavy ion collisions in a model-independent way is proposed within the hydrodynamic approach. It makes it possible to extract a chemical potential of thermal pions at freeze-out, irrespective of the form of freeze-out (isothermal) hypersurface in Minkowski space and transverse flows on it. The contributions of resonance (with masses up to 2 GeV) decays to spectra, interferometry volumes, and phase-space densities are calculated and discussed in detail. The estimates of average phase-space densities and chemical potentials of thermal pions are obtained for SPS and RHIC energies. They demonstrate thatmore » multibosonic phenomena at those energies might be considered as a correction factor rather than as a significant physical effect. The analysis of the evolution of the pion average phase-space density in chemically frozen hadron systems shows that it is almost constant or slightly increases with time while the particle density and phase-space density at each space point decreases rapidly during the system's expansion. We found that, unlike the particle density, the average phase-space density has no direct link to the freeze-out criterion and final thermodynamic parameters, being connected rather to the initial phase-space density of hadronic matter formed in relativistic nucleus-nucleus collisions.« less

  10. Spatial evolution of laser filaments in turbulent air

    NASA Astrophysics Data System (ADS)

    Zeng, Tao; Zhu, Shiping; Zhou, Shengling; He, Yan

    2018-04-01

    In this study, the spatial evolution properties of laser filament clusters in turbulent air were evaluated using numerical simulations. Various statistical parameters were calculated, such as the percolation probability, filling factor, and average cluster size. The results indicate that turbulence-induced multi-filamentation can be described as a new phase transition universality class. In addition, during this process, the relationship between the average cluster size and filling factor could be fit by a power function. Our results are valuable for applications involving filamentation that can be influenced by the geometrical features of multiple filaments.

  11. Analysis of phases in the structure determination of an icosahedral virus

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Plevka, Pavel; Kaufmann, Bärbel; Rossmann, Michael G.

    2012-03-15

    The constraints imposed on structure-factor phases by noncrystallographic symmetry (NCS) allow phase improvement, phase extension to higher resolution and hence ab initio phase determination. The more numerous the NCS redundancy and the greater the volume used for solvent flattening, the greater the power for phase determination. In a case analyzed here the icosahedral NCS phasing appeared to have broken down, although later successful phase extension was possible when the envelope around the NCS region was tightened. The phases from the failed phase-determination attempt fell into four classes, all of which satisfied the NCS constraints. These four classes corresponded to themore » correct solution, opposite enantiomorph, Babinet inversion and opposite enantiomorph with Babinet inversion. These incorrect solutions can be seeded from structure factors belonging to reciprocal-space volumes that lie close to icosahedral NCS axes where the structure amplitudes tend to be large and the phases tend to be 0 or {pi}. Furthermore, the false solutions can spread more easily if there are large errors in defining the envelope designating the region in which NCS averaging is performed.« less

  12. Analysis of phases in the structure determination of an icosahedral virus.

    PubMed

    Plevka, Pavel; Kaufmann, Bärbel; Rossmann, Michael G

    2011-06-01

    The constraints imposed on structure-factor phases by noncrystallographic symmetry (NCS) allow phase improvement, phase extension to higher resolution and hence ab initio phase determination. The more numerous the NCS redundancy and the greater the volume used for solvent flattening, the greater the power for phase determination. In a case analyzed here the icosahedral NCS phasing appeared to have broken down, although later successful phase extension was possible when the envelope around the NCS region was tightened. The phases from the failed phase-determination attempt fell into four classes, all of which satisfied the NCS constraints. These four classes corresponded to the correct solution, opposite enantiomorph, Babinet inversion and opposite enantiomorph with Babinet inversion. These incorrect solutions can be seeded from structure factors belonging to reciprocal-space volumes that lie close to icosahedral NCS axes where the structure amplitudes tend to be large and the phases tend to be 0 or π. Furthermore, the false solutions can spread more easily if there are large errors in defining the envelope designating the region in which NCS averaging is performed. © 2011 International Union of Crystallography

  13. Analysis of phases in the structure determination of an icosahedral virus

    PubMed Central

    Plevka, Pavel; Kaufmann, Bärbel; Rossmann, Michael G.

    2011-01-01

    The constraints imposed on structure-factor phases by non­crystallographic symmetry (NCS) allow phase improvement, phase extension to higher resolution and hence ab initio phase determination. The more numerous the NCS redundancy and the greater the volume used for solvent flattening, the greater the power for phase determination. In a case analyzed here the icosahedral NCS phasing appeared to have broken down, although later successful phase extension was possible when the envelope around the NCS region was tightened. The phases from the failed phase-determination attempt fell into four classes, all of which satisfied the NCS constraints. These four classes corresponded to the correct solution, opposite enantiomorph, Babinet inversion and opposite enantiomorph with Babinet inversion. These incorrect solutions can be seeded from structure factors belonging to reciprocal-space volumes that lie close to icosahedral NCS axes where the structure amplitudes tend to be large and the phases tend to be 0 or π. Furthermore, the false solutions can spread more easily if there are large errors in defining the envelope designating the region in which NCS averaging is performed. PMID:21636897

  14. Polycyclic aromatic hydrocarbons in biomass-burning emissions and their contribution to light absorption and aerosol toxicity.

    PubMed

    Samburova, Vera; Connolly, Jessica; Gyawali, Madhu; Yatavelli, Reddy L N; Watts, Adam C; Chakrabarty, Rajan K; Zielinska, Barbara; Moosmüller, Hans; Khlystov, Andrey

    2016-10-15

    In recent years, brown carbon (BrC) has been shown to be an important contributor to light absorption by biomass-burning atmospheric aerosols in the blue and near-ultraviolet (UV) part of the solar spectrum. Emission factors and optical properties of 113 polycyclic aromatic hydrocarbons (PAHs) were determined for combustion of five globally important fuels: Alaskan, Siberian, and Florida swamp peat, cheatgrass (Bromus tectorum), and ponderosa pine (Pinus ponderosa) needles. The emission factors of total analyzed PAHs were between 1.9±0.43.0±0.6 and 9.6±1.2-42.2±5.4mgPAHkg(-1)fuel for particle- and gas phase, respectively. Spectrophotometric analysis of the identified PAHs showed that perinaphthenone, methylpyrenes, and pyrene contributed the most to the total PAH light absorption with 17.2%, 3.3 to 10.5%, and 7.6% of the total particle-phase PAH absorptivity averaged over analyzed emissions from the fuels. In the gas phase, the top three PAH contributors to BrC were acenaphthylene (32.6%), anthracene (8.2%), and 2,4,5-trimethylnaphthalene (8.0%). Overall, the identified PAHs were responsible for 0.087-0.16% (0.13% on average) and 0.033-0.15% (0.11% on average) of the total light absorption by dichloromethane-acetone extracts of particle and gas emissions, respectively. Toxic equivalency factor (TEF) analysis of 16 PAHs prioritized by the United States Environmental Protection Agency (EPA) showed that benzo(a)pyrene contributed the most to the PAH carcinogenic potency of particle phase emissions (61.8-67.4% to the total carcinogenic potency of Σ16EPA PAHs), while naphthalene played the major role in carcinogenicity of the gas phase PAHs in the biomass-burning emission analyzed here (35.4-46.0% to the total carcinogenic potency of Σ16EPA PAHs). The 16 EPA-prioritized PAHs contributed only 22.1±6.2% to total particle and 23.4±11% to total gas phase PAH mass, thus toxic properties of biomass-burning PAH emissions are most likely underestimated. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Effect of subaperture beamforming on phase coherence imaging.

    PubMed

    Hasegawa, Hideyuki; Kanai, Hiroshi

    2014-11-01

    High-frame-rate echocardiography using unfocused transmit beams and parallel receive beamforming is a promising method for evaluation of cardiac function, such as imaging of rapid propagation of vibration of the heart wall resulting from electrical stimulation of the myocardium. In this technique, high temporal resolution is realized at the expense of spatial resolution and contrast. The phase coherence factor has been developed to improve spatial resolution and contrast in ultrasonography. It evaluates the variance in phases of echo signals received by individual transducer elements after delay compensation, as in the conventional delay-andsum beamforming process. However, the phase coherence factor suppresses speckle echoes because phases of speckle echoes fluctuate as a result of interference of echoes. In the present study, the receiving aperture was divided into several subapertures, and conventional delay-and-sum beamforming was performed with respect to each subaperture to suppress echoes from scatterers except for that at a focal point. After subaperture beamforming, the phase coherence factor was obtained from beamformed RF signals from respective subapertures. By means of this procedure, undesirable echoes, which can interfere with the echo from a focal point, can be suppressed by subaperture beamforming, and the suppression of the phase coherence factor resulting from phase fluctuation caused by such interference can be avoided. In the present study, the effect of subaperture beamforming in high-frame-rate echocardiography with the phase coherence factor was evaluated using a phantom. By applying subaperture beamforming, the average intensity of speckle echoes from a diffuse scattering medium was significantly higher (-39.9 dB) than that obtained without subaperture beamforming (-48.7 dB). As for spatial resolution, the width at half-maximum of the lateral echo amplitude profile obtained without the phase coherence factor was 1.06 mm. By using the phase coherence factor, spatial resolution was improved significantly, and subaperture beamforming achieved a better spatial resolution of 0.75 mm than that of 0.78 mm obtained without subaperture beamforming.

  16. Effect of the Hartmann number on phase separation controlled by magnetic field for binary mixture system with large component ratio

    NASA Astrophysics Data System (ADS)

    Heping, Wang; Xiaoguang, Li; Duyang, Zang; Rui, Hu; Xingguo, Geng

    2017-11-01

    This paper presents an exploration for phase separation in a magnetic field using a coupled lattice Boltzmann method (LBM) with magnetohydrodynamics (MHD). The left vertical wall was kept at a constant magnetic field. Simulations were conducted by the strong magnetic field to enhance phase separation and increase the size of separated phases. The focus was on the effect of magnetic intensity by defining the Hartmann number (Ha) on the phase separation properties. The numerical investigation was carried out for different governing parameters, namely Ha and the component ratio of the mixed liquid. The effective morphological evolutions of phase separation in different magnetic fields were demonstrated. The patterns showed that the slant elliptical phases were created by increasing Ha, due to the formation and increase of magnetic torque and force. The dataset was rearranged for growth kinetics of magnetic phase separation in a plot by spherically averaged structure factor and the ratio of separated phases and total system. The results indicate that the increase in Ha can increase the average size of separated phases and accelerate the spinodal decomposition and domain growth stages. Specially for the larger component ratio of mixed phases, the separation degree was also significantly improved by increasing magnetic intensity. These numerical results provide guidance for setting the optimum condition for the phase separation induced by magnetic field.

  17. Linking Initial Microstructure to ORR Related Property Degradation in SOFC Cathode: A Phase Field Simulation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lei, Y.; Cheng, T. -L.; Wen, Y. H.

    Microstructure evolution driven by thermal coarsening is an important factor for the loss of oxygen reduction reaction rates in SOFC cathode. In this work, the effect of an initial microstructure on the microstructure evolution in SOFC cathode is investigated using a recently developed phase field model. Specifically, we tune the phase fraction, the average grain size, the standard deviation of the grain size and the grain shape in the initial microstructure, and explore their effect on the evolution of the grain size, the density of triple phase boundary, the specific surface area and the effective conductivity in LSM-YSZ cathodes. Itmore » is found that the degradation rate of TPB density and SSA of LSM is lower with less LSM phase fraction (with constant porosity assumed) and greater average grain size, while the degradation rate of effective conductivity can also be tuned by adjusting the standard deviation of grain size distribution and grain aspect ratio. The implication of this study on the designing of an optimal initial microstructure of SOFC cathodes is discussed.« less

  18. Linking Initial Microstructure to ORR Related Property Degradation in SOFC Cathode: A Phase Field Simulation

    DOE PAGES

    Lei, Y.; Cheng, T. -L.; Wen, Y. H.

    2017-07-05

    Microstructure evolution driven by thermal coarsening is an important factor for the loss of oxygen reduction reaction rates in SOFC cathode. In this work, the effect of an initial microstructure on the microstructure evolution in SOFC cathode is investigated using a recently developed phase field model. Specifically, we tune the phase fraction, the average grain size, the standard deviation of the grain size and the grain shape in the initial microstructure, and explore their effect on the evolution of the grain size, the density of triple phase boundary, the specific surface area and the effective conductivity in LSM-YSZ cathodes. Itmore » is found that the degradation rate of TPB density and SSA of LSM is lower with less LSM phase fraction (with constant porosity assumed) and greater average grain size, while the degradation rate of effective conductivity can also be tuned by adjusting the standard deviation of grain size distribution and grain aspect ratio. The implication of this study on the designing of an optimal initial microstructure of SOFC cathodes is discussed.« less

  19. [Satisfaction of Users with Spinal Cord Injury in relation to the Service of Promotion of Personal Autonomy of the Balearic Islands, Spain].

    PubMed

    Capó-Juan, Miguel Ángel; Fiol-Delgado, Rosa Mª; Alzamora-Perelló, Mª Magdalena; Bosch-Gutiérrez, Marta; Serna-López, Lucía; Bennasar-Veny, Miguel; Aguiló-Pons, Antonio; De Pedro-Gómez, Joan E

    2016-11-10

    Public Service Promotion of Personal Autonomy aims to provide care to users with severe physical and/or physical-mental disabilities, including people with spinal cord injury. These users are in a chronic phase and thus they require educational-therapeutic measures of physiotherapy. This study is meant to determine the satisfaction of people with spinal cord injury who attend this service. A descriptive, cross-sectional, quantitative study in the Public Service Promotion of Personal Autonomy after a sixteen-month therapeutic monitoring process was carried out, which began in March 2015. The final study sample was 25 people with spinal cord injury (17 men and 8 women). At the end of therapeutic intervention, users responded to the SERVQHOS questionnaire, which consists in nineteen questions that aim to measure the quality of the care services provided. A statistical analysis was conducted, calculating averages and standard deviations or frecuencies and percentages. The best valued external factor was the staff appearance with 4,5 on average and the worst scored external factor was the ease of access and / or signposting of the center with 2,6 on average. On the other hand, the best valued internal factor was the kindness of the staff with 4,8 on average and the worst scored factor was the speed in which the users receive what they requested with 4,2 on average. We concluded that the quality offered is determined by internal factors (kindness, trust, willingness to help) and weaknesses are related to structural factors of the center (external factors).

  20. Choice of phase in the CS and IOS approximation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Snider, R.F.

    1982-04-01

    With the recognition that the angular momentum representations of unit position and momentum directional states must have different but uniquely related phases, the previously presented expression of scattering amplitude in terms of IOS angle dependent phase shifts must be modified. This resolves a major disagreement between IOS and close coupled degeneracy averaged differential cross sections. It is found that the phase factors appearing in the differential cross section have nothing to do with any particular choice of decoupling parameter. As a consequence, the differential cross section is relatively insensitive to the choice of CS decoupling parameter. The phase relations obtainedmore » are also in agreement with those deduced from the Born approximation.« less

  1. Efficiency for unretained solutes in packed column supercritical fluid chromatography. I. Theory for isothermal conditions and correction factors for carbon dioxide.

    PubMed

    Poe, Donald P

    2005-06-17

    A general theory for efficiency of nonuniform columns with compressible mobile phase fluids is applied to the elution of an unretained solute in packed-column supercritical fluid chromatography (pSFC). The theoretical apparent plate height under isothermal conditions is given by the Knox equation multiplied by a compressibility correction factor f1, which is equal to the ratio of the temporal-to-spatial average densities of the mobile phase. If isothermal conditions are maintained, large pressure drops in pSFC should not result in excessive efficiency losses for elution of unretained solutes.

  2. High-resolution observations of the polar magnetic fields of the sun

    NASA Technical Reports Server (NTRS)

    Lin, H.; Varsik, J.; Zirin, H.

    1994-01-01

    High-resolution magnetograms of the solar polar region were used for the study of the polar magnetic field. In contrast to low-resolution magnetograph observations which measure the polar magnetic field averaged over a large area, we focused our efforts on the properties of the small magnetic elements in the polar region. Evolution of the filling factor (the ratio of the area occupied by the magnetic elements to the total area) of these magnetic elements, as well as the average magnetic field strength, were studied during the maximum and declining phase of solar cycle 22, from early 1991 to mid-1993. We found that during the sunspot maximum period, the polar regions were occupied by about equal numbers of positive and negative magnetic elements, with equal average field strength. As the solar cycle progresses toward sunspot minimum, the magnetic field elements in the polar region become predominantly of one polarity. The average magnetic field of the dominant polarity elements also increases with the filling factor. In the meanwhile, both the filling factor and the average field strength of the non-dominant polarity elements decrease. The combined effects of the changing filling factors and average field strength produce the observed evolution of the integrated polar flux over the solar cycle. We compared the evolutionary histories of both filling factor and average field strength, for regions of high (70-80 deg) and low (60-70 deg) latitudes. For the south pole, we found no significant evidence of difference in the time of reversal. However, the low-latitude region of the north pole did reverse polarity much earlier than the high-latitude region. It later showed an oscillatory behavior. We suggest this may be caused by the poleward migration of flux from a large active region in 1989 with highly imbalanced flux.

  3. Emissions factors for gaseous and particulate pollutants from offshore diesel engine vessels in China

    NASA Astrophysics Data System (ADS)

    Zhang, F.; Chen, Y.; Tian, C.; Li, J.; Zhang, G.; Matthias, V.

    2015-09-01

    Shipping emissions have significant influence on atmospheric environment as well as human health, especially in coastal areas and the harbor districts. However, the contribution of shipping emissions on the environment in China still need to be clarified especially based on measurement data, with the large number ownership of vessels and the rapid developments of ports, international trade and shipbuilding industry. Pollutants in the gaseous phase (carbon monoxide, sulfur dioxide, nitrogen oxides, total volatile organic compounds) and particle phase (particulate matter, organic carbon, elemental carbon, sulfates, nitrate, ammonia, metals) in the exhaust from three different diesel engine power offshore vessels in China were measured in this study. Concentrations, fuel-based and power-based emissions factors for various operating modes as well as the impact of engine speed on emissions were determined. Observed concentrations and emissions factors for carbon monoxide, nitrogen oxides, total volatile organic compounds, and particulate matter were higher for the low engine power vessel than for the two higher engine power vessels. Fuel-based average emissions factors for all pollutants except sulfur dioxide in the low engine power engineering vessel were significantly higher than that of the previous studies, while for the two higher engine power vessels, the fuel-based average emissions factors for all pollutants were comparable to the results of the previous studies. The fuel-based average emissions factor for nitrogen oxides for the small engine power vessel was more than twice the International Maritime Organization standard, while those for the other two vessels were below the standard. Emissions factors for all three vessels were significantly different during different operating modes. Organic carbon and elemental carbon were the main components of particulate matter, while water-soluble ions and elements were present in trace amounts. Best-fit engine speeds during actual operation should be based on both emissions factors and economic costs.

  4. Strong potential wave functions with elastic channel distortion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Macek, J.; Taulbjerg, K.

    1989-06-01

    The strong-potential Born approximation is analyzed in a channel-distorted-wave approach. Channel-distorted SPB wave functions are reduced to a conventional form in which the standard off-energy-shell factor /ital g/ has been replaced by a modified factor ..gamma.., which represents a suitable average of /ital g/ over the momentum distribution of the distorted-channel function. The modified factor is evaluated in a physically realistic model for the distortion potential, and it is found that ..gamma.. is well represented by a slowly varying phase factor. The channel-distorted SPB approximation is accordingly identical to the impulse approximation if the phase variation of ..gamma.. can bemore » ignored. This is generally the case in applications to radiative electron capture and to a good approximation for ordinary capture at not too small velocities.« less

  5. Source Apportionment of Primary and Secondary Organic Aerosol Using Positive Matrix Factorization (PMF) of Molecular Markers

    EPA Science Inventory

    Monthly average ambient concentrations of more than eighty particle-phase organic compounds, as well as total organic carbon (OC) and elemental carbon (EC), were measured from March 2004 through February 2005 in five cities in the Midwestern United States. A multi-variant source...

  6. The cross wavelet analysis of dengue fever variability influenced by meteorological conditions

    NASA Astrophysics Data System (ADS)

    Lin, Yuan-Chien; Yu, Hwa-Lung; Lee, Chieh-Han

    2015-04-01

    The multiyear variation of meteorological conditions induced by climate change causes the changing diffusion pattern of infectious disease and serious epidemic situation. Among them, dengue fever is one of the most serious vector-borne diseases distributed in tropical and sub-tropical regions. Dengue virus is transmitted by several species of mosquito and causing lots amount of human deaths every year around the world. The objective of this study is to investigate the impact of meteorological variables to the temporal variation of dengue fever epidemic in southern Taiwan. Several extreme and average indices of meteorological variables, i.e. temperature and humidity, were used for this analysis, including averaged, maximum and minimum temperature, and average rainfall, maximum 1-hr rainfall, and maximum 24-hr rainfall. This study plans to identify and quantify the nonlinear relationship of meteorological variables and dengue fever epidemic, finding the non-stationary time-frequency relationship and phase lag effects of those time series from 1998-2011 by using cross wavelet method. Results show that meteorological variables all have a significant time-frequency correlation region to dengue fever epidemic in frequency about one year (52 weeks). The associated phases can range from 0 to 90 degrees (0-13 weeks lag from meteorological factors to dengue incidences). Keywords: dengue fever, cross wavelet analysis, meteorological factor

  7. Sensitivity of a phase-sensitive optical time-domain reflectometer with a semiconductor laser source

    NASA Astrophysics Data System (ADS)

    Alekseev, A. E.; Tezadov, Ya A.; Potapov, V. T.

    2018-06-01

    In the present paper we perform, for the first time, an analysis of the average sensitivity of a coherent phase-sensitive optical time-domain reflectometer (phase-OTDR) with a semiconductor laser source to external actions. The sensitivity of this OTDR can be defined in a conventional manner via average SNR at its output, which in turn is defined by the average useful signal power and the average intensity noise power in the OTDR spatial channels in the bandwidth defined by the OTDR sampling frequency. The average intensity noise power is considered in detail in a previous paper. In the current paper we examine the average useful signal power at the output of a phase-OTDR. The analysis of the average useful signal power of a phase-OTDR is based on the study of a fiber scattered-light interferometer (FSLI) which is treated as a constituent part of a phase- OTDR. In the analysis, one of the conventional phase-OTDR schemes with a rectangular dual-pulse probe signal is considered. The FSLI which corresponds to this OTDR scheme has two scattering fiber segments with additional time delay, introduced between backscattered fields. The average useful signal power and the resulting average SNR at the output of this FSLI are determined by the degree of coherence of the semiconductor laser source, the length of the scattering fiber segments, and by the additional time delay between the scattering fiber segments. The average useful signal power characteristic of the corresponding phase-OTDR is determined by analogous parameters: the source coherence, the time durations of the parts constituting the dual-pulse, and the time interval which separates these parts. In the paper an expression for the average useful signal power of a phase-OTDR is theoretically derived and experimentally verified. Based on the found average useful signal power of a phase-OTDR and the average intensity noise power, derived in the previous paper, the average SNR of a phase-OTDR is defined. Setting the average signal SNR to 1, at a defined spectral band the minimum detectable external action amplitude for our particular phase-OTDR setup is determined. We also derive a simple relation for the average useful signal power and the average SNR which results when making the assumption that the laser source coherence is high. The results of the paper can serve as the basis for further development of the concept of phase-OTDR sensitivity.

  8. Relationship between Acute Phase of Chronic Periodontitis and Meteorological Factors in the Maintenance Phase of Periodontal Treatment: A Pilot Study.

    PubMed

    Takeuchi, Noriko; Ekuni, Daisuke; Tomofuji, Takaaki; Morita, Manabu

    2015-08-05

    The acute phase of chronic periodontitis may occur even in patients during supportive periodontal therapy. However, the details are not fully understood. Since the natural environment, including meteorology affects human health, we hypothesized that weather conditions may affect occurrence of acute phase of chronic periodontitis. The aim of this study was to investigate the relationship between weather conditions and acute phase of chronic periodontitis in patients under supportive periodontal therapy. Patients who were diagnosed with acute phase of chronic periodontitis under supportive periodontal therapy during 2011-2013 were selected for this study. We performed oral examinations and collected questionnaires and meteorological data. Of 369 patients who experienced acute phase of chronic periodontitis, 153 had acute phase of chronic periodontitis without direct-triggered episodes. When using the autoregressive integrated moving average model of time-series analysis, the independent covariant of maximum hourly range of barometric pressure, maximum hourly range of temperature, and maximum daily wind speed were significantly associated with occurrence of acute phase of chronic periodontitis (p < 0.05), and 3.1% of the variations in these occurrence over the study period were explained by these factors. Meteorological variables may predict occurrence of acute phase of chronic periodontitis.

  9. Thermodynamically Constrained Averaging Theory (TCAT) Two-Phase Flow Model: Derivation, Closure, and Simulation Results

    NASA Astrophysics Data System (ADS)

    Weigand, T. M.; Miller, C. T.; Dye, A. L.; Gray, W. G.; McClure, J. E.; Rybak, I.

    2015-12-01

    The thermodynamically constrained averaging theory (TCAT) has been usedto formulate general classes of porous medium models, including newmodels for two-fluid-phase flow. The TCAT approach provides advantagesthat include a firm connection between the microscale, or pore scale,and the macroscale; a thermodynamically consistent basis; explicitinclusion of factors such as interfacial areas, contact angles,interfacial tension, and curvatures; and dynamics of interface movementand relaxation to an equilibrium state. In order to render the TCATmodel solvable, certain closure relations are needed to relate fluidpressure, interfacial areas, curvatures, and relaxation rates. In thiswork, we formulate and solve a TCAT-based two-fluid-phase flow model. We detail the formulation of the model, which is a specific instancefrom a hierarchy of two-fluid-phase flow models that emerge from thetheory. We show the closure problem that must be solved. Using recentresults from high-resolution microscale simulations, we advance a set ofclosure relations that produce a closed model. Lastly, we solve the model using a locally conservative numerical scheme and compare the TCAT model to the traditional model.

  10. Solar cycle signal in air temperature in North America - Amplitude, gradient, phase and distribution

    NASA Technical Reports Server (NTRS)

    Currie, R. G.

    1981-01-01

    The considered investigation was motivated by three factors. One is related to an extension of single-channel MESA to multi-channel by Strand (1977), Morf et al. (1978), and Jones (1978). MESA is a high-resolution signal processing and spectrum analysis technique due to Burg (1975). The considered developments resulted in the discovery of the 11-year solar cycle signal in the change of the length of day by Currie (1980, 1981). They also led Currie (1981) to study the phase spectrum of the 11-year term in height H of sea level. The investigation tries to clarify the phase relations among the involved parameters. The second factor is connected with an application of the linear time domain technique used by Currie (1981) to temperature records to obtain more accurate information regarding the signal amplitude. The third factor of motivation is related to increases in the number of stations available for an analysis, the greater average length of the records, and the more accurate data set.

  11. Asteroid (21) Lutetia: Disk-resolved photometric analysis of Baetica region

    NASA Astrophysics Data System (ADS)

    Hasselmann, P. H.; Barucci, M. A.; Fornasier, S.; Leyrat, C.; Carvano, J. M.; Lazzaro, D.; Sierks, H.

    2016-03-01

    (21) Lutetia has been visited by Rosetta mission on July 2010 and observed with a phase angle ranging from 0.15° to 156.8°. The Baetica region, located at the north pole has been extensively observed by OSIRIS cameras system. Baetica encompass a region called North Pole Crater Cluster (NPCC), shows a cluster of superposed craters which presents signs of variegation at the small phase angle images. For studying the location, we used 187 images distributed throughout 14 filter recorded by the NAC (Narrow Angle Camera) and WAC (Wide Angle Camera) of the OSIRIS system on-board Rosetta taken during the fly-by. Then, we photometrically modeled the region using Minnaert disk-function and Akimov phase function to obtain a resolved spectral slope map at phase angles of 5 ° and 20 ° . We observed a dichotomy between Gallicum and Danuvius-Sarnus Labes in the NPCC, but no significant phase reddening (- 0.04 ± 0.045 % μm-1deg-1). In the next step, we applied the Hapke (Hapke, B. [2008]. Icarus 195, 918-926; Hapke, B. [2012]. Theory of Reflectance and Emittance Spectroscopy, second ed. Cambridge University Press) model for the NAC F82+F22 (649.2 nm), WAC F13 (375 nm) and WAC F17 (631.6 nm) and we obtained normal albedo maps and Hapke parameter maps for NAC F82+F22. On Baetica, at 649.2 nm, the geometric albedo is 0.205 ± 0.005 , the average single-scattering albedo is 0.181 ± 0.005 , the average asymmetric factor is - 0.342 ± 0.003 , the average shadow-hiding opposition effect amplitude and width are 0.824 ± 0.002 and 0.040 ± 0.0007 , the average roughness slope is 11.45 ° ± 3 ° and the average porosity is 0.85 ± 0.002 . We are unable to confirm the presence of coherent-backscattering mechanism. In the NPCC, the normal albedo variegation among the craters walls reach 8% brighter for Gallicum Labes and 2% fainter for Danuvius Labes. The Hapke parameter maps also show a dichotomy at the opposition effect coefficients, single-scattering albedo and asymmetric factor, that may be attributed to the maturation degree of the regolith or to compositonal variation. In addition, we compared the Hapke (Hapke, B. [2008]. Icarus 195, 918-926; Hapke, B. [2012]. Theory of Reflectance and Emittance Spectroscopy, second ed. Cambridge University Press) and Hapke (Hapke, B. [1993]. Theory of Reflectance and Emittance Spectroscopy) parameters with laboratory samples and other small Solar System bodies visited by space missions.

  12. Measuring motivation and volition of nursing students in nontraditional learning environments.

    PubMed

    Nagelsmith, Laurie; Bryer, Jason; Yan, Zheng

    2012-01-01

    The purpose of this study was to identify the best fitting model to represent interrelationships between motivation, volition, and academic success for adult nursing students learning in nontraditional environments. Participants (N=297) completed a survey that incorporated two measures: the Motivated Strategies for Learning Questionnaire (MSLQ) and the academic volitional strategies inventory (AVSI) as well as demographic information. Exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and structural equation modeling (SEM) were used for data analysis. In phase 1, EFA resulted in factors that generally aligned with previous theoretical factors as defined by the psychometrics used. In Phase 2 of the analysis, CFA validated the use of predefined factor structures. In Phase 3, SEM analysis revealed that motivation has a larger effect on grade point average (GPA; beta = .28, p < .01) than volition (beta = .15, p < .05). The covariance between motivation and volition (r = .42, p < .01) was also found to be significant. These results suggest that there is a significant relationship among motivation, volition, and academic success for adult learners studying in nontraditional learning environments. These findings are consistent with and elaborate the relationship between motivation and volition with a population and setting underrepresented in the research.

  13. Circadian phase and its relationship to nighttime sleep in toddlers.

    PubMed

    LeBourgeois, Monique K; Carskadon, Mary A; Akacem, Lameese D; Simpkin, Charles T; Wright, Kenneth P; Achermann, Peter; Jenni, Oskar G

    2013-10-01

    Circadian phase and its relation to sleep are increasingly recognized as fundamental factors influencing human physiology and behavior. Dim light melatonin onset (DLMO) is a reliable marker of the timing of the circadian clock, which has been used in experimental, clinical, and descriptive studies in the past few decades. Although DLMO and its relationship to sleep have been well documented in school-aged children, adolescents, and adults, very little is known about these processes in early childhood. The purpose of this study was 1) to describe circadian phase and phase angles of entrainment in toddlers and 2) to examine associations between DLMO and actigraphic measures of children's nighttime sleep. Participants were 45 healthy toddlers aged 30 to 36 months (33.5 ± 2.2 months; 21 females). After sleeping on a parent-selected schedule for 5 days (assessed with actigraphy and diaries), children participated in an in-home DLMO assessment involving the collection of saliva samples every 30 minutes for 6 hours. Average bedtime was 2015 ± 0036 h, average sleep onset time was 2043 ± 0043 h, average midsleep time was 0143 ± 0038 h, and average wake time was 0644 ± 0042 h. Average DLMO was 1929 ± 0051 h, with a 3.5-hour range. DLMO was normally distributed; however, the distribution of the bedtime, sleep onset time, and midsleep phase angles of entrainment were skewed. On average, DLMO occurred 47.8 ± 47.6 minutes (median = 39.4 minutes) before bedtime, 74.6 ± 48.0 minutes (median = 65.4 minutes) before sleep onset time, 6.2 ± 0.7 hours (median = 6.1 hours) before midsleep time, and 11.3 ± 0.7 hours before wake time. Toddlers with later DLMOs had later bedtimes (r = 0.46), sleep onset times (r = 0.51), midsleep times (r = 0.66), and wake times (r = 0.65) (all p < 0.001). Interindividual differences in toddlers' circadian phase are large and associated with their sleep timing. The early DLMOs of toddlers indicate a maturational delay in the circadian timing system between early childhood and adolescence. These findings are a first step in describing the fundamental properties of the circadian system in toddlers and have important implications for understanding the emergence of sleep problems and the consequences of circadian misalignment in early childhood.

  14. Measuring Magnetic Oscillations in the Solar Photosphere: Coordinated Observations with MDI, ASP and MWO

    NASA Astrophysics Data System (ADS)

    Norton, A. A.; Ulrich, R. K.

    2000-03-01

    A comprehensive observing effort was undertaken to simultaneously obtain full Stokes profiles as well as longitudinal magnetogram maps of a positive plage region on 8 December, 1998 with the Michelson Doppler Imager, the Advanced Stokes Polarimeter and Mt. Wilson Observatory magnetograph. We compare 1.2'' spatially-averaged signals of velocities as well as filter magnetograph longitudinal flux signals with Stokes determined fluctuations in filling factor, field inclination, magnetic flux and field strength. The velocity signals are in excellent agreement. Michelson Doppler Imager magnetic flux correlates best with fluctuations in the Advanced Stokes Polarimeter filling factor, not inclination angle or field strength. A correlated flux and filling factor change in the absence of a field strength fluctuation can be understood in terms of internally unperturbed flux tubes being buffeted by external pressure fluctuations. The 12.5'' square aperture spatially averaged Mt. Wilson magnetograph signals are compared with Michelson Doppler Imager signals from the corresponding observing area. Velocity signals are in superb agreement. Magnetic signals exhibit similar oscillatory behavior. Lack of Advanced Stokes Polarimeter data for this time excludes interpretation of magnetic fluctuations as due to filling factor or field inclination angle. Mt. Wilson Observatory simultaneous sampling of the nickel and sodium spectral line profiles with several wing pairs allowed inter-comparison of signals from different heights of formation. Slight phase shifts and large propagation speeds for the velocity signals are indicative of modified standing waves. Phase speeds associated with magnetic signals are characteristic of photospheric Alfvén speeds for plage fields. The phase speed increase with height agrees with the altitude dependence of the Alfvén speed. The observed fluctuations and phases are interpreted as a superposition of signatures from the horizontal component of the driving mechanism sweeping the field lines in/out of the resolution area and the magnetic response of the flux tube to this buffeting.

  15. Relative phase noise induced impairment in M-ary phase-shift-keying coherent optical communication system using distributed fiber Raman amplifier.

    PubMed

    Cheng, Jingchi; Tang, Ming; Fu, Songnian; Shum, Perry Ping; Liu, Deming

    2013-04-01

    We show for the first time, to the best of our knowledge, that, in a coherent communication system that employs a phase-shift-keying signal and Raman amplification, besides the pump relative intensity noise (RIN) transfer to the amplitude, the signal's phase will also be affected by pump RIN through the pump-signal cross-phase modulation. Although the average pump power induced linear phase change can be compensated for by the phase-correction algorithm, a relative phase noise (RPN) parameter has been found to characterize pump RIN induced stochastic phase noise. This extra phase noise brings non-negligible system impairments in terms of the Q-factor penalty. The calculation shows that copumping leads to much more stringent requirements to pump RIN, and relatively larger fiber dispersion helps to suppress the RPN induced impairment. A higher-order phase-shift keying (PSK) signal is less tolerant to noise than a lower-order PSK.

  16. Assessing the long-range transport of PAH to a sub-Arctic site using positive matrix factorization and potential source contribution function

    NASA Astrophysics Data System (ADS)

    Sofowote, Uwayemi M.; Hung, Hayley; Rastogi, Ankit K.; Westgate, John N.; Deluca, Patrick F.; Su, Yushan; McCarry, Brian E.

    2011-02-01

    Gas-phase and particle-phase atmospheric samples collected in a sparsely populated sub-Arctic environment in the Yukon Territory, Canada were analyzed for a wide range of organic pollutants including polycyclic aromatic hydrocarbons (PAH). Receptor modeling using positive matrix factorization (PMF) was applied to a PAH data set from samples collected between August 2007 and December 2008 to afford four factors. These factors were designated as fossil fuel combustion emissions, particle-phase wood combustion emissions, gas-phase wood combustion emissions, and unburned petroleum/petrogenic emissions. The multiple linear regression-derived average contributions of these factors to the total PAH concentrations were 14% for fossil fuel combustion, 6% for particle-phase wood combustion emissions, 46% for gas-phase wood combustion emissions and 34% for petrogenic emissions. When the total PAH concentrations (defined as the sum of twenty-two PAH) and the PMF-modeled PAH concentrations set were compared, the correlation was excellent ( R2 = 0.97). Ten-day back trajectories starting at four different heights were used in a potential source contribution function analysis (PSCF) to assess the potential source regions of these PAH factors. Mapping the computed PSCF values for the four PMF factors revealed different source regions in the northern hemisphere for each PMF factor. Atmospheric transport of PAH occurred from both relatively short and long distances with both continental (North American) and trans-oceanic (Asian) sources contributing significantly to the total PAH. This study provides evidence of the transport of fossil fuel and wood combustion emissions from Asia, continental North America and northern Europe to sub-Arctic Canada (and by extension to the Canadian Arctic) primarily during cooler (fall-winter) months. This study demonstrates for the first time that the combined PMF-PSCF methodology can be used to identify geographically-disperse PAH source contributors on a hemispherical scale.

  17. Positive matrix factorization of PM2.5 - eliminating the effects of gas/particle partitioning of semivolatile organic compounds.

    PubMed

    Xie, M; Barsanti, K C; Hannigan, M P; Dutton, S J; Vedal, S

    2013-01-01

    Gas-phase concentrations of semi-volatile organic compounds (SVOCs) were calculated from gas/particle (G/P) partitioning theory using their measured particle-phase concentrations. The particle-phase data were obtained from an existing filter measurement campaign (27 January 2003-2 October 2005) as a part of the Denver Aerosol Sources and Health (DASH) study, including 970 observations of 71 SVOCs (Xie et al., 2013). In each compound class of SVOCs, the lighter species (e.g. docosane in n alkanes, fluoranthene in PAHs) had higher total concentrations (gas + particle phase) and lower particle-phase fractions. The total SVOC concentrations were analyzed using positive matrix factorization (PMF). Then the results were compared with source apportionment results where only particle-phase SVOC concentrations were used (particle only-based study; Xie et al., 2013). For the particle only-based PMF analysis, the factors primarily associated with primary or secondary sources ( n alkane, EC/sterane and inorganic ion factors) exhibit similar contribution time series ( r = 0.92-0.98) with their corresponding factors ( n alkane, sterane and nitrate+sulfate factors) in the current work. Three other factors (light n alkane/PAH, PAH and summer/odd n alkane factors) are linked with pollution sources influenced by atmospheric processes (e.g. G/P partitioning, photochemical reaction), and were less correlated ( r = 0.69-0.84) with their corresponding factors (light SVOC, PAH and bulk carbon factors) in the current work, suggesting that the source apportionment results derived from particle-only SVOC data could be affected by atmospheric processes. PMF analysis was also performed on three temperature-stratified subsets of the total SVOC data, representing ambient sampling during cold (daily average temperature < 10 °C), warm (≥ 10 °C and ≤ 20 °C) and hot (> 20 °C) periods. Unlike the particle only-based study, in this work the factor characterized by the low molecular weight (MW) compounds (light SVOC factor) exhibited strong correlations ( r = 0.82-0.98) between the full data set and each sub-data set solution, indicating that the impacts of G/P partitioning on receptor-based source apportionment could be eliminated by using total SVOC concentrations.

  18. The Influence of Training Phase on Error of Measurement in Jump Performance.

    PubMed

    Taylor, Kristie-Lee; Hopkins, Will G; Chapman, Dale W; Cronin, John B

    2016-03-01

    The purpose of this study was to calculate the coefficients of variation in jump performance for individual participants in multiple trials over time to determine the extent to which there are real differences in the error of measurement between participants. The effect of training phase on measurement error was also investigated. Six subjects participated in a resistance-training intervention for 12 wk with mean power from a countermovement jump measured 6 d/wk. Using a mixed-model meta-analysis, differences between subjects, within-subject changes between training phases, and the mean error values during different phases of training were examined. Small, substantial factor differences of 1.11 were observed between subjects; however, the finding was unclear based on the width of the confidence limits. The mean error was clearly higher during overload training than baseline training, by a factor of ×/÷ 1.3 (confidence limits 1.0-1.6). The random factor representing the interaction between subjects and training phases revealed further substantial differences of ×/÷ 1.2 (1.1-1.3), indicating that on average, the error of measurement in some subjects changes more than in others when overload training is introduced. The results from this study provide the first indication that within-subject variability in performance is substantially different between training phases and, possibly, different between individuals. The implications of these findings for monitoring individuals and estimating sample size are discussed.

  19. Mitigation of nonlinear fiber distortion using optical phase conjugation for mode-division multiplexed transmission

    NASA Astrophysics Data System (ADS)

    Zhang, Kai; Gao, Guanjun; Zhang, Jie; Fei, Aimei; Cvijetic, Milorad

    2018-07-01

    We have investigated and proposed the use of optical phase conjugation (OPC) technique to mitigate the impact of fiber nonlinearities in mode-division multiplexed transmission systems. Numerical simulations are performed for three wavelengths, each loaded with 200 Gb/s dual-polarization 16-level quadrature amplitude modulation (DP-16QAM) format, in weakly guided two-mode fiber. It is known that differential mode group delay (DMGD) in mode-division multiplexed (MDM) transmission systems could be beneficial for system performance of MDM system with MIMO compensation in place. On the other side, for MDM system with OPC in place, the presence of DMGD may limit the overall benefits since signal power evolution per spatial modes should be symmetrical at the system midpoint in order to realize an effective compensation of the nonlinear effects. Our simulation results show that in the reference case (in the absence of DMGD), the employment of OPC module would lead to an average Q-factor improvement of approximately 10 dB. At the same time, in the presence of DMGD, an average Q-factor improvement would be ∼2.8 dB for WDM case. In addition, due to asymmetrical signal power map, the penalties induced by a periodic amplification process cannot be ideally compensated by the midpoint insertion of OPC. However, by accounting the impacts of both DMGD and asymmetrical signal power map, the insertion of the OPC system will still lead to an average Q-factor improvement of ∼1 dB for WDM channel arrangement.

  20. Exploring community gardens in a health disparate population: findings from a mixed methods pilot study.

    PubMed

    Zoellner, Jamie; Zanko, Ashley; Price, Bryan; Bonner, Jennifer; Hill, Jennie L

    2012-01-01

    Despite recommendations, there have been few efforts to apply the community-based participatory research (CBPR) approach in the development, implementation, and evaluation of community gardens. As guided by the CBPR approach and grounded in a social-ecological model and behavioral theory, the purpose of this mixed methods study was to understand opinions and interests in developing and implementing a community garden and to understand factors impacting fruit, vegetable, and gardening behaviors. Community and academic members collaborated to develop and execute this study. The qualitative phase- targeting regional key informants-was designed to elicit perceived benefits and challenges of community gardens at the environmental, community, and individual levels. The quantitative phase targeted low resourced youth and parents and included a variety of validated theory-based questionnaires to understand factors impacting fruit, vegetable, and gardening behaviors. Major benefits of community gardens that emerged from the 10 qualitative interviews included increasing community cohesion and improving nutrition and physical activity factors. The quantitative phase included 87 youth and 67 parents. Across 16 items for fruits and vegetables, the average willingness to try was 1.32 (standard deviation [SD] = 0.40) on a 2-point scale. The majority of youth indicated they would work in a garden (n = 59; 68%) and eat food grown in their garden (n = 71; 82%). Among parents, gardening attitude, belief, and self-efficacy scores were all above average; however, gardening intentions were neutral. This research illustrates the successful partnering a community-academic team and has provided the partnership with a clearer lens to conceptualize and launch future regional community garden efforts.

  1. Averaging of phase noise in PSK signals by an opto-electrical feed-forward circuit

    NASA Astrophysics Data System (ADS)

    Inoue, K.; Ohta, M.

    2013-10-01

    This paper proposes an opto-electrical feed-forward circuit that reduces phase noise in binary PSK signals by averaging the noise. Random and independent phase noise is averaged over several bit slots by externally modulating a phase-fluctuating PSK signal with feed-forward signal obtained from signal processing of the outputs of delay interferometers. The simulation results demonstrate a reduction in the phase noise.

  2. Simulation of Two-Phase Flow Based on a Thermodynamically Constrained Averaging Theory Flow Model

    NASA Astrophysics Data System (ADS)

    Weigand, T. M.; Dye, A. L.; McClure, J. E.; Farthing, M. W.; Gray, W. G.; Miller, C. T.

    2014-12-01

    The thermodynamically constrained averaging theory (TCAT) has been used to formulate general classes of porous medium models, including new models for two-fluid-phase flow. The TCAT approach provides advantages that include a firm connection between the microscale, or pore scale, and the macroscale; a thermodynamically consistent basis; explicit inclusion of factors such as interfacial areas, contact angles, interfacial tension, and curvatures; and dynamics of interface movement and relaxation to an equilibrium state. In order to render the TCAT model solvable, certain closure relations are needed to relate fluid pressure, interfacial areas, curvatures, and relaxation rates. In this work, we formulate and solve a TCAT-based two-fluid-phase flow model. We detail the formulation of the model, which is a specific instance from a hierarchy of two-fluid-phase flow models that emerge from the theory. We show the closure problem that must be solved. Using recent results from high-resolution microscale simulations, we advance a set of closure relations that produce a closed model. Lastly, we use locally conservative spatial discretization and higher order temporal discretization methods to approximate the solution to this new model and compare the solution to the traditional model.

  3. Three-dimensional conformal radiotherapy by delineations on CT-based simulation in different respiratory phases for the treatment of senile patients with non-small cell lung cancer.

    PubMed

    Wang, Weifeng; Yuan, Feng; Wang, Guoping; Lin, Zhiren; Pan, Yanling; Chen, Longhua

    2015-01-01

    This study aimed to evaluate the application of three-dimensional conformal radiotherapy (3D-CRT) for elderly patients with non-small cell lung cancer (NSCLC) based on computed tomography (CT) simulations in different respiratory phases. A total of 64 patients aged >70 years old with NSCLC were treated by 3D-CRT using CT images in different respiratory phases. The gross tumor volumes (GTVs) at the end of inspiration and end of expiration were combined to obtain the total GTV, which was close to the motional range of tumors during respiration, and no additional expansion of the clinical target volume (CTAV) to planning target volume (PTV) (CTAV:PTV) was included during the recording of respiratory movements. Patients were also planned according to the classic 3D-CRT approach. Efficacy, prognostic factors, and side effects were evaluated. Compared with the classic approach, the average PTV was 18.9% lower (median: 17.3%), and the average lung volume receiving a prescribed dose for a tumor was 22.4% lower (median: 20.9%). The 1-, 2-, and 3-year survival rates were 70.6%, 54.9%, and 29.4%, respectively, with an overall tumor response rate of 79.7%. The Karnofsky performance status and N stage were independent prognostic factors, whereas age was not. Without affecting therapeutic effects, CT simulations in different respiratory phases were well-tolerated in elderly patients with NSCLC, could effectively reduce PTV, and could improve the quality of life.

  4. Flow measurement behind a pair of vertical-axis wind turbines

    NASA Astrophysics Data System (ADS)

    Parker, Colin M.; Hummels, Raymond; Leftwich, Megan C.

    2017-11-01

    The wake from a pair of vertical-axis wind turbines (VAWTs) is measured using particle imaging velocimetry (PIV). The VAWT models are mounted in a low-speed wind tunnel and driven using a motor control system. The rotation of the turbines is synced using a proportional controller that allows the turbine's rotational position to be set relative to each other. The rotation of the turbines is also synced with the PIV system for taking phase averaged results. The VAWTs are tested for both co- and counter-rotating cases over a range of relative phase offsets. Time averaged and phase averaged results are measured at the horizontal mid-plane in the near wake. The time-averaged results compare the bulk wake profiles from the pair of turbines. Phase averaged results look at the vortex interactions in the near wake of the turbines. By changing the phase relation between the turbines we can see the impact of the structure interactions in both the phase and time averaged results.

  5. Emission rates of regulated pollutants from on-road heavy-duty diesel vehicles

    NASA Astrophysics Data System (ADS)

    Shah, Sandip D.; Johnson, Kent C.; Wayne Miller, J.; Cocker, David R.

    Emissions from heavy-duty diesel (HDD) vehicles are affected by many factors. Changes in engine technology, operating mode, fuel properties, vehicle speed and ambient conditions can have significant effects on emission rates of regulated species. This paper presents the results of on-road emissions testing of 11 HDD vehicles (model years 1996-2000) over the ARB Four Phase driving schedule and the urban dynamometer driving schedule (UDDS). Emission rates were found to be highly dependent on vehicle operating mode. Per mile NO x emission rates for vehicle operation at low speeds, in simulated congested traffic, were three times higher per mile emissions then while cruising on the freeway. Comparisons of NO x emission factors to EMFAC baseline emission factors were within 5-40% for vehicles of various model years tested over the UDDS. A comparison of NO x emission factors for a weighted average of the ARB four phase driving schedule yielded values within 17-57% of EMFAC values. Generally, particulate matter (PM) emission rates were lower than EMFAC values.

  6. Experimental study of the oscillating flow characteristics for a regenerator in a pulse tube cryocooler

    NASA Astrophysics Data System (ADS)

    Ju, Yonglin; Jiang, Yan; Zhou, Yuan

    A dynamic experimental apparatus was designed and constructed to investigate oscillating flow characteristics in a regenerator subjected to a periodically reversing flow established by means of a self-made linear compressor. Detailed experimental data of oscillating pressure drops and phase shift characteristics for regenerators in a high frequency pulse tube cryocooler with an operating frequency of 50 Hz were given. The correlation equations for the maximum and cycle-averaged friction factors in terms of Reynolds numbers and dimensionless distance X were obtained. It was found that the value of the cycle-averaged pressure drop in the oscillating flow across the regenerator is two to three times higher than that of a steady flow at the same Reynolds numbers based on the cross-sectional mean velocity. In addition, the relationship of the phase shifts between the velocity and pressure wave is also discussed.

  7. Identifying ontogenetic, environmental and individual components of forest tree growth

    PubMed Central

    Chaubert-Pereira, Florence; Caraglio, Yves; Lavergne, Christian; Guédon, Yann

    2009-01-01

    Background and Aims This study aimed to identify and characterize the ontogenetic, environmental and individual components of forest tree growth. In the proposed approach, the tree growth data typically correspond to the retrospective measurement of annual shoot characteristics (e.g. length) along the trunk. Methods Dedicated statistical models (semi-Markov switching linear mixed models) were applied to data sets of Corsican pine and sessile oak. In the semi-Markov switching linear mixed models estimated from these data sets, the underlying semi-Markov chain represents both the succession of growth phases and their lengths, while the linear mixed models represent both the influence of climatic factors and the inter-individual heterogeneity within each growth phase. Key Results On the basis of these integrative statistical models, it is shown that growth phases are not only defined by average growth level but also by growth fluctuation amplitudes in response to climatic factors and inter-individual heterogeneity and that the individual tree status within the population may change between phases. Species plasticity affected the response to climatic factors while tree origin, sampling strategy and silvicultural interventions impacted inter-individual heterogeneity. Conclusions The transposition of the proposed integrative statistical modelling approach to cambial growth in relation to climatic factors and the study of the relationship between apical growth and cambial growth constitute the next steps in this research. PMID:19684021

  8. A new method to detect event-related potentials based on Pearson's correlation.

    PubMed

    Giroldini, William; Pederzoli, Luciano; Bilucaglia, Marco; Melloni, Simone; Tressoldi, Patrizio

    2016-12-01

    Event-related potentials (ERPs) are widely used in brain-computer interface applications and in neuroscience.  Normal EEG activity is rich in background noise, and therefore, in order to detect ERPs, it is usually necessary to take the average from multiple trials to reduce the effects of this noise.  The noise produced by EEG activity itself is not correlated with the ERP waveform and so, by calculating the average, the noise is decreased by a factor inversely proportional to the square root of N , where N is the number of averaged epochs. This is the easiest strategy currently used to detect ERPs, which is based on calculating the average of all ERP's waveform, these waveforms being time- and phase-locked.  In this paper, a new method called GW6 is proposed, which calculates the ERP using a mathematical method based only on Pearson's correlation. The result is a graph with the same time resolution as the classical ERP and which shows only positive peaks representing the increase-in consonance with the stimuli-in EEG signal correlation over all channels.  This new method is also useful for selectively identifying and highlighting some hidden components of the ERP response that are not phase-locked, and that are usually hidden in the standard and simple method based on the averaging of all the epochs.  These hidden components seem to be caused by variations (between each successive stimulus) of the ERP's inherent phase latency period (jitter), although the same stimulus across all EEG channels produces a reasonably constant phase. For this reason, this new method could be very helpful to investigate these hidden components of the ERP response and to develop applications for scientific and medical purposes. Moreover, this new method is more resistant to EEG artifacts than the standard calculations of the average and could be very useful in research and neurology.  The method we are proposing can be directly used in the form of a process written in the well-known Matlab programming language and can be easily and quickly written in any other software language.

  9. Lyra’s cosmology of hybrid universe in Bianchi-V space-time

    NASA Astrophysics Data System (ADS)

    Yadav, Anil Kumar; Bhardwaj, Vinod Kumar

    2018-06-01

    In this paper we have searched for the existence of Lyra’s cosmology in a hybrid universe with minimal interaction between dark energy and normal matter using Bianchi-V space-time. To derive the exact solution, the average scale factor is taken as a={({t}n{e}kt)}\\frac{1{m}} which describes the hybrid nature of the scale factor and generates a model of the transitioning universe from the early deceleration phase to the present acceleration phase. The quintessence model makes the matter content of the derived universe remarkably able to satisfy the null, dominant and strong energy condition. It has been found that the time varying displacement β(t) co-relates with the nature of cosmological constant Λ(t). We also discuss some physical and geometrical features of the universe.

  10. Incoherent averaging of phase singularities in speckle-shearing interferometry.

    PubMed

    Mantel, Klaus; Nercissian, Vanusch; Lindlein, Norbert

    2014-08-01

    Interferometric speckle techniques are plagued by the omnipresence of phase singularities, impairing the phase unwrapping process. To reduce the number of phase singularities by physical means, an incoherent averaging of multiple speckle fields may be applied. It turns out, however, that the results may strongly deviate from the expected √N behavior. Using speckle-shearing interferometry as an example, we investigate the mechanism behind the reduction of phase singularities, both by calculations and by computer simulations. Key to an understanding of the reduction mechanism during incoherent averaging is the representation of the physical averaging process in terms of certain vector fields associated with each speckle field.

  11. Edge localized mode characteristics during edge localized mode mitigation by supersonic molecular beam injection in Korea Superconducting Tokamak Advanced Research

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, H. Y.; Hong, J. H.; Jang, J. H.

    It has been reported that supersonic molecular beam injection (SMBI) is an effective means of edge localized mode (ELM) mitigation. This paper newly reports the changes in the ELM, plasma profiles, and fluctuation characteristics during ELM mitigation by SMBI in Korea Superconducting Tokamak Advanced Research. During the mitigated ELM phase, the ELM frequency increased by a factor of 2–3 and the ELM size, which was estimated from the D{sub α} amplitude, the fractional changes in the plasma-stored energy and the line-averaged electron density, and divertor heat flux during an ELM burst, decreased by a factor of 0.34–0.43. Reductions in themore » electron and ion temperatures rather than in the electron density were observed during the mitigated ELM phase. In the natural ELM phase, frequency chirping of the plasma fluctuations was observed before the ELM bursts; however, the ELM bursts occurred without changes in the plasma fluctuation frequency in the mitigated ELM phase.« less

  12. Crystal structure of a birefringent andradite-grossular from Crowsnest Pass, Alberta, Canada

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Antao, Sytle M.; Klincker, Allison M.

    2014-02-20

    The structure of a birefringent andradite–grossular sample was refined using single-crystal X-ray diffraction (SCD) and synchrotron high-resolution powder X-ray diffraction (HRPXRD) data. Electron-microprobe results indicate a homogeneous composition of {Ca 2.88Mn 2+ 0.06Mg 0.04Fe 2+ 0.03} Σ3[Fe 3+ 1.29Al 0.49Ti 4+ 0.17Fe 2+ 0.06] Σ2(Si 2.89Al 0.11) Σ3O 12. The Rietveld refinement reduced χ 2 = 1.384 and overall R (F 2) = 0.0315. The HRPXRD data show that the sample contains three phases. For phase-1, the weight %, unit-cell parameter (Å), distances (Å), and site occupancy factor (sof) are 62.85(7)%, a = 12.000 06(2), average = 2.4196, Fe–O =more » 1.9882(5), Si–O = 1.6542(6) Å, Ca(sof) = 0.970(2), Fe(sof) = 0.763(1), and Si(sof) = 0.954(2). The corresponding data for phase-2 are 19.14(9)%, a = 12.049 51(2), average = 2.427, Fe–O = 1.999(1), Si–O = 1.665(1) Å, Ca(sof) = 0.928(4), Fe(sof) = 0.825(3), and Si(sof) = 0.964(4). The corresponding data for phase-3 are 18.01(9)%, a = 12.019 68(3), average = 2.424, Fe–O = 1.992(2), Si–O = 1.658(2) Å, Ca(sof) = 0.896(5), Fe(sof) = 0.754(4), and Si(sof) = 0.936(5). The fine-scale coexistence of the three phases causes strain that arises from the unit-cell and bond distances differences, and gives rise to strain-induced birefringence. The results from the SCD are similar to the dominant phase-1 obtained by the HRPXRD, but the SCD misses the minor phases.« less

  13. Anomalous amplification of a homodyne signal via almost-balanced weak values.

    PubMed

    Liu, Wei-Tao; Martínez-Rincón, Julián; Viza, Gerardo I; Howell, John C

    2017-03-01

    We propose precision measurements of ultra-small angular velocities of a mirror within a modified Sagnac interferometer, where the counter-propagating beams are spatially separated, using the recently proposed technique of almost-balanced weak values amplification (ABWV) [Phys. Rev. Lett.116, 100803 (2016)PRLTAO0031-900710.1103/PhysRevLett.116.100803]. The separation between the two beams provides additional amplification with respect to using collinear beams in a Sagnac interferometer. Within the same setup, the weak-value amplification technique is also performed for comparison. Much higher amplification factors can be obtained using the almost-balanced weak values technique, with the best one achieved in our experiments being as high as 1.2×107. In addition, the amplification factor monotonically increases with decreasing of the post-selection phase for the ABWV case in our experiments, which is not the case for weak-value amplification (WVA) at small post-selection phases. Both techniques consist of measuring the angular velocity. The sensitivity of the ABWV technique is ∼38  nrad/s per averaged pulse for a repetition rate of 1 Hz and ∼33  nrad/s per averaged pulse for the WVA technique.

  14. Controlling the length scale and distribution of the ductile phase in metallic glass composites through friction stir processing

    PubMed Central

    Arora, Harpreet Singh; Mridha, Sanghita; Grewal, Harpreet Singh; Singh, Harpreet; Hofmann, Douglas C; Mukherjee, Sundeep

    2014-01-01

    We demonstrate the refinement and uniform distribution of the crystalline dendritic phase by friction stir processing (FSP) of titanium based in situ ductile-phase reinforced metallic glass composite. The average size of the dendrites was reduced by almost a factor of five (from 24 μm to 5 μm) for the highest tool rotational speed of 900 rpm. The large inter-connected dendrites become more fragmented with increased circularity after processing. The changes in thermal characteristics were measured by differential scanning calorimetry. The reduction in crystallization enthalpy after processing suggests partial devitrification due to the high strain plastic deformation. FSP resulted in increased hardness and modulus for both the amorphous matrix and the crystalline phase. This is explained by interaction of shear bands in amorphous matrix with the strain-hardened dendritic phase. Our approach offers a new strategy for microstructural design in metallic glass composites. PMID:27877687

  15. Controlling the length scale and distribution of the ductile phase in metallic glass composites through friction stir processing.

    PubMed

    Arora, Harpreet Singh; Mridha, Sanghita; Grewal, Harpreet Singh; Singh, Harpreet; Hofmann, Douglas C; Mukherjee, Sundeep

    2014-06-01

    We demonstrate the refinement and uniform distribution of the crystalline dendritic phase by friction stir processing (FSP) of titanium based in situ ductile-phase reinforced metallic glass composite. The average size of the dendrites was reduced by almost a factor of five (from 24 μ m to 5 μ m) for the highest tool rotational speed of 900 rpm. The large inter-connected dendrites become more fragmented with increased circularity after processing. The changes in thermal characteristics were measured by differential scanning calorimetry. The reduction in crystallization enthalpy after processing suggests partial devitrification due to the high strain plastic deformation. FSP resulted in increased hardness and modulus for both the amorphous matrix and the crystalline phase. This is explained by interaction of shear bands in amorphous matrix with the strain-hardened dendritic phase. Our approach offers a new strategy for microstructural design in metallic glass composites.

  16. Factors controlling the geochemical evolution of fumarolic encrustations, Valley of Ten Thousand Smokes, Alaska

    USGS Publications Warehouse

    Kodosky, L.G.; Keith, T.E.C.

    1993-01-01

    Factor and canonical correlation analysis of geochemical data from eight fossil fumaroles suggest that six major factors controlled the formation and evolution of fumarolic encrustations on the 1912 ash-flow sheet in the Valley of Ten Thousand Smokes (VTTS). The six-factor solution model explains a large proportion (low of 74% for Ni to high of 99% for Si) of the individual element data variance. Although the primary fumarolic deposits have been degraded by secondary alteration reactions and up to 75 years of weathering, the relict encrustations still preserve a signature of vapor-phase element transport. This vapor-phase transport probably occurred as halide or oxyhalide species and was significant for As, Sb and Br. At least three, and possibly four, varied temperature leaching events affected the fumarolic deposits. High-temperature gases/liquids heavily altered the ejecta glass and mineral phases adjacent to the fumarolic conduit. As the fumaroles cooled. Fe-rich acidic condensate leached the ejecta and primary fumarolic deposits and resulted in the subsequent precipitation of Fe-hydroxides and/or Fe-oxides. Low- to ambient-temperature leaching and hydration reactions generated abundant hydrated amorphous phases. Up to 87% of the individual element data variance is apparently controlled by the chemistry of the ejecta on which the relict encrustations are found. This matrix chemistry factor illustrates that the primary fumarolic minerals surrounding the active VTTS vents observed by earlier workers have been effectively removed by the dissolution reactions. Element enrichment factors calculated for the VTTS relict encrustations support the statistical factor interpretations. On the average, the relict encrustations are enriched, relative to visibly unaltered matrix protolith, in As, Br, Cr, Sb, Cu, Ni, Pb, Fe, and LOI (an indirect measure of sample H2O content). ?? 1993.

  17. A Real-Time Phase Vector Display for EEG Monitoring

    NASA Technical Reports Server (NTRS)

    Finger, Herbert J.; Anliker, James E.; Rimmer, Tamara

    1973-01-01

    A real-time, computer-based, phase vector display system has been developed which will output a vector whose phase is equal to the delay between a trigger and the peak of a function which is quasi-coherent with respect to the trigger. The system also contains a sliding averager which enables the operator to average successive trials before calculating the phase vector. Data collection, averaging and display generation are performed on a LINC-8 computer. Output displays appear on several X-Y CRT display units and on a kymograph camera/oscilloscope unit which is used to generate photographs of time-varying phase vectors or contourograms of time-varying averages of input functions.

  18. [Survival time of HIV/AIDS cases and related factors in Beijing, 1995-2015].

    PubMed

    Li, Y; Wang, J; He, S F; Chen, J; Lu, H Y

    2017-11-10

    Objective: To analyze the survival time of HIV/AIDS cases and related factors in Beijing from 1995 to 2015. Methods: A retrospective cohort study was conducted to analyze the data of 12 874 HIV/AIDS cases. The data were collected from Chinese HIV/AIDS Comprehensive Information Management System. Life table method was applied to calculate the survival proportion, and Cox proportion hazard regression model were used to identify the factors related with survival time. Results: Among 12 874 HIV/AIDS cases, 303 (2.4%) died of AIDS related diseases; 9 346 (72.6%) received antiretroviral therapy. The average survival time was 226.5 months (95 %CI : 223.0-230.1), and the survival rates of 1, 5, 10, and 15 years were 98.2%, 96.4%, 93.2%, and 91.9% respectively. Multivariate Cox proportion hazard regression model showed that AIDS phase ( HR =1.439, 95 %CI : 1.041-1.989), heterosexual transmission ( HR =1.646, 95 %CI : 1.184-2.289), being married ( HR =2.186, 95 %CI : 1.510-3.164); older age (≥60 years) at diagnosis ( HR =6.608, 95 %CI : 3.546-12.316); lower CD(4)(+)T cell counts at diagnosis (<350 cells/μl) ( HR =8.711, 95 %CI : 5.757-13.181); receiving no antiretroviral therapy (ART) ( HR =18.223, 95 %CI : 13.317-24.937) were the high risk factors influencing the survival of AIDS patients compared with HIV phase, homosexual transmission, being unmarried, younger age (≤30 years), higher CD(4)(+)T cell count (≥350 cell/μl) and receiving ART. Conclusion: The average survival time of HIV/AIDS cases was 226.5 months after diagnoses. Receiving ART, higher CD(4)(+)T cell counts at the first test, HIV phase, younger age, being unmarried and the homosexual transmission were related to the longer survival time of HIV/AIDS cases. Receiving no ART, the lower CD(4)(+)T cell counts at the first test, AIDS phase, older age, being married and heterosexual transmission indicated higher risk of death due to AIDS.

  19. Quasi-static finite element modeling of seismic attenuation and dispersion due to wave-induced fluid flow in poroelastic media

    NASA Astrophysics Data System (ADS)

    Quintal, Beatriz; Steeb, Holger; Frehner, Marcel; Schmalholz, Stefan M.

    2011-01-01

    The finite element method is used to solve Biot's equations of consolidation in the displacement-pressure (u - p) formulation. We compute one-dimensional (1-D) and two-dimensional (2-D) numerical quasi-static creep tests with poroelastic media exhibiting mesoscopic-scale heterogeneities to calculate the complex and frequency-dependent P wave moduli from the modeled stress-strain relations. The P wave modulus is used to calculate the frequency-dependent attenuation (i.e., inverse of quality factor) and phase velocity of the medium. Attenuation and velocity dispersion are due to fluid flow induced by pressure differences between regions of different compressibilities, e.g., regions (or patches) saturated with different fluids (i.e., so-called patchy saturation). Comparison of our numerical results with analytical solutions demonstrates the accuracy and stability of the algorithm for a wide range of frequencies (six orders of magnitude). The algorithm employs variable time stepping and an unstructured mesh which make it efficient and accurate for 2-D simulations in media with heterogeneities of arbitrary geometries (e.g., curved shapes). We further numerically calculate the quality factor and phase velocity for 1-D layered patchy saturated porous media exhibiting random distributions of patch sizes. We show that the numerical results for the random distributions can be approximated using a volume average of White's analytical solution and the proposed averaging method is, therefore, suitable for a fast and transparent prediction of both quality factor and phase velocity. Application of our results to frequency-dependent reflection coefficients of hydrocarbon reservoirs indicates that attenuation due to wave-induced flow can increase the reflection coefficient at low frequencies, as is observed at some reservoirs.

  20. Submicron particle mass concentrations and sources in the Amazonian wet season (AMAZE-08)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Q.; Farmer, D. K.; Rizzo, L. V.

    Real-time mass spectra of non-refractory component of submicron aerosol particles were recorded in a tropical rainforest in the central Amazon basin during the wet season of 2008, as a part of the Amazonian Aerosol Characterization Experiment (AMAZE-08). Organic components accounted on average for more than 80% of the non-refractory submicron particle mass concentrations during the period of measurements. Ammonium was present in sufficient quantities to halfway neutralize sulfate. In this acidic, isoprene-dominated, low-NOx environment the high-resolution mass spectra as well as mass closures with ion chromatography measurements did not provide evidence for significant contributions of organosulfate species, at least atmore » concentrations above uncertainty levels. Positive-matrix factorization of the time series of particle mass spectra identified four statistical factors to account for the variance of the signal intensities of the organic constituents: a factor HOA having a hydrocarbon-like signature and identified as regional emissions of primary organic material, a factor OOA-1 associated with fresh production of secondary organic material by a mechanism of BVOC oxidation followed by gas-to-particle conversion, a factor OOA-2 consistent with reactive uptake of isoprene oxidation products, especially epoxydiols by acidic particles, and a factor OOA-3 associated with long range transport and atmospheric aging. The OOA-1, -2, and -3 factors had progressively more oxidized signatures. Diameter-resolved mass spectral markers also suggested enhanced reactive uptake of isoprene oxidation products to the accumulation mode for the OOA-2 factor, and such size partitioning can be indicative of in-cloud process. The campaign-average factor loadings were in a ratio of 1.1:1.0 for the OOA-1 compared to the OOA-2 pathway, suggesting the comparable importance of gas-phase compared to particle-phase (including cloud waters) production pathways of secondary organic material during the study period.« less

  1. Ab initio phasing by molecular averaging in real space with new criteria: application to structure determination of a betanodavirus.

    PubMed

    Yoshimura, Masato; Chen, Nai Chi; Guan, Hong Hsiang; Chuankhayan, Phimonphan; Lin, Chien Chih; Nakagawa, Atsushi; Chen, Chun Jung

    2016-07-01

    Molecular averaging, including noncrystallographic symmetry (NCS) averaging, is a powerful method for ab initio phase determination and phase improvement. Applications of the cross-crystal averaging (CCA) method have been shown to be effective for phase improvement after initial phasing by molecular replacement, isomorphous replacement, anomalous dispersion or combinations of these methods. Here, a two-step process for phase determination in the X-ray structural analysis of a new coat protein from a betanodavirus, Grouper nervous necrosis virus, is described in detail. The first step is ab initio structure determination of the T = 3 icosahedral virus-like particle using NCS averaging (NCSA). The second step involves structure determination of the protrusion domain of the viral molecule using cross-crystal averaging. In this method, molecular averaging and solvent flattening constrain the electron density in real space. To quantify these constraints, a new, simple and general indicator, free fraction (ff), is introduced, where ff is defined as the ratio of the volume of the electron density that is freely changed to the total volume of the crystal unit cell. This indicator is useful and effective to evaluate the strengths of both NCSA and CCA. Under the condition that a mask (envelope) covers the target molecule well, an ff value of less than 0.1, as a new rule of thumb, gives sufficient phasing power for the successful construction of new structures.

  2. Pulsed Accretion in the T Tauri Binary TWA 3A

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tofflemire, Benjamin M.; Mathieu, Robert D.; Herczeg, Gregory J.

    TWA 3A is the most recent addition to a small group of young binary systems that both actively accrete from a circumbinary disk and have spectroscopic orbital solutions. As such, it provides a unique opportunity to test binary accretion theory in a well-constrained setting. To examine TWA 3A’s time-variable accretion behavior, we have conducted a two-year, optical photometric monitoring campaign, obtaining dense orbital phase coverage (∼20 observations per orbit) for ∼15 orbital periods. From U -band measurements we derive the time-dependent binary mass accretion rate, finding bursts of accretion near each periastron passage. On average, these enhanced accretion events evolvemore » over orbital phases 0.85 to 1.05, reaching their peak at periastron. The specific accretion rate increases above the quiescent value by a factor of ∼4 on average but the peak can be as high as an order of magnitude in a given orbit. The phase dependence and amplitude of TWA 3A accretion is in good agreement with numerical simulations of binary accretion with similar orbital parameters. In these simulations, periastron accretion bursts are fueled by periodic streams of material from the circumbinary disk that are driven by the binary orbit. We find that TWA 3A’s average accretion behavior is remarkably similar to DQ Tau, another T Tauri binary with similar orbital parameters, but with significantly less variability from orbit to orbit. This is only the second clear case of orbital-phase-dependent accretion in a T Tauri binary.« less

  3. Modeling the solid-liquid phase transition in saturated triglycerides

    NASA Astrophysics Data System (ADS)

    Pink, David A.; Hanna, Charles B.; Sandt, Christophe; MacDonald, Adam J.; MacEachern, Ronald; Corkery, Robert; Rousseau, Dérick

    2010-02-01

    We investigated theoretically two competing published scenarios for the melting transition of the triglyceride trilaurin (TL): those of (1) Corkery et al. [Langmuir 23, 7241 (2007)], in which the average state of each TL molecule in the liquid phase is a discotic "Y" conformer whose three chains are dynamically twisted, with an average angle of ˜120° between them, and those of (2) Cebula et al. [J. Am. Oil Chem. Soc. 69, 130 (1992)], in which the liquid-state conformation of the TL molecule in the liquid phase is a nematic h∗-conformer whose three chains are in a modified "chair" conformation. We developed two competing models for the two scenarios, in which TL molecules are in a nematic compact-chair (or "h") conformation, with extended, possibly all-trans, chains at low-temperatures, and in either a Y conformation or an h∗ conformation in the liquid state at temperatures higher than the phase-transition temperature, T∗=319 K. We defined an h-Y model as a realization of the proposal of Corkery et al. [Langmuir 23, 7241 (2007)], and explored its predictions by mapping it onto an Ising model in a temperature-dependent field, performing a mean-field approximation, and calculating the transition enthalpy ΔH. We found that the most plausible realization of the h-Y model, as applied to the solid-liquid phase transition in TL, and likely to all saturated triglycerides, gave a value of ΔH in reasonable agreement with the experiment. We then defined an alternative h-h∗ model as a realization of the proposal of Cebula et al. [J. Am. Oil Chem. Soc. 69, 130 (1992)], in which the liquid phase exhibits an average symmetry breaking similar to an h conformation, but with twisted chains, to see whether it could describe the TL phase transition. The h-h∗ model gave a value of ΔH that was too small by a factor of ˜3-4. We also predicted the temperature dependence of the 1132 cm-1 Raman band for both models, and performed measurements of the ratios of three TL Raman bands in the temperature range of -20 °C≤T ≤90 °C. The experimental results were in accord with the predictions of the h-Y model and support the proposal of Corkery et al. [Langmuir 23, 7241 (2007)] that the liquid state is made up of molecules that are each, on average, in a Y conformation. Finally, we carried out computer simulations of minimal-model TLs in the liquid phase, and concluded that although the individual TL molecules are, on average, Y conformers, long-range discotic order is unlikely to exist.

  4. The fundamentals of average local variance--Part II: Sampling simple regular patterns with optical imagery.

    PubMed

    Bøcher, Peder Klith; McCloy, Keith R

    2006-02-01

    In this investigation, the characteristics of the average local variance (ALV) function is investigated through the acquisition of images at different spatial resolutions of constructed scenes of regular patterns of black and white squares. It is shown that the ALV plot consistently peaks at a spatial resolution in which the pixels has a size corresponding to half the distance between scene objects, and that, under very specific conditions, it also peaks at a spatial resolution in which the pixel size corresponds to the whole distance between scene objects. It is argued that the peak at object distance when present is an expression of the Nyquist sample rate. The presence of this peak is, hence, shown to be a function of the matching between the phase of the scene pattern and the phase of the sample grid, i.e., the image. When these phases match, a clear and distinct peak is produced on the ALV plot. The fact that the peak at half the distance consistently occurs in the ALV plot is linked to the circumstance that the sampling interval (distance between pixels) and the extent of the sampling unit (size of pixels) are equal. Hence, at twice the Nyquist sampling rate, each fundamental period of the pattern is covered by four pixels; therefore, at least one pixel is always completely embedded within one pattern element, regardless of sample scene phase. If the objects in the scene are scattered with a distance larger than their extent, the peak will be related to the size by a factor larger than 1/2. This is suggested to be the explanation to the results presented by others that the ALV plot is related to scene-object size by a factor of 1/2-3/4.

  5. [Analysis of the preferred conformations and determination of the concentrations of ephedrine and pseudoephedrine based on hollow fiber liquid-phase microextraction].

    PubMed

    Chen, Xuan; Bai, Xiaohong; Wang, Xiao; Wang, Jing; Bu, Wei

    2010-12-01

    The preferred conformations of the ephedrine and pseudoephedrine in Ephedra sinica Stapf and rat urine were analyzed by the hollow fiber liquid-phase microextraction (HF-LPME) and their extraction mechanisms were illuminated. The method of the separation of the ephedrine and pseudoephedrine and the determination of their concentrations with high performance liquid chromatography (HPLC) were established. The optimal experimental conditions were as follows: the organic phase carrier was the hollow fiber of polyvinylidene fluoride (MOF-503), organic solvent was n-hexanol, the extraction time was 35 min, the stirring rate was 1200 r/min, the sample phase was the NaOH solution (5 mol/L) of the analyte, the acceptor was 0.01 mol/L H2SO4 solution. The extracts were analyzed by HPLC. Under the optimal conditions, the method is convenient and highly sensitive. In Ephedra sinica Stapf, the linear ranges of ephedrine and pseudoephedrine were 5-100 microg/L, the detection limits were 1.9 microg/L and 1.2 microg/L and the enrichment factors were 38 and 61, respectively. The average recoveries of ephedrine and pseudoephedrine were 100.6% +/- 1.2% and 103.2% +/- 3.5%, respectively. In rat urine, their linear ranges were 100 - 5 x 10(4) microg/L, the detection limits were 30 microg/L and 42 microg/L and the enrichment factors were 20 and 17, respectively. In rat urine, their average recoveries were 108.4% +/- 4.4% and 106. 1% +/- 5.4%, respectively. The obtained results indicated that the method can be successfully applied for the extraction and determination of the ephedrine and pseudoephedrine in Ephedra sinica Stapf and rat urine.

  6. Machine protection system for rotating equipment and method

    DOEpatents

    Lakshminarasimha, Arkalgud N.; Rucigay, Richard J.; Ozgur, Dincer

    2003-01-01

    A machine protection system and method for rotating equipment introduces new alarming features and makes use of full proximity probe sensor information, including amplitude and phase. Baseline vibration amplitude and phase data is estimated and tracked according to operating modes of the rotating equipment. Baseline vibration and phase data can be determined using a rolling average and variance and stored in a unit circle or tracked using short term average and long term average baselines. The sensed vibration amplitude and phase is compared with the baseline vibration amplitude and phase data. Operation of the rotating equipment can be controlled based on the vibration amplitude and phase.

  7. Real-time emission factor measurements of isocyanic acid from light duty gasoline vehicles.

    PubMed

    Brady, James M; Crisp, Timia A; Collier, Sonya; Kuwayama, Toshihiro; Forestieri, Sara D; Perraud, Véronique; Zhang, Qi; Kleeman, Michael J; Cappa, Christopher D; Bertram, Timothy H

    2014-10-07

    Exposure to gas-phase isocyanic acid (HNCO) has been previously shown to be associated with the development of atherosclerosis, cataracts and rheumatoid arthritis. As such, accurate emission inventories for HNCO are critical for modeling the spatial and temporal distribution of HNCO on a regional and global scale. To date, HNCO emission rates from light duty gasoline vehicles, operated under driving conditions, have not been determined. Here, we present the first measurements of real-time emission factors of isocyanic acid from a fleet of eight light duty gasoline-powered vehicles (LDGVs) tested on a chassis dynamometer using the Unified Driving Cycle (UC) at the California Air Resources Board (CARB) Haagen-Smit test facility, all of which were equipped with three-way catalytic converters. HNCO emissions were observed from all vehicles, in contrast to the idealized laboratory measurements. We report the tested fleet averaged HNCO emission factors, which depend strongly on the phase of the drive cycle; ranging from 0.46 ± 0.13 mg kg fuel(-1) during engine start to 1.70 ± 1.77 mg kg fuel(-1) during hard acceleration after the engine and catalytic converter were warm. The tested eight-car fleet average fuel based HNCO emission factor was 0.91 ± 0.58 mg kg fuel(-1), within the range previously estimated for light duty diesel-powered vehicles (0.21-3.96 mg kg fuel(-1)). Our results suggest that HNCO emissions from LDGVs represent a significant emission source in urban areas that should be accounted for in global and regional models.

  8. Pattern, growth, and aging in aggregation kinetics of a Vicsek-like active matter model

    NASA Astrophysics Data System (ADS)

    Das, Subir K.

    2017-01-01

    Via molecular dynamics simulations, we study kinetics in a Vicsek-like phase-separating active matter model. Quantitative results, for isotropic bicontinuous pattern, are presented on the structure, growth, and aging. These are obtained via the two-point equal-time density-density correlation function, the average domain length, and the two-time density autocorrelation function. Both the correlation functions exhibit basic scaling properties, implying self-similarity in the pattern dynamics, for which the average domain size exhibits a power-law growth in time. The equal-time correlation has a short distance behavior that provides reasonable agreement between the corresponding structure factor tail and the Porod law. The autocorrelation decay is a power-law in the average domain size. Apart from these basic similarities, the overall quantitative behavior of the above-mentioned observables is found to be vastly different from those of the corresponding passive limit of the model which also undergoes phase separation. The functional forms of these have been quantified. An exceptionally rapid growth in the active system occurs due to fast coherent motion of the particles, mean-squared-displacements of which exhibit multiple scaling regimes, including a long time ballistic one.

  9. Ab initio phasing by molecular averaging in real space with new criteria: application to structure determination of a betanodavirus

    PubMed Central

    Yoshimura, Masato; Chen, Nai-Chi; Guan, Hong-Hsiang; Chuankhayan, Phimonphan; Lin, Chien-Chih; Nakagawa, Atsushi; Chen, Chun-Jung

    2016-01-01

    Molecular averaging, including noncrystallographic symmetry (NCS) averaging, is a powerful method for ab initio phase determination and phase improvement. Applications of the cross-crystal averaging (CCA) method have been shown to be effective for phase improvement after initial phasing by molecular replacement, isomorphous replacement, anomalous dispersion or combinations of these methods. Here, a two-step process for phase determination in the X-ray structural analysis of a new coat protein from a betanodavirus, Grouper nervous necrosis virus, is described in detail. The first step is ab initio structure determination of the T = 3 icosahedral virus-like particle using NCS averaging (NCSA). The second step involves structure determination of the protrusion domain of the viral molecule using cross-crystal averaging. In this method, molecular averaging and solvent flattening constrain the electron density in real space. To quantify these constraints, a new, simple and general indicator, free fraction (ff), is introduced, where ff is defined as the ratio of the volume of the electron density that is freely changed to the total volume of the crystal unit cell. This indicator is useful and effective to evaluate the strengths of both NCSA and CCA. Under the condition that a mask (envelope) covers the target molecule well, an ff value of less than 0.1, as a new rule of thumb, gives sufficient phasing power for the successful construction of new structures. PMID:27377380

  10. Electromagnetic Charge Radius of the Pion at High Precision

    NASA Astrophysics Data System (ADS)

    Ananthanarayan, B.; Caprini, Irinel; Das, Diganta

    2017-09-01

    We present a determination of the pion charge radius from high precision data on the pion vector form factor from both timelike and spacelike regions, using a novel formalism based on analyticity and unitarity. At low energies, instead of the poorly known modulus of the form factor, we use its phase, known with high accuracy from Roy equations for π π elastic scattering via the Fermi-Watson theorem. We use also the values of the modulus at several higher timelike energies, where the data from e+e- annihilation and τ decay are mutually consistent, as well as the most recent measurements at spacelike momenta. The experimental uncertainties are implemented by Monte Carlo simulations. The results, which do not rely on a specific parametrization, are optimal for the given input information and do not depend on the unknown phase of the form factor above the first inelastic threshold. Our prediction for the charge radius of the pion is rπ=(0.657 ±0.003 ) fm , which amounts to an increase in precision by a factor of about 2.7 compared to the Particle Data Group average.

  11. VAPOR-PHASE TRANSPORT OF TRICHLOROETHENE IN AN INTERMEDIATE-SCALE VADOSE-ZONE SYSTEM: RETENTION PROCESSES AND TRACER-BASED PREDICTION

    PubMed Central

    Costanza-Robinson, Molly S.; Carlson, Tyson D.; Brusseau, Mark L.

    2013-01-01

    Gas-phase miscible-displacement experiments were conducted using a large weighing lysimeter to evaluate retention processes for volatile organic compounds (VOCs) in water-unsaturated (vadoze-zone) systems, and to test the utility of gas-phase tracers for predicting VOC retardation. Trichloroethene (TCE) served as a model VOC, while trichlorofluoromethane (CFM) and heptane were used as partitioning tracers to independently characterize retention by water and the air-water interface, respectively. Retardation factors for TCE ranged between 1.9 and 3.5, depending on water content. The results indicate that dissolution into the bulk water was the primary retention mechanism for TCE under all conditions studied, contributing approximately two thirds of the total measured retention. Accumulation at the air-water interface comprised a significant fraction of the observed retention for all experiments, with an average contribution of approximately 24%. Sorption to the solid phase contributed approximately 10% to retention. Water contents and air-water interfacial areas estimated based on the CFM and heptane tracer data, respectively, were similar to independently measured values. Retardation factors for TCE predicted using the partitioning-tracer data were in reasonable agreement with the measured values. These results suggest that gas-phase tracer tests hold promise for characterizing the retention and transport of VOCs in the vadose-zone. PMID:23333418

  12. Onset of phase separation in the double perovskite oxide La2MnNiO6

    NASA Astrophysics Data System (ADS)

    Spurgeon, Steven R.; Sushko, Peter V.; Devaraj, Arun; Du, Yingge; Droubay, Timothy; Chambers, Scott A.

    2018-04-01

    Identification of kinetic and thermodynamic factors that control crystal nucleation and growth represents a central challenge in materials synthesis. Here we report that apparently defect-free growth of La2MnNiO6 (LMNO) thin films supported on SrTiO3 (STO) proceeds up to 1-5 nm, after which it is disrupted by precipitation of NiO phases. Local geometric phase analysis and ensemble-averaged x-ray reciprocal space mapping show no change in the film strain away from the interface, indicating that mechanisms other than strain relaxation induce the formation of the NiO phases. Ab initio simulations suggest that the electrostatic potential build-up associated with the polarity mismatch at the film-substrate interface promotes the formation of oxygen vacancies with increasing thickness. In turn, oxygen deficiency promotes the formation of Ni-rich regions, which points to the built-in potential as an additional factor that contributes to the NiO precipitation mechanisms. These results suggest that the precipitate-free region could be extended further by either incorporating dopants that suppress the built-in potential or by increasing the oxygen fugacity in order to suppress the formation of oxygen vacancies.

  13. Joint Inversion of Phase and Amplitude Data of Surface Waves for North American Upper Mantle

    NASA Astrophysics Data System (ADS)

    Hamada, K.; Yoshizawa, K.

    2015-12-01

    For the reconstruction of the laterally heterogeneous upper-mantle structure using surface waves, we generally use phase delay information of seismograms, which represents the average phase velocity perturbation along a ray path, while the amplitude information has been rarely used in the velocity mapping. Amplitude anomalies of surface waves contain a variety of information such as anelastic attenuation, elastic focusing/defocusing, geometrical spreading, and receiver effects. The effects of elastic focusing/defocusing are dependent on the second derivative of phase velocity across the ray path, and thus, are sensitive to shorter-wavelength structure than the conventional phase data. Therefore, suitably-corrected amplitude data of surface waves can be useful for improving the lateral resolution of phase velocity models. In this study, we collect a large-number of inter-station phase velocity and amplitude ratio data for fundamental-mode surface waves with a non-linear waveform fitting between two stations of USArray. The measured inter-station phase velocity and amplitude ratios are then inverted simultaneously for phase velocity maps and local amplification factor at receiver locations in North America. The synthetic experiments suggest that, while the phase velocity maps derived from phase data only reflect large-scale tectonic features, those from phase and amplitude data tend to exhibit better recovery of the strength of velocity perturbations, which emphasizes local-scale tectonic features with larger lateral velocity gradients; e.g., slow anomalies in Snake River Plain and Rio Grande Rift, where significant local amplification due to elastic focusing are observed. Also, the spatial distribution of receiver amplification factor shows a clear correlation with the velocity structure. Our results indicate that inter-station amplitude-ratio data can be of help in reconstructing shorter-wavelength structures of the upper mantle.

  14. The Crescent Bypass: A Riparian Restoration Project on the Kings River (Fresno County)

    Treesearch

    Jonathan A. Oldham; Bradley E. Valentine

    1989-01-01

    The Kings River Conservation District planted over 1200 plants of 19 riparian species in the first of two phases of a riparian revegetation project in the San Joaquin Valley. To date, tree survival rates vary from 17 to 96 percent among species, with an overall rate of 62 percent. Shrub survival averages 57 percent and ranges from 23 to 73 percent. Factors affecting...

  15. New determination of the D0→K-π+π0 and D0→K-π+π+π- coherence factors and average strong-phase differences

    NASA Astrophysics Data System (ADS)

    Libby, J.; Malde, S.; Powell, A.; Wilkinson, G.; Asner, D. M.; Bonvicini, G.; Briere, R. A.; Gershon, T.; Naik, P.; Pedlar, T. K.; Rademacker, J.; Ricciardi, S.; Thomas, C.

    2014-04-01

    Measurements of the coherence factors (R and R) and the average strong-phase differences (δDKππ0 and δDK3π) for the decays D0→K-π+π0 and D0→K-π+π+π- are presented. These parameters are important inputs to the determination of the unitarity triangle angle γ in B∓→DK∓ decays, where D designates a D0 or D meson decaying to a common final state. The measurements are made using quantum correlated DDbar decays collected by the CLEO-c experiment at the ψ(3770) resonance, and augment a previously published analysis by the inclusion of new events in which the signal decay is tagged by the mode D→KS0π+π-. The measurements also benefit from improved knowledge of external inputs, namely the D0D mixing parameters, rDKπ and several D-meson branching fractions. The measured values are R=0.82±0.07, δDKππ0=(164-14+20)°, R=0.32-0.28+0.20 and δDK3π=(225-78+21)°. Consideration is given to how these measurements can be improved further by using the larger quantum-correlated data set collected by BESIII.

  16. Effect of phase and orbital wave parameter choices on CS and IOS degeneracy averaged differential cross sections

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Khare, V.; Fitz, D.E.; Kouri, D.J.

    1980-09-15

    The effect of phase choice and partial wave parameter choice on CS and IOS inelastic degeneracy averaged differential cross sections is studied. An approximate simplified CS scattering amplitude for l-bar=1/2(l'+l) is derived and is shown to have a form which closely resembles the McGuire--Kouri scattering amplitude for odd ..delta..j transitions and reduces to it for even ..delta..j transitions. The choice of phase in the CS wave function is shown to result in different approximations which yield significantly different shapes for the degeneracy averaged differential cross section. Time reversal symmetry arguments are employed to select the proper phase choice. IOS calculationsmore » of the degeneracy averaged differential cross sections of He--CO, He--Cl and Ne--HD using l-bar=1/2(l+l') and the phase choice which ensures proper time reversal symmetry are found to correct the phase disagreement which was previously noted for odd ..delta..j transitions using l-bar=l or l' and either the time reversal phase or other phase choices.« less

  17. Bearing tester data compilation analysis, and reporting and bearing math modeling

    NASA Technical Reports Server (NTRS)

    Cody, J. C.

    1986-01-01

    Integration of heat transfer coefficients, modified to account for local vapor quality, into the 45 mm bearing model has been completed. The model has been evaluated with two flow rates and subcooled and saturated coolant. The evaluation showed that by increasing the flow from 3.6 to 7.0 lbs/sec the average ball temperature was decreased by 102 F, using a coolant temperature of -230 F. The average ball temperature was decreased by 63 F by decreasing the inlet coolant temperature from saturated to -230 F at a flow rate of 7.0 lbs/sec. Since other factors such as friction, cage heating, etc., affect bearing temperatures, the above bearing temperature effects should be considered as trends and not absolute values. The two phase heat transfer modification has been installed in the 57 mm bearing model and the effects on bearing temperatures have been evaluated. The average ball temperature was decreased by 60 F by increasing the flow rate from 4.6 to 9.0 lbs/sec for the subcooled case. By decreasing the inlet coolant temperature from saturation to -24 F, the average ball temperature was decreased 57 F for a flow rate of 9.0 lbs/sec. The technique of relating the two phase heat transfer coefficient to local vapor quality will be applied to the tester model and compared with test data.

  18. The Zond Victory Garden Phase 4 windfarm: A planning, installation, and performance case study. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chapman, J.

    1994-07-01

    This is one of a series of reports that document the steps taken to plan and install a utility-scale windfarm and follow its energy production performance. The reports are intended to help utility planners and others better understand the issues involved in installing and operating a windfarm. This report describes the Zond Victory Garden Phase IV (VGIV) windfarm in the Tehachapi mountain region, 100 miles north of Los Angeles. The Victory Garden series of windfarms were planned and installed and are operated by Zond Systems, Inc. of Tehachapi, California. The VGIV installation, which became operational in stages from January throughmore » June 1990, consists of 98 Vestas V27--225 wind turbines. The total rated capacity is 22 MW with a projected annual average net energy production of 54.3 million kWh/yr, equivalent to an annual capacity factor of 0.28. This energy projection, based on extensive wind resource measurements and an average wind turbine availability of 97%, includes the effects of a number of operational loss factors. The report includes descriptions of the windfarm layout, the wind turbine component, and the electrical layout. Particular attention is paid to one of the most important issues in implementing a windfarm, namely, the wind resource assessment and its use in projecting and updating the expected annual-average energy production of the facility. Also included are details of the planning, construction, and commissioning of the windfarm along with a description of the operations and maintenance procedures employed.« less

  19. Atmospheric partitioning and the air-water exchange of polycyclic aromatic hydrocarbons in a large shallow Chinese lake (Lake Chaohu).

    PubMed

    Qin, Ning; He, Wei; Kong, Xiang-Zhen; Liu, Wen-Xiu; He, Qi-Shuang; Yang, Bin; Ouyang, Hui-Ling; Wang, Qing-Mei; Xu, Fu-Liu

    2013-11-01

    The residual levels of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere and in dissolved phase from Lake Chaohu were measured by (GC-MS). The composition and seasonal variation were investigated. The diffusive air-water exchange flux was estimated by a two-film model, and the uncertainty in the flux calculations and the sensitivity of the parameters were evaluated. The following results were obtained: (1) the average residual levels of all PAHs (PAH16) in the atmosphere from Lake Chaohu were 60.85±46.17 ng m(-3) in the gaseous phase and 14.32±23.82 ng m(-3) in the particulate phase. The dissolved PAH16 level was 173.46±132.89 ng L(-1). (2) The seasonal variation of average PAH16 contents ranged from 43.09±33.20 ng m(-3) (summer) to 137.47±41.69 ng m(-3) (winter) in gaseous phase, from 6.62±2.72 ng m(-3) (summer) to 56.13±22.99 ng m(-3) (winter) in particulate phase, and 142.68±74.68 ng L(-1) (winter) to 360.00±176.60 ng L(-1) (summer) in water samples. Obvious seasonal trends of PAH16 concentrations were found in the atmosphere and water. The values of PAH16 for both the atmosphere and the water were significantly correlated with temperature. (3) The monthly diffusive air-water exchange flux of total PAH16 ranged from -1.77×10(4) ng m(-2) d(-1) to 1.11×10(5) ng m(-2) d(-1), with an average value of 3.45×10(4) ng m(-2) d(-1). (4) The results of a Monte Carlo simulation showed that the monthly average PAH fluxes ranged from -3.4×10(3) ng m(-2) d(-1) to 1.6×10(4) ng m(-2) d(-1) throughout the year, and the uncertainties for individual PAHs were compared. (5) According to the sensitivity analysis, the concentrations of dissolved and gaseous phase PAHs were the two most important factors affecting the results of the flux calculations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Mapping of elasticity and damping in an α + β titanium alloy through atomic force acoustic microscopy

    PubMed Central

    Phani, M Kalyan; Kumar, Anish; Jayakumar, T; Samwer, Konrad

    2015-01-01

    Summary The distribution of elastic stiffness and damping of individual phases in an α + β titanium alloy (Ti-6Al-4V) measured by using atomic force acoustic microscopy (AFAM) is reported in the present study. The real and imaginary parts of the contact stiffness k * are obtained from the contact-resonance spectra and by using these two quantities, the maps of local elastic stiffness and the damping factor are derived. The evaluation of the data is based on the mass distribution of the cantilever with damped flexural modes. The cantilever dynamics model considering damping, which was proposed recently, has been used for mapping of indentation modulus and damping of different phases in a metallic structural material. The study indicated that in a Ti-6Al-4V alloy the metastable β phase has the minimum modulus and the maximum damping followed by α′- and α-phases. Volume fractions of the individual phases were determined by using a commercial material property evaluation software and were validated by using X-ray diffraction (XRD) and electron back-scatter diffraction (EBSD) studies on one of the heat-treated samples. The volume fractions of the phases and the modulus measured through AFAM are used to derive average modulus of the bulk sample which is correlated with the bulk elastic properties obtained by ultrasonic velocity measurements. The average modulus of the specimens estimated by AFAM technique is found to be within 5% of that obtained by ultrasonic velocity measurements. The effect of heat treatments on the ultrasonic attenuation in the bulk sample could also be understood based on the damping measurements on individual phases using AFAM. PMID:25977847

  1. Mapping of elasticity and damping in an α + β titanium alloy through atomic force acoustic microscopy.

    PubMed

    Phani, M Kalyan; Kumar, Anish; Jayakumar, T; Arnold, Walter; Samwer, Konrad

    2015-01-01

    The distribution of elastic stiffness and damping of individual phases in an α + β titanium alloy (Ti-6Al-4V) measured by using atomic force acoustic microscopy (AFAM) is reported in the present study. The real and imaginary parts of the contact stiffness k (*) are obtained from the contact-resonance spectra and by using these two quantities, the maps of local elastic stiffness and the damping factor are derived. The evaluation of the data is based on the mass distribution of the cantilever with damped flexural modes. The cantilever dynamics model considering damping, which was proposed recently, has been used for mapping of indentation modulus and damping of different phases in a metallic structural material. The study indicated that in a Ti-6Al-4V alloy the metastable β phase has the minimum modulus and the maximum damping followed by α'- and α-phases. Volume fractions of the individual phases were determined by using a commercial material property evaluation software and were validated by using X-ray diffraction (XRD) and electron back-scatter diffraction (EBSD) studies on one of the heat-treated samples. The volume fractions of the phases and the modulus measured through AFAM are used to derive average modulus of the bulk sample which is correlated with the bulk elastic properties obtained by ultrasonic velocity measurements. The average modulus of the specimens estimated by AFAM technique is found to be within 5% of that obtained by ultrasonic velocity measurements. The effect of heat treatments on the ultrasonic attenuation in the bulk sample could also be understood based on the damping measurements on individual phases using AFAM.

  2. Snow particles extracted from X-ray computed microtomography imagery and their single-scattering properties

    NASA Astrophysics Data System (ADS)

    Ishimoto, Hiroshi; Adachi, Satoru; Yamaguchi, Satoru; Tanikawa, Tomonori; Aoki, Teruo; Masuda, Kazuhiko

    2018-04-01

    Sizes and shapes of snow particles were determined from X-ray computed microtomography (micro-CT) images, and their single-scattering properties were calculated at visible and near-infrared wavelengths using a Geometrical Optics Method (GOM). We analyzed seven snow samples including fresh and aged artificial snow and natural snow obtained from field samples. Individual snow particles were numerically extracted, and the shape of each snow particle was defined by applying a rendering method. The size distribution and specific surface area distribution were estimated from the geometrical properties of the snow particles, and an effective particle radius was derived for each snow sample. The GOM calculations at wavelengths of 0.532 and 1.242 μm revealed that the realistic snow particles had similar scattering phase functions as those of previously modeled irregular shaped particles. Furthermore, distinct dendritic particles had a characteristic scattering phase function and asymmetry factor. The single-scattering properties of particles of effective radius reff were compared with the size-averaged single-scattering properties. We found that the particles of reff could be used as representative particles for calculating the average single-scattering properties of the snow. Furthermore, the single-scattering properties of the micro-CT particles were compared to those of particle shape models using our current snow retrieval algorithm. For the single-scattering phase function, the results of the micro-CT particles were consistent with those of a conceptual two-shape model. However, the particle size dependence differed for the single-scattering albedo and asymmetry factor.

  3. Admission and capacity planning for the implementation of one-stop-shop in skin cancer treatment using simulation-based optimization.

    PubMed

    Romero, H L; Dellaert, N P; van der Geer, S; Frunt, M; Jansen-Vullers, M H; Krekels, G A M

    2013-03-01

    Hospitals and health care institutions are facing the challenge of improving the quality of their services while reducing their costs. The current study presents the application of operations management practices in a dermatology oncology outpatient clinic specialized in skin cancer treatment. An interesting alternative considered by the clinic is the implementation of a one-stop-shop concept for the treatment of new patients diagnosed with basal cell carcinoma. This alternative proposes a significant improvement in the average waiting time that a patient spends between the diagnosis and treatment. This study is focused on the identification of factors that influence the average throughput time of patients treated in the clinic from the logistic perspective. A two-phase approach was followed to achieve the goals stated in this study. The first phase included an integrated approach for the deterministic analysis of the capacity using a demand-supply model for the hospital processes, while the second phase involved the development of a simulation model to include variability to the activities involved in the process and to evaluate different scenarios. Results showed that by managing three factors: the admission rule, resources allocation and capacity planning in the dermato-oncology unit throughput times for treatments of new patients can be decreased with more than 90 %, even with the same resource level. Finally, a pilot study with 16 patients was also conducted to evaluate the impact of implementing the one stop shop concept from a clinical perspective. Patients turned out to be satisfied with the fast diagnosis and treatment.

  4. An Interactive Multi-Model for Consensus on Climate Change

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kocarev, Ljupco

    This project purports to develop a new scheme for forming consensus among alternative climate models, that give widely divergent projections as to the details of climate change, that is more intelligent than simply averaging the model outputs, or averaging with ex post facto weighting factors. The method under development effectively allows models to assimilate data from one another in run time with weights that are chosen in an adaptive training phase using 20th century data, so that the models synchronize with one another as well as with reality. An alternate approach that is being explored in parallel is the automatedmore » combination of equations from different models in an expert-system-like framework.« less

  5. A Semi-flexible 64-channel Receive-only Phased Array for Pediatric Body MRI at 3T

    PubMed Central

    Zhang, Tao; Grafendorfer, Thomas; Cheng, Joseph Y.; Ning, Peigang; Rainey, Bob; Giancola, Mark; Ortman, Sarah; Robb, Fraser J.; Calderon, Paul D.; Hargreaves, Brian A.; Lustig, Michael; Scott, Greig C.; Pauly, John M.; Vasanawala, Shreyas S.

    2015-01-01

    Purpose To design, construct, and validate a semi-flexible 64-channel receive-only phased array for pediatric body MRI at 3T. Methods A 64-channel receive-only phased array was developed and constructed. The designed flexible coil can easily conform to different patient sizes with non-overlapping coil elements in the transverse plane. It can cover a field of view of up to 44 × 28 cm2 and removes the need for coil repositioning for body MRI patients with multiple clinical concerns. The 64-channel coil was compared with a 32-channel standard coil for signal-to-noise ratio (SNR) and parallel imaging performances on different phantoms. With IRB approval and informed consent/assent, the designed coil was validated on 21 consecutive pediatric patients. Results The pediatric coil provided higher SNR than the standard coil on different phantoms, with the averaged SNR gain at least 23% over a depth of 7 cm along the cross-section of phantoms. It also achieved better parallel imaging performance under moderate acceleration factors. Good image quality (average score 4.6 out of 5) was achieved using the developed pediatric coil in the clinical studies. Conclusion A 64-channel semi-flexible receive-only phased array has been developed and validated to facilitate high quality pediatric body MRI at 3T. PMID:26418283

  6. Acoustic Effects in Classical Nucleation Theory

    NASA Technical Reports Server (NTRS)

    Baird, J. K.; Su, C.-H.

    2017-01-01

    The effect of sound wave oscillations on the rate of nucleation in a parent phase can be calculated by expanding the free energy of formation of a nucleus of the second phase in powers of the acoustic pressure. Since the period of sound wave oscillation is much shorter than the time scale for nucleation, the acoustic effect can be calculated as a time average of the free energy of formation of the nucleus. The leading non-zero term in the time average of the free energy is proportional to the square of the acoustic pressure. The Young-Laplace equation for the surface tension of the nucleus can be used to link the time average of the square of the pressure in the parent phase to its time average in the nucleus of the second phase. Due to the surface tension, the pressure in the nuclear phase is higher than the pressure in the parent phase. The effect is to lower the free energy of formation of the nucleus and increase the rate of nucleation.

  7. A Gaussian wave packet phase-space representation of quantum canonical statistics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Coughtrie, David J.; Tew, David P.

    2015-07-28

    We present a mapping of quantum canonical statistical averages onto a phase-space average over thawed Gaussian wave-packet (GWP) parameters, which is exact for harmonic systems at all temperatures. The mapping invokes an effective potential surface, experienced by the wave packets, and a temperature-dependent phase-space integrand, to correctly transition from the GWP average at low temperature to classical statistics at high temperature. Numerical tests on weakly and strongly anharmonic model systems demonstrate that thermal averages of the system energy and geometric properties are accurate to within 1% of the exact quantum values at all temperatures.

  8. Highly-controlled, reproducible measurements of aerosol emissions from African biomass combustion

    NASA Astrophysics Data System (ADS)

    Haslett, Sophie; Thomas, J. Chris; Morgan, William; Hadden, Rory; Liu, Dantong; Allan, James; Williams, Paul; Sekou, Keïta; Liousse, Catherine; Coe, Hugh

    2017-04-01

    Particulate emissions from biomass burning can alter the atmosphere's radiative balance and cause significant harm to human health. However, the relationship between these emissions and fundamental combustion processes is, to date, poorly characterised. In atmospheric models, aerosol emissions are represented by emission factors based on mass loss, which are averaged over an entire combustion event for each particulate species. This approach, however, masks huge variability in emissions during different phases of the combustion period. Laboratory tests have shown that even small changes to the burning environment can lead to huge variation in observed aerosol emission factors (Akagi et al., 2011). In order to address this gap in understanding, in this study, small wood samples sourced from Côte D'Ivoire were burned in a highly-controlled laboratory environment. The shape and mass of samples, available airflow and surrounding heat were carefully regulated. Organic aerosol and refractory black carbon emissions were measured in real-time using an Aerosol Mass Spectrometer and a Single Particle Soot Photometer, respectively. Both of these instruments are used regularly to measure aerosol concentrations in the field. This methodology produced remarkably repeatable results, allowing three different phases of combustion to be identified by their emissions. Black carbon was emitted predominantly during flaming combustion; organic aerosols were emitted during pyrolysis before ignition and from smouldering-dominated behaviour near the end of combustion. During the flaming period, there was a strong correlation between the emission of black carbon and the rate of mass loss, which suggests there is value in employing a mass-based emission factor for this species. However, very little correlation was seen between organic aerosol and mass loss throughout the tests. As such, results here suggest that emission factors averaged over an entire combustion event are unlikely to be useful for organic aerosol emissions. The two different phases producing organic aerosol, pyrolysis and smouldering, were observed to have different mass spectra. In previous ambient experiments, two organic factors with very comparable signatures to these have been identified using positive matrix factorisation (Young et al., 2015). As such, it is postulated that these ambient organic factors are likely associated with the two combustion phases identified here. References: Akagi, S. K., Yokelson, R. J., Wiedinmyer, C., Alvarado, M. J., Reid, J. S., Karl, T., Crounse, J. D. and Wennberg, P. O., Emission factors for open and domestic biomass burning for use in atmospheric models. Atmos. Chem. Phys., 11, 4039-4072 (2011) Young, D. E., Allan, J. D., Williams, P. I., Green, D. C., Harrison, R. M., Yin, J., Flynn, M. J., Gallagher, M. W., Coe, H., Investigating a two-component model of solid fuel organic aerosol in London: processes, PM1 contribution, and seasonality. Atmos. Chem. Phys, 15, 2429-2443 (2015)

  9. V458 Vul (Nova Vul 2007) becomes a highly-variable supersoft X-ray source

    NASA Astrophysics Data System (ADS)

    Drake, J. J.; Page, K. L.; Osborne, J. P.; Beardmore, A. P.; Ness, J.-U.; Starrfield, S.; Schwarz, G.; Tsujimoto, M.; Wesson, R.; Bode, M.; Rodriguez-Gil, P.; Gaensicke, B.; Steeghs, D.; Knigge, C.; Takei, D.; Zijlstra, A.

    2008-09-01

    Swift X-ray Telescope (XRT) monitoring observations of V458 Vul (Nova Vul 2007, S. Nakano, IAUC 8861) have found it to be entering a new phase characterised by a highly variable supersoft X-ray component accompanied by partially anti-correlated variations in the ultraviolet. An earlier report of entry into the supersoft phase (ATel #1246) has proven premature. XRT observations obtained from 2008 June 18 - September 1 found the nova to have declined in X-ray luminosity by a factor of 3 to an average of 0.02 count/s in the 0.3-10 keV band compared with the 2007 November-December period (ATel #1603).

  10. Quantitative methods for estimating the anisotropy of the strength properties and the phase composition of Mg-Al alloys

    NASA Astrophysics Data System (ADS)

    Betsofen, S. Ya.; Kolobov, Yu. R.; Volkova, E. F.; Bozhko, S. A.; Voskresenskaya, I. I.

    2015-04-01

    Quantitative methods have been developed to estimate the anisotropy of the strength properties and to determine the phase composition of Mg-Al alloys. The efficiency of the methods is confirmed for MA5 alloy subjected to severe plastic deformation. It is shown that the Taylor factors calculated for basal slip averaged over all orientations of a polycrystalline aggregate with allowance for texture can be used for a quantitative estimation of the contribution of the texture of semifinished magnesium alloy products to the anisotropy of their strength properties. A technique of determining the composition of a solid solution and the intermetallic phase Al12Mg17 content is developed using the measurement of the lattice parameters of the solid solution and the known dependence of these lattice parameters on the composition.

  11. Intensity noise limit in a phase-sensitive optical time-domain reflectometer with a semiconductor laser source

    NASA Astrophysics Data System (ADS)

    E Alekseev, A.; Tezadov, Ya A.; Potapov, V. T.

    2017-05-01

    In the present paper we perform, for the first time, the analysis of the average intensity noise power level at the output of a coherent phase-sensitive optical time-domain reflectometer (phase-OTDR) with a semiconductor laser source. The origin of the considered intensity noise lies in random phase fluctuations of a semiconductor laser source field. These phase fluctuations are converted to intensity noise in the process of interference of backscattered light. This intensity noise inevitably emerges in every phase-OTDR spatial channel and limits its sensitivity to external phase actions. The analysis of intensity noise in a phase-OTDR was based on the study of a fiber scattered-light interferometer (FSLI) which is treated as the constituent part of OTDR. When considered independently, FSLI has a broad intensity noise spectrum at its output; when FSLI is treated as a part of a phase-OTDR, due to aliasing effect, the wide FSLI noise spectrum is folded within the spectral band, determined by the probe pulse repetition frequency. In the analysis one of the conventional phase-OTDR schemes with rectangular dual-pulse probe signal was considered, the FSLI, which corresponds to this OTDR scheme, has two scattering fiber segments with additional time delay introduced between backscattered fields. The average intensity noise power and resulting noise spectrum at the output of this FSLI are determined by the degree of coherence of the semiconductor laser source, the length of the scattering fiber segments and by the additional time delay between the scattering segments. The average intensity noise characteristics at the output of the corresponding phase-OTDR are determined by the analogous parameters: the source coherence, the lengths of the parts constituting the dual-pulse and the time interval which separates the parts of the dual-pulse. In the paper the expression for the average noise power spectral density (NPSD) at the output of FSLI was theoretically derived and experimentally verified. Based on the found average NPSD of FSLI, a simple relation connecting the phase-OTDR parameters and the limiting level of full average intensity noise power at its output was derived. This relation was verified by experimental measurement of the average noise power at the output of phase-OTDR. The limiting noise level, considered in the paper, determines the fundamental noise floor for the phase-OTDR with given parameters of the source coherence, probe pulse length and time delay between two pulses constituting the dual-pulse.

  12. Scattering and extinction by spherical particles immersed in an absorbing host medium

    NASA Astrophysics Data System (ADS)

    Mishchenko, Michael I.; Dlugach, Janna M.

    2018-05-01

    Many applications of electromagnetic scattering involve particles immersed in an absorbing rather than lossless medium, thereby making the conventional scattering theory potentially inapplicable. To analyze this issue quantitatively, we employ the FORTRAN program developed recently on the basis of the first-principles electromagnetic theory to study far-field scattering by spherical particles embedded in an absorbing infinite host medium. We further examine the phenomenon of negative extinction identified recently for monodisperse spheres and uncover additional evidence in favor of its interference origin. We identify the main effects of increasing the width of the size distribution on the ensemble-averaged extinction efficiency factor and show that negative extinction can be eradicated by averaging over a very narrow size distribution. We also analyze, for the first time, the effects of absorption inside the host medium and ensemble averaging on the phase function and other elements of the Stokes scattering matrix. It is shown in particular that increasing absorption significantly suppresses the interference structure and can result in a dramatic expansion of the areas of positive polarization. Furthermore, the phase functions computed for larger effective size parameters can develop a very deep minimum at side-scattering angles bracketed by a strong diffraction peak in the forward direction and a pronounced backscattering maximum.

  13. Measurements and source apportionment of particle-associated polycyclic aromatic hydrocarbons in ambient air in Riyadh, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Bian, Qijing; Alharbi, Badr; Collett, Jeffrey; Kreidenweis, Sonia; Pasha, Mohammad J.

    2016-07-01

    Ambient air samples were obtained in Riyadh, the capital and largest city of Saudi Arabia, during two measurement campaigns spanning September 2011 to September 2012. Sixteen particle-phase polycyclic aromatic hydrocarbons (PAH) were quantified in 167 samples. Pyrene and fluoranthene were the most abundant PAH, with average of 3.37 ± 14.01 ng m-3 and 8.00 ± 44.09 ng m-3, respectively. A dominant contribution from low molecular weight (LMW) PAH (MW < 228) suggested a large influence of industrial emissions on PAH concentrations. Monte Carlo source apportionment using diagnostic ratios showed that 80 ± 10% of the average LMW PAH concentrations were contributed by petroleum vapor emissions, while 53 ± 19% of high molecular weight (HMW) PAH were from solid fuel combustion emissions. The positive matrix factorization model estimated that oil combustion emissions dominated total PAH concentrations, accounting for on average 96%, likely due to widespread use of oil fuels in energy production (power plants and industries). Our results demonstrate the significant influence of petroleum product production and consumption on particulate-phase PAH concentrations in Riyadh, but also point to the importance of traffic and solid fuel burning, including coke burning and seasonal biomass burning, especially as they contribute to the ambient levels of HMW PAH.

  14. Vapor-phase transport of trichloroethene in an intermediate-scale vadose-zone system: retention processes and tracer-based prediction.

    PubMed

    Costanza-Robinson, Molly S; Carlson, Tyson D; Brusseau, Mark L

    2013-02-01

    Gas-phase transport experiments were conducted using a large weighing lysimeter to evaluate retention processes for volatile organic compounds (VOCs) in water-unsaturated (vadose-zone) systems, and to test the utility of gas-phase tracers for predicting VOC retardation. Trichloroethene (TCE) served as a model VOC, while trichlorofluoromethane (CFM) and heptane were used as partitioning tracers to independently characterize retention by water and the air-water interface, respectively. Retardation factors for TCE ranged between 1.9 and 3.5, depending on water content. The results indicate that dissolution into the bulk water was the primary retention mechanism for TCE under all conditions studied, contributing approximately two-thirds of the total measured retention. Accumulation at the air-water interface comprised a significant fraction of the observed retention for all experiments, with an average contribution of approximately 24%. Sorption to the solid phase contributed approximately 10% to retention. Water contents and air-water interfacial areas estimated based on the CFM and heptane tracer data, respectively, were similar to independently measured values. Retardation factors for TCE predicted using the partitioning-tracer data were in reasonable agreement with the measured values. These results suggest that gas-phase tracer tests hold promise for characterizing the retention and transport of VOCs in the vadose-zone. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. The Forkhead transcription factor Hcm1 regulates chromosome segregation genes and fills the S-phase gap in the transcriptional circuitry of the cell cycle.

    PubMed

    Pramila, Tata; Wu, Wei; Miles, Shawna; Noble, William Stafford; Breeden, Linda L

    2006-08-15

    Transcription patterns shift dramatically as cells transit from one phase of the cell cycle to another. To better define this transcriptional circuitry, we collected new microarray data across the cell cycle of budding yeast. The combined analysis of these data with three other cell cycle data sets identifies hundreds of new highly periodic transcripts and provides a weighted average peak time for each transcript. Using these data and phylogenetic comparisons of promoter sequences, we have identified a late S-phase-specific promoter element. This element is the binding site for the forkhead protein Hcm1, which is required for its cell cycle-specific activity. Among the cell cycle-regulated genes that contain conserved Hcm1-binding sites, there is a significant enrichment of genes involved in chromosome segregation, spindle dynamics, and budding. This may explain why Hcm1 mutants show 10-fold elevated rates of chromosome loss and require the spindle checkpoint for viability. Hcm1 also induces the M-phase-specific transcription factors FKH1, FKH2, and NDD1, and two cell cycle-specific transcriptional repressors, WHI5 and YHP1. As such, Hcm1 fills a significant gap in our understanding of the transcriptional circuitry that underlies the cell cycle.

  16. Onset of phase separation in the double perovskite oxide La 2 MnNiO 6

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Spurgeon, Steven R.; Sushko, Peter V.; Devaraj, Arun

    2018-04-01

    Identification of kinetic and thermodynamic factors that control crystal nucleation and growth represents a central challenge in materials synthesis. Here we report that apparently defect-free growth of La2MnNiO6 (LMNO) thin films supported on SrTiO3 (STO) proceeds up to 1–5 nm, after which it is disrupted by precipitation of NiO phases. Local geometric phase analysis and ensemble-averaged x-ray reciprocal space mapping show no change in the film strain away from the interface, indicating that mechanisms other than strain relaxation induce the formation of the NiO phases. Ab initio simulations suggest that the electrostatic potential build-up associated with the polarity mismatch atmore » the film-substrate interface promotes the formation of oxygen vacancies with increasing thickness. In turn, oxygen deficiency promotes the formation of Ni-rich regions, which points to the built-in potential as an additional factor that contributes to the NiO precipitation mechanisms. These results suggest that the precipitate-free region could be extended further by either incorporating dopants that suppress the built-in potential or by increasing the oxygen fugacity in order to suppress the formation of oxygen vacancies.« less

  17. An approach to compute the C factor for universal soil loss equation using EOS-MODIS vegetation index (VI)

    NASA Astrophysics Data System (ADS)

    Li, Hui; He, Huizhong; Chen, Xiaoling; Zhang, Lihua

    2008-12-01

    C factor, known as cover and management factor in USLE, is one of the most important factors since it represents the combined effects of plant, soil cover and management on erosion, whereas it also most easily changed variables by men for it itself is time-variant and the uncertainty nature. So it's vital to compute C factor properly in order to model erosion effectively. In this paper we attempt to present a new method for calculating C value using Vegetation Index (VI) derived from multi-temporal MODIS imagery, which can estimate C factor in a more scientific way. Based on the theory that C factor is strongly correlated with VI, the average annual C value is estimated by adding the VI value of three growth phases within a year with different weights. Modified Fournier Index (MFI) is employed to determine the weight of each growth phase for the vegetation growth and agricultural activities are significantly influenced by precipitation. The C values generated by the proposed method were compared with that of other method, and the results showed that the results of our method is highly correlated with the others. This study is helpful to extract C value from satellite data in a scientific and efficient way, which in turn could be used to facilitate the prediction of erosion.

  18. Electrokinetic coupling in unsaturated porous media.

    PubMed

    Revil, A; Linde, N; Cerepi, A; Jougnot, D; Matthäi, S; Finsterle, S

    2007-09-01

    We consider a charged porous material that is saturated by two fluid phases that are immiscible and continuous on the scale of a representative elementary volume. The wetting phase for the grains is water and the nonwetting phase is assumed to be an electrically insulating viscous fluid. We use a volume-averaging approach to derive the linear constitutive equations for the electrical current density as well as the seepage velocities of the wetting and nonwetting phases on the scale of a representative elementary volume. These macroscopic constitutive equations are obtained by volume-averaging Ampère's law together with the Nernst-Planck equation and the Stokes equations. The material properties entering the macroscopic constitutive equations are explicitly described as functions of the saturation of the water phase, the electrical formation factor, and parameters that describe the capillary pressure function, the relative permeability functions, and the variation of electrical conductivity with saturation. New equations are derived for the streaming potential and electro-osmosis coupling coefficients. A primary drainage and imbibition experiment is simulated numerically to demonstrate that the relative streaming potential coupling coefficient depends not only on the water saturation, but also on the material properties of the sample, as well as the saturation history. We also compare the predicted streaming potential coupling coefficients with experimental data from four dolomite core samples. Measurements on these samples include electrical conductivity, capillary pressure, the streaming potential coupling coefficient at various levels of saturation, and the permeability at saturation of the rock samples. We found very good agreement between these experimental data and the model predictions.

  19. Factors affecting pregnancy length and phases of parturition in Martina Franca jennies.

    PubMed

    Carluccio, Augusto; Gloria, Alessia; Veronesi, Maria Cristina; De Amicis, Ippolito; Noto, Federico; Contri, Alberto

    2015-09-01

    The knowledge of normal pregnancy length, duration of parturition stages, and neonatal early adaptation is mandatory for a rationale management of birth, especially in monotocous species with long gestations. This study reports data obtained from a large number of Martina Franca jennies with normal healthy pregnancies and spontaneous eutocic delivery of a mature, healthy, and viable donkey foal. Pregnancy lasts, on average, 371 days, and only the fetal gender significantly determines pregnancy length, with longer gestations observed in jennies bearing male fetuses. Other factors such as the year of foaling, month of ovulation, month of parturition, birth weight of the foal, and age of the jenny did not influence pregnancy length. The first stage of foaling lasted on average 65 minutes, the second stage 19 minutes, and the third stage 58 minutes. The umbilical cord ruptured on average within 16 minutes after birth; the foal stood up in 61 minutes and suckled the colostrum for the first time within 10 minutes after birth and again after 143 minutes of birth; meconium passage occurred, on average, 86 minutes after birth. Although times reported for the process of foaling are similar to data reported for the horse, the times for early neonatal donkey foal adaptation are longer as compared to the horse foal. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Shed vortex structure and phase-averaged velocity statistics in symmetric/asymmetric turbulent flat plate wakes

    NASA Astrophysics Data System (ADS)

    Rai, Man Mohan

    2018-05-01

    The near wake of a flat plate is investigated via direct numerical simulations. Many earlier experimental investigations have used thin plates with sharp trailing edges and turbulent boundary layers to create the wake. This results in large θ/DTE values (θ is the boundary layer momentum thickness toward the end of the plate and DTE is the trailing edge thickness). In the present study, the emphasis is on relatively thick plates with circular trailing edges (CTEs) resulting in θ/D values less than one (D is the plate thickness and the diameter of the CTE) and vigorous vortex shedding. The Reynolds numbers based on the plate length and D are 1.255 × 106 and 10 000, respectively. Two cases are computed: one with turbulent boundary layers on both the upper and lower surfaces of the plate (statistically the same, symmetric wake, Case TT) and the other with turbulent and laminar boundary layers on the upper and lower surfaces, respectively (asymmetric case, Case TL). The data and understanding obtained are of considerable engineering interest, particularly in turbomachinery where the pressure side of an airfoil can remain laminar or transitional because of a favorable pressure gradient and the suction side is turbulent. Shed-vortex structure and phase-averaged velocity statistics obtained in the two cases are compared here. The upper negative shed vortices in Case TL (turbulent separating boundary layer) are weaker than the lower positive ones (laminar separating boundary layer) at inception (a factor of 1.27 weaker in terms of peak phase-averaged spanwise vorticity at the first appearance of a peak). The upper vortices weaken rapidly as they travel downstream. A second feature of interest in Case TL is a considerable increase in the peak phase-averaged, streamwise normal intensity (random component) with increasing streamwise distance (x/D) that occurs near the positive vortex cores. This behavior is observed for a few diameters in the near wake. This is counter to Case TT where the peak value essentially decreases with increasing x/D. Both these effects are examined in detail, and the important contributors are identified.

  1. A pilot study of the behavior of gas- and particle-phase ETS tracers in residences

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Apte, Michael; Gundel, Lara; Dod, Raymond

    2002-02-01

    Our previous study of environmental tobacco smoke (ETS) in a three-room environmental chamber showed that smoking history significantly influenced inter-room ETS transport, particularly of gas-phase nicotine. We conducted a three-home pilot study where smoking was limited to one room. Single-smoker residences were monitored during five one-week periods while the smoker participated in a smoking cessation program. Nicotine traced ETS particles were detected reliably in the smoking rooms (SRs) and unreliably in the non-smoking rooms (NSRs). On average, the ventilation- and volume-normalized smoking rate, 0.1 Cigarette-h{sup -1} m{sup -3}, added about 17 and 4 {micro}g m{sup -3} of ETS particles intomore » the SR and NSR, while average nicotine concentration increases were 2 and 0.06 {micro}g m{sup -3}, respectively. Thus, nicotine tracers may underestimate ETS particle exposure in a NSR (e.g., a child's bedroom) by a factor of 2 to 8. In other words, ETS exposure predicted from nicotine concentrations could be almost an order of magnitude lower than actual exposure.« less

  2. Single-drop reactive extraction/extractive reaction with forced convective diffusion and interphase mass transfer

    NASA Technical Reports Server (NTRS)

    Kleinman, Leonid S.; Red, X. B., Jr.

    1995-01-01

    An algorithm has been developed for time-dependent forced convective diffusion-reaction having convection by a recirculating flow field within the drop that is hydrodynamically coupled at the interface with a convective external flow field that at infinity becomes a uniform free-streaming flow. The concentration field inside the droplet is likewise coupled with that outside by boundary conditions at the interface. A chemical reaction can take place either inside or outside the droplet, or reactions can take place in both phases. The algorithm has been implemented, and for comparison results are shown here for the case of no reaction in either phase and for the case of an external first order reaction, both for unsteady behavior. For pure interphase mass transfer, concentration isocontours, local and average Sherwood numbers, and average droplet concentrations have been obtained as a function of the physical properties and external flow field. For mass transfer enhanced by an external reaction, in addition to the above forms of results, we present the enhancement factor, with the results now also depending upon the (dimensionless) rate of reaction.

  3. Analysis of the Effect of Menstrual Cycle Phases on Aerobic-Anaerobic Capacity and Muscle Strength

    ERIC Educational Resources Information Center

    Kose, Bereket

    2018-01-01

    The objective of this study is to examine the effect of menstrual cycle phases on aerobic-anaerobic capacity and muscle strength. 10 female kickboxing athletes with an average age of 21.40 ± 2.01 years; average height of 169.60 ± 6.14 cm; average weight of 63.90 ± 5.76 kg and average training age of 7.41 ± 2.10 participated in the study. On the…

  4. Evaluation of Respiratory Muscle Strength in the Acute Phase of Stroke: The Role of Aging and Anthropometric Variables.

    PubMed

    Luvizutto, Gustavo José; Dos Santos, Maria Regina Lopes; Sartor, Lorena Cristina Alvarez; da Silva Rodrigues, Josiela Cristina; da Costa, Rafael Dalle Molle; Braga, Gabriel Pereira; de Oliveira Antunes, Letícia Cláudia; Souza, Juli Thomaz; de Carvalho Nunes, Hélio Rubens; Bazan, Silméia Garcia Zanati; Bazan, Rodrigo

    2017-10-01

    During hospitalization, stroke patients are bedridden due to neurologic impairment, leading to loss of muscle mass, weakness, and functional limitation. There have been few studies examining respiratory muscle strength (RMS) in the acute phase of stroke. This study aimed to evaluate the RMS of patients with acute stroke compared with predicted values and to relate this to anthropometric variables, risk factors, and neurologic severity. This is a cross-sectional study in the acute phase of stroke. After admission, RMS was evaluated by maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP); anthropometric data were collected; and neurologic severity was evaluated by the National Institutes of Health Stroke Scale. The analysis of MIP and MEP with predicted values was performed by chi-square test, and the relationship between anthropometric variables, risk factors, and neurologic severity was determined through multiple linear regression followed by residue analysis by the Shapiro-Wilk test; P < .05 was considered statistically significant. In the 32 patients studied, MIP and MEP were reduced when compared with the predicted values. MIP declined significantly by 4.39 points for each 1 kg/m 2 increase in body mass index (BMI), and MEP declined significantly by an average of 3.89 points for each 1 kg/m 2 increase in BMI. There was no statistically significant relationship between MIP or MEP and risk factors, and between MIP or MIP and neurologic severity in acute phase of stroke. There is a reduction of RMS in the acute phase of stroke, and RMS was lower in individuals with increased age and BMI. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  5. Chromatographic test methods for characterizing alkylsiloxane-bonded silica columns for reversed-phase liquid chromatography.

    PubMed

    Poole, Colin F

    2018-06-07

    Major obstacles to formulating a simple retention mechanism for reversed-phase liquid chromatography have a direct impact on the development of experimental methods for column characterization as they limit our capability to understand observed differences in retention at a system level. These problems arise from the heterogeneous composition of the stationary phase, the difficulty of providing a working definition for the phase ratio, and uncertainty as to whether the distribution mechanism for varied compounds is a partition, adsorption or mixed (combination) of these models. Retention factor and separation factor measurements offer little guidance as they represent an average of various and variable contributing factors that can only be interpreted by assuming a specific model. Column characterization methods have tended to ignore these difficulties by inventing a series of terms to describe column properties, such as hydrophobicity, hydrophilicity, silanol activity, steric resistance, etc., without proper definition. This has allowed multiple scales to be proposed for the same property which generally are only weakly correlated. Against this background we review the major approaches for the characterization of alkylsiloxane-bonded silica stationary phases employing prototypical compounds, the hydrophobic-subtraction model and the solvation parameter model. Those methods using prototypical compounds are limited by the lack of compounds with a singular dominant interaction. The multivariate approaches that extract column characteristic properties from the retention of varied compounds are more hopeful but it is important to be more precise in defining the characteristic column properties and cognizant that general interpretation of these properties for varied columns cannot escape the problem of a poor understanding of the distribution mechanism. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Anisotropic ghost dark energy cosmological model with hybrid expansion law

    NASA Astrophysics Data System (ADS)

    Mahanta, Chandra Rekha; Sarma, Nitin

    2017-11-01

    In this paper, we study the anisotropic Bianchi type-VI0 metric filled with dark matter and anisotropic ghost dark energy. We have solved the Einstein's field equations by considering hybrid expansion law (HEL) for the average scale factor. It is found that at later times the universe becomes spatially homogeneous, isotropic and flat. From a state finder diagnosis, it is found that our model is having similar behavior like ɅCDM model at late phase of cosmic time.

  7. Multitime correlators in continuous measurement of qubit observables

    NASA Astrophysics Data System (ADS)

    Atalaya, Juan; Hacohen-Gourgy, Shay; Martin, Leigh S.; Siddiqi, Irfan; Korotkov, Alexander N.

    2018-02-01

    We consider multitime correlators for output signals from linear detectors, continuously measuring several qubit observables at the same time. Using the quantum Bayesian formalism, we show that for unital (symmetric) evolution in the absence of phase backaction, an N -time correlator can be expressed as a product of two-time correlators when N is even. For odd N , there is a similar factorization, which also includes a single-time average. Theoretical predictions agree well with experimental results for two detectors, which simultaneously measure noncommuting qubit observables.

  8. A classical phase r-centroid approach to molecular wave packet dynamics illustrating the danger of using an incomplete set of initial states for thermal averaging

    NASA Astrophysics Data System (ADS)

    Hansson, Tony

    1999-08-01

    An inexpensive semiclassical method to simulate time-resolved pump-probe spectroscopy on molecular wave packets is applied to NaK molecules at high temperature. The method builds on the introduction of classical phase factors related to the r-centroids for vibronic transitions and assumes instantaneous laser-molecule interaction. All observed quantum mechanical features are reproduced - for short times where experimental data are available even quantitatively. Furthermore, it is shown that fully quantum dynamical molecular wave packet calculations on molecules at elevated temperatures, which do not include all rovibrational states, must be regarded with caution, as they easily might yield even qualitatively incorrect results.

  9. Modified PTS-based PAPR Reduction for FBMC-OQAM Systems

    NASA Astrophysics Data System (ADS)

    Deng, Honggui; Ren, Shuang; Liu, Yan; Tang, Chengying

    2017-10-01

    The filter bank multicarrier with offset quadrature amplitude modulation (FBMC-OQAM) has been raised great concern in the 5G communication research. However FBMC-OQAM has also the inherent drawback of high peak-to-average power ratio (PAPR) that should be addressed. Due to the overlapping structure of FBMC-OQAM signals, it is proven that directly employing conventional partial transmit sequence (PTS) scheme proposed for OFDM to FBMC-OQAM is ineffective. In this paper, we propose a modified PTS-based scheme by employing phase rotation factors to optimize only the phase of the sparse peak signals, called as sparse PTS (S-PTS) scheme. Theoretical analysis and simulation results show that the proposed S-PTS scheme provides a significant PAPR reduction performance with lower computational complexity.

  10. Smoke and fire characteristics for cerrado and deforestation burns in Brazil - BASE-B experiment

    NASA Technical Reports Server (NTRS)

    Ward, D. E.; Susott, R. A.; Kauffman, J. B.; Babbitt, R. E.; Cummings, D. L.; Dias, B.; Holben, B. N.; Kaufman, Y. J.; Rasmussen, R. A.; Setzer, A. W.

    1992-01-01

    Five test fires were performed during August and September 1990 in the cerrado (savannalike region) in central Brazil (three fires) and tropical moist forest (two fires) in the eastern Amazon. This paper details the gases released, the ratios of the gases to each other and to particulate matter, fuel loads, and the fraction consumed (combustion factors), and the fire behavior associated with biomass consumption. Models are presented for evaluating emission factors for CH4, CO2, CO, H2, and particles less than 2.5 micron diam (PM2.5) as a function of combustion efficiency. The ratio of carbon released as CO2 (combustion efficiency) for the cerrado fires averaged 0.94 and for the deforestation fires it decreased from 0.88 for the flaming phase to less than 0.80 during the smoldering phase of combustion. For tropical ecosystems, emissions of most products of incomplete combustion are projected to be lower than previous estimates for savanna ecosystems and somewhat higher for fires used for deforestation purposes.

  11. E-O Sensor Signal Recognition Simulation: Computer Code SPOT I.

    DTIC Science & Technology

    1978-10-01

    scattering phase function PDCO , defined at the specified wavelength, given for each of the scattering angles defined. Currently, a maximum of sixty-four...PHASE MATRIX DATA IS DEFINED PDCO AVERAGE PROBABILITY FOR PHASE MATRIX DEFINITION NPROB PROBLEM NUMBER 54 Fig. 12. FLOWCHART for the SPOT Computer Code...El0.1 WLAM(N) Wavelength at which the aerosol single-scattering phase function set is defined (microns) 3 8El0.1 PDCO (N,I) Average probability for

  12. Effect of parameters in moving average method for event detection enhancement using phase sensitive OTDR

    NASA Astrophysics Data System (ADS)

    Kwon, Yong-Seok; Naeem, Khurram; Jeon, Min Yong; Kwon, Il-bum

    2017-04-01

    We analyze the relations of parameters in moving average method to enhance the event detectability of phase sensitive optical time domain reflectometer (OTDR). If the external events have unique frequency of vibration, then the control parameters of moving average method should be optimized in order to detect these events efficiently. A phase sensitive OTDR was implemented by a pulsed light source, which is composed of a laser diode, a semiconductor optical amplifier, an erbium-doped fiber amplifier, a fiber Bragg grating filter, and a light receiving part, which has a photo-detector and high speed data acquisition system. The moving average method is operated with the control parameters: total number of raw traces, M, number of averaged traces, N, and step size of moving, n. The raw traces are obtained by the phase sensitive OTDR with sound signals generated by a speaker. Using these trace data, the relation of the control parameters is analyzed. In the result, if the event signal has one frequency, then the optimal values of N, n are existed to detect the event efficiently.

  13. Modelling the average velocity of propagation of the flame front in a gasoline engine with hydrogen additives

    NASA Astrophysics Data System (ADS)

    Smolenskaya, N. M.; Smolenskii, V. V.

    2018-01-01

    The paper presents models for calculating the average velocity of propagation of the flame front, obtained from the results of experimental studies. Experimental studies were carried out on a single-cylinder gasoline engine UIT-85 with hydrogen additives up to 6% of the mass of fuel. The article shows the influence of hydrogen addition on the average velocity propagation of the flame front in the main combustion phase. The dependences of the turbulent propagation velocity of the flame front in the second combustion phase on the composition of the mixture and operating modes. The article shows the influence of the normal combustion rate on the average flame propagation velocity in the third combustion phase.

  14. Blocking carbohydrate absorption and weight loss: a clinical trial using Phase 2 brand proprietary fractionated white bean extract.

    PubMed

    Udani, Jay; Hardy, Mary; Madsen, Damian C

    2004-03-01

    Phase 2' starch neutralizer brand bean extract product ("Phase 2") is a water-extract of a common white bean (Phaseolus vulgaris) that has been shown in vitro to inhibit the digestive enzyme alpha-amylase. Inhibiting this enzyme may prevent the digestion of complex carbohydrates, thus decreasing the number of carbohydrate calories absorbed and potentially promoting weight loss. Fifty obese adults were screened to participate in a randomized, double-blind, placebo-controlled study evaluating the effects of treatment with Phase 2 versus placebo on weight loss. Participants were randomized to receive either 1500 mg Phase 2 or an identical placebo twice daily with meals. The active study period was eight weeks. Thirty-nine subjects completed the initial screening process and 27 subjects completed the study. The results after eight weeks demonstrated the Phase 2 group lost an average of 3.79 lbs (average of 0.47 lb per week) compared with the placebo group, which lost an average of 1.65 lbs (average of 0.21 lb per week), representing a difference of 129 percent (p=0.35). Triglyceride levels in the Phase 2 group were reduced an average of 26.3 mg/dL, more than three times greater a reduction than observed in the placebo group (8.2 mg/dL) (p=0.07). No adverse events during the study were attributed to the study medication. Clinical trends were identified for weight loss and a decrease in triglycerides, although statistical significance was not reached. Phase 2 shows potential promise as an adjunct therapy in the treatment of obesity and hypertriglyceridemia and further studies with larger numbers of subjects are warranted to conclusively demonstrate effectiveness.

  15. Resting Energy Expenditure in Patients with Stroke during the Subacute Phases - Relationships with Stroke Types, Location, Severity of Paresis, and Activities of Daily Living.

    PubMed

    Kawakami, Michiyuki; Liu, Meigen; Wada, Ayako; Otsuka, Tomoyoshi; Nishimura, Atsuko

    2015-01-01

    The energy demands in patients with stroke during the subacute phases are unclear. However, this information is essential for appropriate clinical and nutritional management. The aims of this study were to determine the resting energy expenditure (REE) during the subacute phases, examine its relationships with stroke types, location, severity of hemiparesis, and activities of daily living (ADL), and evaluate whether estimation of REE from the Harris-Benedict equation (HB) requires the addition of a 'stress factor' to capture possible additional REE imposed by stroke. We measured REE in 95 patients with subacute stroke (53.5 ± 16.6 days post-stroke) with indirect calorimetry, and compared it with predicted values of energy expenditure estimated from the HB (expressed as percentage). Patients were admitted for rehabilitation of their first ischemic or nonsurgical hemorrhagic stroke. The severity of hemiparesis was assessed with the motor items of the Stroke Impairment Assessment Set (SIAS). The ADL was assessed with the Functional Independence Measure (FIM). We compared REE and %HB of the two groups divided by hemiparesis severity and ADL limitation using the Student's t-test, and those of the five groups divided by stroke location. The correlations between REE and the motor items of the SIAS and the FIM score were assessed with the Spearman rank correlation test. A multiple regression analysis for REE was conducted. The average body weight (BW) was 57.1 ± 11.3 kg. The average body mass index (BMI) was 22.5 ± 4.0. The mean REE (%HB) was 1,271 ± 284 kcal/day (106.0 ± 17.3%). REE and %HB of the low ADL group was less than that of the high ADL group (p < 0.05). The REE had a positive correlation with the FIM score (rs = 0.51, p < 0.01). The motor items of the SIAS were not significantly correlated with REE. BW, FIM, and stroke location were independent predictors of REE. Analysis of energy expenditure suggests that stroke patients are not hypermetabolic during the subacute phase. The 'stress factor' in stroke patients during the subacute phase was 1.0-1.1. This finding provides important information for improving nutritional management during the subacute phase in patients with stroke. © 2015 S. Karger AG, Basel.

  16. DSPI technique for nanometer vibration mode measurement

    NASA Astrophysics Data System (ADS)

    Yue, Kaiduan; Jia, Shuhai; Tan, Yushan

    2000-05-01

    A time-average DSPI method for nanometer vibration mode measurement is presented in this paper. The phase continuous scan technique is combined with the Bessel fringe-shifting technique to quantitatively analyze the vibration mode by time-average DSPI is used in measurement system. Through the phase continuous scan, the background and speckle items are completely eliminated, which improves the fringe quality and enhances the signal-to-noise ratio of interferogram. There is no need to calibrate the optical phase-shifter exactly in this method. The anti-disturbance capability of this method is higher than that of the phase-stepping technique, so it is robust and easy to be used. In the vibration measurement system, the speckle average technology is used, so the high quality measuring results are obtained.

  17. Static structure of active Brownian hard disks

    NASA Astrophysics Data System (ADS)

    de Macedo Biniossek, N.; Löwen, H.; Voigtmann, Th; Smallenburg, F.

    2018-02-01

    We explore the changes in static structure of a two-dimensional system of active Brownian particles (ABP) with hard-disk interactions, using event-driven Brownian dynamics simulations. In particular, the effect of the self-propulsion velocity and the rotational diffusivity on the orientationally-averaged fluid structure factor is discussed. Typically activity increases structural ordering and generates a structure factor peak at zero wave vector which is a precursor of motility-induced phase separation. Our results provide reference data to test future statistical theories for the fluid structure of active Brownian systems. This manuscript was submitted for the special issue of the Journal of Physics: Condensed Matter associated with the Liquid Matter Conference 2017.

  18. Relative impact of short-term emissions controls on gas and particle-phase oxidative potential during the 2015 China Victory Day Parade in Beijing, China

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Fang, Dongqing; Shang, Jing; Li, Zhengqiang; Zhang, Yang; Huo, Peng; Liu, Zhaoying; Schauer, James J.; Zhang, Yuanxun

    2018-06-01

    A field observation focusing on reactive oxygen species (ROS) was conducted before, during, and after the 2015 China Victory Day Parade to understand the influence of short-term emissions controls on atmospheric oxidative activity. The hourly average concentrations of PM2.5, SO2, NO, NO2, CO, O3, as well as gas and particle-phase ROS, were measured using a series of online instruments. PM2.5 concentrations during control days were significantly lower than non-control days, which directly lead to the "Parade Blue", yet reductions of most gaseous pollutants except SO2 were not so obvious as PM. Similarly, the control measures also led to a great loss of particle-phase ROS throughout the control period, while the reduction of ROS in gas phase was not obvious until the more stringent measures implemented since September 1. Furthermore, only weak positive correlations were observed among ROS and some other measured species, indicating ROS concentrations were affected by a number of comprehensive factors that single marker could not capture. Meanwhile, meteorological condition and regional transportation were also shown to be the minor factors affecting atmospheric oxidizing capacity. The results of this observation mainly revealed the control measures were conducive to reducing particle-related ROS. However, the reduction of gas-phase ROS activity was less effective given the menu of controls employed for the 2015 China Victory Day Parade. Therefore, short-term emissions controls only aimed to PM reduction and visibility improvement will produce the blue sky but will not equivalently reduce the gas-phase ROS. Supplemental control measures will be needed to further reduce gas-phase ROS concentrations.

  19. [Comparison of family functioning profile in adolescents with and without drug-dependency in a high school].

    PubMed

    Cruz-Salmerón, Víctor Hugo; Martínez-Martínez, Martha Leticia; Garibay-López, Leticia; Camacho-Calderón, Nicolás

    2011-02-01

    To compare the family functioning profile (FFP) in adolescents addicted to drugs and those not addicted to drugs. Cross-sectional study comparative. A high school in Querétaro State, Mexico. Study of 63 adolescents with and without addiction, of both sexes between the ages of 13 and 19, enrolled in high school; two groups formed, one not addicted to drugs (systematic probabilistic sampling was carried out); and compared with drug addicts (database). FFP(Alpha Cronbach 91). Descriptive and inferential statistical analysis. Adolescents with drug addiction (n=20), average age 17.5±0.4 (range 16-19), and group of non-addicts (n=43), average age 16.9±0.1 (range 15-18) and P=0.000. All the adolescents lived in an urban area with a predominantly simple nuclear modern, working family type. Half (50%) of addicted adolescents came from broken families P=0.002. The dispersion phase was a protective factor in preventing drug addiction in adolescents (P=0.003 OR 0.6 95% Cl;1.8-21.0). Significant statistical differences were observed in authority (OR=29.7, 95% Cl; 5.8-150.5), supervision (OR 10.3, 95% Cl; 2.8-37.2) and support (OR 0.04, 95% Cl; 5.5-109.8). The overall family dysfunctionality, (P=0.000, OR 1.8, 95% Cl; 1.3-2.3). Dysfunctional families are a risk factor for drug addiction in adolescents, when there is insufficient authority and supervision within the family. On the other hand, family support, as well as the dispersion phase, are protective factors. Copyright © 2010 Elsevier España, S.L. All rights reserved.

  20. Registration of interferometric SAR images

    NASA Technical Reports Server (NTRS)

    Lin, Qian; Vesecky, John F.; Zebker, Howard A.

    1992-01-01

    Interferometric synthetic aperture radar (INSAR) is a new way of performing topography mapping. Among the factors critical to mapping accuracy is the registration of the complex SAR images from repeated orbits. A new algorithm for registering interferometric SAR images is presented. A new figure of merit, the average fluctuation function of the phase difference image, is proposed to evaluate the fringe pattern quality. The process of adjusting the registration parameters according to the fringe pattern quality is optimized through a downhill simplex minimization algorithm. The results of applying the proposed algorithm to register two pairs of Seasat SAR images with a short baseline (75 m) and a long baseline (500 m) are shown. It is found that the average fluctuation function is a very stable measure of fringe pattern quality allowing very accurate registration.

  1. Analysis of In-Flight Vibration Measurements from Helicopter Transmissions

    NASA Technical Reports Server (NTRS)

    Mosher, Marianne; Huff, Ed; Barszcz

    2004-01-01

    In-flight vibration measurements from the transmission of an OH-58C KIOWA are analyzed. In order to understand the effect of normal flight variation on signal shape, the first gear mesh components of the planetary gear system and bevel gear are studied in detail. Systematic patterns occur in the amplitude and phase of these signal components with implications for making time synchronous averages and interpreting gear metrics in flight. The phase of the signal component increases as the torque increases; limits on the torque range included in a time synchronous average may now be selected to correspond to phase change limits on the underlying signal. For some sensors and components, an increase in phase variation and/or abrupt change in the slope of the phase dependence on torque are observed in regions of very low amplitude of the signal component. A physical mechanism for this deviation is postulated. Time synchronous averages should not be constructed in torque regions with wide phase variation.

  2. Acceleration of high resolution temperature based optimization for hyperthermia treatment planning using element grouping.

    PubMed

    Kok, H P; de Greef, M; Bel, A; Crezee, J

    2009-08-01

    In regional hyperthermia, optimization is useful to obtain adequate applicator settings. A speed-up of the previously published method for high resolution temperature based optimization is proposed. Element grouping as described in literature uses selected voxel sets instead of single voxels to reduce computation time. Elements which achieve their maximum heating potential for approximately the same phase/amplitude setting are grouped. To form groups, eigenvalues and eigenvectors of precomputed temperature matrices are used. At high resolution temperature matrices are unknown and temperatures are estimated using low resolution (1 cm) computations and the high resolution (2 mm) temperature distribution computed for low resolution optimized settings using zooming. This technique can be applied to estimate an upper bound for high resolution eigenvalues. The heating potential of elements was estimated using these upper bounds. Correlations between elements were estimated with low resolution eigenvalues and eigenvectors, since high resolution eigenvectors remain unknown. Four different grouping criteria were applied. Constraints were set to the average group temperatures. Element grouping was applied for five patients and optimal settings for the AMC-8 system were determined. Without element grouping the average computation times for five and ten runs were 7.1 and 14.4 h, respectively. Strict grouping criteria were necessary to prevent an unacceptable exceeding of the normal tissue constraints (up to approximately 2 degrees C), caused by constraining average instead of maximum temperatures. When strict criteria were applied, speed-up factors of 1.8-2.1 and 2.6-3.5 were achieved for five and ten runs, respectively, depending on the grouping criteria. When many runs are performed, the speed-up factor will converge to 4.3-8.5, which is the average reduction factor of the constraints and depends on the grouping criteria. Tumor temperatures were comparable. Maximum exceeding of the constraint in a hot spot was 0.24-0.34 degree C; average maximum exceeding over all five patients was 0.09-0.21 degree C, which is acceptable. High resolution temperature based optimization using element grouping can achieve a speed-up factor of 4-8, without large deviations from the conventional method.

  3. 7 CFR 1437.11 - Average market price and payment factors.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Average market price and payment factors. 1437.11... ASSISTANCE PROGRAM General Provisions § 1437.11 Average market price and payment factors. (a) An average... average market price by the applicable payment factor (i.e., harvested, unharvested, or prevented planting...

  4. Cycle-Averaged Phase-Space States for the Harmonic and the Morse Oscillators, and the Corresponding Uncertainty Relations

    ERIC Educational Resources Information Center

    Nicolaides, Cleanthes A.; Constantoudis, Vasilios

    2009-01-01

    In Planck's model of the harmonic oscillator (HO) a century ago, both the energy and the phase space were quantized according to epsilon[subscript n] = nhv, n = 0, 1, 2..., and [double integral]dp[subscript x] dx = h. By referring to just these two relations, we show how the adoption of "cycle-averaged phase-space states" (CAPSSs) leads to the…

  5. Factors that affect the flow of patients through triage.

    PubMed

    Lyons, Melinda; Brown, Ruth; Wears, Robert

    2007-02-01

    To use observational methods to objectively evaluate the organisation of triage and what issues may affect the effectiveness of the process. A two-phase study comprising observation of 16 h of triage in a London hospital emergency department and interviews with the triage staff to build a qualitative task analysis and study protocol for phase 2; observation and timing in triage for 1870 min including 257 patients and for 16 different members of the triage staff. No significant difference was found between grades of staff for the average triage time or the fraction of time absent from triage. In all, 67% of the time spent absent from triage was due to escorting patients into the department. The average time a patient waited in the reception before triage was 13 min 34 s; the average length of time to triage for a patient was 4 min 17 s. A significant increase in triage time was found when patients were triaged to a specialty, expected by a specialty, or were actively "seen and treated" in triage. Protocols to prioritise patients with potentially serious conditions to the front of the queue had a significantly positive effect on their waiting time. Supplementary tasks and distractions had varying effects on the timely assessment and triage of patients. The human factors method is applicable to the triage process and can identify key factors that affect the throughput at triage. Referring a patient to a specialty at triage affects significantly the triage workload; hence, alternative methods or management should be suggested. The decision to offer active treatment at triage increases the time taken, and should be based on clinical criteria and the workload determined by staffing levels. The proportion of time absent from triage could be markedly improved by support from porters or other non-qualified staff, as well as by proceduralised handovers from triage to the main clinical area. Triage productivity could be improved by all staff by becoming aware of the effect of the number of interruptions on the throughput of patients.

  6. [SWOT analysis: the analytical method in the process of planning and its application in the development of orthopaedic hospital department].

    PubMed

    Terzić, Zorica; Vukasinović, Zoran; Bjegović-Mikanović, Vesna; Jovanović, Vesna; Janicić, Radmila

    2010-01-01

    SWOT analysis is a managerial tool used to evaluate internal and external environment through strengths and weaknesses, opportunities and threats. The aim was to demonstrate the application of the SWOT analysis on the example of the Department for Paediatric Orthopaedics and Traumatology at the Institute of Orthopaedic Surgery "Banjica" in Belgrade. Qualitative research was conducted during December 2008 at the Department for Paediatric Orthopaedics and Traumatology of the Institute of Orthopaedic Surgery "Banjica" by applying the focus group technique. Participants were members of the medical staff and patients. In the first phase of the focus group brainstorming was applied to collect the factors of internal and external environment, and to identify strengths and weaknesses, opportunities and threats, respectively. In the second phase the nominal group technique was applied in order to reduce the list of factors. The factors were assessed according to their influence on the Department. Factors ranked by the three point Likert scale from 3 (highest impact) to 1 (lowest impact). The most important strengths of the Department are competent and skilled staff, high quality of services, average hospital bed utilization, the Department providing the educational basis of the School of Medicine, satisfied patients, pleasant setting, and additional working hours. The weaknesses are: poor spatial organization, personnel unmotivated to refresh knowledge, lack of specifically trained personnel, inadequate sanitary facilities, and uncovered services by the Insurance Fund, long average hospital stay, and low economic status of patients. The opportunities are: legislative regulations, formed paediatric traumatology service at the City level, good regional position of the Institute, and extension of referral areas. The threats are: absent Department autonomy in the personnel policy of the Institute, competitions within the Institute, impossibility to increase the Department capacities, inadequate nutrition, low opportunities for expert training of the personnel, outdated equipment, and presence of informal payments. SWOT analysis is a frequently used managerial instrument, which enables the systematic approach in decision making process.

  7. Sensitivity of Cirrus and Mixed-phase Clouds to the Ice Nuclei Spectra in McRAS-AC: Single Column Model Simulations

    NASA Technical Reports Server (NTRS)

    Betancourt, R. Morales; Lee, D.; Oreopoulos, L.; Sud, Y. C.; Barahona, D.; Nenes, A.

    2012-01-01

    The salient features of mixed-phase and ice clouds in a GCM cloud scheme are examined using the ice formation parameterizations of Liu and Penner (LP) and Barahona and Nenes (BN). The performance of LP and BN ice nucleation parameterizations were assessed in the GEOS-5 AGCM using the McRAS-AC cloud microphysics framework in single column mode. Four dimensional assimilated data from the intensive observation period of ARM TWP-ICE campaign was used to drive the fluxes and lateral forcing. Simulation experiments where established to test the impact of each parameterization in the resulting cloud fields. Three commonly used IN spectra were utilized in the BN parameterization to described the availability of IN for heterogeneous ice nucleation. The results show large similarities in the cirrus cloud regime between all the schemes tested, in which ice crystal concentrations were within a factor of 10 regardless of the parameterization used. In mixed-phase clouds there are some persistent differences in cloud particle number concentration and size, as well as in cloud fraction, ice water mixing ratio, and ice water path. Contact freezing in the simulated mixed-phase clouds contributed to transfer liquid to ice efficiently, so that on average, the clouds were fully glaciated at T approximately 260K, irrespective of the ice nucleation parameterization used. Comparison of simulated ice water path to available satellite derived observations were also performed, finding that all the schemes tested with the BN parameterization predicted 20 average values of IWP within plus or minus 15% of the observations.

  8. Assessment of the menstrual cycle upon total hemoglobin, water concentration, and oxygen saturation in the female breast

    NASA Astrophysics Data System (ADS)

    Jiang, Shudong; Pogue, Brian W.; Srinivasan, Subhadra; Soho, Sandra; Poplack, Steven P.; Tosteson, Tor D.; Paulsen, Keith D.

    2003-07-01

    Near-infrared imaging can be used in humans to characterize changes in breast tumor tissue by imaging total hemoglobin and water concentrations as well as oxygen saturation. In order to improve our understanding of these changes, we need to carefully quantify the range of variation possible in normal tissues for these parameters. In this study, the effect of the subject"s menstrual cycle was examined by imaging their breast at the follicular (7-14 days of the cycle) and secretory phases (21-28 days of the cycle), using our NIR tomographic system. In this system, a three layer patient interface is used to measure 3 planes along the breast from chest wall towards the nipple at 1cm increments. Seven volunteers in their 40s were observed for 2 menstrual cycles and all of these volunteers recently had normal mammograms (ACR 1) with heterogeneously dense breast composition. The results show that average total hemoglobin in the breast increased in many subjects between 0 to 15% from the follicular phase to secretory phase. Oxygen saturation and water concentration changes between these 2 parts of the cycle were between -6.5% to 12% for saturation and between -33% to 28% for water concentration. While the data averaged between subjects showed no significant change existed between phases, it was clear that individual subjects did exhibit changes in composition which were consistent from cycle to cycle. Understanding what leads to this heterogeneity between subjects will be an important factor in utilizing these measurements in clinical practice.

  9. Evaluating the role of phase I expansion cohorts in oncologic drug development.

    PubMed

    Norris, Robin E; Behtaj, Mohadese; Fu, Pingfu; Dowlati, Afshin

    2017-02-01

    Importance Use of expansion cohorts (EC) in phase I trials is increasing. However, the utility of phase I EC in aiding drug development is unclear. We sought to determine factors associated with the inclusion of EC in phase I studies and the impact of EC on subsequent clinical development. Methods We performed a systematic review of all phase I trials published in the Journal of Clinical Oncology between June 2004 and May 2014. Presence of an EC, number of participants, funding source, class of agent, tumor type, and maximum tolerated dose (MTD)/recommended phase 2 dose (RP2D) were identified. Subsequent conduct of phase II studies and FDA approval of the study agent was also assessed. Results We identified 252 phase I studies. An EC was included in 105 studies. Average accrual on EC studies was 47 compared to 31 in studies without EC (p < 0.0001). There was no impact of time on the inclusion of EC. Only 4 % of phase I studies with an EC provided sample size justification. Source of funding had the only significant association with inclusion of EC. Addition of a phase I EC did not impact the phase I MTD/RP2D, subsequent phase II trial, or FDA approval. Conclusion The importance of including an EC in phase I trials is subject to ongoing debate. Our results demonstrated little benefit to including EC in phase I studies. These findings support that innovative design strategies are needed to optimize the utility of EC in phase I studies.

  10. Coincidence probability as a measure of the average phase-space density at freeze-out

    NASA Astrophysics Data System (ADS)

    Bialas, A.; Czyz, W.; Zalewski, K.

    2006-02-01

    It is pointed out that the average semi-inclusive particle phase-space density at freeze-out can be determined from the coincidence probability of the events observed in multiparticle production. The method of measurement is described and its accuracy examined.

  11. Ensemble Sampling vs. Time Sampling in Molecular Dynamics Simulations of Thermal Conductivity

    DOE PAGES

    Gordiz, Kiarash; Singh, David J.; Henry, Asegun

    2015-01-29

    In this report we compare time sampling and ensemble averaging as two different methods available for phase space sampling. For the comparison, we calculate thermal conductivities of solid argon and silicon structures, using equilibrium molecular dynamics. We introduce two different schemes for the ensemble averaging approach, and show that both can reduce the total simulation time as compared to time averaging. It is also found that velocity rescaling is an efficient mechanism for phase space exploration. Although our methodology is tested using classical molecular dynamics, the ensemble generation approaches may find their greatest utility in computationally expensive simulations such asmore » first principles molecular dynamics. For such simulations, where each time step is costly, time sampling can require long simulation times because each time step must be evaluated sequentially and therefore phase space averaging is achieved through sequential operations. On the other hand, with ensemble averaging, phase space sampling can be achieved through parallel operations, since each ensemble is independent. For this reason, particularly when using massively parallel architectures, ensemble sampling can result in much shorter simulation times and exhibits similar overall computational effort.« less

  12. Graphical method to design multilayer phase retarders.

    PubMed

    Apfel, J H

    1981-03-15

    When multilayer reflectors are used at nonnormal incidence, the two planes of polarization generally have different phase shifts. This difference, known as phase retardance, depends on the multilayer design, the incidence angle, and the wavelength. Heretofore, the design of reflectors with specific phase retardance has been carried out by computer optimization except for the case of a single layer on a metal substrate. A graph of phase retardance D vs the average phase shift A as a function of layer thickness provides a means for visualization that is useful in reflector designs. A D-A graph predicts the phase properties of a reflector as a function of the index and thickness of an added layer. Graphs of phase retardance vs average phase for two different materials can be superposed to predict the composite performance of a multilayer reflector. This graphical technique is employed to design and analyze reflectors with specified phase retardance.

  13. A proposed method for wind velocity measurement from space

    NASA Technical Reports Server (NTRS)

    Censor, D.; Levine, D. M.

    1980-01-01

    An investigation was made of the feasibility of making wind velocity measurements from space by monitoring the apparent change in the refractive index of the atmosphere induced by motion of the air. The physical principle is the same as that resulting in the phase changes measured in the Fizeau experiment. It is proposed that this phase change could be measured using a three cornered arrangement of satellite borne source and reflectors, around which two laser beams propagate in opposite directions. It is shown that even though the velocity of the satellites is much larger than the wind velocity, factors such as change in satellite position and Doppler shifts can be taken into account in a reasonable manner and the Fizeau phase measured. This phase measurement yields an average wind velocity along the ray path through the atmosphere. The method requires neither high accuracy for satellite position or velocity, nor precise knowledge of the refractive index or its gradient in the atmosphere. However, the method intrinsically yields wind velocity integrated along the ray path; hence to obtain higher spatial resolution, inversion techniques are required.

  14. Growth and development of spring towers at Shiqiang, Yunnan Province, China

    NASA Astrophysics Data System (ADS)

    Jones, Brian; Peng, Xiaotong

    2017-01-01

    Throughout the world, high artesian pressures in hydrothermal areas have led to the growth of tall spring towers that have their vents at their summits. The factors that control their development and formative precipitates are poorly understood because these springs, irrespective of location, are mostly inactive. Spring towers found at Shiqiang (Yunnan Province, China), which are up to 4 m high and 3 m in diameter, are formed largely of calcite and aragonite crystal bushes, euhedral calcite crystals and coated grains with alternating Fe-poor and Fe-rich zones, calcite rafts, and cements formed of various combinations of calcite, aragonite, strontianite, Mg-Si reticulate, needle fiber calcite, calcified and non-calcified microbes, diatoms, and insects. Collectively, the limestones that form the towers can be divided into (1) Group A that are friable, porous and form the cores of the towers and have δ18OSMOW values of + 15.7 to + 19.7‰ (average 17.8‰) and δ13CPDB values of + 5.1 to + 6.9‰ (average 5.9‰), and (2) Group B that are hard and well lithified and found largely around the vents and the tower sides, and have δ18OSMOW values of + 13.0 to + 22.0‰ (average 17.6‰) and δ13CPDB values of + 1.4 to + 3.6‰ (average 2.6‰). The precipitates and the isotopic values indicate that these were thermogene springs. Growth of the Shiqiang spring towers involved (1) Phase IA when precipitation of calcite and aragonite bushes formed the core of the tower and Phase IB when calcite, commonly Fe-rich, was precipitated locally, (2) Phase II that involved the precipitation of white cements, formed of calcite, aragonite, strontianite, and Mg-Si reticulate coatings in cavities amid the Phase I precipitates, and (3) Phase III, which formed probably after spring activity ceased, when needle-fiber calcite was precipitated and the mounds were invaded by microbes (some now calcified), diatoms, and insects. At various times during this complex history, pore waters mediated dissolution of the calcite and aragonite and sometimes partial alteration of the aragonite. The diverse array of precipitates, depositional fabrics and diagenetic changes clearly indicate that the composition of the spring water changed frequently. Growth of the spring towers at Shiqiang continued until there was insufficient artesian pressure to lift the water above the top of the tower vent.

  15. The influence of lumbar extensor muscle fatigue on lumbar-pelvic coordination during weightlifting.

    PubMed

    Hu, Boyi; Ning, Xiaopeng

    2015-01-01

    Lumbar muscle fatigue is a potential risk factor for the development of low back pain. In this study, we investigated the influence of lumbar extensor muscle fatigue on lumbar-pelvic coordination patterns during weightlifting. Each of the 15 male subjects performed five repetitions of weightlifting tasks both before and after a lumbar extensor muscle fatiguing protocol. Lumbar muscle electromyography was collected to assess fatigue. Trunk kinematics was recorded to calculate lumbar-pelvic continuous relative phase (CRP) and CRP variability. Results showed that fatigue significantly reduced the average lumbar-pelvic CRP value (from 0.33 to 0.29 rad) during weightlifting. The average CRP variability reduced from 0.17 to 0.15 rad, yet this change ws statistically not significant. Further analyses also discovered elevated spinal loading during weightlifting after the development of lumbar extensor muscle fatigue. Our results suggest that frequently experienced lumbar extensor muscle fatigue should be avoided in an occupational environment. Lumbar extensor muscle fatigue generates more in-phase lumbar-pelvic coordination patterns and elevated spinal loading during lifting. Such increase in spinal loading may indicate higher risk of back injury. Our results suggest that frequently experienced lumbar muscle fatigue should be avoided to reduce the risk of LBP.

  16. Risk Perception and Risk Communication for Training Women Apprentice Welders: A Challenge for Public Health Nursing

    PubMed Central

    Bonow, Clarice Alves; Cezar-Vaz, Marta Regina; de Almeida, Marlise Capa Verde; Rocha, Laurelize Pereira; Borges, Anelise Miritz; Piexak, Diéssica Roggia; Vaz, Joana Cezar

    2013-01-01

    This research has aimed to identify the perceptions of women apprentice welders about physical, chemical, biological, and physiological risk factors to which they are exposed and evaluate the identification of health disorders self-reported for women apprentice welders before and after implementation of a nursing socioenvironmental intervention. A quantitative study was performed with 27 women apprentice welders (first phase) and before and after an intervention with 18 women (second phase) in Southern Brazil in 2011. The data were analysed using SPSS 19.0. The participants identified the following risk types: physical (96.2%), chemical (96.2%), physiological (88.8%), and biological (62.9%). The results show a significant difference of the pre- and posttest averages for the musculoskeletal system and a posttest average increase for the integumentary, respiratory, and auditory system. A correlation of the women apprentices' ages and the identification of health disorders were made. It was understood that the perception of women apprentices regarding a particular set of occupational risks is essential for public health nursing to develop an effective risk communication as a positive tool for teaching and learning. PMID:24288604

  17. Structure of high alumina content Al2O3-SiO2 composition glasses.

    PubMed

    Weber, Richard; Sen, Sabyasachi; Youngman, Randall E; Hart, Robert T; Benmore, Chris J

    2008-12-25

    The structure of binary aluminosilicate glasses containing 60-67 mol % Al2O3 were investigated using high-resolution 27Al NMR and X-ray and neutron diffraction. The glasses were made by aerodynamic levitation of molten oxides. The 67% alumina composition required a cooling rate of approximately 1600 degrees C s(1-) to form glass from submillimeter sized samples. NMR results show that the glasses contain aluminum in 4-, 5-, and 6-fold coordination in the approximate ratio 4:5:1. The average Al coordination increases from 4.57 to 4.73 as the fraction of octahedral Al increases with alumina content. The diffraction results on the 67% composition are consistent with a disordered Al framework with Al ions in a range of coordination environments that are substantially different from those found in the equilibrium crystalline phases. Analysis of the neutron and X-ray structure factors yields an average bond angle of 125 +/- 4 degrees between an Al ion and the adjoining cation via a bridging oxygen. We propose that the structure of the glass is a "transition state" between the alumina-rich liquid and the equilibrium mullite phase that are dominated by 4- and 6-coordinated aluminum ions, respectively.

  18. The effect of mortality salience on women's judgments of male faces.

    PubMed

    Vaughn, James E; Bradley, Kristopher I; Byrd-Craven, Jennifer; Kennison, Shelia M

    2010-08-30

    Previous research has shown that individuals who are reminded of their death exhibited a greater desire for offspring than those who were not reminded of their death. The present research investigated whether being reminded of mortality affects mate selection behaviors, such as facial preference judgments. Prior research has shown that women prefer more masculine faces when they are at the high versus low fertility phase of their menstrual cycles. We report an experiment in which women were tested either at their high or fertility phase. They were randomly assigned to either a mortality salience (MS) or control condition and then asked to judge faces ranging from extreme masculine to extreme feminine. The results showed that women's choice of the attractive male face was determined by an interaction between fertility phase and condition. In control conditions, high fertility phase women preferred a significantly more masculine face than women who were in a lower fertility phase of their menstrual cycles. In MS conditions, high fertility phase women preferred a significantly less masculine (i.e., more average) face than women who were in a low fertility phase. The results indicate that biological processes, such as fertility phase, involved in mate selection are sensitive to current environmental factors, such as death reminders. This sensitivity may serve as an adaptive compromise when choosing a mate in potentially adverse environmental conditions.

  19. Pre-admission criteria and pre-clinical achievement: Can they predict medical students performance in the clinical phase?

    PubMed

    Salem, Raneem O; Al-Mously, Najwa; AlFadil, Sara; Baalash, Amal

    2016-01-01

    Various factors affect medical students' performance during clinical phase. Identifying these factors would help in mentoring weak students and help in selection process for residency programmes. Our study objective is to evaluate the impact of pre-admission criteria, and pre-clinical grade point average (GPA) on undergraduate medical students' performance during clinical phase. This study has a cross-sectional design that includes fifth- and sixth-year female medical students (71). Data of clinical and pre-clinical GPA in medical school and pre-admission to medical school tests scores were collected. A significant correlation between clinical GPA with the pre-clinical GPA was observed (p < 0.05). Such significant correlation was not seen with other variables under study. A regression analysis was performed, and the only significant predictor of students clinical performance was the pre-clinical GPA (p < 0.001). However, no significant difference between students' clinical and pre-clinical GPA for both cohorts was observed (p > 0.05). Pre-clinical GPA is strongly correlated with and can predict medical students' performance during clinical years. Our study highlighted the importance of evaluating the academic performances of students in pre-clinical years before they move into clinical years in order to identify weak students to mentor them and monitor their progress.

  20. Shed Vortex Structure and Phase-Averaged Velocity Statistics in Symmetric/Asymmetric Turbulent Flat Plate Wakes

    NASA Technical Reports Server (NTRS)

    Rai, Man Mohan

    2017-01-01

    The near wake of a flat plate is investigated via direct numerical simulations (DNS). Many earlier experimental investigations have used thin plates with sharp trailing edges and turbulent boundary layers to create the wake. This results in large theta divided by D (sub TE) values (theta is the boundary layer momentum thickness towards the end of the plate and D (sub TE) is the trailing edge thickness). In the present study the emphasis is on relatively thick plates with circular trailing edges (CTE) resulting in theta divided by D values less than one (D is the plate thickness and the diameter of the CTE), and vigorous vortex shedding. The Reynolds numbers based on the plate length and D are 1.255 x 10 (sup 6) and 10,000, respectively. Two cases are computed; one with turbulent boundary layers on both the upper and lower surfaces of the plate (statistically the same, symmetric wake, Case TT) and, a second with turbulent and laminar boundary layers on the upper and lower surfaces, respectively (asymmetric case, Case TL). The data and understanding obtained is of considerable engineering interest, particularly in turbomachinery where the pressure side of an airfoil can remain laminar or transitional because of a favorable pressure gradient and the suction side is turbulent. Shed-vortex structure and phase-averaged velocity statistics obtained in the two cases are compared here. The upper negative shed vortices in Case TL (turbulent separating boundary layer) are weaker than the lower positive ones (laminar separating boundary layer) at inception (a factor 1.27 weaker in terms of peak phase-averaged spanwise vorticity at first appearance of a peak). The upper vortices weaken rapidly as they travel downstream. A second feature of interest in Case TL is a considerable increase in the peak phase-averaged, streamwise normal intensity (random component) with increasing streamwise distance (x divided by D) that occurs nears the positive vortex cores. This behavior is observed for a few diameters in the near wake. This is counter to Case TT where the peak value essentially decreases with increasing x divided by D. Both these effects are examined in detail and the important contributors are identified.

  1. Photometric properties of comet 67P/Churyumov-Gerasimenko from VIRTIS-M onboard Rosetta

    NASA Astrophysics Data System (ADS)

    Ciarniello, M.; Capaccioni, F.; Filacchione, G.; Raponi, A.; Tosi, F.; De Sanctis, M. C.; Capria, M. T.; Erard, S.; Bockelee-Morvan, D.; Leyrat, C.; Arnold, G.; Barucci, A.; Beck, P.; Bellucci, G.; Fornasier, S.; Longobardo, A.; Mottola, S.; Palomba, E.; Quirico, E.; Schmitt, B.

    2015-11-01

    Aims: We investigate the nucleus photometric properties of the comet 67P/Churyumov-Gerasimenko as observed by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) onboard the Rosetta spacecraft. Both full-disk and disk-resolved images of the comet have been analyzed, deriving light and phase curves as well as a photometric reduction of the radiance factor (I/F) to single scattering albedo (SSA) in the 0.4-3.5 μm range. Methods: Hyperspectral cubes from VIRTIS were calibrated and corrected for instrumental artifacts. We computed integrated fluxes from full-disk acquisitions to derive nucleus light curves and phase curves at low phase angles (1.2°<α < 14.9°). Disk-resolved observations in the phase angle range 27.2°<α< 111.5° were reduced to SSA by means of a simplified Hapke model, deriving average spectrophotometric properties of the surface and producing SSA maps at different wavelengths. Spectral phase reddening in the visible (VIS) and infrared (IR) ranges was measured. Finally, full-disk and disk-resolved data were used together to derive a phase curve of the nucleus in the 1.2°<α < 111.5° range. Results: We measure an asymmetric double-peaked light curve that is due to the elongated shape of the nucleus. The average SSA albedo shows a reddish spectrum with a strong absorption feature centered at 3.2 μm, while the surface exhibits a backscattering behavior. The derived geometric albedo is Ageo = 0.062 ± 0.002 at 0.55 μm, indicating a very dark surface. Phase reddening is significant both in the VIS and IR ranges, and we report spectral slopes of 0.20/kÅ and 0.033/kÅ, respectively, after applying photometric reduction. SSA maps indicate that Hapi and Imothep regions are the brightest in the VIS, with the former showing a bluer spectrum with respect to the rest of the surface. The phase curve of the nucleus shows a strong opposition effect, with β = 0.077 ± 0.002 for α < 15°.

  2. Survival and growth of epidemically successful and nonsuccessful Salmonella enterica clones after freezing and dehydration.

    PubMed

    Müller, Karoline; Aabo, Søren; Birk, Tina; Mordhorst, Hanne; Bjarnadóttir, Björg; Agersø, Yvonne

    2012-03-01

    The spread of epidemically successful nontyphoidal Salmonella clones has been suggested as the most important cause of salmonellosis in industrialized countries. Factors leading to the emergence of success clones are largely unknown, but their ability to survive and grow after physical stress may contribute. During epidemiological studies, a mathematical model was developed that allowed estimation of a factor (q) accounting for the relative ability of Salmonella serovars with different antimicrobial resistances to survive in the food chain and cause human disease. Based on this q-factor, 26 Salmonella isolates were characterized as successful or nonsuccessful. We studied the survival and growth of stationary- and exponential-phase cells of these isolates after freezing for up to 336 days in minced meat. We also investigated survival and growth after dehydration at 10°C and 82% relative humidity (RH) and 25°C and 49% RH for 112 days. Stationary-phase cells were reduced by less than 1 log unit during 1 year of freezing, and growth was initiated with an average lag phase of 1.7 h. Survival was lower in exponentialphase cells, but lag phases tended to be shorter. High humidity and low temperature were less harmful to Salmonella than were low humidity and high temperature. Tolerance to adverse conditions was highest for Salmonella Infantis and one Salmonella Typhimurium U292 isolate and lowest for Salmonella Derby and one Salmonella Typhimurium DT170 isolate. Dehydration, in contrast to freezing, was differently tolerated by the Salmonella strains in this study, but tolerance to freezing and dehydration does not appear to contribute to the emergence of successful Salmonella clones.

  3. A single center analysis of factors influencing study start-up timeline in clinical trials.

    PubMed

    Krafcik, Brianna M; Doros, Gheorghe; Malikova, Marina A

    2017-11-01

    Efficient start-up phase in clinical trials is crucial to execution. The goal was to determine factors contributing to delays. The start-up milestones were assessed for 38 studies and analyzed. Total start-up time was shorter for following studies: device trials, no outsourcing, fewer ancillary services used and in interventional versus observational designs. The use of a centralized Institutional Review Board (IRB) versus a local IRB reduced time to approval. Studies that never enrolled took longer on average to finalize their budget/contract, and obtain IRB than ones that did enroll. Different features of clinical trials can affect timeline of start-up process. An understanding of the impact of each feature allows for optimization.

  4. Mean phase predictor for maximum a posteriori demodulator

    NASA Technical Reports Server (NTRS)

    Altes, Richard A. (Inventor)

    1996-01-01

    A system and method for optimal maximum a posteriori (MAP) demodulation using a novel mean phase predictor. The mean phase predictor conducts cumulative averaging over multiple blocks of phase samples to provide accurate prior mean phases, to be input into a MAP phase estimator.

  5. Averaged variational principle for autoresonant Bernstein-Greene-Kruskal modes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Khain, P.; Friedland, L.

    2010-10-15

    Whitham's averaged variational principle is applied in studying dynamics of formation of autoresonant (continuously phase-locked) Bernstein-Greene-Kruskal (BGK) modes in a plasma driven by a chirped frequency ponderomotive wave. A flat-top electron velocity distribution is used as a model allowing a variational formulation within the water bag theory. The corresponding Lagrangian, averaged over the fast phase variable yields evolution equations for the slow field variables, allows uniform description of all stages of excitation of driven-chirped BGK modes, and predicts modulational stability of these nonlinear phase-space structures. Numerical solutions of the system of slow variational equations are in good agreement with Vlasov-Poissonmore » simulations.« less

  6. Crystal structure across the β to α phase transition in thermoelectric Cu 2–xSe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Eikeland, Espen; Blichfeld, Anders B.; Borup, Kasper A.

    Here, the crystal structure uniquely imparts the specific properties of a material, and thus provides the starting point for any quantitative understanding of thermoelectric properties. Cu 2–xSe is an intensely studied high performing, non-toxic and cheap thermoelectric material, and here for the first time, the average structure of β-Cu 2–xSe is reported based on analysis of multi-temperature single-crystal X-ray diffraction data. It consists of Se–Cu layers with additional copper between every alternate layer. The structural changes during the peculiar zT enhancing phase transition mainly consist of changes in the inter-layer distance coupled with subtle Cu migration. Just prior to themore » transition the structure exhibits strong negative thermal expansion due to the reordering of Cu atoms, when approached from low temperatures. The phase transition is fully reversible and group–subgroup symmetry relations are derived that relate the low-temperature β-phase to the high-temperature α-phase. Weak superstructure reflections are observed and a possible Cu ordering is proposed. The structural rearrangement may have a significant impact on the band structure and the Cu rearrangement may also be linked to an entropy increase. Both factors potentially contribute to the extraordinary zT enhancement across the phase transition.« less

  7. Crystal structure across the β to α phase transition in thermoelectric Cu 2–xSe

    DOE PAGES

    Eikeland, Espen; Blichfeld, Anders B.; Borup, Kasper A.; ...

    2017-06-13

    Here, the crystal structure uniquely imparts the specific properties of a material, and thus provides the starting point for any quantitative understanding of thermoelectric properties. Cu 2–xSe is an intensely studied high performing, non-toxic and cheap thermoelectric material, and here for the first time, the average structure of β-Cu 2–xSe is reported based on analysis of multi-temperature single-crystal X-ray diffraction data. It consists of Se–Cu layers with additional copper between every alternate layer. The structural changes during the peculiar zT enhancing phase transition mainly consist of changes in the inter-layer distance coupled with subtle Cu migration. Just prior to themore » transition the structure exhibits strong negative thermal expansion due to the reordering of Cu atoms, when approached from low temperatures. The phase transition is fully reversible and group–subgroup symmetry relations are derived that relate the low-temperature β-phase to the high-temperature α-phase. Weak superstructure reflections are observed and a possible Cu ordering is proposed. The structural rearrangement may have a significant impact on the band structure and the Cu rearrangement may also be linked to an entropy increase. Both factors potentially contribute to the extraordinary zT enhancement across the phase transition.« less

  8. Chesapeake Bay Low Freshwater Inflow Study. Phase II. MAP FOLIO. Biota Assessment.

    DTIC Science & Technology

    1982-05-01

    conditions. These were: 1) Base Average -- average freshwater inflow conditions. by increased water consumption projected for the year 2020. 3) Base Drought...RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS. 1963- A TAI m - ii J May 1982 Chesapeake Bay Low Freshwater Inflow Study Phase II Biota Assessment Map...A PERIOD ZOVERED change was found to CIESAPEAKE BAY LOW FRESHWATER INFLOW STUDY FINAL BIOTA ASSESSMENT PHASE II: FINAL REPORT MAP FOLIO s PERFORMING

  9. Singing in the moonlight: dawn song performance of a diurnal bird varies with lunar phase

    PubMed Central

    York, Jennifer E.; Young, Andrew J.; Radford, Andrew N.

    2014-01-01

    It is well established that the lunar cycle can affect the behaviour of nocturnal animals, but its potential to have a similar influence on diurnal species has received less research attention. Here, we demonstrate that the dawn song of a cooperative songbird, the white-browed sparrow weaver (Plocepasser mahali), varies with moon phase. When the moon was above the horizon at dawn, males began singing on average 10 min earlier, if there was a full moon compared with a new moon, resulting in a 67% mean increase in performance period and greater total song output. The lack of a difference between full and new moon dawns when the moon was below the horizon suggests that the observed effects were driven by light intensity, rather than driven by other factors associated with moon phase. Effects of the lunar cycle on twilight signalling behaviour have implications for both pure and applied animal communication research. PMID:24429683

  10. Heat transfer and pressure drop of condensation of hydrocarbons in tubes

    NASA Astrophysics Data System (ADS)

    Fries, Simon; Skusa, Severin; Luke, Andrea

    2018-03-01

    The heat transfer coefficient and pressure drop are investigated for propane. Two different mild steel plain tubes and saturation pressures are considered for varying mass flux and vapour quality. The pressure drop is compared to the Friedel-Correlation with two different approaches to determine the friction factor. The first is calculation as proposed by Friedel and the second is through single phase pressure drop investigations. For lower vapour qualities the experimental results are in better agreement with the approach of the calculated friction factor. For higher vapour qualities the experimental friction factor is more precise. The pressure drop increases for a decreasing tube diameter and saturation pressure. The circumferential temperature profile and heat transfer coefficients are shown for a constant vapour quality at varying mass fluxes. The subcooling is highest for the bottom of the tube and lowest for the top. The average subcooling as well as the circumferential deviation decreases for rising mass fluxes. The averaged heat transfer coefficients are compared to the model proposed by Thome and Cavallini. The experimental results are in good agreement with both correlations, however the trend is better described with the correlation from Thome. The experimental heat transfer coefficients are under predicted by Thome and over predicted by Cavallini.

  11. Phase measurement system using a dithered clock

    DOEpatents

    Fairley, C.R.; Patterson, S.R.

    1991-05-28

    A phase measurement system is disclosed which measures the phase shift between two signals by dithering a clock signal and averaging a plurality of measurements of the phase differences between the two signals. 8 figures.

  12. Effects of the rate of releases from Sam Rayburn Reservoir on the Aeration Capacity of the Angelina River, eastern Texas

    USGS Publications Warehouse

    Rawson, Jack; Goss, Richard L.; Rathbun, Ira G.

    1980-01-01

    A three-phase study was conducted during July and August 1979 to determine the effects of varying release rates through the power-outlet works at Sam Rayburn Reservoir, eastern Texas, on aeration capacity of a 14-mile reach of the Angelina River below Sam Rayburn Dam. The dominant factors that affected the aeration capacity during the study time were time of travel and the dissolved-oxygen deficit of the releases. Aeration was low throughout the study but increased in response to increases in the dissolved-oxygen deficit and the duration of time that the releases were exposed to the atmosphere (time of travel). The average concentration of dissolved oxygen sustained by release of 8,800 cubic feet per second decreased from 5.0 milligrams per liter at a site near the power outlet to 4.8 milligrams per liter at a site about 14 miles downstream; the time of travel averaged about 8 hours. The average concentration of dissolved oxygen in flow sustained by releases of 2,200 cubic feet per second increased from 5.2 to 5.5 milligrams per liter; the time of travel averaged about 20 hours. (USGS)

  13. Comparison and Correlation of Subsurface Media Properties Reflected in Both Extracted Soil Pore Water From Sectioned Cores and Homogenized Groundwater From Monitoring Wells

    NASA Astrophysics Data System (ADS)

    Moon, J. W.; Paradis, C. J.; von Netzer, F.; Dixon, E.; Majumder, E.; Joyner, D.; Zane, G.; Fitzgerald, K.; Xiaoxuan, G.; Thorgersen, M. P.; Lui, L.; Adams, B.; Brewer, S. S.; Williams, D.; Lowe, K. A.; Rodriguez, M., Jr.; Mehlhorn, T. L.; Pfiffner, S. M.; Chakraborty, R.; Arkin, A. P.; Terry, A. Y.; Wall, J. D.; Stahl, D. A.; Elias, D. A.; Hazen, T. C.

    2017-12-01

    Conventional monitoring wells have produced useful long-term data about the contaminants, carbon flux, microbial population and their evolution. The averaged homogenized groundwater matrix from these wells is insufficient to represent all media properties in subsurface. This pilot study investigated the solid, liquid and gas phases from soil core samples from both uncontaminated and contaminated areas of the ENIGMA field research site at Oak Ridge, Tennessee. We focused on a site-specific assessment with depth perspective that included soil structure, soil minerals, major and trace elements and biomass for the solid phase; centrifuged soil pore water including cations, anions, organic acid, pH and conductivity for the liquid phase; and gas (CO2, CH4, N2O) evolution over a 4 week incubation with soil and unfiltered groundwater. Pore water from soil core sections showed a correlation between contamination levels with depth and the potential abundance of sulfate- and nitrate-reducing bacteria based on the 2-order of magnitude decreased concentration. A merged interpretation with mineralogical consideration revealed a more complicated correlation among contaminants, soil texture, clay minerals, groundwater levels, and biomass. This sampling campaign emphasized that subsurface microbial activity and metabolic reactions can be influenced by a variety of factors but can be understood by considering the influence of multiple geochemical factors from all subsurface phases including water, air, and solid along depth rather than homogenized groundwater.

  14. Vapor-phase concentrations of PAHs and their derivatives determined in a large city: correlations with their atmospheric aerosol concentrations.

    PubMed

    Barrado, Ana Isabel; García, Susana; Sevillano, Marisa Luisa; Rodríguez, Jose Antonio; Barrado, Enrique

    2013-11-01

    Thirteen PAHs, five nitro-PAHs and two hydroxy-PAHs were determined in 55 vapor-phase samples collected in a suburban area of a large city (Madrid, Spain), from January 2008 to February 2009. The data obtained revealed correlations between the concentrations of these compounds and a series of meteorological factors (e.g., temperature, atmospheric pressure) and physical-chemical factors (e.g., nitrogen and sulfur oxides). As a consequence, seasonal trends were observed in the atmospheric pollutants. A "mean sample" for the 14-month period would contain a total PAH concentration of 13835±1625 pg m(-3) and 122±17 pg m(-3) of nitro-PAHs. When the data were stratified by season, it emerged that a representative sample of the coldest months would contain 18900±2140 pg m(-3) of PAHs and 150±97 pg m(-3) of nitro-PAHs, while in an average sample collected in the warmest months, these values drop to 9293±1178 pg m(-3) for the PAHs and to 97±13 pg m(-3) for the nitro-PAHs. Total vapor phase concentrations of PAHs were one order of magnitude higher than concentrations detected in atmospheric aerosol samples collected on the same dates. Total nitro-PAH concentrations were comparable to their aerosol concentrations whereas vapor phase OH-PAHs were below their limits of the detection, indicating these were trapped in airborne particles. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Determination of the D{sup 0}{yields}K{sup -}{pi}{sup +}{pi}{sup 0} and D{sup 0}{yields}K{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -} coherence factors and average strong-phase differences using quantum-correlated measurements

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lowrey, N.; Mehrabyan, S.; Selen, M.

    The first measurements of the coherence factors (R{sub K{pi}}{sub {pi}{sup 0}} and R{sub K3{pi}}) and the average strong-phase differences ({delta}{sub D}{sup K{pi}}{sup {pi}{sup 0}} and {delta}{sub D}{sup K3{pi}}) for D{sup 0}{yields}K{sup -}{pi}{sup +}{pi}{sup 0} and D{sup 0}{yields}K{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -} are presented. These parameters can be used to improve the determination of the unitarity triangle angle {gamma} in B{sup -}{yields}DK{sup -} decays, where D is a D{sup 0} or D{sup 0} meson decaying to the same final state. The measurements are made using quantum-correlated, fully reconstructed D{sup 0}D{sup 0} pairs produced in e{sup +}e{sup -} collisions at the {psi}(3770)more » resonance. The measured values are: R{sub K{pi}}{sub {pi}{sup 0}}=0.84{+-}0.07, {delta}{sub D}{sup K{pi}}{sup {pi}{sup 0}}=(227{sub -17}{sup +14}) deg., R{sub K3{pi}}=0.33{sub -0.23}{sup +0.20}, and {delta}{sub D}{sup K3{pi}}=(114{sub -23}{sup +26}) deg. These results indicate significant coherence in the decay D{sup 0}{yields}K{sup -}{pi}{sup +}{pi}{sup 0}, whereas lower coherence is observed in the decay D{sup 0}{yields}K{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -}. The analysis also results in a small improvement in the knowledge of other D-meson parameters, in particular, the strong-phase difference for D{sup 0}{yields}K{sup -}{pi}{sup +}, {delta}{sub D}{sup K{pi}}, and the mixing parameter y.« less

  16. Multiple linear regression to estimate time-frequency electrophysiological responses in single trials

    PubMed Central

    Hu, L.; Zhang, Z.G.; Mouraux, A.; Iannetti, G.D.

    2015-01-01

    Transient sensory, motor or cognitive event elicit not only phase-locked event-related potentials (ERPs) in the ongoing electroencephalogram (EEG), but also induce non-phase-locked modulations of ongoing EEG oscillations. These modulations can be detected when single-trial waveforms are analysed in the time-frequency domain, and consist in stimulus-induced decreases (event-related desynchronization, ERD) or increases (event-related synchronization, ERS) of synchrony in the activity of the underlying neuronal populations. ERD and ERS reflect changes in the parameters that control oscillations in neuronal networks and, depending on the frequency at which they occur, represent neuronal mechanisms involved in cortical activation, inhibition and binding. ERD and ERS are commonly estimated by averaging the time-frequency decomposition of single trials. However, their trial-to-trial variability that can reflect physiologically-important information is lost by across-trial averaging. Here, we aim to (1) develop novel approaches to explore single-trial parameters (including latency, frequency and magnitude) of ERP/ERD/ERS; (2) disclose the relationship between estimated single-trial parameters and other experimental factors (e.g., perceived intensity). We found that (1) stimulus-elicited ERP/ERD/ERS can be correctly separated using principal component analysis (PCA) decomposition with Varimax rotation on the single-trial time-frequency distributions; (2) time-frequency multiple linear regression with dispersion term (TF-MLRd) enhances the signal-to-noise ratio of ERP/ERD/ERS in single trials, and provides an unbiased estimation of their latency, frequency, and magnitude at single-trial level; (3) these estimates can be meaningfully correlated with each other and with other experimental factors at single-trial level (e.g., perceived stimulus intensity and ERP magnitude). The methods described in this article allow exploring fully non-phase-locked stimulus-induced cortical oscillations, obtaining single-trial estimate of response latency, frequency, and magnitude. This permits within-subject statistical comparisons, correlation with pre-stimulus features, and integration of simultaneously-recorded EEG and fMRI. PMID:25665966

  17. Strain-Detecting Composite Materials

    NASA Technical Reports Server (NTRS)

    Wallace, Terryl A. (Inventor); Smith, Stephen W. (Inventor); Piascik, Robert S. (Inventor); Horne, Michael R. (Inventor); Messick, Peter L. (Inventor); Alexa, Joel A. (Inventor); Glaessgen, Edward H. (Inventor); Hailer, Benjamin T. (Inventor)

    2016-01-01

    A composite material includes a structural material and a shape-memory alloy embedded in the structural material. The shape-memory alloy changes crystallographic phase from austenite to martensite in response to a predefined critical macroscopic average strain of the composite material. In a second embodiment, the composite material includes a plurality of particles of a ferromagnetic shape-memory alloy embedded in the structural material. The ferromagnetic shape-memory alloy changes crystallographic phase from austenite to martensite and changes magnetic phase in response to the predefined critical macroscopic average strain of the composite material. A method of forming a composite material for sensing the predefined critical macroscopic average strain includes providing the shape-memory alloy having an austenite crystallographic phase, changing a size and shape of the shape-memory alloy to thereby form a plurality of particles, and combining the structural material and the particles at a temperature of from about 100-700.degree. C. to form the composite material.

  18. Examining science achievement of African American females in suburban middle schools: A mixed methods study

    NASA Astrophysics Data System (ADS)

    Topping, Kecia C.

    This dissertation examined factors that affected the science achievement of African American females in suburban middle schools. The research literature informed that African American females are facing the barriers of race, gender, socioeconomic status, and cultural learning style preferences. Nationally used measurements of science achievement such as the Standardized Achievement Test, Tenth edition (SAT-10), National Assessment for Educational Progress, and National Center for Educational Statistics showed that African American females are continuing to falter in the areas of science when compared to other ethnic groups. This study used a transformative sequential explanatory mixed methods design. In the first, quantitative, phase, the relationships among the dependent variables, science subscale SAT-10 NCE scores, yearly averages, and the independent variables, attitude toward science scores obtained from the Modified Fennema-Sherman Attitudes toward Science Scale, socioeconomics, and caregiver status were tested. The participants were 150 African American females in grades 6 through 8 in four suburban middle schools located in the Southeastern United States. The results showed a positive, significant linear relationship between the females' attitude and their science subscale SAT-10 NCE scores and a positive, significant linear relationship between the females' attitudes and their yearly averages in science. The results also confirmed that attitude was a significant predictor of science subscale SAT-10 NCE scores for these females and that attitude and socioeconomics were significant predictors of the females' yearly averages in science. In the second, qualitative, phase, nine females purposefully selected from those who had high and low attitude towards science scores on the scale in the quantitative phase were interviewed. The themes that emerged revealed seven additional factors that impacted the females' science achievement. They were usefulness of science, exposure to science, parent influence, peer influence, teacher expectations, strategies for academic success in science, and perception of self in a predominantly Caucasian population. This information should be used to create interactive suburban middle school science classrooms that encourage the participation of African American females. These females should experience increased involvement with activities that expose them to science that is relevant to their lives. As a result, these females will be inspired to excel in science and one day enter into science careers.

  19. Observations of the Space-time Structure of Flow, Vorticity and Stress over Orbital-scale Ripples

    NASA Astrophysics Data System (ADS)

    Hare, J.; Hay, A. E.; Cheel, R. A.; Zedel, L. J.

    2012-12-01

    Results are presented from a laboratory investigation of the spatial and temporal structure at turbulence-resolving scales of the flow, vorticity and stress over equilibrium orbital-scale sand ripples. The ripples were created in 0.153 mm median diameter sand, at 10 s period and an excursion of 0.5 m, using the oscillating tray apparatus described in Hay et al. (JGR-Oceans, 2012). Vertical profiles of velocity above the bed were obtained at 40 Hz and 3 mm vertical resolution using a wide-band coherent Doppler profiler (MFDop). Through runs at different positions of the MFDop relative to a particular ripple crest, phase-averaged measures of the flow over a full ripple wavelength were obtained as a function of phase during the forcing cycle. These measurements are used to determine the formation of the lee vortex and the position of the point of reattachment. Estimates of the phase-averaged bottom stress (obtained using the vertical integral of the defect acceleration, the Reynolds stress and the law-of-the-wall) as a function of position along the ripple profile are inter-compared.Phase-averaged horizontal velocity over one ripple where the black line indicates the sediment-water interface. Phase-averaged vertical velocity over one ripple where the black line indicates the sediment-water interface.

  20. Thomson scattering from a three-component plasma.

    PubMed

    Johnson, W R; Nilsen, J

    2014-02-01

    A model for a three-component plasma consisting of two distinct ionic species and electrons is developed and applied to study x-ray Thomson scattering. Ions of a specific type are assumed to be identical and are treated in the average-atom approximation. Given the plasma temperature and density, the model predicts mass densities, effective ionic charges, and cell volumes for each ionic type, together with the plasma chemical potential and free-electron density. Additionally, the average-atom treatment of individual ions provides a quantum-mechanical description of bound and continuum electrons. The model is used to obtain parameters needed to determine the dynamic structure factors for x-ray Thomson scattering from a three-component plasma. The contribution from inelastic scattering by free electrons is evaluated in the random-phase approximation. The contribution from inelastic scattering by bound electrons is evaluated using the bound-state and scattering wave functions obtained from the average-atom calculations. Finally, the partial static structure factors for elastic scattering by ions are evaluated using a two-component version of the Ornstein-Zernike equations with hypernetted chain closure, in which electron-ion interactions are accounted for using screened ion-ion interaction potentials. The model is used to predict the x-ray Thomson scattering spectrum from a CH plasma and the resulting spectrum is compared with experimental results obtained by Feltcher et al. [Phys. Plasmas 20, 056316 (2013)].

  1. [Prognosis and progression of cognitive impairment. Preventive measures].

    PubMed

    López Mongil, Rosa; López Trigo, José Antonio

    2016-06-01

    Because of the substantial increase in population ageing, age-related processes, such as dementia and Alzheimer disease (AD), are becoming highly prevalent. The course of this disease, including preprodromic phases, lasts at least 20 years. The presence of comorbidities, especially those of vascular origin, can trigger and aggravate disease progression. On the other hand, cognitive reserve, the absence or control of comorbid factors and healthy lifestyles can protect or modify -in the sense of slow down- disease progression. Knowledge of the phases of AD and their functional impact on affected individuals helps to identify the average prognosis and, in particular, to establish and predict care plans based on the individual's needs. Copyright © 2016 Sociedad Española de Geriatría y Gerontología. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. SU-F-T-253: Volumetric Comparison Between 4D CT Amplitude and Phase Binning Mode

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yang, G; Ma, R; Reyngold, M

    2016-06-15

    Purpose: Motion artifact in 4DCT images can affect radiation treatment quality. To identify the most robust and accurate binning method, we compare the volume difference between targets delineated on amplitude and phase binned 4DCT scans. Methods: Varian RPM system and CT scanner were used to acquire 4DCTs of a Quasar phantom with embedded cubic and spherical objects having superior-inferior motion. Eight patients’ respiration waveforms were used to drive the phantom. The 4DCT scan was reconstructed into 10 phase and 10 amplitude bins (2 mm slices). A scan of the static phantom was also acquired. For each waveform, sphere and cubemore » volumes were generated automatically on each phase using HU thresholding. Phase (amplitude) ITVs were the union of object volumes over all phase (amplitude) binned images. The sphere and cube volumes measured in the static phantom scan were V{sub sphere}=4.19cc and V{sub cube}=27.0cc. Volume difference (VD) and dice similarity coefficient (DSC) of the ITVs, and mean volume error (MVE) defined as the average target volume percentage difference between each phase image and the static image, were used to evaluate the performance of amplitude and phase binning. Results: Averaged over the eight breathing traces, the VD and DSC of the internal target volume (ITV) between amplitude and phase binning were 3.4%±3.2% (mean ± std) and 95.9%±2.1% for sphere; 2.1%±3.3% and 98.0% ±1.5% for cube, respectively.For all waveforms, the average sphere MVE of amplitude and phase binning was 6.5% ± 5.0% and 8.2%±6.3%, respectively; and the average cube MVE of amplitude and phase binning was 5.7%±3.5%and 12.9%±8.9%, respectively. Conclusion: ITV volume and spatial overlap as assessed by VD and DSC are similar between amplitude and phase binning. Compared to phase binning, amplitude binning results in lower MVE suggesting it is less susceptible to motion artifact.« less

  3. Key cost drivers of pharmaceutical clinical trials in the United States.

    PubMed

    Sertkaya, Aylin; Wong, Hui-Hsing; Jessup, Amber; Beleche, Trinidad

    2016-04-01

    The increasing cost of clinical research has significant implications for public health, as it affects drug companies' willingness to undertake clinical trials, which in turn limits patient access to novel treatments. Thus, gaining a better understanding of the key cost drivers of clinical research in the United States is important. The study which is based on a report prepared by Eastern Research Group, Inc., for the US Department of Health and Human Services, examined different factors, such as therapeutic area, patient recruitment, administrative staff, and clinical procedure expenditures, and their contribution to pharmaceutical clinical trial costs in the United States by clinical trial phase. The study used aggregate data from three proprietary databases on clinical trial costs provided by Medidata Solutions. We evaluated per-study costs across therapeutic areas by aggregating detailed (per patient and per site) cost information. We also compared average expenditures on cost drivers with the use of weighted mean and standard deviation statistics. Therapeutic area was an important determinant of clinical trial costs by phase. The average cost of a Phase 1 study conducted at a US site ranged from US$1.4 million (pain and anesthesia) to US$6.6 million (immunomodulation), including estimated site overhead and monitoring costs of the sponsoring organization. A Phase 2 study cost from US$7.0 million (cardiovascular) to US$19.6 million (hematology), whereas a Phase 3 study cost ranged from US$11.5 million (dermatology) to US$52.9 (pain and anesthesia) on average. Across all study phases and excluding estimated site overhead costs and costs for sponsors to monitor the study, the top three cost drivers of clinical trial expenditures were clinical procedure costs (15%-22% of total), administrative staff costs (11%-29% of total), and site monitoring costs (9%-14% of total). The data were from 2004 through 2012 and were not adjusted for inflation. Additionally, the databases used represented a convenience, that is, non-probability, sample and did not allow for statistically valid estimates of cost drivers. Finally, the data were from trials funded by the global pharmaceutical and biotechnology industry only. Hence, our study findings are limited to that segment. Therapeutic area being studied as well as number and types of clinical procedures involved were the key drivers of direct costs in Phase 1 through Phase 3 studies. Research shows that strategies exist for reducing the price tag of some of these major direct cost components. Therefore, to increase clinical trial efficiency and reduce costs, gaining a better understanding of the key direct cost drivers is an important step. © The Author(s) 2016.

  4. Ice Particle Transport Analysis With Phase Change for the E(sup 3) Turbofan Engine Using LEWICE3D Version 3.2

    NASA Technical Reports Server (NTRS)

    Bidwell, Colin, S.

    2012-01-01

    Ice Particle trajectory calculations with phase change were made for the Energy Efficient Engine (E(sup 3)) using the LEWICE3D Version 3.2 software. The particle trajectory computations were performed using the new Glenn Ice Particle Phase Change Model which has been incorporated into the LEWICE3D Version 3.2 software. The E(sup 3) was developed by NASA and GE in the early 1980 s as a technology demonstrator and is representative of a modern high bypass turbofan engine. The E(sup 3) flow field was calculated using the NASA Glenn ADPAC turbomachinery flow solver. Computations were performed for the low pressure compressor of the E(sup 3) for a Mach 0.8 cruise condition at 11,887 m assuming a standard warm day for ice particle sizes of 5, 20, and 100 microns and a free stream particle concentration of 0.3 g/cu m. The impingement efficiency results showed that as particle size increased average impingement efficiencies and scoop factors increased for the various components. The particle analysis also showed that the amount of mass entering the inner core decreased with increased particle size because the larger particles were less able to negotiate the turn into the inner core due to particle inertia. The particle phase change analysis results showed that the larger particles warmed less as they were transported through the low pressure compressor. Only the smallest 5 micron particles were warmed enough to produce melting and the amount of melting was relatively small with a maximum average melting fraction of 0.836. The results also showed an appreciable amount of particle sublimation and evaporation for the 5 micron particles entering the engine core (22 percent).

  5. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Antao, Sytle M.; Cruickshank, Laura A.

    The crystal structure of an optically anisotropic kimzeyite garnet from Magnet Cove, Arkansas, USA, where it was first discovered, was refined with the Rietveld method, cubic space group, Ia\\overline 3 d, and monochromatic [λ = 0.41422 (2) Å] synchrotron high-resolution powder X-ray diffraction (HRPXRD) data. The Rietveld refinement reduced χ 2and overallR(F 2) values are 1.840 and 0.0647, respectively. The sample, with the general garnet formula [8]X 3 [6]Y 2 [4]Z 3 [4]O 12, contains an intergrowth of two cubic phases that occur initially as oscillatory growth zoning, and patchy intergrowths arise later from fluid-enhanced dissolution and re-precipitation. The twomore » compositions obtained with electron-probe microanalyses (EPMA) are Ca 3.00(Zr 1.31Ti 4+ 0.46Fe 3+ 0.22Mn 3+ 0.01) Σ2[Al 0.76Fe 3+ 1.01Si 1.23] Σ3O 12for phase 1aand Ca 2.99(Zr 1.48Ti 4+ 0.37Fe 3+ 0.15) Σ2[Al 0.87Fe 3+ 0.98Si 1.15] Σ3O 12for phase 1b. The weight percentage, unit-cell parameter (Å), distances (Å), and site occupancy factors (s.o.f.s) for phase 1aare as follows: 42.6 (2)%,a= 12.46553 (3) Å, average = 2.482,Y—O = 2.059 (2),Z—O = 1.761 (2) Å, Ca (Xs.o.f.) = 0.960 (4), Zr (Ys.o.f.) = 0.809 (3), and Fe (Zs.o.f.) = 0.623 (2). The corresponding values for phase 1bare 57.4 (2)%,a= 12.47691 (2) Å, average = 2.482,Y—O = 2.062 (1),Z—O = 1.762 (1) Å, Ca (Xs.o.f.) = 0.957 (3), Zr (Ys.o.f.) = 0.828 (2) and Fe (Zs.o.f.) = 0.617 (2). The main structural differences between the two phases are in the unit-cell parameter, Δa= 0.01138 Å,Y(s.o.f.), andY—O distance. Structural mismatch between the two cubic phases in a crystal gives rise to strain-induced optical anisotropy.« less

  6. Interdiffusion and Intrinsic Diffusion in the Mg-Al System

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Brennan, Sarah; Bermudez, Katrina; Sohn, Yong Ho

    2012-01-01

    Solid-to-solid diffusion couples were assembled and annealed to examine the diffusion between pure Mg (99.96%) and Al (99.999%). Diffusion anneals were carried out at 300 , 350 , and 400 C for 720, 360, and 240 hours, respectively. Optical and scanning electron microscopes were utilized to identify the formation of the intermetallic phases, -Al12Mg17 and -Al3Mg2 and absence of the -phase in the diffusion couples. Thicknesses of the -Al12Mg17 and -Al3Mg2 phases were measured and the parabolic growth constants were calculated to determine the activation energies for the growth, 165 and 86 KJ/mole, respectively. Concentration profiles were determined with electronmore » microprobe analysis using pure elemental standards. Composition-dependent interdiffusion coefficients in Mg-solid solution, -Al12Mg17 and - Al3Mg2 and Al-solid solutions were calculated based on the Boltzmann-Matano analysis. Average effective interdiffusion coefficients for each phase were also calculated, and the magnitude was the highest for the -Al3Mg2 phase, followed by -Al12Mg17, Al-solid solution and Mg-solid solution. Intrinsic diffusion coefficients based on Huemann s analysis (e.g., marker plane) were determined for the ~38 at.% Mg in the -Al3Mg2 phase. Activation energies and the pre-exponential factors for the inter- and intrinsic diffusion coefficients were calculated for the temperature range examined. The -Al3Mg2 phase was found to have the lowest activation energies for growth and interdiffusion among all four phases studied. At the marker location in the -Al3Mg2 phase, the intrinsic diffusion of Al was found to be faster than that of Mg. Extrapolations of the impurity diffusion coefficients in the terminal solid solutions were made and compared to the available self- and impurity diffusion data from literature. Thermodynamic factor, tracer diffusion coefficients and atomic mobilities at the marker plane composition were approximated using available literature values of Mg activity in the -Al3Mg2 phase.« less

  7. Entropy generation, particle creation, and quantum field theory in a cosmological spacetime: When do number and entropy increase\\?

    NASA Astrophysics Data System (ADS)

    Kandrup, Henry E.

    1988-06-01

    This paper reexamines the statistical quantum field theory of a free, minimally coupled, real scalar field Φ in a statically bounded, classical Friedmann cosmology, where the time-dependent scale factor Ω(t) tends to constant values Ω1 and Ω2 for tt2. The principal objective is to investigate the intuition that ``entropy'' S correlates with average particle number , so that increases in induced by parametric amplification manifest a one-to-one connection with increases in S. The definition of particle number Nk becomes unambiguous for t>t2 and t- is guaranteed generically to be positive only for special initial data which, in a number representation, are characterized by ``random phases'' in the sense that any relative phase for the projection of ρ(t1) into two different number eigenstates is ``random'' or ``unobservable physically,'' and averaged over in a density matrix. More importantly for the notion of entropy, random-phase initial data also guarantee an increase in the spread of P(\\{k,Nk\\}), so that, e.g., the sum of the variances Δ2N+/-k(t2) exceeds the initial Δ2N+/-k(t1). It is this increasing spread in P, rather than the growth in average numbers per se, which suggests that, for initial data manifesting random phases, SN(t2)>SN(t1), a result established rigorously in the limits of strong and weak particle creation.

  8. An organic khorasan wheat-based replacement diet improves risk profile of patients with acute coronary syndrome: a randomized crossover trial.

    PubMed

    Whittaker, Anne; Sofi, Francesco; Luisi, Maria Luisa Eliana; Rafanelli, Elena; Fiorillo, Claudia; Becatti, Matteo; Abbate, Rosanna; Casini, Alessandro; Gensini, Gian Franco; Benedettelli, Stefano

    2015-05-11

    Khorasan wheat is an ancient grain with previously reported health benefits in clinically healthy subjects. The aim of this study was to examine whether a replacement diet, thereby substituting all other cereal grains, with products made with organic khorasan wheat could provide additive protective effects in reducing lipid, oxidative and inflammatory risk factors, in patients with Acute Coronary Syndromes (ACS) in comparison to a similar replacement diet using products made from organic modern wheat. A randomized double-blinded crossover trial with two intervention phases was conducted on 22 ACS patients (9 F; 13 M). The patients were assigned to consume products (bread, pasta, biscuits and crackers) made either from organic semi-whole khorasan wheat or organic semi-whole control wheat for eight weeks in a random order. On average, patients ingested 62.0 g dry weight (DW) day-1 khorasan or control semolina; and 140.5 g DW day-1 khorasan or control flour, respectively. An eight-week washout period was implemented between the respective interventions. Blood analyses were performed both at the beginning and end of each intervention phase; thereby permitting a comparison of both the khorasan and control intervention phases, respectively, on circulatory risk factors for the same patient. Consumption of products made with khorasan wheat resulted in a significant amelioration in total cholesterol (-6.8%), low-density lipoprotein cholesterol (LDL-C) (-8.1%) glucose (-8%) and insulin (-24.6%) from baseline levels, independently of age, sex, traditional risk factors, medication and diet quality. Moreover, there was a significant reduction in reactive oxygen species (ROS), lipoperoxidation of circulating monocytes and lymphocytes, as well as in the levels of Tumor Necrosis Factor-alpha. No significant differences from baseline in the same patients were observed after the conventional control wheat intervention phase. The present results suggest that a replacement diet with cereal products made from organic khorasan wheat provides additional protection in patients with ACS. Circulating cardiovascular risk factors, including lipid parameters, and markers of both oxidative stress and inflammatory status, were reduced, irrespective of the number and combination of medicinal therapies with proven efficacy in secondary prevention.

  9. Time-dependent local and average structural evolution of δ-phase 239Pu-Ga alloys

    DOE PAGES

    Smith, Alice I.; Page, Katharine L.; Siewenie, Joan E.; ...

    2016-08-05

    Here, plutonium metal is a very unusual element, exhibiting six allotropes at ambient pressure, between room temperature and its melting point, a complicated phase diagram, and a complex electronic structure. Many phases of plutonium metal are unstable with changes in temperature, pressure, chemical additions, or time. This strongly affects structure and properties, and becomes of high importance, particularly when considering effects on structural integrity over long periods of time [1]. This paper presents a time-dependent neutron total scattering study of the local and average structure of naturally aging δ-phase 239Pu-Ga alloys, together with preliminary results on neutron tomography characterization.

  10. Robust Measurements of Phase Response Curves Realized via Multicycle Weighted Spike-Triggered Averages

    NASA Astrophysics Data System (ADS)

    Imai, Takashi; Ota, Kaiichiro; Aoyagi, Toshio

    2017-02-01

    Phase reduction has been extensively used to study rhythmic phenomena. As a result of phase reduction, the rhythm dynamics of a given system can be described using the phase response curve. Measuring this characteristic curve is an important step toward understanding a system's behavior. Recently, a basic idea for a new measurement method (called the multicycle weighted spike-triggered average method) was proposed. This paper confirms the validity of this method by providing an analytical proof and demonstrates its effectiveness in actual experimental systems by applying the method to an oscillating electric circuit. Some practical tips to use the method are also presented.

  11. Quantitative tomographic measurements of opaque multiphase flows

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    GEORGE,DARIN L.; TORCZYNSKI,JOHN R.; SHOLLENBERGER,KIM ANN

    2000-03-01

    An electrical-impedance tomography (EIT) system has been developed for quantitative measurements of radial phase distribution profiles in two-phase and three-phase vertical column flows. The EIT system is described along with the computer algorithm used for reconstructing phase volume fraction profiles. EIT measurements were validated by comparison with a gamma-densitometry tomography (GDT) system. The EIT system was used to accurately measure average solid volume fractions up to 0.05 in solid-liquid flows, and radial gas volume fraction profiles in gas-liquid flows with gas volume fractions up to 0.15. In both flows, average phase volume fractions and radial volume fraction profiles from GDTmore » and EIT were in good agreement. A minor modification to the formula used to relate conductivity data to phase volume fractions was found to improve agreement between the methods. GDT and EIT were then applied together to simultaneously measure the solid, liquid, and gas radial distributions within several vertical three-phase flows. For average solid volume fractions up to 0.30, the gas distribution for each gas flow rate was approximately independent of the amount of solids in the column. Measurements made with this EIT system demonstrate that EIT may be used successfully for noninvasive, quantitative measurements of dispersed multiphase flows.« less

  12. Temperature dependent barrier height and ideality factor of electrodeposited n-CdSe/Cu Schottky barrier diode

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mahato, S., E-mail: som.phy.ism@gmail.com; Shiwakoti, N.; Kar, A. K.

    2015-06-24

    This article reports the measurement of temperature-dependent barrier height and ideality factor of n-CdSe/Cu Schottky barrier diode. The Cadmium Selenide (CdSe) thin films have been deposited by simple electrodeposition technique. The XRD measurements ravels the deposited single phase CdSe films are highly oriented on (002) plane and the average particle size has been calculated to be ~18 nm. From SEM characterization, it is clear that the surface of CdSe thin films are continuous, homogeneous and the film is well adhered to the substrate and consists of fine grains which are irregular in shape and size. Current-Voltage characteristics have been measured atmore » different temperatures in the range (298 K – 353 K). The barrier height and ideality factor are found to be strongly temperature dependent. The inhomogenious barrier height increases and ideality factor decreases with increase in temperature. The expectation value has been calculated and its value is 0.30 eV.« less

  13. Seed Rain and Seed Bank Reveal that Seed Limitation Strongly Influences Plant Community Assembly in Grasslands

    PubMed Central

    Marteinsdóttir, Bryndís

    2014-01-01

    Dispersal is an important factor in plant community assembly, but assembly studies seldom include information on actual dispersal into communities, i.e. the local propagule pool. The aim of this study was to determine which factors influence plant community assembly by focusing on two phases of the assembly process: the dispersal phase and the establishment phase. At 12 study sites in grazed ex-arable fields in Sweden the local plant community was determined and in a 100-m radius around the centre of each site, the regional species pool was measured. The local seed bank and the seed rain was explored to estimate the local propagule pool. Trait-based models were then applied to investigate if species traits (height, seed mass, clonal abilities, specific leaf area and dispersal method) and regional abundance influenced which species from the regional species pool, dispersed to the local community (dispersal phase) and which established (establishment phase). Filtering of species during the dispersal phase indicates the effect of seed limitation while filtering during the establishment phase indicates microsite limitation. On average 36% of the regional species pool dispersed to the local sites and of those 78% did establish. Species with enhanced dispersal abilities, e.g. higher regional abundance, smaller seeds and dispersed by cattle, were more likely to disperse to the sites than other species. At half the sites, dispersal was influenced by species height. Species establishment was however mainly unlinked to the traits included in this study. This study underlines the importance of seed limitation in local plant community assembly. It also suggests that without information on species dispersal into a site, it is difficult to distinguish between the influence of dispersal and establishment abilities, and thus seed and microsite limitation, as both can be linked to the same trait. PMID:25057815

  14. Triacylglycerols profiling in plant oils important in food industry, dietetics and cosmetics using high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

    PubMed

    Lísa, Miroslav; Holcapek, Michal

    2008-07-11

    Optimized non-aqueous reversed-phase high-performance liquid chromatography method using acetonitrile-2-propanol gradient elution and the column coupling in the total length of 45 cm has been applied for the high resolution separation of plant oils important in food industry, dietetics and cosmetics. Positive-ion atmospheric pressure chemical ionization mass spectrometry is used for the unambiguous identification and also the reliable quantitation with the response factors approach. Based on the precise determination of individual triacyglycerol concentrations, the calculation of average parameters important in the nutrition is performed, i.e. average carbon number, average double bond number, relative concentrations of essential, saturated, monounsaturated and polyunsaturated fatty acids. Results are reported in the form of both chromatographic fingerprints and tables containing relative concentrations for all triacylglycerols and fatty acids in individual samples. In total, 264 triacylglycerols consisting of 28 fatty acids with the alkyl chain length from 6 to 26 carbon atoms and 0 to 4 double bonds have been identified in 26 industrial important plant oils.

  15. Phase-stable, multi-µJ femtosecond pulses from a repetition-rate tunable Ti:Sa-oscillator-seeded Yb-fiber amplifier

    NASA Astrophysics Data System (ADS)

    Saule, T.; Holzberger, S.; De Vries, O.; Plötner, M.; Limpert, J.; Tünnermann, A.; Pupeza, I.

    2017-01-01

    We present a high-power, MHz-repetition-rate, phase-stable femtosecond laser system based on a phase-stabilized Ti:Sa oscillator and a multi-stage Yb-fiber chirped-pulse power amplifier. A 10-nm band around 1030 nm is split from the 7-fs oscillator output and serves as the seed for subsequent amplification by 54 dB to 80 W of average power. The µJ-level output is spectrally broadened in a solid-core fiber and compressed to 30 fs with chirped mirrors. A pulse picker prior to power amplification allows for decreasing the repetition rate from 74 MHz by a factor of up to 4 without affecting the pulse parameters. To compensate for phase jitter added by the amplifier to the feed-forward phase-stabilized seeding pulses, a self-referencing feed-back loop is implemented at the system output. An integrated out-of-loop phase noise of less than 100 mrad was measured in the band from 0.4 Hz to 400 kHz, which to the best of our knowledge corresponds to the highest phase stability ever demonstrated for high-power, multi-MHz-repetition-rate ultrafast lasers. This system will enable experiments in attosecond physics at unprecedented repetition rates, it offers ideal prerequisites for the generation and field-resolved electro-optical sampling of high-power, broadband infrared pulses, and it is suitable for phase-stable white light generation.

  16. THE PHASE COHERENCE OF INTERSTELLAR DENSITY FLUCTUATIONS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Burkhart, Blakesley; Lazarian, A.

    2016-08-10

    Studies of MHD turbulence often investigate the Fourier power spectrum to provide information on the nature of the turbulence cascade. However, the Fourier power spectrum only contains the Fourier amplitudes and rejects all information regarding the Fourier phases. Here, we investigate the utility of two statistical diagnostics for recovering information on Fourier phases in ISM column density maps: the averaged amplitudes of the bispectrum and the phase coherence index (PCI), a new phase technique for the ISM. We create three-dimensional density and two-dimensional column density maps using a set of simulations of isothermal ideal MHD turbulence with a wide rangemore » of sonic and Alfvénic Mach numbers. We find that the bispectrum averaged along different angles with respect to either the k {sub 1} or k {sub 2} axis is primarily sensitive to the sonic Mach number while averaging the bispectral amplitudes over different annuli is sensitive to both the sonic and Alfvénic Mach numbers. The PCI of density suggests that the most correlated phases occur in supersonic sub-Alfvénic turbulence and near the shock scale. This suggests that nonlinear interactions with correlated phases are strongest in shock-dominated regions, in agreement with findings from the solar wind. Our results suggest that the phase information contained in the bispectrum and PCI can be used to find the turbulence parameters in column density maps.« less

  17. Aquarius Instrument Science Calibration During the Risk Reduction Phase

    NASA Technical Reports Server (NTRS)

    Ruf, Christopher S.

    2004-01-01

    This final report presents the results of work performed under NASA Grant NAG512726 during the period 15 January 2003 through 30 June 2004. An analysis was performed of a possible vicarious calibration method for use by Aquarius to monitor and stabilize the absolute and relative calibration of its microwave radiometer. Stationary statistical properties of the brightness temperature (T(sub B)) measured by a low Earth orbiting radiometer operating at 1.4135 GHz are considered as a means of validating its absolute calibration. The global minimum, maximum, and average T(sub B) are considered, together with a vicarious cold reference method that detects the presence of a sharp lower bound on naturally occurring values for T(sub B). Of particular interest is the reliability with which these statistics can be extracted from a realistic distribution of T(sub B) measurements that would be observed by a typical sensor. Simulations of measurements are performed that include the effects of instrument noise and variable environmental factors such as the global water vapor and ocean surface temperature, salinity and wind distributions. Global minima can vary widely due to instrument noise and are not a reliable calibration reference. Global maxima are strongly influenced by several environmental factors as well as instrument noise and are even less stationary. Global averages are largely insensitive to instrument noise and, in most cases, to environmental conditions as well. The global average T(sub B) varies at only the 0.1 K RMS level except in cases of anomalously high winds, when it can increase considerably more. The vicarious cold reference is similarly insensitive to instrument effects and most environmental factors. It is not significantly affected by high wind conditions. The stability of the vicarious reference is, however, found to be somewhat sensitive (at the several tenths of Kelvins level) to variations in the background cold space brightness, T(sub c). The global average is much less sensitive to this parameter and so using two approaches together can be mutually beneficial.

  18. The gas-phase metallicities of star-forming galaxies in aperture-matched SDSS samples follow potential rather than mass or average surface density

    NASA Astrophysics Data System (ADS)

    D'Eugenio, Francesco; Colless, Matthew; Groves, Brent; Bian, Fuyan; Barone, Tania M.

    2018-05-01

    We present a comparative study of the relation between the aperture-based gas-phase metallicity and three structural parameters of star-forming galaxies: mass (M ≡ M*), average potential (Φ ≡ M*/Re) and average surface mass density (Σ ≡ M_*/R_e^2; where Re is the effective radius). We use a volume-limited sample drawn from the publicly available SDSS DR7, and base our analysis on aperture-matched sampling by selecting sets of galaxies where the SDSS fibre probes a fixed fraction of Re. We find that between 0.5 and 1.5 Re, the gas-phase metallicity correlates more tightly with Φ than with either {M} or Σ, in that for all aperture-matched samples, the potential-metallicity relation has (i) less scatter, (ii) higher Spearman rank correlation coefficient and (iii) less residual trend with Re than either the mass-metallicity relation and the average surface density-metallicity relation. Our result is broadly consistent with the current models of gas enrichment and metal loss. However, a more natural explanation for our findings is a local relation between the gas-phase metallicity and escape velocity.

  19. The 'North American shale composite' - Its compilation, major and trace element characteristics

    NASA Technical Reports Server (NTRS)

    Gromet, L. P.; Dymek, R. F.; Haskin, L. A.; Korotev, R. L.

    1984-01-01

    North American shale composite (NASC) major element composition and compilation are presented, together with rare earth element (REE) redeterminations obtained by high precision analytical methods. The major element composition of the NASC compares closely with other average shale compositions, and significant portions of the REE and some other trace elements are contained in minor phases. The uneven REE distribution in NASC powder appears to yield the heterogeneity in analyzed aliquants. REE distributions of detrital sediments may to some extent be dependent on their minor mineral assemblages and the sedimentological factors controlling these assemblages.

  20. Weak phases γ and α from B+, or B0 and Bs decays

    NASA Astrophysics Data System (ADS)

    Gronau, Michael; Pirjol, Dan

    1999-03-01

    An improved flavor SU(3) method is presented for determining the weak angle γ of the unitarity triangle using decay rates for B+-->Kπ,B+-- >K+K¯0 and B+-->π+η (or B0-->Kπ and Bs-->Kπ), their CP-conjugate modes and the CP-averaged rate for B+/--->π+/-π0. Rescattering (color-suppressed) contribution in B+(B0)-->Kπ is subtracted away. The only significant SU(3) breaking effects are accounted for in the factorization approximation of tree amplitudes. The weak angle α is obtained as a byproduct.

  1. Development and study of self-efficacy scale in medication adherence among Iranian patients with hypertension

    PubMed Central

    Najimi, Arash; Mostafavi, Firoozeh; Sharifirad, Gholamreza; Golshiri, Parastoo

    2017-01-01

    BACKGROUND: This study was aimed at developing and studying the scale of self-efficacy in adherence to treatment in Iranian patients with hypertension. METHODS: A mix-method study was conducted on the two stages: in the first phase, a qualitative study was done using content analysis through deep and semi-structured interviews. After data analysis, the draft of tool was prepared. Items in the draft were selected based on the extracted concepts. In the second phase, validity and reliability of the instrument were implemented using a quantitative study. The prepared instrument in the first phase was studied among 612 participants. To test the construct validity and internal consistency, exploratory factor analysis and Cronbach's alpha were used, respectively. To study the validity of the final scale, the average score of self-efficacy in patients with controlled hypertension were compared with patients with uncontrolled hypertension. RESULTS: In overall, 16 patients were interviewed. Twenty-six items were developed to assess different concepts of self-efficacy. Concept-related items were extracted from interviews to study the face validity of the tool from patient's point of view. Four items were deleted because scored 0.79 in content validity. The mean of questionnaire content validity was 0.85. Items were collected in two factors with an eigenvalue >1. Four items were deleted with load factor <0.4. Reliability was 0.84 for the entire instrument. CONCLUSION: Self-efficacy scale in patients with hypertension is a valid and reliable instrument that can effectively evaluate the self-efficacy in medication adherence in the management of hypertension. PMID:29114551

  2. SU-F-T-366: Dosimetric Parameters Enhancement of 120-Leaf Millennium MLC Using EGSnrc and IAEA Phase-Space Data

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Haddad, K; Alopoor, H

    Purpose: Recently, the multileaf collimators (MLC) have become an important part of any LINAC collimation systems because they reduce the treatment planning time and improves the conformity. Important factors that affects the MLCs collimation performance are leaves material composition and their thickness. In this study, we investigate the main dosimetric parameters of 120-leaf Millennium MLC including dose in the buildup point, physical penumbra as well as average and end leaf leakages. Effects of the leaves geometry and density on these parameters are evaluated Methods: From EGSnrc Monte Carlo code, BEAMnrc and DOSXYZnrc modules are used to evaluate the dosimetric parametersmore » of a water phantom exposed to a Varian xi for 100cm SSD. Using IAEA phasespace data just above MLC (Z=46cm) and BEAMnrc, for the modified 120-leaf Millennium MLC a new phase space data at Z=52cm is produces. The MLC is modified both in leaf thickness and material composition. EGSgui code generates 521ICRU library for tungsten alloys. DOSXYZnrc with the new phase space evaluates the dose distribution in a water phantom of 60×60×20 cm3 with voxel size of 4×4×2 mm3. Using DOSXYZnrc dose distributions for open beam and closed beam as well as the leakages definition, end leakage, average leakage and physical penumbra are evaluated. Results: A new MLC with improved dosimetric parameters is proposed. The physical penumbra for proposed MLC is 4.7mm compared to 5.16 mm for Millennium. Average leakage in our design is reduced to 1.16% compared to 1.73% for Millennium, the end leaf leakage suggested design is also reduced to 4.86% compared to 7.26% of Millennium. Conclusion: The results show that the proposed MLC with enhanced dosimetric parameters could improve the conformity of treatment planning.« less

  3. Automatic extraction of three-dimensional thoracic aorta geometric model from phase contrast MRI for morphometric and hemodynamic characterization.

    PubMed

    Volonghi, Paola; Tresoldi, Daniele; Cadioli, Marcello; Usuelli, Antonio M; Ponzini, Raffaele; Morbiducci, Umberto; Esposito, Antonio; Rizzo, Giovanna

    2016-02-01

    To propose and assess a new method that automatically extracts a three-dimensional (3D) geometric model of the thoracic aorta (TA) from 3D cine phase contrast MRI (PCMRI) acquisitions. The proposed method is composed of two steps: segmentation of the TA and creation of the 3D geometric model. The segmentation algorithm, based on Level Set, was set and applied to healthy subjects acquired in three different modalities (with and without SENSE reduction factors). Accuracy was evaluated using standard quality indices. The 3D model is characterized by the vessel surface mesh and its centerline; the comparison of models obtained from the three different datasets was also carried out in terms of radius of curvature (RC) and average tortuosity (AT). In all datasets, the segmentation quality indices confirmed very good agreement between manual and automatic contours (average symmetric distance < 1.44 mm, DICE Similarity Coefficient > 0.88). The 3D models extracted from the three datasets were found to be comparable, with differences of less than 10% for RC and 11% for AT. Our method was found effective on PCMRI data to provide a 3D geometric model of the TA, to support morphometric and hemodynamic characterization of the aorta. © 2015 Wiley Periodicals, Inc.

  4. Assessing the failure of continuum formula for solid-solid drag force using discrete element method in large size ratios

    NASA Astrophysics Data System (ADS)

    Jalali, Payman; Hyppänen, Timo

    2017-06-01

    In loose or moderately-dense particle mixtures, the contact forces between particles due to successive collisions create average volumetric solid-solid drag force between different granular phases (of different particle sizes). The derivation of the mathematical formula for this drag force is based on the homogeneity of mixture within the calculational control volume. This assumption especially fails when the size ratio of particles grows to a large value of 10 or greater. The size-driven inhomogeneity is responsible to the deviation of intergranular force from the continuum formula. In this paper, we have implemented discrete element method (DEM) simulations to obtain the volumetric mean force exchanged between the granular phases with the size ratios greater than 10. First, the force is calculated directly from DEM averaged over a proper time window. Second, the continuum formula is applied to calculate the drag forces using the DEM quantities. We have shown the two volumetric forces are in good agreement as long as the homogeneity condition is maintained. However, the relative motion of larger particles in a cloud of finer particles imposes the inhomogeneous distribution of finer particles around the larger ones. We have presented correction factors to the volumetric force from continuum formula.

  5. Phase Angle of Bioelectrical Impedance Analysis as Prognostic Factor in Palliative Care Patients at the National Cancer Institute in Mexico.

    PubMed

    Pérez Camargo, Dana A; Allende Pérez, Silvia R; Rivera Franco, Mónica M; Álvarez Licona, Nelson E; Urbalejo Ceniceros, Víctor I; Figueroa Baldenegro, Lilian E

    2017-01-01

    Patients with advanced cancer often experience symptoms of disease and treatment that contribute to distress such as weight loss, which is present in up to 85% of cancer patients. Palliative care in these patients focuses on care aimed at improving quality of life. Phase angle (PA) is obtained by bioelectric impedance analysis (BIA) and is associated with cellular function. It is considered a reliable marker of malnutrition. A low PA may suggest deterioration of the cell membrane, which in palliative patients may result in a short-term survival. The aim of this study was to associate PA and survival in palliative patients of the National Cancer Institute of Mexico. We included 452 patients (women, 56.4%); the average PA was 4.0°. The most frequent disease was gastric cancer (39.2%). Mean body mass index (BMI) was 22.84. The average survival of patients with PA ≤ 4° was 86 days, while in the group with PA > 4°, it was 163 days (P > 0.0001). PA showed significant positive correlation with survival time and BMI. Our results corroborate the reliability of PA in Mexican population, as an indicator of survival in palliative care patients compared to the reported literature in other countries.

  6. Strategy for stabilization of the antiferroelectric phase (Pbma) over the metastable ferroelectric phase (P2{sub 1}ma) to establish double loop hysteresis in lead-free (1−x)NaNbO{sub 3}-xSrZrO{sub 3} solid solution

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Guo, Hanzheng, E-mail: hug17@psu.edu; Randall, Clive A.; Shimizu, Hiroyuki

    A new lead-free antiferroelectric solid solution system, (1−x)NaNbO{sub 3}-xSrZrO{sub 3}, was rationalized through noting the crystal chemistry trend, of decreasing the tolerance factor and an increase in the average electronegativity of the system. The SrZrO{sub 3} doping was found to effectively stabilize the antiferroelectric (P) phase in NaNbO{sub 3} without changing its crystal symmetry. Preliminary electron diffraction and polarization measurements were presented which verified the enhanced antiferroelectricity. In view of our recent report of another lead-free antiferroelectric system (1−x)NaNbO{sub 3}-xCaZrO{sub 3} [H. Shimizu et al. “Lead-free antiferroelectric: xCaZrO{sub 3} - (1−x)NaNbO{sub 3} system (0 ≤ x ≤ 0.10),” Dalton Trans.more » (published online)], the present results point to a general strategy of utilizing tolerance factor to develop a broad family of new lead-free antiferroelectrics with double polarization hysteresis loops. We also speculate on a broad family of possible solid solutions that could be identified and tested for this important type of dielectric.« less

  7. A Phase Field Study of the Effect of Microstructure Grain Size Heterogeneity on Grain Growth

    NASA Astrophysics Data System (ADS)

    Crist, David J. D.

    Recent studies conducted with sharp-interface models suggest a link between the spatial distribution of grain size variance and average grain growth rate. This relationship and its effect on grain growth rate was examined using the diffuse-interface Phase Field Method on a series of microstructures with different degrees of grain size gradation. Results from this work indicate that the average grain growth rate has a positive correlation with the average grain size dispersion for phase field simulations, confirming previous observations. It is also shown that the grain growth rate in microstructures with skewed grain size distributions is better measured through the change in the volume-weighted average grain size than statistical mean grain size. This material is based upon work supported by the National Science Foundation under Grant No. 1334283. The NSF project title is "DMREF: Real Time Control of Grain Growth in Metals" and was awarded by the Civil, Mechanical and Manufacturing Innovation division under the Designing Materials to Revolutionize and Engineer our Future (DMREF) program.

  8. Primary and secondary aerosols in Beijing in winter: sources, variations and processes

    NASA Astrophysics Data System (ADS)

    Sun, Yele; Du, Wei; Fu, Pingqing; Wang, Qingqing; Li, Jie; Ge, Xinlei; Zhang, Qi; Zhu, Chunmao; Ren, Lujie; Xu, Weiqi; Zhao, Jian; Han, Tingting; Worsnop, Douglas R.; Wang, Zifa

    2016-07-01

    Winter has the worst air pollution of the year in the megacity of Beijing. Despite extensive winter studies in recent years, our knowledge of the sources, formation mechanisms and evolution of aerosol particles is not complete. Here we have a comprehensive characterization of the sources, variations and processes of submicron aerosols that were measured by an Aerodyne high-resolution aerosol mass spectrometer from 17 December 2013 to 17 January 2014 along with offline filter analysis by gas chromatography/mass spectrometry. Our results suggest that submicron aerosols composition was generally similar across the winter of different years and was mainly composed of organics (60 %), sulfate (15 %) and nitrate (11 %). Positive matrix factorization of high- and unit-mass resolution spectra identified four primary organic aerosol (POA) factors from traffic, cooking, biomass burning (BBOA) and coal combustion (CCOA) emissions as well as two secondary OA (SOA) factors. POA dominated OA, on average accounting for 56 %, with CCOA being the largest contributor (20 %). Both CCOA and BBOA showed distinct polycyclic aromatic hydrocarbons (PAHs) spectral signatures, indicating that PAHs in winter were mainly from coal combustion (66 %) and biomass burning emissions (18 %). BBOA was highly correlated with levoglucosan, a tracer compound for biomass burning (r2 = 0.93), and made a considerable contribution to OA in winter (9 %). An aqueous-phase-processed SOA (aq-OOA) that was strongly correlated with particle liquid water content, sulfate and S-containing ions (e.g. CH2SO2+) was identified. On average aq-OOA contributed 12 % to the total OA and played a dominant role in increasing oxidation degrees of OA at high RH levels (> 50 %). Our results illustrate that aqueous-phase processing can enhance SOA production and oxidation states of OA as well in winter. Further episode analyses highlighted the significant impacts of meteorological parameters on aerosol composition, size distributions, oxidation states of OA and evolutionary processes of secondary aerosols.

  9. Quantitative measurement of mean inner potential and specimen thickness from high-resolution off-axis electron holograms of ultra-thin layered WSe2.

    PubMed

    Winkler, Florian; Tavabi, Amir H; Barthel, Juri; Duchamp, Martial; Yucelen, Emrah; Borghardt, Sven; Kardynal, Beata E; Dunin-Borkowski, Rafal E

    2017-07-01

    The phase and amplitude of the electron wavefunction that has passed through ultra-thin flakes of WSe 2 is measured from high-resolution off-axis electron holograms. Both the experimental measurements and corresponding computer simulations are used to show that, as a result of dynamical diffraction, the spatially averaged phase does not increase linearly with specimen thickness close to an [001] zone axis orientation even when the specimen has a thickness of only a few layers. It is then not possible to infer the local specimen thickness of the WSe 2 from either the phase or the amplitude alone. Instead, we show that the combined analysis of phase and amplitude from experimental measurements and simulations allows an accurate determination of the local specimen thickness. The relationship between phase and projected potential is shown to be approximately linear for extremely thin specimens that are tilted by several degrees in certain directions from the [001] zone axis. A knowledge of the specimen thickness then allows the electrostatic potential to be determined from the measured phase. By using this combined approach, we determine a value for the mean inner potential of WSe 2 of 18.9±0.8V, which is 12% lower than the value calculated from neutral atom scattering factors. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Flight Crew Sleep in Long-Haul Aircraft Bunk Facilities: Survey Results

    NASA Technical Reports Server (NTRS)

    Rosekind, Mark R.; Miller, Donna L.; Gregory, Kevin B.; Dinges, David F.; Shafto, Michael G. (Technical Monitor)

    1995-01-01

    Modem long-haul aircraft can fly up to 16 continuous hours and provide a 24-hour, global capability. Extra (augmented) flight crew are available on long flights to allow planned rest periods, on a rotating basis, away from the flight deck in onboard crew rest facilities (2 bunks). A NASA/FAA study is under-way to examine the quantity and quality of sleep obtained in long-haul aircraft bunks and the factors that promote or interfere with that sleep. The first phase of the study involved a retrospective survey, followed by a second phase field study to collect standard polysomnographic data during inflight bunk sleep periods. A summary of the Phase I survey results are reported here. A multi-part 54-question retrospective survey was completed by 1,404 flight crew (37% return rate) at three different major US air carriers flying B747-100, 200, 400, and MD- 11 long-haul aircraft. The questions examined demographics, quantity and quality of sleep at home and in onboard bunks, factors that promote or interfere with sleep, and effects on subsequent performance and alertness. Flight crew reported a mean bunk sleep latency of 39.4 mins (SD=28.3 mins) (n=1,276) and a mean total sleep time of 2.2 hrs (SD=1.3 hrs) (n=603). (Different flight lengths could affect overall time available for sleep.) Crew rated 25 factors for their interference or promotion of bunk sleep. Figure I portrays the average ratings for each factor across all three carriers. A principal components analysis of the 25 factors revealed three areas that promoted bunk sleep: physiological (e.g., readiness for sleep), physical environment (e.g., bunk size, privacy), and personal comfort (e.g., blankets, pillows). Five areas were identified that interfered with sleep: environmental disturbance (e.g., background noise, turbulence), luminosity (e.g., lighting), personal disturbances (e.g., bathroom trips, random thoughts), environmental discomfort (e.g., low humidity, cold), and interpersonal disturbances (e.g., bunk partner).

  11. Intercomparison of radiation measurements on STS-63.

    PubMed

    Badhwar, G D; Atwell, W; Cash, B; Weyland, M; Petrov, V M; Tchernykh, I V; Akatov YuA; Shurshakov, V A; Arkhangelsky, V V; Kushin, V V; Klyachin, N A; Benton, E V; Frank, A L; Benton, E R; Frigo, L A; Dudkin, V E; Potapov YuV; Vana, N; Schoner, W; Fugger, M

    1996-11-01

    A joint NASA Russia study of the radiation environment inside the Space Shuttle was performed on STS-63. This was the second flight under the Shuttle-Mir Science Program (Phase 1). The Shuttle was launched on 2 February 1995, in a 51.65 degrees inclination orbit and landed at Kennedy Space Center on 11 February 1995, for a total flight duration of 8.27 days. The Shuttle carried a complement of both passive and active detectors distributed throughout the Shuttle volume. The crew exposure varied from 1962 to 2790 microGy with an average of 2265.8 microGy or 273.98 microGy/day. Crew exposures varied by a factor of 1.4, which is higher than usual for STS mission. The flight altitude varied from 314 to 395 km and provided a unique opportunity to obtain dose variation with altitude. Measurements of the average east-west dose variation were made using two active solid state detectors. The dose rate in the Spacehab locker, measured using a tissue equivalent proportional counter (TEPC), was 413.3 microGy/day, consistent with measurements made using thermoluminescent detectors (TLDs) in the same locker. The average quality factor was 2.33, and although it was higher than model calculations, it was consistent with values derived from high temperature peaks in TLDs. The dose rate due to galactic cosmic radiation was 110.6 microGy/day and agreed with model calculations. The dose rate from trapped particles was 302.7 microGy/day, nearly a factor of 2 lower than the prediction of the AP8 model. The neutrons in the intermediate energy range of 1-20 MeV contributed 13 microGy/day and 156 microSv/day, respectively. Analysis of data from the charged particle spectrometer has not yet been completed.

  12. 24 CFR Appendix B to Part 1000 - IHBG Block Grant Formula Mechanisms

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... weighted average for AEL (NAEL). The FMR factor is also defined in § 1000.302 as the relative difference between a local area Fair Market Rent (FMR) and the national weighted average for FMR. OPSUB = [LR * LRSUB... FMR Factor weighted by national average of AEL Factor and FRM Factor. AEL FACTOR = AEL/NAEL. AEL...

  13. Detailed validation of the bidirectional effect in various Case I and Case II waters.

    PubMed

    Gleason, Arthur C R; Voss, Kenneth J; Gordon, Howard R; Twardowski, Michael; Sullivan, James; Trees, Charles; Weidemann, Alan; Berthon, Jean-François; Clark, Dennis; Lee, Zhong-Ping

    2012-03-26

    Simulated bidirectional reflectance distribution functions (BRDF) were compared with measurements made just beneath the water's surface. In Case I water, the set of simulations that varied the particle scattering phase function depending on chlorophyll concentration agreed more closely with the data than other models. In Case II water, however, the simulations using fixed phase functions agreed well with the data and were nearly indistinguishable from each other, on average. The results suggest that BRDF corrections in Case II water are feasible using single, average, particle scattering phase functions, but that the existing approach using variable particle scattering phase functions is still warranted in Case I water.

  14. A PRESTO-SENSE sequence with alternating partial-Fourier encoding for rapid susceptibility-weighted 3D MRI time series.

    PubMed

    Klarhöfer, Markus; Dilharreguy, Bixente; van Gelderen, Peter; Moonen, Chrit T W

    2003-10-01

    A 3D sequence for dynamic susceptibility imaging is proposed which combines echo-shifting principles (such as PRESTO), sensitivity encoding (SENSE), and partial-Fourier acquisition. The method uses a moderate SENSE factor of 2 and takes advantage of an alternating partial k-space acquisition in the "slow" phase encode direction allowing an iterative reconstruction using high-resolution phase estimates. Offering an isotropic spatial resolution of 4 x 4 x 4 mm(3), the novel sequence covers the whole brain including parts of the cerebellum in 0.5 sec. Its temporal signal stability is comparable to that of a full-Fourier, full-FOV EPI sequence having the same dynamic scan time but much less brain coverage. Initial functional MRI experiments showed consistent activation in the motor cortex with an average signal change slightly less than that of EPI. Copyright 2003 Wiley-Liss, Inc.

  15. Attrition and carbon formation on iron catalysts

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kohler, S.D.; Harrington, M.S.; Jackson, N.B.

    1994-08-01

    A serious engineering problem that needs to be addressed in the scale-up of slurry-phase, Fischer-Tropsch reactors is attrition of the precipitated iron catalyst. Attrition, which can break down the catalyst into particles too small to filter, results from both mechanical and chemical forces. This study examines the chemical causes of attrition in iron catalysts. A bench-scale, slurry-phase CSTR is used to simulate operating conditions that lead to attrition of the catalyst. The average particle size and size distribution of the catalyst samples are used to determine the effect of slurry temperature, reducing gas, gas flow rate and time upon attritionmore » of the catalyst. Carbon deposition, a possible contributing factor to attrition, has been examined using gravimetric analysis and TEM. Conditions affecting the rate of carbon deposition have been compared to those leading to attrition of the precipitated iron catalyst.« less

  16. Radiative transfer in the surfaces of atmosphereless bodies. III - Interpretation of lunar photometry

    NASA Technical Reports Server (NTRS)

    Lumme, K.; Irvine, W. M.

    1982-01-01

    Narrowband and UBV photoelectric phase curves of the entire lunar disk and surface photometry of some craters have been interpreted using a newly developed generalized radiative transfer theory for planetary regoliths. The data are well fitted by the theory, yielding information on both macroscopic and microscopic lunar properties. Derived values for the integrated disk geometric albedo are considerably higher than quoted previously, because of the present inclusion of an accurately determined opposition effect. The mean surface roughness, defined as the ratio of the height to the radius of a typical irregularity, is found to be 0.9 + or - 0.1, or somewhat less than the mean value of 1.2 obtained for the asteroids. From the phase curves, wavelength-dependent values of the single scattering albedo and the Henyey-Greenstein asymmetry factor for the average surface particle are derived.

  17. Equations of state for the fully flexible WCA chains in the fluid and solid phases based on Wertheims-TPT2

    NASA Astrophysics Data System (ADS)

    Mirzaeinia, Ali; Feyzi, Farzaneh; Hashemianzadeh, Seyed Majid

    2018-03-01

    Based on Wertheim's second order thermodynamic perturbation theory (TPT2), equations of state (EOSs) are presented for the fluid and solid phases of tangent, freely jointed spheres. It is considered that the spheres interact with each other through the Weeks-Chandler-Anderson (WCA) potential. The developed TPT2 EOS is the sum of a monomeric reference term and a perturbation contribution due to bonding. MC NVT simulations are performed to determine the structural properties of the reference system in the reduced temperature range of 0.6 ≤ T* ≤ 4.0 and the packing fraction range of 0.1 ≤ η ≤ 0.72. Mathematical functions are fitted to the simulation results of the reference system and employed in the framework of Wertheim's theory to develop TPT2 EOSs for the fluid and solid phases. The extended EOSs are compared to the MC NPT simulation results of the compressibility factor and internal energy of the fully flexible chain systems. Simulations are performed for the WCA chain system for chain lengths of up to 15 at T* = 1.0, 1.5, 2.0, 3.0. Across all the reduced temperatures, the agreement between the results of the TPT2 EOS and MC simulations is remarkable. Overall Average Absolute Relative Percent Deviation at T* = 1.0 for the compressibility factor in the entire chain lengths we covered is 0.51 and 0.77 for the solid and fluid phases, respectively. Similar features are observed in the case of residual internal energy.

  18. A novel inlet system for online chemical analysis of semi-volatile submicron particulate matter

    NASA Astrophysics Data System (ADS)

    Eichler, P.; Müller, M.; D'Anna, B.; Wisthaler, A.

    2015-03-01

    We herein present a novel modular inlet system designed to be coupled to low-pressure gas analyzers for online chemical characterization of semi-volatile submicron particles. The "chemical analysis of aerosol online" (CHARON) inlet consists of a gas-phase denuder for stripping off gas-phase analytes, an aerodynamic lens for particle collimation combined with an inertial sampler for the particle-enriched flow and a thermodesorption unit for particle volatilization prior to chemical analysis. The denuder was measured to remove gas-phase organics with an efficiency > 99.999% and to transmit particles in the 100-750 nm size range with a 75-90% efficiency. The measured average particle enrichment factor in the subsampling flow from the aerodynamic lens was 25.6, which is a factor of 3 lower than the calculated theoretical optimum. We coupled the CHARON inlet to a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) which quantitatively detects most organic analytes and ammonia. The combined CHARON-PTR-ToF-MS setup is thus capable of measuring both the organic and the ammonium fraction in submicron particles in real time. Individual organic compounds can be detected down to levels of 10-20 ng m-3. Two proof-of-principle studies were carried out for demonstrating the analytical power of this new instrumental setup: (i) oxygenated organics and their partitioning between the gas and the particulate phase were observed from the reaction of limonene with ozone and (ii) nicotine was measured in cigarette smoke particles demonstrating that selected organic target compounds can be detected in submicron particles in real time.

  19. Equations of state for the fully flexible WCA chains in the fluid and solid phases based on Wertheims-TPT2.

    PubMed

    Mirzaeinia, Ali; Feyzi, Farzaneh; Hashemianzadeh, Seyed Majid

    2018-03-14

    Based on Wertheim's second order thermodynamic perturbation theory (TPT2), equations of state (EOSs) are presented for the fluid and solid phases of tangent, freely jointed spheres. It is considered that the spheres interact with each other through the Weeks-Chandler-Anderson (WCA) potential. The developed TPT2 EOS is the sum of a monomeric reference term and a perturbation contribution due to bonding. MC NVT simulations are performed to determine the structural properties of the reference system in the reduced temperature range of 0.6 ≤ T* ≤ 4.0 and the packing fraction range of 0.1 ≤ η ≤ 0.72. Mathematical functions are fitted to the simulation results of the reference system and employed in the framework of Wertheim's theory to develop TPT2 EOSs for the fluid and solid phases. The extended EOSs are compared to the MC NPT simulation results of the compressibility factor and internal energy of the fully flexible chain systems. Simulations are performed for the WCA chain system for chain lengths of up to 15 at T* = 1.0, 1.5, 2.0, 3.0. Across all the reduced temperatures, the agreement between the results of the TPT2 EOS and MC simulations is remarkable. Overall Average Absolute Relative Percent Deviation at T* = 1.0 for the compressibility factor in the entire chain lengths we covered is 0.51 and 0.77 for the solid and fluid phases, respectively. Similar features are observed in the case of residual internal energy.

  20. SPARSE—A subgrid particle averaged Reynolds stress equivalent model: testing with a priori closure

    PubMed Central

    Davis, Sean L.; Sen, Oishik; Udaykumar, H. S.

    2017-01-01

    A Lagrangian particle cloud model is proposed that accounts for the effects of Reynolds-averaged particle and turbulent stresses and the averaged carrier-phase velocity of the subparticle cloud scale on the averaged motion and velocity of the cloud. The SPARSE (subgrid particle averaged Reynolds stress equivalent) model is based on a combination of a truncated Taylor expansion of a drag correction function and Reynolds averaging. It reduces the required number of computational parcels to trace a cloud of particles in Eulerian–Lagrangian methods for the simulation of particle-laden flow. Closure is performed in an a priori manner using a reference simulation where all particles in the cloud are traced individually with a point-particle model. Comparison of a first-order model and SPARSE with the reference simulation in one dimension shows that both the stress and the averaging of the carrier-phase velocity on the cloud subscale affect the averaged motion of the particle. A three-dimensional isotropic turbulence computation shows that only one computational parcel is sufficient to accurately trace a cloud of tens of thousands of particles. PMID:28413341

  1. SPARSE-A subgrid particle averaged Reynolds stress equivalent model: testing with a priori closure.

    PubMed

    Davis, Sean L; Jacobs, Gustaaf B; Sen, Oishik; Udaykumar, H S

    2017-03-01

    A Lagrangian particle cloud model is proposed that accounts for the effects of Reynolds-averaged particle and turbulent stresses and the averaged carrier-phase velocity of the subparticle cloud scale on the averaged motion and velocity of the cloud. The SPARSE (subgrid particle averaged Reynolds stress equivalent) model is based on a combination of a truncated Taylor expansion of a drag correction function and Reynolds averaging. It reduces the required number of computational parcels to trace a cloud of particles in Eulerian-Lagrangian methods for the simulation of particle-laden flow. Closure is performed in an a priori manner using a reference simulation where all particles in the cloud are traced individually with a point-particle model. Comparison of a first-order model and SPARSE with the reference simulation in one dimension shows that both the stress and the averaging of the carrier-phase velocity on the cloud subscale affect the averaged motion of the particle. A three-dimensional isotropic turbulence computation shows that only one computational parcel is sufficient to accurately trace a cloud of tens of thousands of particles.

  2. Design methodology and performance analysis of a wideband 90° phase switch for radiometer applications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Villa, Enrique, E-mail: villae@unican.es; Aja, Beatriz; Cagigas, Jaime

    2013-12-15

    This paper presents the analysis, design, and characterization of a wideband 90° phase switch in Ka-band. The phase switch is based on two microstrip bandpass filters in which the commutation is performed by a novel single-pole double-throw (SPDT) switch. The analysis of π-network bandpass filters is provided, obtaining the phase difference and amplitude imbalance between filters and their scattering parameters; tested results show an average phase difference of 88.9° ± 5° and an amplitude imbalance of 0.15 dB from 24 to 37 GHz. The new broadband SPDT switch is based on a coplanar waveguide-to-slotline-to-microstrip structure, which enables a full planarmore » integration with shifting branches. PIN diodes are used to perform the switching between outputs. The SPDT shows isolation better than 19 dB, insertion loss of around 1.8 dB, and return loss better than 15 dB. The full integration of the phase switch achieves a return loss better than 11 dB and insertion loss of around 4 dB over the band 26–36 GHz, with an average phase difference of 87.1° ± 4° and an average amplitude imbalance of 0.3 dB. It provides an excellent performance for this frequency range, suitable for radio-astronomy receivers.« less

  3. Changes of Polyphenolic Substances in the Anatomical Parts of Buckwheat (Fagopyrum esculentum Moench.) during Its Growth Phases

    PubMed Central

    Bystricka, Judita; Musilova, Janette; Tomas, Jan; Vollmannova, Alena; Lachman, Jaromir; Kavalcova, Petra

    2014-01-01

    In this study the changes of total polyphenolics in different anatomical parts (stems, leaves, flowers and seeds) of common buckwheat (Fagopyrum esculentum Moench.) during vegetation period were analysed. The content of total polyphenolics was evaluated in growth phase I (formation of buds), phase II (at the beginning of flowering), phase III (full blossoming) and phase IV (full ripeness). In all growth phases (GP) the stems and leaves were evaluated and statistically significant differences in polyphenolics content between the two parts were confirmed. Statistically significant differences (p < 0.01) in polyphenolics content (in GP II and III) between stems and leaves; and between stems and flowers were found. In flowers an average of 13.8 times higher and in leaves 6 times higher concentration of polyphenolics in comparison with stems was measured. In GP III the content of polyphenolics in common buckwheat was following: flowers > leaves > achene > stems. In flowers an average of 11.9 times higher, in leaves 8.3 times higher and in achenes 5.9 times higher contents of polyphenolics compared with stems were found. In GP III and IV (leaves, achenes, stems) the leaves contained in average 20 times higher and achenes 5.6 times higher polyphenolics than stems. PMID:28234337

  4. Spatio-Temporal Variability of the Phase of Total Ozone Quasi-Decennial Oscillations

    NASA Astrophysics Data System (ADS)

    Visheratin, K. N.

    2017-12-01

    The SBUV/SBUV2 (65° S-65° N) and Bodeker Scientific (90° S-90° N) satellite databases have been used for composite and cross-wavelet analyses of the spatio-temporal variability of phase relations between a 11-year cycle of solar activity (SA) and quasi-decennial oscillations (QDOs) of total ozone content (TOC). For globally average TOC values, the QDO maxima coincide in phase with the solar-activity maxima, and amplitude variations of TOC correlate with those of the 11-year solar cycle. According to the analysis of amplitude and phase of QDOs for the zonal average TOC fields, a QDO amplitude is about 6-7 Dobson Units (DU) in the high northern and southern latitudes, and it does not exceed 2-3 DU in the tropic regions. The latitudinal TOC variations are distinguished by a delay of the quasi-decennial oscillation phase in the southern latitudes in comparison with the northern latitudes. The TOC maxima phase coincides with the SA maxima phase in the tropic regions; the TOC variations go ahead of the SA variations, on average, in moderate and high latitudes of the Northern Hemisphere; the TOC variations are behind the SA variations in the Southern Hemisphere. The phase delay between TOC QDO maxima in the northern and southern latitudes appears to increase in the course of time, and the TOC quasi-decennial variations in the Arctic and Antarctic subpolar regions occur approximately in an antiphase over the last two decades.

  5. Highly-accelerated quantitative 2D and 3D localized spectroscopy with linear algebraic modeling (SLAM) and sensitivity encoding

    NASA Astrophysics Data System (ADS)

    Zhang, Yi; Gabr, Refaat E.; Zhou, Jinyuan; Weiss, Robert G.; Bottomley, Paul A.

    2013-12-01

    Noninvasive magnetic resonance spectroscopy (MRS) with chemical shift imaging (CSI) provides valuable metabolic information for research and clinical studies, but is often limited by long scan times. Recently, spectroscopy with linear algebraic modeling (SLAM) was shown to provide compartment-averaged spectra resolved in one spatial dimension with many-fold reductions in scan-time. This was achieved using a small subset of the CSI phase-encoding steps from central image k-space that maximized the signal-to-noise ratio. Here, SLAM is extended to two- and three-dimensions (2D, 3D). In addition, SLAM is combined with sensitivity-encoded (SENSE) parallel imaging techniques, enabling the replacement of even more CSI phase-encoding steps to further accelerate scan-speed. A modified SLAM reconstruction algorithm is introduced that significantly reduces the effects of signal nonuniformity within compartments. Finally, main-field inhomogeneity corrections are provided, analogous to CSI. These methods are all tested on brain proton MRS data from a total of 24 patients with brain tumors, and in a human cardiac phosphorus 3D SLAM study at 3T. Acceleration factors of up to 120-fold versus CSI are demonstrated, including speed-up factors of 5-fold relative to already-accelerated SENSE CSI. Brain metabolites are quantified in SLAM and SENSE SLAM spectra and found to be indistinguishable from CSI measures from the same compartments. The modified reconstruction algorithm demonstrated immunity to maladjusted segmentation and errors from signal heterogeneity in brain data. In conclusion, SLAM demonstrates the potential to supplant CSI in studies requiring compartment-average spectra or large volume coverage, by dramatically reducing scan-time while providing essentially the same quantitative results.

  6. Assessment of Musculoskeletal Strength and Levels of Fatigue during Different Phases of Menstrual Cycle in Young Adults

    PubMed Central

    D Souza, Urban John; Shivaprakash, G

    2017-01-01

    Introduction Some of the physiological factors and athletic performance might show variation along the phases of menstrual cycle. The alterations seen in these physiological parameters of various systems relating to oscillations in hormonal levels do affect the autonomic nervous system and metabolic functions. Former studies heave inconclusively about the influence of hormones on exercise performance, predominantly muscle strength and rate of fatigue during different phases of the menstrual cycle. Studies regarding influence of these variations during bleeding phase were not done. Aim To evaluate the muscle strength variations and also the rate of fatigue during various phases of the menstrual cycle in young adults. Materials and Methods This was a prospective study conducted among 100 healthy adult female volunteers aged 18-24 years, with normal regular menstrual cycles persistent between 26- 32 days (average of 28 days), for a minimum of last 6 months. Muscle strength was assessed by calculating the work done and fatigue rate using Mosso’s ergograph and by handgrip dynamometer strength. Each subject was evaluated consecutively for two menstrual cycles in all three phases which were classified as Phase 1- Menstrual phase, Phase 2- Follicular phase and Phase 3- Luteal phase. The data obtained was analysed by statistical tool One-way ANOVA followed by a post-hoc Tukeys test. A p-value of ≤ 0.05 was considered significant. Results The amount of work done and handgrip strength was significantly higher in phase 2 (p<0.001) and relatively reduced in phase 1 and 3 (p<0.001) of menstrual cycle. In terms of fatigue rate percentage, phase 2 showed significantly lesser values (p<0.001) as compared to phase 1 and 3 of menstrual cycle. Conclusion We conclude that the cyclical variation in endogenous reproductive hormones increases the muscle strength in follicular phase of the menstrual cycle. Thus provide support for the influence of these hormones in regulation of these parameters in the premenopausal age group. PMID:28384857

  7. Upgrade project and plans for the ATLAS detector and trigger

    NASA Astrophysics Data System (ADS)

    Pastore, Francesca; Atlas Collaboration

    2013-08-01

    The LHC is expected to under go upgrades over the coming years in order to extend its scientific potential. Through two different phases (namely Phase-I and Phase-II), the average luminosity will be increased by a factor 5-10 above the design luminosity, 1034 cm-2 s-1. Consequently, the LHC experiments will need upgraded detectors and new infrastructure of the trigger and DAQ systems, to take into account the increase of radiation level and of particle rates foreseen at such high luminosity. In this paper we describe the planned changes and the investigations for the ATLAS experiment, focusing on the requirements for the trigger system to handle the increase rate of collisions per beam crossing, while maintaining widely inclusive selections. In different steps, the trigger detectors will improve their selectivity by benefiting from increased granularity. To improve the flexibility of the system, the use of the tracking information in the lower levels of the trigger selection is also discussed. Lastly different scenarios are compared, based on the expected physics potential of ATLAS in this high luminosity regime.

  8. A propofol microemulsion with low free propofol in the aqueous phase: formulation, physicochemical characterization, stability and pharmacokinetics.

    PubMed

    Cai, WeiHui; Deng, WanDing; Yang, HuiHui; Chen, XiaoPing; Jin, Fang

    2012-10-15

    The purpose of this study was to develop a propofol microemulsion with a low concentration of free propofol in the aqueous phase. Propofol microemulsions were prepared based on single-factor experiments and orthogonal design. The optimal microemulsion was evaluated for pH, osmolarity, particle size, zeta potential, morphology, free propofol in the aqueous phase, stability, and pharmacokinetics in beagle dogs, and comparisons made with the commercial emulsion, Diprivan(®). The pH and osmolarity of the microemulsion were similar to those of Diprivan(®). The average particle size was 22.6±0.2 nm, and TEM imaging indicated that the microemulsion particles were spherical in appearance. The concentration of free propofol in the microemulsion was 21.3% lower than that of Diprivan(®). Storage stability tests suggested that the microemulsion was stable long-term under room temperature conditions. The pharmacokinetic profile for the microemulsion showed rapid distribution and elimination compared to Diprivan(®). We conclude that the prepared microemulsion may be clinically useful as a potential carrier for propofol delivery. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Supplementation of Dried Mealworm (Tenebrio molitor larva) on Growth Performance, Nutrient Digestibility and Blood Profiles in Weaning Pigs

    PubMed Central

    Jin, X. H.; Heo, P. S.; Hong, J. S.; Kim, N. J.; Kim, Y. Y.

    2016-01-01

    This experiment was conducted to investigate the effects of dried mealworm (Tenebrio molitor larva) on growth performance, nutrient digestibility and blood profiles in weaning pigs. A total of 120 weaning pigs (28±3 days and 8.04±0.08 kg of body weight) were allotted to one of five treatments, based on sex and body weight, in 6 replicates with 4 pigs per pen by a randomized complete block design. Supplementation level of dried mealworm was 0%, 1.5%, 3.0%, 4.5%, or 6.0% in experimental diet as treatment. Two phase feeding programs (phase I from 0 day to 14 day, phase II from 14 day to 35 day) were used in this experiment. All animals were allowed to access diet and water ad libitum. During phase I, increasing level of dried mealworm in diet linearly improved the body weight (p<0.01), average daily gain (ADG) (p<0.01) and average daily feed intake (ADFI) (p<0.01). During phase II, ADG also tended to increase linearly when pigs were fed higher level of dried mealworm (p = 0.08). In addition, increasing level of dried mealworm improved the ADG (p<0.01), ADFI (p<0.05) and tended to increase gain to feed ratio (p = 0.07) during the whole experimental period. As dried mealworm level was increased, nitrogen retention and digestibility of dry matter as well as crude protein were linearly increased (p = 0.05). In the results of blood profiles, decrease of blood urea nitrogen (linear, p = 0.05) and increase of insulin-like growth factor (linear, p = 0.03) were observed as dried mealworm was increased in diet during phase II. However, there were no significant differences in immunoglobulin A (IgA) and IgG concentration by addition of dried mealworm in the growth trial. Consequently, supplementation of dried mealworm up to 6% in weaning pigs’ diet improves growth performance and nutrient digestibility without any detrimental effect on immune responses. PMID:27282974

  10. Acid base properties of cyanobacterial surfaces I: Influences of growth phase and nitrogen metabolism on cell surface reactivity

    NASA Astrophysics Data System (ADS)

    Lalonde, S. V.; Smith, D. S.; Owttrim, G. W.; Konhauser, K. O.

    2008-03-01

    Significant efforts have been made to elucidate the chemical properties of bacterial surfaces for the purposes of refining surface complexation models that can account for their metal sorptive behavior under diverse conditions. However, the influence of culturing conditions on surface chemical parameters that are modeled from the potentiometric titration of bacterial surfaces has received little regard. While culture age and metabolic pathway have been considered as factors potentially influencing cell surface reactivity, statistical treatments have been incomplete and variability has remained unconfirmed. In this study, we employ potentiometric titrations to evaluate variations in bacterial surface ligand distributions using live cells of the sheathless cyanobacterium Anabaena sp. strain PCC 7120, grown under a variety of batch culture conditions. We evaluate the ability for a single set of modeled parameters, describing acid-base surface properties averaged over all culture conditions tested, to accurately account for the ligand distributions modeled for each individual culture condition. In addition to considering growth phase, we assess the role of the various assimilatory nitrogen metabolisms available to this organism as potential determinants of surface reactivity. We observe statistically significant variability in site distribution between the majority of conditions assessed. By employing post hoc Tukey-Kramer analysis for all possible pair-wise condition comparisons, we conclude that the average parameters are inadequate for the accurate chemical description of this cyanobacterial surface. It was determined that for this Gram-negative bacterium in batch culture, ligand distributions were influenced to a greater extent by nitrogen assimilation pathway than by growth phase.

  11. Phase Averaged Measurements of the Coherent Structure of a Mach Number 0.6 Jet. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Emami, S.

    1983-01-01

    The existence of a large scale structure in a Mach number 0.6, axisymmetric jet of cold air was proven. In order to further characterize the coherent structure, phase averaged measurements of the axial mass velocity, radial velocity, and the product of the two were made. These measurements yield information about the percent of the total fluctuations contained in the coherent structure. These measured values were compared to the total fluctuation levels for each quantity and the result expressed as a percent of the total fluctuation level contained in the organized structure at a given frequency. These measurements were performed for five frequencies (St=0.16, 0.32, 0.474, 0.95, and 1.26). All of the phase averaged measurements required that the jet be artificially excited.

  12. The lifetime cost of hepatocellular carcinoma : a claims data analysis from a medical centre in Taiwan.

    PubMed

    Lang, Hui-Chu; Wu, Jaw-Ching; Yen, Sang-Hue; Lan, Chung-Fu; Wu, Shi-Liang

    2008-01-01

    Hepatocellular carcinoma (HCC) is the second most common cancer in Taiwan. For males in Taiwan, it is the most dangerous cancer, with both the highest incidence and mortality rate. To determine cancer-related medical care costs for long-term survivors of HCC. The estimation of the lifetime cost was based on the insurer perspective and adopted an incidence-based approach. Data was sourced from the 1999-2002 cancer registry statistics of patients with HCC and the claims data of Taipei Veterans General Hospital (TVGH). In total there were 2873 HCC patients at TVGH. In addition to this data, the research used population National Health Insurance claims data from the National Health Research Institutes (1996-2002) as the comparison group. The probabilities of survival, dying of cancer or dying of other causes were estimated using cancer registry statistics. To estimate lifetime (10-year) cost, we divided the disease process into three phases: initial, continuing and terminal. The cost of HCC was calculated as the sum of the average cost of each phase. The expected lifetime cost for treatment of an HCC patient was estimated by incorporating the phase-specific costs with the survival and mortality rates. The results showed that 895 patients survived <1 year, and treatment for each of these patients cost on average New Taiwan dollars ($NT) 206 573 ($US 1 = $NT 33, year 2002 value) over this period. For those who survived > or =1 year, the terminal phase of treatment resulted in the highest costs, $NT 237 032. On average, for each patient, the initial phase cost was $NT 140 403 and the monthly cost for the continuing phase was $NT 8687. For the average HCC patient, the 10-year lifetime cost was $NT 418 554 (in nominal $NT). Our study showed that the terminal phase cost the most out of the three treatment phases. The aggregate lifetime cost of HCC is useful for health policy making and clinical decision making.

  13. Negative DC corona discharge current characteristics in a flowing two-phase (air + suspended smoke particles) fluid

    NASA Astrophysics Data System (ADS)

    Berendt, Artur; Domaszka, Magdalena; Mizeraczyk, Jerzy

    2017-04-01

    The electrical characteristics of a steady-state negative DC corona discharge in a two-phase fluid (air with suspended cigarette smoke particles) flowing along a chamber with a needle-to-plate electrode arrangement were experimentally investigated. The two-phase flow was transverse in respect to the needle-to-plate axis. The velocity of the transverse two-phase flow was limited to 0.8 m/s, typical of the electrostatic precipitators. We found that three discharge current modes of the negative corona exist in the two-phase (air + smoke particles) fluid: the Trichel pulses mode, the "Trichel pulses superimposed on DC component" mode and the DC component mode, similarly as in the corona discharge in air (a single-phase fluid). The shape of Trichel pulses in the air + suspended particles fluid is similar to that in air. However, the Trichel pulse amplitudes are higher than those in "pure" air while their repetition frequency is lower. As a net consequence of that the averaged corona discharge current in the two-phase fluid is lower than in "pure" air. It was also found that the average discharge current decreases with increasing suspended particle concentration. The calculations showed that the dependence of the average negative corona current (which is a macroscopic corona discharge parameter) on the particle concentration can be explained by the particle-concentration dependencies of the electric charge of Trichel pulse and the repetition frequency of Trichel pulses, both giving a microscopic insight into the electrical phenomena in the negative corona discharge. Our investigations showed also that the average corona discharge current in the two-phase fluid is almost unaffected by the transverse fluid flow up to a velocity of 0.8 m/s. Contribution to the topical issue "The 15th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XV)", edited by Nicolas Gherardi and Tomáš Hoder

  14. Determination of Internal Target Volume for Radiation Treatment Planning of Esophageal Cancer by Using 4-Dimensional Computed Tomography (4DCT)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Xiaojian; Lu, Haijun; Radiation Oncology Center, Affiliated Hospital of Medical College, Qingdao University, Qingdao

    2014-09-01

    Purpose: To determine an efficient strategy for the generation of the internal target volume (ITV) for radiation treatment planning for esophageal cancer using 4-dimensional computed tomography (4DCT). Methods and Materials: 4DCT sets acquired for 20 patients with esophageal carcinoma were analyzed. Each of the 4DCT sets was binned into 10 respiratory phases. For each patient, the gross tumor volume (GTV) was delineated on the 4DCT set at each phase. Various strategies to derive ITV were explored, including the volume from the maximum intensity projection (MIP; ITV{sub M}IP), unions of the GTVs from selected multiple phases ITV2 (0% and 50% phases), ITV3 (ITV2more » plus 80%), and ITV4 (ITV3 plus 60%), as well as the volumes expanded from ITV2 and ITV3 with a uniform margin. These ITVs were compared to ITV10 (the union of the GTVs for all 10 phases) and the differences were measured with the overlap ratio (OR) and relative volume ratio (RVR) relative to ITV10 (ITVx/ITV10). Results: For all patients studied, the average GTV from a single phase was 84.9% of ITV10. The average ORs were 91.2%, 91.3%, 94.5%, and 96.4% for ITV{sub M}IP, ITV2, ITV3, and ITV4, respectively. Low ORs were associated with irregular breathing patterns. ITV3s plus 1 mm uniform margins (ITV3+1) led to an average OR of 98.1% and an average RVR of 106.4%. Conclusions: The ITV generated directly from MIP underestimates the range of the respiration motion for esophageal cancer. The ITV generated from 3 phases (ITV3) may be used for regular breathers, whereas the ITV generated from 4 phases (ITV4) or ITV3 plus a 1-mm uniform margin may be applied for irregular breathers.« less

  15. A Multiphase Validation of Atlas-Based Automatic and Semiautomatic Segmentation Strategies for Prostate MRI

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Martin, Spencer; Rodrigues, George, E-mail: george.rodrigues@lhsc.on.ca; Department of Epidemiology/Biostatistics, University of Western Ontario, London

    2013-01-01

    Purpose: To perform a rigorous technological assessment and statistical validation of a software technology for anatomic delineations of the prostate on MRI datasets. Methods and Materials: A 3-phase validation strategy was used. Phase I consisted of anatomic atlas building using 100 prostate cancer MRI data sets to provide training data sets for the segmentation algorithms. In phase II, 2 experts contoured 15 new MRI prostate cancer cases using 3 approaches (manual, N points, and region of interest). In phase III, 5 new physicians with variable MRI prostate contouring experience segmented the same 15 phase II datasets using 3 approaches: manual,more » N points with no editing, and full autosegmentation with user editing allowed. Statistical analyses for time and accuracy (using Dice similarity coefficient) endpoints used traditional descriptive statistics, analysis of variance, analysis of covariance, and pooled Student t test. Results: In phase I, average (SD) total and per slice contouring time for the 2 physicians was 228 (75), 17 (3.5), 209 (65), and 15 seconds (3.9), respectively. In phase II, statistically significant differences in physician contouring time were observed based on physician, type of contouring, and case sequence. The N points strategy resulted in superior segmentation accuracy when initial autosegmented contours were compared with final contours. In phase III, statistically significant differences in contouring time were observed based on physician, type of contouring, and case sequence again. The average relative timesaving for N points and autosegmentation were 49% and 27%, respectively, compared with manual contouring. The N points and autosegmentation strategies resulted in average Dice values of 0.89 and 0.88, respectively. Pre- and postedited autosegmented contours demonstrated a higher average Dice similarity coefficient of 0.94. Conclusion: The software provided robust contours with minimal editing required. Observed time savings were seen for all physicians irrespective of experience level and baseline manual contouring speed.« less

  16. Determination of internal target volume for radiation treatment planning of esophageal cancer by using 4-dimensional computed tomography (4DCT).

    PubMed

    Chen, Xiaojian; Lu, Haijun; Tai, An; Johnstone, Candice; Gore, Elizabeth; Li, X Allen

    2014-09-01

    To determine an efficient strategy for the generation of the internal target volume (ITV) for radiation treatment planning for esophageal cancer using 4-dimensional computed tomography (4DCT). 4DCT sets acquired for 20 patients with esophageal carcinoma were analyzed. Each of the 4DCT sets was binned into 10 respiratory phases. For each patient, the gross tumor volume (GTV) was delineated on the 4DCT set at each phase. Various strategies to derive ITV were explored, including the volume from the maximum intensity projection (MIP; ITV_MIP), unions of the GTVs from selected multiple phases ITV2 (0% and 50% phases), ITV3 (ITV2 plus 80%), and ITV4 (ITV3 plus 60%), as well as the volumes expanded from ITV2 and ITV3 with a uniform margin. These ITVs were compared to ITV10 (the union of the GTVs for all 10 phases) and the differences were measured with the overlap ratio (OR) and relative volume ratio (RVR) relative to ITV10 (ITVx/ITV10). For all patients studied, the average GTV from a single phase was 84.9% of ITV10. The average ORs were 91.2%, 91.3%, 94.5%, and 96.4% for ITV_MIP, ITV2, ITV3, and ITV4, respectively. Low ORs were associated with irregular breathing patterns. ITV3s plus 1 mm uniform margins (ITV3+1) led to an average OR of 98.1% and an average RVR of 106.4%. The ITV generated directly from MIP underestimates the range of the respiration motion for esophageal cancer. The ITV generated from 3 phases (ITV3) may be used for regular breathers, whereas the ITV generated from 4 phases (ITV4) or ITV3 plus a 1-mm uniform margin may be applied for irregular breathers. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Marginal Emissions Factors for Electricity Generation in the Midcontinent ISO.

    PubMed

    Thind, Maninder P S; Wilson, Elizabeth J; Azevedo, Inês L; Marshall, Julian D

    2017-12-19

    Environmental consequences of electricity generation are often determined using average emission factors. However, as different interventions are incrementally pursued in electricity systems, the resulting marginal change in emissions may differ from what one would predict based on system-average conditions. Here, we estimate average emission factors and marginal emission factors for CO 2 , SO 2 , and NO x from fossil and nonfossil generators in the Midcontinent Independent System Operator (MISO) region during years 2007-2016. We analyze multiple spatial scales (all MISO; each of the 11 MISO states; each utility; each generator) and use MISO data to characterize differences between the two emission factors (average; marginal). We also explore temporal trends in emissions factors by hour, day, month, and year, as well as the differences that arise from including only fossil generators versus total generation. We find, for example, that marginal emission factors are generally higher during late-night and early morning compared to afternoons. Overall, in MISO, average emission factors are generally higher than marginal estimates (typical difference: ∼20%). This means that the true environmental benefit of an energy efficiency program may be ∼20% smaller than anticipated if one were to use average emissions factors. Our analysis can usefully be extended to other regions to support effective near-term technical, policy and investment decisions based on marginal rather than only average emission factors.

  18. Cost effectiveness of adopted quality requirements in hospital laboratories.

    PubMed

    Hamza, Alneil; Ahmed-Abakur, Eltayib; Abugroun, Elsir; Bakhit, Siham; Holi, Mohamed

    2013-01-01

    The present study was designed in quasi-experiment to assess adoption of the essential clauses of particular clinical laboratory quality management requirements based on international organization for standardization (ISO 15189) in hospital laboratories and to evaluate the cost effectiveness of compliance to ISO 15189. The quality management intervention based on ISO 15189 was conceded through three phases; pre - intervention phase, Intervention phase and Post-intervention phase. In pre-intervention phase the compliance to ISO 15189 was 49% for study group vs. 47% for control group with P value 0.48, while the post intervention results displayed 54% vs. 79% for study group and control group respectively in compliance to ISO 15189 and statistically significant difference (P value 0.00) with effect size (Cohen's d) of (0.00) in pre-intervention phase and (0.99) in post - intervention phase. The annual average cost per-test for the study group and control group was 1.80 ± 0.25 vs. 1.97 ± 0.39, respectively with P value 0.39 whereas the post-intervention results showed that the annual average total costs per-test for study group and control group was 1.57 ± 0.23 vs 2.08 ± 0.38, P value 0.019 respectively, with cost-effectiveness ratio of (0.88) in pre -intervention phase and (0.52) in post-intervention phase. The planned adoption of quality management requirements (QMS) in clinical laboratories had great effect to increase the compliance percent with quality management system requirement, raise the average total cost effectiveness, and improve the analytical process capability of the testing procedure.

  19. A Nongraded Phase Elective Senior High English Curriculum.

    ERIC Educational Resources Information Center

    South Bend Community School Corp., IN.

    The course content in this nongraded phase elective curriculum is classified into Phase 1, designed for students who find reading, writing, and speaking difficult, Phase 2 for students who need to improve and refine basic skills at a somewhat slower pace, Phase 3 for those who have an average command of basic language skills and want to advance at…

  20. Translating landfill methane generation parameters among first-order decay models.

    PubMed

    Krause, Max J; Chickering, Giles W; Townsend, Timothy G

    2016-11-01

    Landfill gas (LFG) generation is predicted by a first-order decay (FOD) equation that incorporates two parameters: a methane generation potential (L 0 ) and a methane generation rate (k). Because non-hazardous waste landfills may accept many types of waste streams, multiphase models have been developed in an attempt to more accurately predict methane generation from heterogeneous waste streams. The ability of a single-phase FOD model to predict methane generation using weighted-average methane generation parameters and tonnages translated from multiphase models was assessed in two exercises. In the first exercise, waste composition from four Danish landfills represented by low-biodegradable waste streams was modeled in the Afvalzorg Multiphase Model and methane generation was compared to the single-phase Intergovernmental Panel on Climate Change (IPCC) Waste Model and LandGEM. In the second exercise, waste composition represented by IPCC waste components was modeled in the multiphase IPCC and compared to single-phase LandGEM and Australia's Solid Waste Calculator (SWC). In both cases, weight-averaging of methane generation parameters from waste composition data in single-phase models was effective in predicting cumulative methane generation from -7% to +6% of the multiphase models. The results underscore the understanding that multiphase models will not necessarily improve LFG generation prediction because the uncertainty of the method rests largely within the input parameters. A unique method of calculating the methane generation rate constant by mass of anaerobically degradable carbon was presented (k c ) and compared to existing methods, providing a better fit in 3 of 8 scenarios. Generally, single phase models with weighted-average inputs can accurately predict methane generation from multiple waste streams with varied characteristics; weighted averages should therefore be used instead of regional default values when comparing models. Translating multiphase first-order decay model input parameters by weighted average shows that single-phase models can predict cumulative methane generation within the level of uncertainty of many of the input parameters as defined by the Intergovernmental Panel on Climate Change (IPCC), which indicates that decreasing the uncertainty of the input parameters will make the model more accurate rather than adding multiple phases or input parameters.

  1. Towards the control of the modal energy transfer in transverse mode instabilities

    NASA Astrophysics Data System (ADS)

    Stihler, Christoph; Jauregui, Cesar; Tünnermann, Andreas; Limpert, Jens

    2018-02-01

    Thermally-induced refractive index gratings (RIG) in high-power fiber laser systems lead to transverse mode instabilities (TMI) above a certain average power threshold. The effect of TMI is currently the main limitation for the further average power scaling of fiber lasers and amplifiers with nearly diffraction-limited beam quality. In this work we experimentally investigate, for the first time, the growth of the RIG strength by introducing a phase-shift between the RIG and the modal interference pattern in a fiber amplifier. The experiments reveal that the RIG is strong enough to couple energy between different transverse modes even at powers significantly below the TMI threshold, provided that the introduced phase-shift is high enough. This indicates that, as the strength of the RIG further increases with increasing average output power, the RIG becomes more and more sensitive to even small noise-induced phase-shifts, which ultimately trigger TMI. Furthermore, it is shown that a beam cleaning also occurs when a positive phase-shift is introduced, even above the TMI threshold. This finding will pave the way for the development of a new class of mitigation strategies for TMI, which key feature is the control of the introduced phase-shift.

  2. Cine phase-contrast MRI evaluation of normal aqueductal cerebrospinal fluid flow according to sex and age.

    PubMed

    Unal, Ozkan; Kartum, Alp; Avcu, Serhat; Etlik, Omer; Arslan, Halil; Bora, Aydin

    2009-12-01

    The aim of this study was cerebrospinal flow quantification in the cerebral aqueduct using cine phase-contrast magnetic resonance imaging (MRI) technique in both sexes and five different age groups to provide normative data. Sixty subjects with no cerebral pathology were included in this study. Subjects were divided into five age groups: < or =14 years, 15-24 years, 25-34 years, 35-44 years, and > or =45 years. Phase, rephase, and magnitude images were acquired by 1.5 T MR unit at the level of cerebral aqueduct with spoiled gradient echo through-plane, which is a cine phase-contrast sequence. At this level, peak flow velocity (cm/s), average flow rate (cm/ s), average flow (L/min), volumes in cranial and caudal directions (mL), and net volumes (mL) were studied. There was a statistically significant difference in peak flow between the age group of < or =14 years and the older age groups. There were no statistically significant differences in average velocity, cranial and caudal volume, net volume, and average flow parameters among different age groups. Statistically significant differences were not detected in flow parameters between sexes. When using cine-phase contrast MRI in the cerebral aqueduct, only the peak velocity showed a statistically significant difference between age groups; it was higher in subjects aged < or =14 years than those in older age groups. When performing age-dependent clinical studies including adolescents, this should be taken into consideration.

  3. Apportionment of sources of fine and coarse particles in four major Australian cities by positive matrix factorisation

    NASA Astrophysics Data System (ADS)

    Chan, Yiu-Chung; Cohen, David D.; Hawas, Olga; Stelcer, Eduard; Simpson, Rod; Denison, Lyn; Wong, Neil; Hodge, Mary; Comino, Eva; Carswell, Stewart

    In this study, 437 days of 6-daily, 24-h samples of PM 2.5, PM 2.5-10 and PM 10 were collected over a 12-month period during 2003-2004 in Melbourne, Sydney, Brisbane and Adelaide. The elemental, ionic and polycyclic aromatic hydrocarbon composition of the particles were determined. Source apportionment was carried out by using the positive matrix factorisation software (PMF2). Eight factors were identified for the fine particle samples including 'motor vehicles', 'industry', 'other combustion sources', 'ammonium sulphates', 'nitrates', 'marine aerosols', 'chloride depleted marine aerosols' and 'crustal/soil dust'. On average combustion sources, secondary nitrates/sulphates and natural origin dust contributed about 46%, 25% and 26% of the mass of the fine particle samples, respectively. 'Crustal/soil dust', 'marine aerosols', 'nitrates' and 'road side dust' were the four factors identified for the coarse particle samples. On average natural origin dust contributed about 76% of the mass of the coarse particle samples. The contributions of the sources to the sample mass basically reflect the emission source characteristics of the sites. Secondary sulphates and nitrates were found to spread out evenly within each city. The average contribution of secondary nitrates to fine particles was found to be rather uniform in different seasons, rather than higher in winter as found in other studies. This could be due to the low humidity conditions in winter in most of the Australian cities which made the partitioning of the particle phase less favourable in the NH 4NO 3 equilibrium system. A linear relationship was found between the average contribution of marine aerosols and the distance of the site from the bay side. Wind erosion was found associated with higher contribution of crustal dust on average and episodes of elevated concentration of coarse particles in spring and summer.

  4. Measurement of average density and relative volumes in a dispersed two-phase fluid

    DOEpatents

    Sreepada, Sastry R.; Rippel, Robert R.

    1992-01-01

    An apparatus and a method are disclosed for measuring the average density and relative volumes in an essentially transparent, dispersed two-phase fluid. A laser beam with a diameter no greater than 1% of the diameter of the bubbles, droplets, or particles of the dispersed phase is directed onto a diffraction grating. A single-order component of the diffracted beam is directed through the two-phase fluid and its refraction is measured. Preferably, the refracted beam exiting the fluid is incident upon a optical filter with linearly varing optical density and the intensity of the filtered beam is measured. The invention can be combined with other laser-based measurement systems, e.g., laser doppler anemometry.

  5. D-region differential-phase measurements and ionization variability studies

    NASA Technical Reports Server (NTRS)

    Weiland, R. M.; Bowhill, S. A.

    1978-01-01

    Measurements of electron densities in the D region are made by the partial-reflection differential-absorption and differential-phase techniques. The differential-phase data are obtained by a hard-wired phase-measuring system. Electron-sensity profiles obtained by the two techniques on six occasions are plotted and compared. Electron-density profiles obtained at the same time on 30 occasions during the years 1975 through 1977 are averaged to form a single profile for each technique. The effect of varying the assumed collision-frequency profile on these averaged profiles is studied. Time series of D-region electron-sensity data obtained by 3.4 minute intervals on six days during the summer of 1977 are examined for wave-like disturbances and tidal oscillations.

  6. Phase-factor-dependent symmetries and quantum phases in a three-level cavity QED system.

    PubMed

    Fan, Jingtao; Yu, Lixian; Chen, Gang; Jia, Suotang

    2016-05-03

    Unlike conventional two-level particles, three-level particles may support some unitary-invariant phase factors when they interact coherently with a single-mode quantized light field. To gain a better understanding of light-matter interaction, it is thus necessary to explore the phase-factor-dependent physics in such a system. In this report, we consider the collective interaction between degenerate V-type three-level particles and a single-mode quantized light field, whose different components are labeled by different phase factors. We mainly establish an important relation between the phase factors and the symmetry or symmetry-broken physics. Specifically, we find that the phase factors affect dramatically the system symmetry. When these symmetries are breaking separately, rich quantum phases emerge. Finally, we propose a possible scheme to experimentally probe the predicted physics of our model. Our work provides a way to explore phase-factor-induced nontrivial physics by introducing additional particle levels.

  7. Pore-level influence of micro-fracture parameters on visco-capillary behavior of two-phase displacements in porous media

    NASA Astrophysics Data System (ADS)

    Rokhforouz, M. R.; Akhlaghi Amiri, H. A.

    2018-03-01

    In this work, coupled Cahn-Hilliard phase field and Navier-Stokes equations were solved using finite element method to address the effects of micro-fracture and its characterizations on water-oil displacements in a heterogeneous porous medium. Sensitivity studies at a wide range of viscosity ratios (M) and capillary numbers (Ca), and the resultant log Ca-log M stability phase diagram, revealed that in both media, with/without fracture, the three regimes of viscous fingering, capillary fingering and stable displacement similarly occur. However, presence of the fracture caused water channeling phenomenon which resulted in reduction of the number of active fingers and hence the final oil recovery factor. At high Ca (especially in the stable regime, with log Ca ≥ -2.5 and log M ≥ 0), recovery factor for the fractured medium was relatively identical with the non-fractured one. At log M ≥ 0, the fracture was fully swept, but flow instabilities were observed inside the fracture at lower M values, especially for log Ca > -4.6. In the case of the fractured medium at log Ca = -4.6 and log M = 0 (capillary dominant flow), it is observed that the primary breakthrough took place by a finger progressed through the matrix, not those channeled through the fracture. Geometrical properties of the fracture, including length, aperture and orientation, highly affected both displacement profile and efficiency. The fracture length inversely influenced the oil recovery factor. It was observed that there is a critical fracture width (almost half of the medium average pore diameter) at which the recovery factor of the medium during displacement is minimum, compared to the media having thinner and thicker fractures. Minor channeling effect in the media with thinner fracture and larger fracture swept volume as well as high fracture/matrix cross flow in the media with thicker fracture were detected as the main cause of this non-monotonic behavior. In the models with thick fractures (with the thickness higher than the average pore diameter), considerable trapped oil volumes were observed inside the fracture at low M values. The fracture orientation had the most impressive effect on oil recovery compared to the other studied parameters; where the oil recovery factor incremented more than 20% as the fracture rotated 90° from flow direction. Due to the dominant effect of the channeling phenomenon, the change in the medium wettability from slightly oil-wet to slightly water-wet, did not considerably affect the displacement profile in the fractured medium. However, oil recovery factor increased as the medium became more water-wet. The fracture area was fully swept by the injected water in the oil-wet and neutral-wet media. However, flow instabilities were observed inside the fracture of the water-wet medium due to counter-current imbibition between fracture/matrix. Micro-scale mechanisms of pore doublet effect, interface coalesce, snap-off and reverse movements were captured during the studied unstable displacements.

  8. Instantaneous, phase-averaged, and time-averaged pressure from particle image velocimetry

    NASA Astrophysics Data System (ADS)

    de Kat, Roeland

    2015-11-01

    Recent work on pressure determination using velocity data from particle image velocimetry (PIV) resulted in approaches that allow for instantaneous and volumetric pressure determination. However, applying these approaches is not always feasible (e.g. due to resolution, access, or other constraints) or desired. In those cases pressure determination approaches using phase-averaged or time-averaged velocity provide an alternative. To assess the performance of these different pressure determination approaches against one another, they are applied to a single data set and their results are compared with each other and with surface pressure measurements. For this assessment, the data set of a flow around a square cylinder (de Kat & van Oudheusden, 2012, Exp. Fluids 52:1089-1106) is used. RdK is supported by a Leverhulme Trust Early Career Fellowship.

  9. Preliminary evaluation of factors associated with premature trial closure and feasibility of accrual benchmarks in phase III oncology trials.

    PubMed

    Schroen, Anneke T; Petroni, Gina R; Wang, Hongkun; Gray, Robert; Wang, Xiaofei F; Cronin, Walter; Sargent, Daniel J; Benedetti, Jacqueline; Wickerham, Donald L; Djulbegovic, Benjamin; Slingluff, Craig L

    2010-08-01

    A major challenge for randomized phase III oncology trials is the frequent low rates of patient enrollment, resulting in high rates of premature closure due to insufficient accrual. We conducted a pilot study to determine the extent of trial closure due to poor accrual, feasibility of identifying trial factors associated with sufficient accrual, impact of redesign strategies on trial accrual, and accrual benchmarks designating high failure risk in the clinical trials cooperative group (CTCG) setting. A subset of phase III trials opened by five CTCGs between August 1991 and March 2004 was evaluated. Design elements, experimental agents, redesign strategies, and pretrial accrual assessment supporting accrual predictions were abstracted from CTCG documents. Percent actual/predicted accrual rate averaged per month was calculated. Trials were categorized as having sufficient or insufficient accrual based on reason for trial termination. Analyses included univariate and bivariate summaries to identify potential trial factors associated with accrual sufficiency. Among 40 trials from one CTCG, 21 (52.5%) trials closed due to insufficient accrual. In 82 trials from five CTCGs, therapeutic trials accrued sufficiently more often than nontherapeutic trials (59% vs 27%, p = 0.05). Trials including pretrial accrual assessment more often achieved sufficient accrual than those without (67% vs 47%, p = 0.08). Fewer exclusion criteria, shorter consent forms, other CTCG participation, and trial design simplicity were not associated with achieving sufficient accrual. Trials accruing at a rate much lower than predicted (<35% actual/predicted accrual rate) were consistently closed due to insufficient accrual. This trial subset under-represents certain experimental modalities. Data sources do not allow accounting for all factors potentially related to accrual success. Trial closure due to insufficient accrual is common. Certain trial design factors appear associated with attaining sufficient accrual. Defining accrual benchmarks for early trial termination or redesign is feasible, but better accrual prediction methods are critically needed. Future studies should focus on identifying trial factors that allow more accurate accrual predictions and strategies that can salvage open trials experiencing slow accrual.

  10. Preliminary evaluation of factors associated with premature trial closure and feasibility of accrual benchmarks in phase III oncology trials

    PubMed Central

    Schroen, Anneke T; Petroni, Gina R; Wang, Hongkun; Gray, Robert; Wang, Xiaofei F; Cronin, Walter; Sargent, Daniel J; Benedetti, Jacqueline; Wickerham, Donald L; Djulbegovic, Benjamin; Slingluff, Craig L

    2014-01-01

    Background A major challenge for randomized phase III oncology trials is the frequent low rates of patient enrollment, resulting in high rates of premature closure due to insufficient accrual. Purpose We conducted a pilot study to determine the extent of trial closure due to poor accrual, feasibility of identifying trial factors associated with sufficient accrual, impact of redesign strategies on trial accrual, and accrual benchmarks designating high failure risk in the clinical trials cooperative group (CTCG) setting. Methods A subset of phase III trials opened by five CTCGs between August 1991 and March 2004 was evaluated. Design elements, experimental agents, redesign strategies, and pretrial accrual assessment supporting accrual predictions were abstracted from CTCG documents. Percent actual/predicted accrual rate averaged per month was calculated. Trials were categorized as having sufficient or insufficient accrual based on reason for trial termination. Analyses included univariate and bivariate summaries to identify potential trial factors associated with accrual sufficiency. Results Among 40 trials from one CTCG, 21 (52.5%) trials closed due to insufficient accrual. In 82 trials from five CTCGs, therapeutic trials accrued sufficiently more often than nontherapeutic trials (59% vs 27%, p = 0.05). Trials including pretrial accrual assessment more often achieved sufficient accrual than those without (67% vs 47%, p = 0.08). Fewer exclusion criteria, shorter consent forms, other CTCG participation, and trial design simplicity were not associated with achieving sufficient accrual. Trials accruing at a rate much lower than predicted (<35% actual/predicted accrual rate) were consistently closed due to insufficient accrual. Limitations This trial subset under-represents certain experimental modalities. Data sources do not allow accounting for all factors potentially related to accrual success. Conclusion Trial closure due to insufficient accrual is common. Certain trial design factors appear associated with attaining sufficient accrual. Defining accrual benchmarks for early trial termination or redesign is feasible, but better accrual prediction methods are critically needed. Future studies should focus on identifying trial factors that allow more accurate accrual predictions and strategies that can salvage open trials experiencing slow accrual. PMID:20595245

  11. Field-theoretical approach to a dense polymer with an ideal binary mixture of clustering centers.

    PubMed

    Fantoni, Riccardo; Müller-Nedebock, Kristian K

    2011-07-01

    We propose a field-theoretical approach to a polymer system immersed in an ideal mixture of clustering centers. The system contains several species of these clustering centers with different functionality, each of which connects a fixed number segments of the chain to each other. The field theory is solved using the saddle point approximation and evaluated for dense polymer melts using the random phase approximation. We find a short-ranged effective intersegment interaction with strength dependent on the average segment density and discuss the structure factor within this approximation. We also determine the fractions of linkers of the different functionalities.

  12. Muscle Invasive Bladder Cancer: From Diagnosis to Survivorship

    PubMed Central

    Mohamed, N. E.; Diefenbach, M. A.; Goltz, H. H.; Lee, C. T.; Latini, D.; Kowalkowski, M.; Philips, C.; Hassan, W.; Hall, S. J.

    2012-01-01

    Bladder cancer is the fifth most commonly diagnosed cancer and the most expensive adult cancer in average healthcare costs incurred per patient in the USA. However, little is known about factors influencing patients' treatment decisions, quality of life, and responses to treatment impairments. The main focus of this paper is to better understand the impact of muscle invasive bladder cancer on patient quality of life and its added implications for primary caregivers and healthcare providers. In this paper, we discuss treatment options, side effects, and challenges that patients and family caregivers face in different phases along the disease trajectory and further identify crucial areas of needed research. PMID:22924038

  13. TU-F-17A-08: The Relative Accuracy of 4D Dose Accumulation for Lung Radiotherapy Using Rigid Dose Projection Versus Dose Recalculation On Every Breathing Phase

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lamb, J; Lee, C; Tee, S

    2014-06-15

    Purpose: To investigate the accuracy of 4D dose accumulation using projection of dose calculated on the end-exhalation, mid-ventilation, or average intensity breathing phase CT scan, versus dose accumulation performed using full Monte Carlo dose recalculation on every breathing phase. Methods: Radiotherapy plans were analyzed for 10 patients with stage I-II lung cancer planned using 4D-CT. SBRT plans were optimized using the dose calculated by a commercially-available Monte Carlo algorithm on the end-exhalation 4D-CT phase. 4D dose accumulations using deformable registration were performed with a commercially available tool that projected the planned dose onto every breathing phase without recalculation, as wellmore » as with a Monte Carlo recalculation of the dose on all breathing phases. The 3D planned dose (3D-EX), the 3D dose calculated on the average intensity image (3D-AVE), and the 4D accumulations of the dose calculated on the end-exhalation phase CT (4D-PR-EX), the mid-ventilation phase CT (4D-PR-MID), and the average intensity image (4D-PR-AVE), respectively, were compared against the accumulation of the Monte Carlo dose recalculated on every phase. Plan evaluation metrics relating to target volumes and critical structures relevant for lung SBRT were analyzed. Results: Plan evaluation metrics tabulated using 4D-PR-EX, 4D-PR-MID, and 4D-PR-AVE differed from those tabulated using Monte Carlo recalculation on every phase by an average of 0.14±0.70 Gy, - 0.11±0.51 Gy, and 0.00±0.62 Gy, respectively. Deviations of between 8 and 13 Gy were observed between the 4D-MC calculations and both 3D methods for the proximal bronchial trees of 3 patients. Conclusions: 4D dose accumulation using projection without re-calculation may be sufficiently accurate compared to 4D dose accumulated from Monte Carlo recalculation on every phase, depending on institutional protocols. Use of 4D dose accumulation should be considered when evaluating normal tissue complication probabilities as well as in clinical situations where target volumes are directly inferior to mobile critical structures.« less

  14. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zheng, Ce; Auger, Maria A.; Moody, Michael P.

    In this study, Ferritic/Martensitic (F/M) HT9 steel was irradiated to 20 displacements per atom (dpa) at 600 nm depth at 420 and 440 °C, and to 1, 10 and 20 dpa at 600 nm depth at 470 °C using 5 MeV Fe++ ions. The characterization was conducted using ChemiSTEM and Atom Probe Tomography (APT), with a focus on radiation induced segregation and precipitation. Ni and/or Si segregation at defect sinks (grain boundaries, dislocation lines, carbide/matrix interfaces) together with Ni, Si, Mn rich G-phase precipitation were observed in self-ion irradiated HT9 except in very low dose case (1 dpa at 470more » °C). Some G-phase precipitates were found to nucleate heterogeneously at defect sinks where Ni and/or Si segregated. In contrast to what was previously reported in the literature for neutron irradiated HT9, no Cr-rich α' phase, χ-phases, η phase and voids were found in self-ion irradiated HT9. The difference of observed microstructures is probably due to the difference of irradiation dose rate between ion irradiation and neutron irradiation. In addition, the average size and number density of G-phase precipitates were found to be sensitive to both irradiation temperature and dose. With the same irradiation dose, the average size of G-phase increased whereas the number density decreased with increasing irradiation temperature. Within the same irradiation temperature, the average size increased with increasing irradiation dose.« less

  15. Unindicated multiphase CT scans in non-traumatic abdominal emergencies for women of reproductive age: a significant source of unnecessary exposure.

    PubMed

    Giannitto, Caterina; Campoleoni, Mauro; Maccagnoni, Sara; Angileri, Alessio Salvatore; Grimaldi, Maria Carmela; Giannitto, Nino; De Piano, Francesca; Ancona, Eleonora; Biondetti, Pietro Raimondo; Esposito, Andrea Alessandro

    2018-03-01

    To determine the frequency of unindicated CT phases and the resultant excess of absorbed radiation doses to the uterus and ovaries in women of reproductive age who have undergone CT for non-traumatic abdomino-pelvic emergencies. We reviewed all abdomino-pelvic CT examinations in women of reproductive age (40 years or less), between 1 June 2012 and 31 January 2015. We evaluated the appropriateness of each CT phase on the basis of clinical indications, according to ACR appropriateness criteria and evidence-based data from the literature. The doses to uterus and ovaries for each phase were calculated with the CTEXPO software, taking into consideration the size-specific dose estimate (SSDE) after measuring the size of every single patient. The final cohort was composed of 76 female patients with an average age of 30 (from 19 to 40 years). In total, 197 CT phases were performed with an average of 2.6 phases per patient. Out of these, 93 (47%) were unindicated with an average of 1.2 inappropriate phases per patient. Unindicated scans were most frequent for appendicitis and unlocalized abdominal pain. The excesses of mean radiation doses to the uterus and ovaries due to unindicated phases were, respectively, of 38 and 33 mSv per patient. In our experience, unindicated additional CT phases were numerous with a significant excess radiation dose without an associated clinical benefit. This excess of radiation could have been avoided by widespread adoption of the ACR appropriateness criteria and evidence-based data from the literature.

  16. Normal and radial impact of composites with embedded penny-shaped cracks

    NASA Technical Reports Server (NTRS)

    Sih, G. C.

    1979-01-01

    A method is developed for the dynamic stress analysis of a layered composite containing an embedded penny-shaped crack and subjected to normal and radial impact. The material properties of the layers are chosen such that the crack lies in a layer of matrix material while the surrounding material possesses the average elastic properties of a two-phase medium consisting of a large number of fibers embedded in the matrix. Quantitatively, the time-dependent stresses near the crack border can be described by the dynamic stress intensity factors. Their magnitude depends on time, on the material properties of the composite and on the relative size of the crack compared to the composite local geometry. Results obtained show that, for the same material properties and geometry of the composite, the dynamic stress intensity factors for an embedded (penny-shaped) crack reach their peak values within a shorter period of time and with a lower magnitude than the corresponding dynamic stress intensity factors for a through-crack.

  17. Resource utilization pattern and cost of tuberculosis treatment from the provider and patient perspectives in the state of Penang, Malaysia.

    PubMed

    Atif, Muhammad; Sulaiman, Syed Azhar Syed; Shafie, Asrul Akmal; Asif, Muhammad; Babar, Zaheer-Ud-Din

    2014-08-19

    Studies from both developed and developing countries have demonstrated a considerable fluctuation in the average cost of TB treatment. The objective of this study was to analyze the medical resource utilization among new smear positive pulmonary tuberculosis patients. We also estimated the cost of tuberculosis treatment from the provider and patient perspectives, and identified the significant cost driving factors. All new smear positive pulmonary tuberculosis patients who were registered at the chest clinic of the Penang General Hospital, between March 2010 and February 2011, were invited to participate in the study. Provider sector costs were estimated using bottom-up, micro-costing technique. For the calculation of costs from the patients' perspective, all eligible patients who agreed to participate in the study were interviewed after the intensive phase and subsequently at the end of the treatment by a trained nurse. PASW was used to analyze the data (Predictive Analysis SoftWare, version 19.0, Armonk, NY: IBM Corp.). During the study period, 226 patients completed the treatment. However, complete costing data were available for 212 patients. The most highly utilized resources were chest X-ray followed by sputum smear examination. Only a smaller proportion of the patients were hospitalized. The average provider sector cost was MYR 992.34 (i.e., USD 325.35 per patient) whereby the average patient sector cost was MYR 1225.80 (i.e., USD 401.90 per patient). The average patient sector cost of our study population accounted for 5.7% of their annual family income. In multiple linear regression analysis, prolonged treatment duration (i.e., > 6 months) was the only predictor of higher provider sector costs whereby higher patient sector costs were determined by greater household income and persistent cough at the end of the intensive phase of the treatment. In relation to average provider sector cost, our estimates are substantially higher than the budget allocated by the Ministry of Health for the treatment of a tuberculosis case in Malaysia. The expenses borne by the patients and their families on the treatment of the current episode of tuberculosis were not catastrophic for them.

  18. Clinical evaluation of new automatic coronary-specific best cardiac phase selection algorithm for single-beat coronary CT angiography.

    PubMed

    Wang, Hui; Xu, Lei; Fan, Zhanming; Liang, Junfu; Yan, Zixu; Sun, Zhonghua

    2017-01-01

    The aim of this study was to evaluate the workflow efficiency of a new automatic coronary-specific reconstruction technique (Smart Phase, GE Healthcare-SP) for selection of the best cardiac phase with least coronary motion when compared with expert manual selection (MS) of best phase in patients with high heart rate. A total of 46 patients with heart rates above 75 bpm who underwent single beat coronary computed tomography angiography (CCTA) were enrolled in this study. CCTA of all subjects were performed on a 256-detector row CT scanner (Revolution CT, GE Healthcare, Waukesha, Wisconsin, US). With the SP technique, the acquired phase range was automatically searched in 2% phase intervals during the reconstruction process to determine the optimal phase for coronary assessment, while for routine expert MS, reconstructions were performed at 5% intervals and a best phase was manually determined. The reconstruction and review times were recorded to measure the workflow efficiency for each method. Two reviewers subjectively assessed image quality for each coronary artery in the MS and SP reconstruction volumes using a 4-point grading scale. The average HR of the enrolled patients was 91.1±19.0bpm. A total of 204 vessels were assessed. The subjective image quality using SP was comparable to that of the MS, 1.45±0.85 vs 1.43±0.81 respectively (p = 0.88). The average time was 246 seconds for the manual best phase selection, and 98 seconds for the SP selection, resulting in average time saving of 148 seconds (60%) with use of the SP algorithm. The coronary specific automatic cardiac best phase selection technique (Smart Phase) improves clinical workflow in high heart rate patients and provides image quality comparable with manual cardiac best phase selection. Reconstruction of single-beat CCTA exams with SP can benefit the users with less experienced in CCTA image interpretation.

  19. Phase synchronization of oxygenation waves in the frontal areas of children with attention-deficit hyperactivity disorder detected by optical diffusion spectroscopy correlates with medication

    NASA Astrophysics Data System (ADS)

    Wigal, Sharon B.; Polzonetti, Chiara M.; Stehli, Annamarie; Gratton, Enrico

    2012-12-01

    The beneficial effects of pharmacotherapy on children with attention-deficit hyperactivity disorder (ADHD) are well documented. We use near-infrared spectroscopy (NIRS) methodology to determine reorganization of brain neurovascular properties following the medication treatment. Twenty-six children with ADHD (ages six through 12) participated in a modified laboratory school protocol to monitor treatment response with lisdexamfetamine dimesylate (LDX; Vyvanse, Shire US Inc.). All children refrained from taking medication for at least two weeks (washout period). To detect neurovascular reorganization, we measured changes in synchronization of oxy (HbO2) and deoxy (HHb) hemoglobin waves between the two frontal lobes. Participants without medication displayed average baseline HbO2 phase difference at about -7-deg. and HHb differences at about 240-deg.. This phase synchronization index changed after pharmacological intervention. Medication induced an average phase changes of HbO2 after first medication to 280-deg. and after medication optimization to 242-deg.. Instead first medication changed of the average HHb phase difference at 186-deg. and then after medication optimization to 120-deg. In agreement with findings of White et al., and Varela et al., we associated the phase synchronization differences of brain hemodynamics in children with ADHD with lobe specific hemodynamic reorganization of HbO2- and HHB oscillations following medication status.

  20. Estimating patient time costs associated with colorectal cancer care.

    PubMed

    Yabroff, K Robin; Warren, Joan L; Knopf, Kevin; Davis, William W; Brown, Martin L

    2005-07-01

    Nonmedical costs of care, such as patient time associated with travel to, waiting for, and seeking medical care, are rarely measured systematically with population-based data. The purpose of this study was to estimate patient time costs associated with colorectal cancer care. We identified categories of key medical services for colorectal cancer care and then estimated patient time associated with each service category using data from national surveys. To estimate average service frequencies for each service category, we used a nested case control design and SEER-Medicare data. Estimates were calculated by phase of care for cases and controls, using data from 1995 to 1998. Average service frequencies were then combined with estimates of patient time for each category of service, and the value of patient time assigned. Net patient time costs were calculated for each service category, summarized by phase of care, and compared with previously reported net direct costs of colorectal cancer care. Net patient time costs for the 3 phases of colorectal cancer care averaged dollar 4592 (95% confidence interval [CI] dollar 4427-4757) over the 12 months of the initial phase, dollar 2788 (95% CI dollar 2614-2963) over the 12 months of the terminal phase, and dollar 25 (95% CI: dollar 23-26) per month in the continuing phase of care. Hospitalizations accounted for more than two thirds of these estimates. Patient time costs were 19.3% of direct medical costs in the initial phase, 15.8% in the continuing phase, and 36.8% in the terminal phase of care. Patient time costs are an important component of the costs of colorectal cancer care. Application of this method to other tumor sites and inclusion of other components of the costs of medical care will be important in delineating the economic burden of cancer in the United States.

  1. Cost Effectiveness of Adopted Quality Requirements in Hospital Laboratories

    PubMed Central

    HAMZA, Alneil; AHMED-ABAKUR, Eltayib; ABUGROUN, Elsir; BAKHIT, Siham; HOLI, Mohamed

    2013-01-01

    Background The present study was designed in quasi-experiment to assess adoption of the essential clauses of particular clinical laboratory quality management requirements based on international organization for standardization (ISO 15189) in hospital laboratories and to evaluate the cost effectiveness of compliance to ISO 15189. Methods: The quality management intervention based on ISO 15189 was conceded through three phases; pre – intervention phase, Intervention phase and Post-intervention phase. Results: In pre-intervention phase the compliance to ISO 15189 was 49% for study group vs. 47% for control group with P value 0.48, while the post intervention results displayed 54% vs. 79% for study group and control group respectively in compliance to ISO 15189 and statistically significant difference (P value 0.00) with effect size (Cohen’s d) of (0.00) in pre-intervention phase and (0.99) in post – intervention phase. The annual average cost per-test for the study group and control group was 1.80 ± 0.25 vs. 1.97 ± 0.39, respectively with P value 0.39 whereas the post-intervention results showed that the annual average total costs per-test for study group and control group was 1.57 ± 0.23 vs 2.08 ± 0.38, P value 0.019 respectively, with cost-effectiveness ratio of (0.88) in pre -intervention phase and (0.52) in post-intervention phase. Conclusion: The planned adoption of quality management requirements (QMS) in clinical laboratories had great effect to increase the compliance percent with quality management system requirement, raise the average total cost effectiveness, and improve the analytical process capability of the testing procedure. PMID:23967422

  2. 76 FR 68381 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Pennsylvania Clean...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-04

    ... period within which vehicle manufacturers could comply with the program's fleet average non-methane... year meets the specified phase-in requirements according to the fleet average non- methane hydrocarbon requirement for that year. The fleet average non- methane hydrocarbon emission limits become progressively...

  3. 40 CFR 1051.740 - Are there special averaging provisions for snowmobiles?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Averaging... redesignated engines. Calculate credits using this average emission level relative to the specific pollutant in... equation in § 1051.103), then your credits are the difference between the Phase 3 reduction requirement of...

  4. 40 CFR 1051.740 - Are there special averaging provisions for snowmobiles?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Averaging... redesignated engines. Calculate credits using this average emission level relative to the specific pollutant in... equation in § 1051.103), then your credits are the difference between the Phase 3 reduction requirement of...

  5. Photometric models of disk-integrated observations of the OSIRIS-REx target Asteroid (101955) Bennu

    NASA Astrophysics Data System (ADS)

    Takir, Driss; Clark, Beth Ellen; Drouet d'Aubigny, Christian; Hergenrother, Carl W.; Li, Jian-Yang; Lauretta, Dante S.; Binzel, Richard P.

    2015-05-01

    We used ground-based photometric phase curve data of the OSIRIS-REx target Asteroid (101955) Bennu and low phase angle data from Asteroid (253) Mathilde as a proxy to fit Bennu data with Minnaert, Lommel-Seeliger, (RObotic Lunar Orbiter) ROLO, Hapke, and McEwen photometric models, which capture the global light scattering properties of the surface and subsequently allow us to calculate the geometric albedo, phase integral, spherical Bond albedo, and the average surface normal albedo for Bennu. We find that Bennu has low reflectance and geometric albedo values, such that multiple scattering is expected to be insignificant. Our photometric models relate the reflectance from Bennu's surface to viewing geometry as functions of the incidence, emission, and phase angles. Radiance Factor functions (RADFs) are used to model the disk-resolved brightness of Bennu. The Minnaert, Lommel-Seeliger, ROLO, and Hapke photometric models work equally well in fitting the best ground-based photometric phase curve data of Bennu. The McEwen model works reasonably well at phase angles from 20° to 70°. Our calculated geometric albedo values of 0.047-0.014+0.012,0.047-0.014+0.005 , and 0.048-0.022+0.012 for the Minnaert, the Lommel-Seeliger, and the ROLO models respectively are consistent with the geometric albedo of 0.045 ± 0.015 computed by Emery et al. (Emery, J.P. et al. [2014]. Icarus 234, 17-35) and Hergenrother et al. (Hergenrother, C.W. et al. [2014].

  6. Cost of illness of oral lichen planus in a U.K. population--a pilot study.

    PubMed

    Ni Riordain, Richeal; Christou, Joanna; Pinder, Denise; Squires, Vanessa; Hodgson, Tim

    2016-05-01

    To assess the economic burden of oral lichen planus (OLP) from the perspective of the healthcare provider in a U.K. population. This prevalence-based cost-of-illness analysis was carried out via a cross-sectional study conducted in the Oral Medicine Unit of the Eastman Dental Hospital. This study was conducted in three phases - phase 1 involved framing of the cost-of-illness analysis, development of the cost inventory and design of the patient questionnaire for ease of data collection. Data collected from patients were inputted during phase 2, and costings were determined. The final phase consisted of the calculation of the cost of illness of OLP. One hundred patients were enrolled in the study, 30 males and 70 females, with an average age of 59.9 years (±13.4 years). The average OLP patient, based on our cohort, attends the oral medicine unit 2.64 times per year, their general medical practitioner 1.13 times annually, their general dental practitioner 0.82 times in a year and fills on average 3.37 prescriptions annually. This leads to an average annual cost of £398.58 (€541.16) per patient per year from the perspective of the healthcare provider. The annual average cost of OLP to the healthcare provider in the U.K. is substantial. The prevalence-based cost-of-illness data generated in this study will facilitate comparison with other chronic oral mucosal diseases and with chronic diseases managed in allied medical specialties. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Glenohumeral contact force during flat and topspin tennis forehand drives.

    PubMed

    Blache, Yoann; Creveaux, Thomas; Dumas, Raphaël; Chèze, Laurence; Rogowski, Isabelle

    2017-03-01

    The primary role of the shoulder joint in tennis forehand drive is at the expense of the loadings undergone by this joint. Nevertheless, few studies investigated glenohumeral (GH) contact forces during forehand drives. The aim of this study was to investigate GH compressive and shearing forces during the flat and topspin forehand drives in advanced tennis players. 3D kinematics of flat and topspin forehand drives of 11 advanced tennis players were recorded. The Delft Shoulder and Elbow musculoskeletal model was implemented to assess the magnitude and orientation of GH contact forces during the forehand drives. The results showed no differences in magnitude and orientation of GH contact forces between the flat and topspin forehand drives. The estimated maximal GH contact force during the forward swing phase was 3573 ± 1383 N, which was on average 1.25 times greater than during the follow-through phase, and 5.8 times greater than during the backswing phase. Regardless the phase of the forehand drive, GH contact forces pointed towards the anterior-superior part of the glenoid therefore standing for shearing forces. Knowledge of GH contact forces during real sport tasks performed at high velocity may improve the understanding of various sport-specific adaptations and causative factors for shoulder problems.

  8. Averaging, passage through resonances, and capture into resonance in two-frequency systems

    NASA Astrophysics Data System (ADS)

    Neishtadt, A. I.

    2014-10-01

    Applying small perturbations to an integrable system leads to its slow evolution. For an approximate description of this evolution the classical averaging method prescribes averaging the rate of evolution over all the phases of the unperturbed motion. This simple recipe does not always produce correct results, because of resonances arising in the process of evolution. The phenomenon of capture into resonance consists in the system starting to evolve in such a way as to preserve the resonance property once it has arisen. This paper is concerned with application of the averaging method to a description of evolution in two-frequency systems. It is assumed that the trajectories of the averaged system intersect transversally the level surfaces of the frequency ratio and that certain other conditions of general position are satisfied. The rate of evolution is characterized by a small parameter \\varepsilon. The main content of the paper is a proof of the following result: outside a set of initial data with measure of order \\sqrt \\varepsilon the averaging method describes the evolution to within O(\\sqrt \\varepsilon \\vert\\ln\\varepsilon\\vert) for periods of time of order 1/\\varepsilon. This estimate is sharp. The exceptional set of measure \\sqrt \\varepsilon contains the initial data for phase points captured into resonance. A description of the motion of such phase points is given, along with a survey of related results on averaging. Examples of capture into resonance are presented for some problems in the dynamics of charged particles. Several open problems are stated. Bibliography: 65 titles.

  9. Global and local skin friction diagnostics from TSP surface patterns on an underwater cylinder in crossflow

    NASA Astrophysics Data System (ADS)

    Miozzi, Massimo; Capone, Alessandro; Di Felice, Fabio; Klein, Christian; Liu, Tianshu

    2016-12-01

    A systematical method is formulated for extracting skin-friction fields from Temperature Sensitive Paint (TSP) images in the sense of time-averaging and phase-averaging. The method is applied to an underwater cylinder in crossflow at two subcritical regimes (Re = 72 000 and 144 000). TSP maps are decomposed in a time-averaged, a phase-averaged, and a random component. The asymptotic form of the energy equation at the wall provides an Euler-Lagrange equation set that is solved numerically to gain the relative skin friction time- and phase-averaged fields from the TSP surface temperature maps. The comparison of the time averaged relative skin-friction profiles with the literature data shows an excellent agreement on the whole laminar boundary layer up to the laminar separation line. Downstream of separation, time averaged results identify the secondary reattachment/separation events, which are lost in the available literature data. The periodic behavior of the skin-friction is taken, describing how the laminar separation bubble evolves by providing the time history of the laminar separation line and of the secondary reattachment/separation over the entire vortex shedding period. Instantaneous skin friction maps reveal the existence of coherent structures by capturing their footprint on the cylinder's surface. An array of Π-shaped traces marks the existence of counter-rotating, streamwise-oriented vortices just before the laminar separation line. Their interaction with the laminar boundary layer and with the separation line is briefly described. An example of the intermittent excerpt of their influence through the laminar separation line is reported.

  10. Spectrophotometric properties of the nucleus of comet 67P/Churyumov-Gerasimenko from the OSIRIS instrument onboard the ROSETTA spacecraft

    NASA Astrophysics Data System (ADS)

    Fornasier, S.; Hasselmann, P. H.; Barucci, M. A.; Feller, C.; Besse, S.; Leyrat, C.; Lara, L.; Gutierrez, P. J.; Oklay, N.; Tubiana, C.; Scholten, F.; Sierks, H.; Barbieri, C.; Lamy, P. L.; Rodrigo, R.; Koschny, D.; Rickman, H.; Keller, H. U.; Agarwal, J.; A'Hearn, M. F.; Bertaux, J.-L.; Bertini, I.; Cremonese, G.; Da Deppo, V.; Davidsson, B.; Debei, S.; De Cecco, M.; Fulle, M.; Groussin, O.; Güttler, C.; Hviid, S. F.; Ip, W.; Jorda, L.; Knollenberg, J.; Kovacs, G.; Kramm, R.; Kührt, E.; Küppers, M.; La Forgia, F.; Lazzarin, M.; Lopez Moreno, J. J.; Marzari, F.; Matz, K.-D.; Michalik, H.; Moreno, F.; Mottola, S.; Naletto, G.; Pajola, M.; Pommerol, A.; Preusker, F.; Shi, X.; Snodgrass, C.; Thomas, N.; Vincent, J.-B.

    2015-11-01

    Context. The Rosetta mission of the European Space Agency has been orbiting the comet 67P/Churyumov-Gerasimenko (67P) since August 2014 and is now in its escort phase. A large complement of scientific experiments designed to complete the most detailed study of a comet ever attempted are onboard Rosetta. Aims: We present results for the photometric and spectrophotometric properties of the nucleus of 67P derived from the OSIRIS imaging system, which consists of a Wide Angle Camera (WAC) and a Narrow Angle Camera (NAC). The observations presented here were performed during July and the beginning of August 2014, during the approach phase, when OSIRIS was mapping the surface of the comet with several filters at different phase angles (1.3°-54°). The resolution reached up to 2.1 m/px. Methods: The OSIRIS images were processed with the OSIRIS standard pipeline, then converted into I/F radiance factors and corrected for the illumination conditions at each pixel using the Lommel-Seeliger disk law. Color cubes of the surface were produced by stacking registered and illumination-corrected images. Furthermore, photometric analysis was performed both on disk-averaged photometry in several filters and on disk-resolved images acquired with the NAC orange filter, centered at 649 nm, using Hapke modeling. Results: The disk-averaged phase function of the nucleus of 67P shows a strong opposition surge with a G parameter value of -0.13 ± 0.01 in the HG system formalism and an absolute magnitude Hv(1,1,0) = 15.74 ± 0.02 mag. The integrated spectrophotometry in 20 filters covering the 250-1000 nm wavelength range shows a red spectral behavior, without clear absorption bands except for a potential absorption centered at ~290 nm that is possibly due to SO2 ice. The nucleus shows strong phase reddening, with disk-averaged spectral slopes increasing from 11%/(100 nm) to 16%/(100 nm) in the 1.3°-54° phase angle range. The geometric albedo of the comet is 6.5 ± 0.2% at 649 nm, with local variations of up to ~16% in the Hapi region. From the disk-resolved images we computed the spectral slope together with local spectrophotometry and identified three distinct groups of regions (blue, moderately red, and red). The Hapi region is the brightest, the bluest in term of spectral slope, and the most active surface on the comet. Local spectrophotometry shows an enhancement of the flux in the 700-750 nm that is associated with coma emissions. Table 1 is available in electronic form at http://www.aanda.org

  11. Improving substance information in USEtox® , part 1: Discussion on data and approaches for estimating freshwater ecotoxicity effect factors.

    PubMed

    Saouter, Erwan; Aschberger, Karin; Fantke, Peter; Hauschild, Michael Z; Bopp, Stephanie K; Kienzler, Aude; Paini, Alicia; Pant, Rana; Secchi, Michela; Sala, Serenella

    2017-12-01

    The scientific consensus model USEtox ® is recommended by the European Commission as the reference model to characterize life cycle chemical emissions in terms of their potential human toxicity and freshwater aquatic ecotoxicity impacts in the context of the International Reference Life Cycle Data System Handbook and the Environmental Footprint pilot phase looking at products (PEF) and organizations (OEF). Consequently, this model has been systematically used within the PEF/OEF pilot phase by 25 European Union industry sectors, which manufacture a wide variety of consumer products. This testing phase has raised some questions regarding the derivation of and the data used for the chemical-specific freshwater ecotoxicity effect factor in USEtox. For calculating the potential freshwater aquatic ecotoxicity impacts, USEtox bases the effect factor on the chronic hazard concentration (HC50) value for a chemical calculated as the arithmetic mean of all logarithmized geometric means of species-specific chronic median lethal (or effect) concentrations (L[E]C50). We investigated the dependency of the USEtox effect factor on the selection of ecotoxicological data source and toxicological endpoints, and we found that both influence the ecotoxicity ranking of chemicals and may hence influence the conclusions of a PEF/OEF study. We furthermore compared the average measure (HC50) with other types of ecotoxicity effect indicators, such as the lowest species EC50 or no-observable-effect concentration, frequently used in regulatory risk assessment, and demonstrated how they may also influence the ecotoxicity ranking of chemicals. We acknowledge that these indicators represent different aspects of a chemical's ecotoxicity potential and discuss their pros and cons for a comparative chemical assessment as performed in life cycle assessment and in particular within the PEF/OEF context. Environ Toxicol Chem 2017;36:3450-3462. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

  12. Four-phase or two-phase signal plan? A study on four-leg intersection by cellular automaton simulations

    NASA Astrophysics Data System (ADS)

    Jin, Cheng-Jie; Wang, Wei; Jiang, Rui

    2016-08-01

    The proper setting of traffic signals at signalized intersections is one of the most important tasks in traffic control and management. This paper has evaluated the four-phase traffic signal plans at a four-leg intersection via cellular automaton simulations. Each leg consists of three lanes, an exclusive left-turn lane, a through lane, and a through/right-turn lane. For a comparison, we also evaluate the two-phase signal plan. The diagram of the intersection states in the space of inflow rate versus turning ratio has been presented, which exhibits four regions: In region I/II/III, congestion will propagate upstream and laterally and result in queue spillover with both signal plans/two-phase signal plan/four-phase signal plan, respectively. Therefore, neither signal plan works in region I, and only the four-phase signal plan/two-phase signal plan works in region II/III. In region IV, both signal plans work, but two-phase signal plan performs better in terms of average delays of vehicles. Finally, we study the diagram of the intersection states and average delays in the asymmetrical configurations.

  13. Implementation hurdles of an interactive, integrated, point-of-care computerised decision support system for hospital antibiotic prescription.

    PubMed

    Chow, A L; Ang, A; Chow, C Z; Ng, T M; Teng, C; Ling, L M; Ang, B S; Lye, D C

    2016-02-01

    Antimicrobial stewardship is used to combat antimicrobial resistance. In Singapore, a tertiary hospital has integrated a computerised decision support system, called Antibiotic Resistance Utilisation and Surveillance-Control (ARUSC), into the electronic inpatient prescribing system. ARUSC is launched either by the physician to seek guidance for an infectious disease condition or via auto-trigger when restricted antibiotics are prescribed. This paper describes the implementation of ARUSC over three phases from 1 May 2011 to 30 April 2013, compared factors between ARUSC launches via auto-trigger and for guidance, examined factors associated with acceptance of ARUSC recommendations, and assessed user acceptability. During the study period, a monthly average of 9072 antibiotic prescriptions was made, of which 2370 (26.1%) involved ARUSC launches. Launches via auto-trigger comprised 48.1% of ARUSC launches. In phase 1, 23% of ARUSC launches were completed. This rose to 38% in phase 2, then 87% in phase 3, as escapes from the ARUSC programme were sequentially disabled. Amongst completed launches for guidance, 89% of ARUSC recommendations were accepted versus 40% amongst completed launches via auto-trigger. Amongst ARUSC launches for guidance, being from a medical department [adjusted odds ratio (aOR)=1.20, 95% confidence interval (CI) 1.04-1.37] and ARUSC launch during on-call (aOR=1.81, 95% CI 1.61-2.05) were independently associated with acceptance of ARUSC recommendations. Junior physicians found ARUSC useful. Senior physicians found ARUSC reliable but admitted to having preferences for antibiotics that may conflict with ARUSC. Hospital-wide implementation of ARUSC encountered hurdles from physicians. With modifications, the completion rate improved. Copyright © 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  14. Strain and grain size of TiO2 nanoparticles from TEM, Raman spectroscopy and XRD: The revisiting of the Williamson-Hall plot method

    NASA Astrophysics Data System (ADS)

    Kibasomba, Pierre M.; Dhlamini, Simon; Maaza, Malik; Liu, Chuan-Pu; Rashad, Mohamed M.; Rayan, Diaa A.; Mwakikunga, Bonex W.

    2018-06-01

    The Williamson-Hall (W-H) equation, which has been used to obtain relative crystallite sizes and strains between samples since 1962, is revisited. A modified W-H equation is derived which takes into account the Scherrer equation, first published in 1918, (which traditionally gives more absolute crystallite size prediction) and strain prediction from Raman spectra. It is found that W-H crystallite sizes are on average 2.11 ± 0.01 times smaller than the sizes from Scherrer equation. Furthermore the strain from the W-H plots when compared to strain obtained from Raman spectral red-shifts yield factors whose values depend on the phases in the materials - whether anatase, rutile or brookite. Two main phases are identified in the annealing temperatures (350 °C-700 °C) chosen herein - anatase and brookite. A transition temperature of 550 °C has been found for nano-TiO2 to irreversibly transform from brookite to anatase by plotting the Raman peak shifts against the annealing temperatures. The W-H underestimation on the strain in the brookite phase gives W-H/Raman factor of 3.10 ± 0.05 whereas for the anatase phase, one gets 2.46 ± 0.03. The new βtot2cos2θ-sinθ plot and when fitted with a polynomial yield less strain but much better matching with experimental TEM crystallite sizes and the agglomerates than both the traditional Williamson-Hall and the Scherrer methods. There is greater improvement in the model when linearized - that is the βtotcos2θ-sinθ plot rather than the βtot2cos2θ-sinθ plot.

  15. Oil biosynthesis and transcriptome profiles in developing endosperm and oil characteristic analyses in Paeonia ostii var. lishizhenii.

    PubMed

    Xiu, Yu; Wu, Guodong; Tang, Wensi; Peng, Zhengfeng; Bu, Xiangpan; Chao, Longjun; Yin, Xue; Xiong, Jiannan; Zhang, Haiwu; Zhao, Xiaoqing; Ding, Jing; Ma, Lvyi; Wang, Huafang; van Staden, Johannes

    2018-06-04

    Paeonia ostii var. lishizhenii, a well-known medicinal and horticultural plant, is indigenous to China. Recent studies have shown that its seed has a high oil content, and it was approved as a novel resource of edible oil with a high level of α-linolenic acid by the Chinese Government. This study measured the seed oil contents and fatty acid components of P. ostii var. lishizhenii and six other peonies, P. suffruticosa, P. ludlowii, P. decomposita, P. rockii, and P. lactiflora Pall. 'Heze' and 'Gansu'. The results show that P. ostii var. lishizhenii exhibits the average oil characteristics of tested peonies, with an oil content of 21.3%, α-linolenic acid 43.8%, and unsaturated fatty acids around 92.1%. Hygiene indicators for the seven peony seed oils met the Chinese national food standards. P. ostii var. lishizhenii seeds were used to analyze transcriptome gene regulation networks on endosperm development and oil biosynthesis. In total, 124,117 transcripts were obtained from six endosperm developing stages (S0-S5). The significant changes in differential expression genes (DEGs) clarify three peony endosperm developmental phases: the endosperm cell mitotic phase (S0-S1), the TAG biosynthesis phase (S1-S4), and the mature phase (S5). The DEGs in plant hormone signal transduction, DNA replication, cell division, differentiation, transcription factors, and seed dormancy pathways regulate the endosperm development process. Another 199 functional DEGs participate in glycolysis, pentose phosphate pathway, citrate cycle, FA biosynthesis, TAG assembly, and other pathways. A key transcription factor (WRI1) and some important target genes (ACCase, FATA, LPCAT, FADs, and DGAT etc.) were found in the comprehensive genetic networks of oil biosynthesis. Copyright © 2018 Elsevier GmbH. All rights reserved.

  16. [Carbetocin use to prevent obstetric hemorrhage].

    PubMed

    Posadas Robledo, Francisco Javier

    2011-07-01

    in Mexico, obstetric hemorrhage and its complications are the second leading cause of maternal death and is the origin of irreversible functional consequences. Carbetocin is a synthetic analogue of oxytocin with an average lifespan four times that of oxytocin and pharmacological effects of 120 minutes produces a tonic contraction which reduces postpartum blood loss. To evaluate the usefulness of carbetocin to prevent uterine bleeding complications and maternal deaths and assess the benefits, effectiveness and side effects. Prospective, observational clinical research in two phases, the first from May 2005 to January 2006 with a sample of 40 patients and the second from January to December of 2008 with a sample of 72 patients conducted at the Hospital Materno Infantil Dr. Alberto López Hermosa, San Luis Potosi. All were high-risk pregnancies and medical complications that warranted specialty hospital management. The intervention consisted of applying undiluted single dose of 100 micrograms of intravenous carbetocin at the time of delivery, as prophylaxis in patients with uterine overdistention in the first phase of the study and complicated pregnancies in the second phase. Were born by caesarean section over 60%. Initially, the hemoglobin showed a reduction of 17% after delivery. Seven patients required blood transfusion (17.5%). In the second phase, 65 patients (90%) did not require transfusion, only 6 patients (8%) required transfusion. No side effects were documented. Uterine overdistension was the main risk factor for bleeding and transfusion. Carbetocin combines the safety of oxytocin and the strength of the ergonovine preparations. To determine where carbetocin will be situated in the future as an useful oxytocic, it requires more than a simple demonstration of its effectiveness. This should be determined in each clinical situation, with factors such as overdistended uterus, indicating the convenience and economic constraints.

  17. Synthesis and microwave dielectric behavior of (Bi1-xPbx)NbO4 ceramics

    NASA Astrophysics Data System (ADS)

    Butee, S. P.; Kambale, K. R.; Upadhyay, Shaishav; Bashaiah, S.; Raju, K. C. James; Panda, Himanshu

    2016-03-01

    Ceramic samples of (Bi1-xPbx)NbO4 (x=0, 0.025, 0.05, 0.10, 0.15, 0.20) with 0.75wt.% V2O5 addition sintered at 920∘C, 940∘C and 960∘C are investigated. Pb is selected as a substitute for Bi3+ in BiNbO4 ceramics as it exists in two stable valence states of +2 and +4 and the average valency matches to that of Bi3+. The average Shannon radius (for octahedral coordination) of Pb2+ (1.19Å) and Pb4+(0.775Å) cations is 0.9825Å, which is similar to that of Bi3+ ion (1.03Å). The dense (>94%) polycrystalline (Bi1-xPbx)NbO4 samples fabricated mostly reveal orthorhombic (Pnna) phase (α-BiNbO4, Sp. Gp. 52) by powder XRD. Presence of satellite Pb2Nb2O7 phase, the amount of which is increasing with increase in Pb content, is also noticed. The microwave dielectric constant (ɛr‧) values of the niobates are found to increase from 42 to 71, whereas the quality factor (Qu.f) values are found to decrease from 5400 to 550 GHz with increasing substitution of Pb. The compositions so synthesized are important as hardly there are any microwave dielectric ceramics available with 45<ɛr‧<75.

  18. Grosnaja ABCs: Magnesium isotope compositions

    NASA Technical Reports Server (NTRS)

    Goswami, J. N.; Srinivasan, G.; Ulyanov, A. A.

    1993-01-01

    Three CAI's from the Grosnaja CV3 chondrite were analyzed for their magnesium isotopic compositions by the ion microprobe. The selected CAI's represent three distinct types: GR4(compact Type A), GR7(Type B) and GR2(Type C). Petrographic studies indicate that all three Grosnaja inclusions were subjected to secondary alterations. The Type A CAI GR4 is primarily composed of melilite with spinel and pyroxene occurring as minor phases. The rim of the inclusion does not exhibit distinct layered structure and secondary alteration products (garnet, Fe-rich olivine and Na-rich plagioclase) are present in some localized areas near the rim region. The average major element compositions of different mineral phases in GR4 are given. Preliminary REE data suggest a depletion of HREE relative to LREE by about a factor of 3 without any clear indication of interelement fractionation. The CAI GR7 has textural and minerological characteristics similar to Type B inclusions. The REE data show a pattern that is similar to Group 6 with enrichment in Eu and Yb. In addition, a depletion of HREE compared to LREE is also evident in this object. Melilite composition shows a broad range of akermanite content (Ak(sub 15-55)). Detailed petrographic study is in progress. GR2 is a anorthite-rich Type C inclusion with large plagioclase laths intergrown with Ti-rich pyroxene. The average plagioclase composition is close to pure anorthite (An99).

  19. Texture and phase analysis of deformed SUS304 by using HIPPO

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Takajo, Shigehiro; Vogel, Sven C.

    2016-11-15

    These slides represent the author's research activity at Los Alamos National Laboratory (LANL), which is about texture and phase analysis of deformed SUS304 by using HIPPO. The following topics are covered: diffraction histogram at each sample position, diffraction histogram (all bank data averaged), possiblity of ε-phase, MAUD analysis with including ε-phase.

  20. Thermal adaptiveness of plumage color in screech owls

    USGS Publications Warehouse

    Mosher, James A.; Henny, Charles J.

    1976-01-01

    Clinal variation in the relative proportions of red and gray plum- age phases in Screech Owls (Otus asio) was analyzed by Owen (1963) and Marshall (1967). This variation was well known prior to Owen's work, but was misinterpreted (Baird, et al. 1874, Hasbrouck 1893, Allen 1893).]Laurel VanCamp and Charles Henny (MS) have 30 years of data on a northern Ohio Screech Owl population. They observed an over- winter decline (from about 25% to 15%) in the proportion of red phase birds in the winter of 1951-52. This decline was correlated with a severe winter of above normal snowfall and below average temperatures. They examined banding and recovery data and found overwinter survival of red and gray birds to be the same except for this one severe winter when 44% more red phase birds were lost than grays (VanCamp and Henny MS). Differential mortality was reported by Gullion and Marshall (1968) for red and gray phase Ruffed Grouse (Bonasa umbellus) where snow conditions for roosting is apparently the critical factor for grouse overwinter survival and is related to predation. Snow- roosting has not, to our knowledge, been observed in Screech Owls. VanCamp and Henny (MS) discuss the observations of Ruffed Grouse and Screech Owls and suggest that possible thermoregulatory differences between red and gray phase birds could account for differential overwinter survival.Our objective was to test for differences between color phase in oxygen uptake at several ambient temperatures. We hypothesized that oxygen uptake would be greater by red phase birds, especially at lower temperatures.

  1. Stable phase post-MI patients have elevated VEGF levels correlated with inflammation markers, but not with atherosclerotic burden.

    PubMed

    ErŽen, Barbara; Šilar, Mira; Šabovič, Mišo

    2014-11-22

    The role of vascular endothelial growth factor (VEGF) in patients in the stable phase after myocardial infarction (MI) has not yet been explored. Therefore, we compared the values of VEGF in post-MI patients with those obtained in healthy controls. Furthermore, we investigated whether the values of VEGF correlate to either inflammation markers or the atherosclerotic burden. 41 male patients (on average 44 years old) in the stable phase after MI (on average 20.5 months after MI) were recruited, while 25 healthy age-matched males served as controls. Plasma levels of VEGF and several markers of inflammation were measured by standard procedures. The atherosclerotic burden was determined by the angiographic severity of coronary atherosclerosis, endothelial dysfunction (measured by ultrasound measurement of the flow mediated dilation of the brachial artery), the intima-media thickness of the common carotid artery and the ankle-brachial pressure index. VEGF values were significantly elevated in post-MI patients compared to the controls (53.8 ± 42.7 pg/ml vs. 36.3 ± 8.9 pg/ml, p = 0.014). The elevated VEGF values significantly correlated to the (increased) values of the inflammatory molecules interleukin 6 and 8 (r = 0.37, p = 0.017; and r = 0.45, p = 0.003; respectively). In contrast, no correlation was found between VEGF and the parameters of the atherosclerotic burden, although FMD and IMT were significantly impaired in patients. We found that plasma levels of VEGF are increased in the stable phase after MI and correlate with inflammation cytokines, but not with the atherosclerotic burden. Thus, this suggests that increased levels of VEGF are a part of ongoing inflammatory activity. Since VEGF in these patients stimulates neovascularization of inflamed plaques and induces their destabilization, the VEGF level can have an important negative prognostic value. Clearly, further studies are needed to clarify the role of VEGF as a prognostic marker.

  2. The effects of prenatal cocaine use on infant development.

    PubMed

    Richardson, Gale A; Goldschmidt, Lidush; Willford, Jennifer

    2008-01-01

    This study examined the effect of prenatal cocaine use on infant physical, cognitive, and motor development, and temperamental characteristics, controlling for other factors that affect infant development. Women were, on average, 26.8 years old, had 12 years of education, and 46% were African American. During the first trimester, 18% were frequent users of cocaine (> or =1 line/day). The infants were, on average, 14.6 months old at this follow-up phase. Women who used cocaine during pregnancy rated their infants as more fussy/difficult and unadaptable than did women who did not use cocaine. Cocaine use in the second trimester was associated with significantly lower motor scores on the Bayley Scales of Infant Development (BSID) [N. Bayley, Manual for the Bayley Scales of Infant Development, Psychological Corporation, New York, 1969.]. There was no effect of prenatal cocaine use on BSID mental performance or on growth. These findings are consistent with other reports in the literature and with the hypothesis that prenatal cocaine exposure affects development through changes in neurotransmitter systems.

  3. Biological Rhythms Modelisation of Vigilance and Sleep in Microgravity State with COSINOR and Volterra's Kernels Methods

    NASA Astrophysics Data System (ADS)

    Gaudeua de Gerlicz, C.; Golding, J. G.; Bobola, Ph.; Moutarde, C.; Naji, S.

    2008-06-01

    The spaceflight under microgravity cause basically biological and physiological imbalance in human being. Lot of study has been yet release on this topic especially about sleep disturbances and on the circadian rhythms (alternation vigilance-sleep, body, temperature...). Factors like space motion sickness, noise, or excitement can cause severe sleep disturbances. For a stay of longer than four months in space, gradual increases in the planned duration of sleep were reported. [1] The average sleep in orbit was more than 1.5 hours shorter than the during control periods on earth, where sleep averaged 7.9 hours. [2] Alertness and calmness were unregistered yield clear circadian pattern of 24h but with a phase delay of 4h.The calmness showed a biphasic component (12h) mean sleep duration was 6.4 structured by 3-5 non REM/REM cycles. Modelisations of neurophysiologic mechanisms of stress and interactions between various physiological and psychological variables of rhythms have can be yet release with the COSINOR method. [3

  4. Our contaminated atmosphere: The danger of climate change, phases 1 and 2. [effect of atmospheric particulate matter on surface temperature and earth's radiation budget

    NASA Technical Reports Server (NTRS)

    Cimorelli, A. J.; House, F. B.

    1974-01-01

    The effects of increased concentrations of atmospheric particulate matter on average surface temperature and on the components of the earth's radiation budget are studied. An atmospheric model which couples particulate loading to surface temperature and to changes in the earth's radiation budget was used. A determination of the feasibility of using satellites to monitor the effect of increased atmospheric particulate concentrations is performed. It was found that: (1) a change in man-made particulate loading of a factor of 4 is sufficient to initiate an ice age; (2) variations in the global and hemispheric weighted averages of surface temperature, reflected radiant fluz and emitted radiant flux are nonlinear functions of particulate loading; and (3) a black satellite sphere meets the requirement of night time measurement sensitivity, but not the required day time sensitivity. A nonblack, spherical radiometer whose external optical properties are sensitive to either the reflected radiant fluz or the emitted radiant flux meets the observational sensitivity requirements.

  5. Intrinsic Patterns of Human Activity

    NASA Astrophysics Data System (ADS)

    Hu, Kun; Ivanov, Plamen Ch.; Chen, Zhi; Hilton, Michael; Stanley, H. Eugene; Shea, Steven

    2003-03-01

    Activity is one of the defining features of life. Control of human activity is complex, being influenced by many factors both extrinsic and intrinsic to the body. The most obvious extrinsic factors that affect activity are the daily schedule of planned events, such as work and recreation, as well as reactions to unforeseen or random events. These extrinsic factors may account for the apparently random fluctuations in human motion observed over short time scales. The most obvious intrinsic factors are the body clocks including the circadian pacemaker that influences our sleep/wake cycle and ultradian oscillators with shorter time scales [2, 3]. These intrinsic rhythms may account for the underlying regularity in average activity level over longer periods of up to 24 h. Here we ask if the known extrinsic and intrinsic factors fully account for all complex features observed in recordings of human activity. To this end, we measure activity over two weeks from forearm motion in subjects undergoing their regular daily routine. Utilizing concepts from statistical physics, we demonstrate that during wakefulness human activity possesses previously unrecognized complex dynamic patterns. These patterns of activity are characterized by robust fractal and nonlinear dynamics including a universal probability distribution and long-range power-law correlations that are stable over a wide range of time scales (from minutes to hours). Surprisingly, we find that these dynamic patterns are unaffected by changes in the average activity level that occur within individual subjects throughout the day and on different days of the week, and between subjects. Moreover, we find that these patterns persist when the same subjects undergo time-isolation laboratory experiments designed to account for the phase of the circadian pacemaker, and control the known extrinsic factors by restricting behaviors and manipulating scheduled events including the sleep/wake cycle. We attribute these newly discovered patterns to a robust intrinsic multi-scale dynamic regulation of human activity that is independent of known extrinsic factors, and independent from the circadian and ultradian rhythms.

  6. Experimental studies on cycling stable characteristics of inorganic phase change material CaCl2·6H2O-MgCl2·6H2O modified with SrCl2·6H2O and CMC

    NASA Astrophysics Data System (ADS)

    He, Meizhi; Yang, Luwei; Zhang, Zhentao

    2018-01-01

    By means of mass ratio method, binary eutectic hydrated salts inorganic phase change thermal energy storage system CaCl2·6H2O-20wt% MgCl2·6H2O was prepared, and through adding nucleating agent 1wt% SrCl2·6H2O and thickening agent 0.5wt% carboxy methyl cellulose (CMC), inoganic phase change material (PCM) modified was obtained. With recording cooling-melting curves simultaneously, this PCM was frozen and melted for 100 cycles under programmable temperature control. After per 10 cycles, the PCM was charaterized by differential scanning calorimeter (DSC), X-ray diffraction (XRD) and density meter, then analysing variation characteristics of phase change temperature, supercooling degree, superheat degree, latent heat, crystal structure and density with the increase of cycle index. The results showed that the average values of average phase change temperature for cooling and heating process were 25.70°C and 27.39°C respectively with small changes. The average values of average supercooling and superheat degree were 0.59°C and 0.49°C respectively, and the maximum value was 1.10°C. The average value and standard deviation of latent heat of fusion were 120.62 J/g and 1.90 J/g respectively. Non-molten white solid sediments resulted from phase separation were tachyhydrite (CaMg2Cl6·12H2O), which was characterized by XRD. Measuring density of the PCM after per 10 cycles, and the results suggested that the total mass of tachyhydrite was limited. In summary, such modified inoganic PCM CaCl2·6H2O-20wt% MgCl2·6H2O-1wt% SrCl2·6H2O-0.5wt% CMC could stay excellent circulation stability within 100 cycles, and providing reference value in practical use.

  7. Application of the holmium:YAG laser for refractive surgery: an update of clinical progress

    NASA Astrophysics Data System (ADS)

    Thompson, Vance M.; Durrie, Daniel S.; Hunkeler, John D.; Hurt, Art C., III; Mann, P. M.; Seiler, Theo; King, Michael C.; Sacharoff, Alex C.; Muller, David F.

    1993-06-01

    We describe the results of a 30 patient Phase I clinical trial using the Laser Thermokeratoplasty (LTK) treatment for correction of hyperopic astigmatism. We report the results for 29 patients who have reached 2 months post-operative. The average pre-op cylinder was reduced from -3.06 Diopters (D) to -1.21 D. Average spherical equivalent (SE) refractive error was reduced from +2.28 to +1.34 D. Six patients have reached 4 months post-op; the average cylinder of these patients has been reduced from -1.92 to -0.79 D while the average SE has been reduced from +1.29 to +0.31 D. Although patients had varying degrees of astigmatism pre-op, all treatments were performed with identical parameters (intended to correct a small amount of astigmatism) to enable us to determine the effect of the procedure without the influence of other factors such as varying zone diameter or laser fluence. The predictability and stability of the LTK procedure are supported by a recent study of 20 patients treated in Germany by Seiler for low to moderate degrees (2 - 4 D) of hyperopia. After 6 months post-op, 16 of 20 patients are within +/- 1 D of the attempted correction. Longer-term follow-up will be necessary to determine the ultimate refractive stability of the LTK procedure.

  8. Three-dimensional numerical simulation of the 20 June 1991, Orlando microburst

    NASA Technical Reports Server (NTRS)

    Proctor, Fred H.

    1992-01-01

    On 20 June 1991, NASA's Boeing 737, equipped with in-situ and look-ahead wind-shear detection systems, made direct low-level penetrations (300-350 m AGL) through a microburst during several stages of its evolution. This microburst was located roughly 20 km northeast of Orlando International Airport and was monitored by a Terminal Doppler Weather Radar (TDWR) located about 10 km south of the airport. The first NASA encounter with this microburst (Event 142), at approximately 2041 UTC, was during its intensification phase. At flight level, in-situ measurements indicated a peak 1-km (averaged) F-factor of approximately 0.1. The second NASA encounter (Event 143) occurred at approximately 2046 UTC, about the time of microburst peak intensity. It was during this penetration that a peak 1-km F-factor of approximately 17 was encountered, which was the largest in-situ measurement of the 1991 summer deployment. By the third encounter (Event 144), at approximately 2051 UTC, the microburst had expanded into a macroburst. During this phase of evolution, an in-situ 1-km F-factor of 0.08 was measured. The focus of this paper is to examine this microburst via numerical simulation from an unsteady, three-dimensional meteorological cloud model. The simulated high-resolution data fields of wind, temperature, radar reflectivity factor, and precipitation are closely examined so as to derive information not readily available from 'observations' and to enhance our understanding of the actual event. Characteristics of the simulated microburst evolution are compared with TDWR and in-situ measurements.

  9. Salting-out assisted liquid-liquid extraction for the determination of biogenic amines in fruit juices and alcoholic beverages after derivatization with 1-naphthylisothiocyanate and high performance liquid chromatography.

    PubMed

    Jain, Archana; Gupta, Manju; Verma, Krishna K

    2015-11-27

    A new method for determining biogenic amines in fruit juices and alcoholic beverages is described involving reaction of biogenic amines with 1-naphthylisothiocyanate followed by extraction of 1-naphthylthiourea derivatives with water-miscible organic solvent acetonitrile when solvents phase separation occurred using ammonium sulphate, a process called salting-out assisted liquid-liquid extraction. The extract was analyzed by high-performance liquid chromatography with UV detection at 254nm. The new reagent avoided many of the inconveniences as observed with existing derivatizing agents, such as dansyl chloride and benzoyl chloride, in regard to their inselectivity, instability, adverse effect of excess reagent, and necessity to remove excess reagent. The procedure has been optimized with respect to reaction time and temperature, water-miscible extraction solvent, and salt for solvents phase separation. Use of reagent as dispersed phase in aqueous medium produced derivatives in high yield. A linear calibration was obtained between the amount of biogenic amines in range 1-1000μgL(-1) and peak areas of corresponding thioureas formed; the correlation coefficient was 0.9965, and the limit of detection and limit of quantification found were 1.1μgL(-1) and 3.2μgL(-1), respectively. The pre-concentration method gave an average enrichment factor of 94. The application of the method has been demonstrated in the determination of biogenic amines in commercial samples of fruit juices and alcoholic beverages. In spiking experiments to real samples, the average recovery found by the present method was 94.5% that agreed well with 95.8% obtained by established comparison methods. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. A Lagrangian parcel based mixing plane method for calculating water based mixed phase particle flows in turbo-machinery

    NASA Astrophysics Data System (ADS)

    Bidwell, Colin S.

    2015-05-01

    A method for calculating particle transport through turbo-machinery using the mixing plane analogy was developed and used to analyze the energy efficient engine . This method allows the prediction of temperature and phase change of water based particles along their path and the impingement efficiency and particle impact property data on various components in the engine. This methodology was incorporated into the LEWICE3D V3.5 software. The method was used to predict particle transport in the low pressure compressor of the . The was developed by NASA and GE in the early 1980s as a technology demonstrator and is representative of a modern high bypass turbofan engine. The flow field was calculated using the NASA Glenn ADPAC turbo-machinery flow solver. Computations were performed for a Mach 0.8 cruise condition at 11,887 m assuming a standard warm day for ice particle sizes of 5, 20 and 100 microns and a free stream particle concentration of . The impingement efficiency results showed that as particle size increased average impingement efficiencies and scoop factors increased for the various components. The particle analysis also showed that the amount of mass entering the inner core decreased with increased particle size because the larger particles were less able to negotiate the turn into the inner core due to particle inertia. The particle phase change analysis results showed that the larger particles warmed less as they were transported through the low pressure compressor. Only the smallest 5 micron particles were warmed enough to produce melting with a maximum average melting fraction of 0.18. The results also showed an appreciable amount of particle sublimation and evaporation for the 5 micron particles entering the engine core (22.6 %).

  11. Microtremor exploration for shallow S-wave velocity structure in Bandung Basin, Indonesia

    NASA Astrophysics Data System (ADS)

    Pramatadie, Andi Muhamad; Yamanaka, Hiroaki; Chimoto, Kosuke; Afnimar Collaboration; Koketsu, Kazuki; Sakaue, Minoru; Miyake, Hiroe; Sengara, I. Wayan; Sadisun, Imam A.

    2017-05-01

    We have conducted a microtremor survey for shallow S-wave velocity profiles to be used for seismic hazard evaluation in the Bandung Basin, Indonesia. In the survey, two arrays were deployed temporarily at each of 29 sites, by installing seven vertical sensors in triangular configurations with side lengths from 1 to 16 m. Records of vertical microtremors from each array were used to estimate Rayleigh wave phase velocity spectra using the spatial autocorrelation method, as well as the horizontal-to-vertical spectral ratio obtained at the centre of the arrays. Phase velocities at sites on the basin margin exhibit higher values than those obtained in the central part of the basin, in a frequency range of 7 to 30 Hz. The phase velocity data were used to deduce S-wave velocity profiles of shallow soil using a hybrid heuristic inversion method. We validated our inversion models by comparing observed horizontal-to-vertical spectral ratios with ellipticities of the fundamental mode of Rayleigh waves, calculated for the inversion models. The S-wave velocity profiles in the area can be characterised by two soft layers over a firm engineering basement that has an S-wave velocity of 500 m/s. The S-wave velocities of the two layers are 120 and 280 m/s on average. The distribution of the averaged S-wave velocity in the top 30 m clearly indicates low values in the eastern central part and high values in the edge of the basin. The amplification is large in the areas with low velocity layers. In addition, we have proposed an empirical relation between the amplification factor and the topographical slope in the area.

  12. Molecular and Physiological Effects on the Small Intestine of Weaner Pigs Following Feeding with Deoxynivalenol-Contaminated Feed.

    PubMed

    Pasternak, J Alex; Aiyer, Vaishnavi Iyer Aka; Hamonic, Glenn; Beaulieu, A Denise; Columbus, Daniel A; Wilson, Heather L

    2018-01-12

    We intended to assess how exposure of piglets to deoxynivalenol (DON)-contaminated feed impacted their growth, immune response and gut development. Piglets were fed traditional Phase I, Phase II and Phase III diets with the control group receiving 0.20-0.40 ppm DON (referred to as the Control group) and treatment group receiving much higher level of DON-contaminated wheat (3.30-3.80 ppm; referred to as DON-contaminated group). Feeding a DON-contaminated diet had no impact on average daily feed intake (ADFI) ( p < 0.08) or average daily gain (ADG) ( p > 0.10) but it did significantly reduce body weight over time relative to the control piglets ( p < 0.05). Cytokine analysis after initial exposure to the DON-contaminated feed did not result in significant differences in serum interleukin (IL) IL1β, IL-8, IL-13, tumor necrosis factor (TNF)-α or interferon (IFN)-γ. After day 24, no obvious changes in jejunum or ileum gut morphology, histology or changes in gene expression for IL-1β, IL-6, IL-10, TNFα, or Toll-like receptor (TLR)-4 genes. IL-8 showed a trend towards increased expression in the ileum in DON-fed piglets. A significant increase in gene expression for claudin (CLDN) 7 gene expression and a trend towards increased CLDN 2-expression was observed in the ileum in piglets fed the highly DON-contaminated wheat. Because CLDN localization was not negatively affected, we believe that it is unlikely that gut permeability was affected. Exposure to DON-contaminated feed did not significantly impact weaner piglet performance or gut physiology.

  13. Study on characteristics of the aperture-averaging factor of atmospheric scintillation in terrestrial optical wireless communication

    NASA Astrophysics Data System (ADS)

    Shen, Hong; Liu, Wen-xing; Zhou, Xue-yun; Zhou, Li-ling; Yu, Long-Kun

    2018-02-01

    In order to thoroughly understand the characteristics of the aperture-averaging effect of atmospheric scintillation in terrestrial optical wireless communication and provide references for engineering design and performance evaluation of the optics system employed in the atmosphere, we have theoretically deduced the generally analytic expression of the aperture-averaging factor of atmospheric scintillation, and numerically investigated characteristics of the apertureaveraging factor under different propagation conditions. The limitations of the current commonly used approximate calculation formula of aperture-averaging factor have been discussed, and the results showed that the current calculation formula is not applicable for the small receiving aperture under non-uniform turbulence link. Numerical calculation has showed that aperture-averaging factor of atmospheric scintillation presented an exponential decline model for the small receiving aperture under non-uniform turbulent link, and the general expression of the model was given. This model has certain guiding significance for evaluating the aperture-averaging effect in the terrestrial optical wireless communication.

  14. The Analysis of the Strength, Distribution and Direction for the EEG Phase Synchronization by Musical Stimulus

    NASA Astrophysics Data System (ADS)

    Ogawa, Yutaro; Ikeda, Akira; Kotani, Kiyoshi; Jimbo, Yasuhiko

    In this study, we propose the EEG phase synchronization analysis including not only the average strength of the synchronization but also the distribution and directions under the conditions that evoked emotion by musical stimuli. The experiment is performed with the two different musical stimuli that evoke happiness or sadness for 150 seconds. It is found that the average strength of synchronization indicates no difference between the right side and the left side of the frontal lobe during the happy stimulus, the distribution and directions indicate significant differences. Therefore, proposed analysis is useful for detecting emotional condition because it provides information that cannot be obtained only by the average strength of synchronization.

  15. Reproduction of European eel jeopardised by high levels of dioxins and dioxin-like PCBs?

    PubMed

    Geeraerts, C; Focant, J-F; Eppe, G; De Pauw, E; Belpaire, C

    2011-09-01

    Dioxins, furans and dioxin-like polychlorinated biphenyls (PCBs) were analysed in muscle tissue from yellow phased European eel (Anguilla anguilla) from 38 sites in Belgium. Dioxin concentrations in eel vary considerably between sampling locations, indicating that yellow eel is a good indicator of local pollution levels. Measured levels of dioxin-like PCBs are much higher than those of the dioxins and furans. In the majority of the sites, eel has levels considered to be detrimental for their reproduction. Field levels of dioxin and dioxin-like PCBs are therefore suggested as an additional causal factor contributing to the decline of the European eel. 42% of the sampling sites show especially dioxin-like PCB levels exceeding the European consumption level (with a factor 3 on average). Human consumption of eel, especially in these highly contaminated sites, seems unjustified. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Bacteriophage T4 Infection of Stationary Phase E. coli: Life after Log from a Phage Perspective

    PubMed Central

    Bryan, Daniel; El-Shibiny, Ayman; Hobbs, Zack; Porter, Jillian; Kutter, Elizabeth M.

    2016-01-01

    Virtually all studies of phage infections investigate bacteria growing exponentially in rich media. In nature, however, phages largely encounter non-growing cells. Bacteria entering stationary phase often activate well-studied stress defense mechanisms that drastically alter the cell, facilitating its long-term survival. An understanding of phage-host interactions in such conditions is of major importance from both an ecological and therapeutic standpoint. Here, we show that bacteriophage T4 can efficiently bind to, infect and kill E. coli in stationary phase, both in the presence and absence of a functional stationary-phase sigma factor, and explore the response of T4-infected stationary phase cells to the addition of fresh nutrients 5 or 24 h after that infection. An unexpected new mode of response has been identified. “Hibernation” mode is a persistent but reversible dormant state in which the infected cells make at least some phage enzymes, but halt phage development until appropriate nutrients become available before producing phage particles. Our evidence indicates that the block in hibernation mode occurs after the middle-mode stage of phage development; host DNA breakdown and the incorporation of the released nucleotides into phage DNA indicate that the enzymes of the nucleotide synthesizing complex, under middle-mode control, have been made and assembled into a functional state. Once fresh glucose and amino acids become available, the standard lytic infection process rapidly resumes and concentrations of up to 1011 progeny phage (an average of about 40 phage per initially present cell) are produced. All evidence is consistent with the hibernation-mode control point lying between middle mode and late mode T4 gene expression. We have also observed a “scavenger” response, where the infecting phage takes advantage of whatever few nutrients are available to produce small quantities of progeny within 2 to 5 h after infection. The scavenger response seems able to produce no more than an average of one phage per originally available cell, and few if any further progeny are produced by cells in this mode even if fresh nutrients are made available later. PMID:27660625

  17. Radiation induced segregation and precipitation behavior in self-ion irradiated Ferritic/Martensitic HT9 steel

    DOE PAGES

    Zheng, Ce; Auger, Maria A.; Moody, Michael P.; ...

    2017-04-24

    In this study, Ferritic/Martensitic (F/M) HT9 steel was irradiated to 20 displacements per atom (dpa) at 600 nm depth at 420 and 440 °C, and to 1, 10 and 20 dpa at 600 nm depth at 470 °C using 5 MeV Fe++ ions. The characterization was conducted using ChemiSTEM and Atom Probe Tomography (APT), with a focus on radiation induced segregation and precipitation. Ni and/or Si segregation at defect sinks (grain boundaries, dislocation lines, carbide/matrix interfaces) together with Ni, Si, Mn rich G-phase precipitation were observed in self-ion irradiated HT9 except in very low dose case (1 dpa at 470more » °C). Some G-phase precipitates were found to nucleate heterogeneously at defect sinks where Ni and/or Si segregated. In contrast to what was previously reported in the literature for neutron irradiated HT9, no Cr-rich α' phase, χ-phases, η phase and voids were found in self-ion irradiated HT9. The difference of observed microstructures is probably due to the difference of irradiation dose rate between ion irradiation and neutron irradiation. In addition, the average size and number density of G-phase precipitates were found to be sensitive to both irradiation temperature and dose. With the same irradiation dose, the average size of G-phase increased whereas the number density decreased with increasing irradiation temperature. Within the same irradiation temperature, the average size increased with increasing irradiation dose.« less

  18. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Song, Gian; Sun, Zhiqian; Poplawsky, Jonathan D.

    The microstructures of a hierarchical-precipitate-strengthened ferritic alloy are characterized, using transmission-electron microscopy (TEM) and atom-probe tomography (APT). The alloy shows duplex precipitates. The primary precipitate with an average edge length of 90 nm consists of NiAl- and Ni2TiAl-type phases, while the secondary precipitate with an average radius of 2 nm is a NiAl-type phase. Based on the APT results, the volume fractions of the primary and secondary precipitates were calculated, using the lever rule to be 17.3 and 2.3 %, respectively.

  19. Advanced, phase-locked, 100 kW, 1.3 GHz magnetron

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Read, Michael; Ives, R. Lawrence; Bui, Thuc

    Calabazas Creek Research, Inc., in collaboration with Fermilab and Communications & Power Industries, LLC, is developing a phase-locked, 100 kW peak, 10 kW average power magnetron-based RF system for driving accelerators. Here, phase locking will be achieved using an approach originating at Fermilab that includes control of both amplitude and phase on a fast time scale.

  20. Advanced, phase-locked, 100 kW, 1.3 GHz magnetron

    DOE PAGES

    Read, Michael; Ives, R. Lawrence; Bui, Thuc; ...

    2017-03-06

    Calabazas Creek Research, Inc., in collaboration with Fermilab and Communications & Power Industries, LLC, is developing a phase-locked, 100 kW peak, 10 kW average power magnetron-based RF system for driving accelerators. Here, phase locking will be achieved using an approach originating at Fermilab that includes control of both amplitude and phase on a fast time scale.

  1. On Using Taylor's Hypothesis for Three-Dimensional Mixing Layers

    NASA Technical Reports Server (NTRS)

    LeBoeuf, Richard L.; Mehta, Rabindra D.

    1995-01-01

    In the present study, errors in using Taylor's hypothesis to transform measurements obtained in a temporal (or phase) frame onto a spatial one were evaluated. For the first time, phase-averaged ('real') spanwise and streamwise vorticity data measured on a three-dimensional grid were compared directly to those obtained using Taylor's hypothesis. The results show that even the qualitative features of the spanwise and streamwise vorticity distributions given by the two techniques can be very different. This is particularly true in the region of the spanwise roller pairing. The phase-averaged spanwise and streamwise peak vorticity levels given by Taylor's hypothesis are typically lower (by up to 40%) compared to the real measurements.

  2. Magnetic Tunnel Junction-Based On-Chip Microwave Phase and Spectrum Analyzer

    NASA Technical Reports Server (NTRS)

    Fan, Xin; Chen, Yunpeng; Xie, Yunsong; Kolodzey, James; Wilson, Jeffrey D.; Simons, Rainee N.; Xiao, John Q.

    2014-01-01

    A magnetic tunnel junction (MTJ)-based microwave detector is proposed and investigated. When the MTJ is excited by microwave magnetic fields, the relative angle between the free layer and pinned layer alternates, giving rise to an average resistance change. By measuring the average resistance change, the MTJ can be utilized as a microwave power sensor. Due to the nature of ferromagnetic resonance, the frequency of an incident microwave is directly determined. In addition, by integrating a mixer circuit, the MTJ-based microwave detector can also determine the relative phase between two microwave signals. Thus, the MTJ-based microwave detector can be used as an on-chip microwave phase and spectrum analyzer.

  3. Magnetic Tunnel Junction-Based On-Chip Microwave Phase and Spectrum Analyzer

    NASA Technical Reports Server (NTRS)

    Fan, Xin; Chen, Yunpeng; Xie, Yunsong; Kolodzey, James; Wilson, Jeffrey D.; Simons, Rainee N.; Xiao, John Q.

    2014-01-01

    A magnetic tunnel junction (MTJ)-based microwave detector is proposed and investigated. When the MTJ is excited by microwave magnetic fields, the relative angle between the free layer and pinned layer alternates, giving rise to an average resistance change. By measuring the average resistance change, the MTJ can be utilized as a microwave power sensor. Due to the nature of ferromagnetic resonance, the frequency of an incident microwave is directly determined. In addition, by integrating a mixer circuit, the MTJ-based microwave detector can also determine the relative phase between two microwave signals. Thus, the MTJbased microwave detector can be used as an on-chip microwave phase and spectrum analyzer.

  4. Localization and partitioning of deformation in experimentally produced granitoid fault rocks

    NASA Astrophysics Data System (ADS)

    Peč, Matěj.; Stünitz, Holger; Heilbronner, Renée.

    2010-05-01

    The complex interplay between frictional and viscous deformation processes taking place in the "brittle-ductile transition" is still poorly understood. Fracturing, as one of the most effective grain size reducing mechanisms, occurs under a wide range of conditions and seems to be an important pre-cursor for the onset of viscous deformation in the crust. The aim of this work is to study localization and partitioning of brittle and viscous deformation in experimentally produced fault gouges and to identify the active deformation mechanism(s) via quantitative microstructural analysis. We performed a series of simple shear experiments on granitoid fault gouge in a Griggs solid medium deformation rig at 500 MPa confining pressure and 300 or 500°C. Before deformation, the artificially produced gouge consists of 28% Qtz, 25% Kfs, 15% Plg, 3% Bi and 0.5% Msk. The average thickness of the shear zone is ˜1 mm and the porosity is ˜28%. All three major phases (Qtz, Kfs and Plg) deform by fracturing along grain-to-grain contacts and have a similar aspect ratio (L/S) ˜2.13. Two measures for concavity were determined: paris factor ~7.6% and deltaA factor ~6.5%. Finally, a measure for angularity, omega factor, is slightly higher in Qtz (24.8%) than in feldspars (˜20%) (Heilbronner & Keulen 2006). Micas deform mainly by kinking. We observe a slight shape preferred orientation of the grains perpendicular to the applied load indicating that the applied pressure during the pumping up of the experiment is not entirely isotropic. After fast frictional deformation (shear strain rates of 10^-4 sec^-1 and 10^-3 sec^-1) to a gamma value of up to 2.7, the average thickness of the shear zone is reduced to 0.7 mm and the porosity drops below 3%. We observe overall grain size reduction and shear localization through the development of S-C-Ć fabric with Ć shear bands being the dominant feature. The Ć shear bands form at an angle of 18° to sigma 1 resp. 27° to the shear zone boundary and contain the smallest grains (< 10 nm). Locally, where the amount of fine grain fraction is high or where mica is present, the Ć shear bands change their orientation to C shear bands (boundary parallel). Due to the widespread grain-size reduction it is often hard to identify individual grains even at high magnifications. Therefore we analyze individual grains (well identifiable grains) and grain aggregates (delimited by phase to phase contacts) separately. The fractured qtz grains have a slightly higher average aspect ration (2.3) than the feldspar grains (2.0) and seem to be the strongest phase. Average paris, deltaA and omega values for Qtz grains are higher (12.3%, 7.3% and 21%) than for feldspar grains (10.6%, 5.2% and 16%) due to cleavage effects on fracturing. The grain aggregates have higher aspect ratios (Qtz = 2.4, Kfs = 2.8, Plg = 2.3) a monoclinic symmetry and often form "core-and-mantle" structures where the core is formed by a less fractured porphyroclast and the mantle is formed by finely fractured material of the same phase. These aggregates show a strong SPO synthetic with the induced sense of shear. After one week of stress relaxation or constant load creep we observe the reorientation of the Ć shear bands to an angle of 30° to sigma 1 resp. 15° to shear zone boundary. The smallest grain fraction is no longer present and we see an overall grain-size increase due to cementation of fine grains into bigger ones with lobate grain boundaries. The observed microstructures, together with the mechanical data, suggest that the fine-grained material along the Ć shear bands is exploited by viscous deformation. The envisaged deformation mechanism is dissolution - precipitation creep. References: Heilbronner, R. and Keulen N. (2006) Grain size and grain shape analysis of fault rocks. Tectonophysics 427:199-216

  5. Stormtime ring current and radiation belt ion transport: Simulations and interpretations

    NASA Technical Reports Server (NTRS)

    Lyons, Larry R.; Gorney, David J.; Chen, Margaret W.; Schulz, Michael

    1995-01-01

    We use a dynamical guiding-center model to investigate the stormtime transport of ring current and radiation-belt ions. We trace the motion of representative ions' guiding centers in response to model substorm-associated impulses in the convection electric field for a range of ion energies. Our simple magnetospheric model allows us to compare our numerical results quantitatively with analytical descriptions of particle transport, (e.g., with the quasilinear theory of radial diffusion). We find that 10-145-keV ions gain access to L approximately 3, where they can form the stormtime ring current, mainly from outside the (trapping) region in which particles execute closed drift paths. Conversely, the transport of higher-energy ions (approximately greater than 145 keV at L approximately 3) turns out to resemble radial diffusion. The quasilinear diffusion coefficient calculated for our model storm does not vary smoothly with particle energy, since our impulses occur at specific (although randomly determined) times. Despite the spectral irregularity, quasilinear theory provides a surprisingly accurate description of the transport process for approximately greater than 145-keV ions, even for the case of an individual storm. For 4 different realizations of our model storm, the geometric mean discrepancies between diffusion coefficients D(sup sim, sub LL) obtained from the simulations and the quasilinear diffusion coefficient D(sup ql, sub LL) amount to factors of 2.3, 2.3, 1.5, and 3.0, respectively. We have found that these discrepancies between D(sup sim, sub LL) and D(sup ql, sub LL) can be reduced slightly by invoking drift-resonance broadening to smooth out the sharp minima and maxima in D(sup ql, sub LL). The mean of the remaining discrepancies between D(sup sim, sub LL) and D(sup ql, sub LL) for the 4 different storms then amount to factors of 1.9, 2.1, 1.5, and 2.7, respectively. We find even better agreement when we reduce the impulse amplitudes systematically in a given model storm (e.g., reduction of all the impulse amplitudes by half reduces the discrepancy factor by at least its square root) and also when we average our results over an ensemble of 20 model storms (agreement is within a factor of 1.2 without impulse-amplitude reduction). We use our simulation results also to map phase-space densities f in accordance with Liouville's theorem. We find that the stormtime transport of approximately greater than 145-keV ions produces little change in f-bar the drift-averaged phase-space density on any drift shell of interest. However, the stormtime transport produces a major enhancement from the pre-storm phase-space density at energies approximately 30-145 keV, which are representative of the stormtime ring current.

  6. A New Shape Description Method Using Angular Radial Transform

    NASA Astrophysics Data System (ADS)

    Lee, Jong-Min; Kim, Whoi-Yul

    Shape is one of the primary low-level image features in content-based image retrieval. In this paper we propose a new shape description method that consists of a rotationally invariant angular radial transform descriptor (IARTD). The IARTD is a feature vector that combines the magnitude and aligned phases of the angular radial transform (ART) coefficients. A phase correction scheme is employed to produce the aligned phase so that the IARTD is invariant to rotation. The distance between two IARTDs is defined by combining differences in the magnitudes and aligned phases. In an experiment using the MPEG-7 shape dataset, the proposed method outperforms existing methods; the average BEP of the proposed method is 57.69%, while the average BEPs of the invariant Zernike moments descriptor and the traditional ART are 41.64% and 36.51%, respectively.

  7. The Nosé–Hoover looped chain thermostat for low temperature thawed Gaussian wave-packet dynamics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Coughtrie, David J.; Tew, David P.

    2014-05-21

    We have used a generalised coherent state resolution of the identity to map the quantum canonical statistical average for a general system onto a phase-space average over the centre and width parameters of a thawed Gaussian wave packet. We also propose an artificial phase-space density that has the same behaviour as the canonical phase-space density in the low-temperature limit, and have constructed a novel Nosé–Hoover looped chain thermostat that generates this density in conjunction with variational thawed Gaussian wave-packet dynamics. This forms a new platform for evaluating statistical properties of quantum condensed-phase systems that has an explicit connection to themore » time-dependent Schrödinger equation, whilst retaining many of the appealing features of path-integral molecular dynamics.« less

  8. Comprehensive time average digital holographic vibrometry

    NASA Astrophysics Data System (ADS)

    Psota, Pavel; Lédl, Vít; Doleček, Roman; Mokrý, Pavel; Vojtíšek, Petr; Václavík, Jan

    2016-12-01

    This paper presents a method that simultaneously deals with drawbacks of time-average digital holography: limited measurement range, limited spatial resolution, and quantitative analysis of the measured Bessel fringe patterns. When the frequency of the reference wave is shifted by an integer multiple of frequency at which the object oscillates, the measurement range of the method can be shifted either to smaller or to larger vibration amplitudes. In addition, phase modulation of the reference wave is used to obtain a sequence of phase-modulated fringe patterns. Such fringe patterns can be combined by means of phase-shifting algorithms, and amplitudes of vibrations can be straightforwardly computed. This approach independently calculates the amplitude values in every single pixel. The frequency shift and phase modulation are realized by proper control of Bragg cells and therefore no additional hardware is required.

  9. [Perforated duodenal ulcer: benefits and risks of laparoscopic repair].

    PubMed

    Lunevicius, Raimundas; Morkevicius, Matas

    2004-01-01

    Laparoscopic perforated duodenal ulcer repair is a minimally invasive technique. Just like any other type of surgery, the laparoscopic approach carries operative risks in itself. The primary goal of this article is to describe the possible risk factors in laparoscopic duodenal ulcer repair. The secondary goal is to clarify benefits of the laparoscopic surgery. The Medline/Pubmed database was used; 73 articles were analyzed and evaluated. Six retrospective and nine prospective studies are summarized. The retrospective studies' results are as follows: total complication rate is 7-28% (average--16%); conversion rate is 6-30% (average--18%); postoperative mortality rate is 0-20% (average--6%); and average hospital stay is 6-17 days (average--8 days). The results of the prospective studies are the following: total complication rate is lower--5-25% (average--11%); conversion rate is lower - 0-27% (average--14%); postoperative mortality is lower 0-10% (average--3%); and average hospital stay is shorter--4-10 days (average--6 days). The difference is not significant but the results are better than in prospective studies. The risk factors were identical. Shock, delayed presentation (>24 hours), confounding medical condition, age >70 years, American Society of Anesthesiology III-IV degrees and Boey score--all above should be considered as preoperative laparoscopic repair risk factors. Inadequate ulcer localization, large perforation size (>6 mm diameter according to ones, >10 mm according to others) and ulcers with friable edges are also considered as laparoscopic repair risk factors: each of the factors independently is an indication for an open repair.

  10. Discrimination against Obese Exercise Clients: An Experimental Study of Personal Trainers.

    PubMed

    Fontana, Fabio; Bopes, Jonathan; Bendixen, Seth; Speed, Tyler; George, Megan; Mack, Mick

    2018-01-01

    The aim of the study was to compare exercise recommendations, attitudes, and behaviors of personal trainers toward clients of different weight statuses. Fifty-two personal trainers participated in the study. The data collection was organized into two phases. In phase one, trainers read a profile and watched the video displaying an interview of either an obese or an average-weight client. Profiles and video interviews were identical except for weight status. Then, trainers provided exercise recommendations and rated their attitude toward the client. In phase two, trainers personally met an obese or an average-weight mock client. Measures were duration and number of advices provided by the trainer to a question posed by the client and sitting distance between trainer and client. There were no significant differences in exercise intensity ( p = .94), duration of first session ( p = .65), and total exercise duration of first week ( p = .76) prescribed to the obese and average-weight clients. The attitude of the personal trainers toward the obese client were not significantly different from the attitude of personal trainers toward the average-weight client ( p = .58). The number of advices provided ( p = .49), the duration of the answer ( p = .55), and the distance personal trainers sat from the obese client ( p = .68) were not significantly different from the behaviors displayed toward the average-weight client. Personal trainers did not discriminate against obese clients in professional settings.

  11. Multivariate study of parameters in the determination of pesticide residues in apple by headspace solid phase microextraction coupled to gas chromatography-mass spectrometry using experimental factorial design.

    PubMed

    Abdulra'uf, Lukman Bola; Tan, Guan Huat

    2013-12-15

    Solid-phase microextraction (SPME) is a solvent-less sample preparation method which combines sample preparation, isolation, concentration and enrichment into one step. In this study, multivariate strategy was used to determine the significance of the factors affecting the solid phase microextraction of pesticide residues (fenobucarb, diazinon, chlorothalonil and chlorpyrifos) using a randomised factorial design. The interactions and effects of temperature, time and salt addition on the efficiency of the extraction of the pesticide residues were evaluated using 2(3) factorial designs. The analytes were extracted with 100 μm PDMS fibres according to the factorial design matrix and desorbed into a gas chromatography-mass spectrometry detector. The developed method was applied for the analysis of apple samples and the limits of detection were between 0.01 and 0.2 μg kg(-)(1), which were lower than the MRLs for apples. The relative standard deviations (RSD) were between 0.1% and 13.37% with average recovery of 80-105%. The linearity ranges from 0.5-50 μg kg(-)(1) with correlation coefficient greater than 0.99. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Comprehensive atmospheric modeling of reactive cyclic siloxanes and their oxidation products

    NASA Astrophysics Data System (ADS)

    Janechek, Nathan J.; Hansen, Kaj M.; Stanier, Charles O.

    2017-07-01

    Cyclic volatile methyl siloxanes (cVMSs) are important components in personal care products that transport and react in the atmosphere. Octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), and their gas-phase oxidation products have been incorporated into the Community Multiscale Air Quality (CMAQ) model. Gas-phase oxidation products, as the precursor to secondary organic aerosol from this compound class, were included to quantify the maximum potential for aerosol formation from gas-phase reactions with OH. Four 1-month periods were modeled to quantify typical concentrations, seasonal variability, spatial patterns, and vertical profiles. Typical model concentrations showed parent compounds were highly dependent on population density as cities had monthly averaged peak D5 concentrations up to 432 ng m-3. Peak oxidized D5 concentrations were significantly less, up to 9 ng m-3, and were located downwind of major urban areas. Model results were compared to available measurements and previous simulation results. Seasonal variation was analyzed and differences in seasonal influences were observed between urban and rural locations. Parent compound concentrations in urban and peri-urban locations were sensitive to transport factors, while parent compounds in rural areas and oxidized product concentrations were influenced by large-scale seasonal variability in OH.

  13. Cellular Automaton Study of Hydrogen Porosity Evolution Coupled with Dendrite Growth During Solidification in the Molten Pool of Al-Cu Alloys

    NASA Astrophysics Data System (ADS)

    Gu, Cheng; Wei, Yanhong; Yu, Fengyi; Liu, Xiangbo; She, Lvbo

    2017-09-01

    Welding porosity defects significantly reduce the mechanical properties of welded joints. In this paper, the hydrogen porosity evolution coupled with dendrite growth during solidification in the molten pool of Al-4.0 wt pct Cu alloy was modeled and simulated. Three phases, including a liquid phase, a solid phase, and a gas phase, were considered in this model. The growth of dendrites and hydrogen gas pores was reproduced using a cellular automaton (CA) approach. The diffusion of solute and hydrogen was calculated using the finite difference method (FDM). Columnar and equiaxed dendrite growth with porosity evolution were simulated. Competitive growth between different dendrites and porosities was observed. Dendrite morphology was influenced by porosity formation near dendrites. After solidification, when the porosities were surrounded by dendrites, they could not escape from the liquid, and they made pores that existed in the welded joints. With the increase in the cooling rate, the average diameter of porosities decreased, and the average number of porosities increased. The average diameter of porosities and the number of porosities in the simulation results had the same trend as the experimental results.

  14. Information measures for a local quantum phase transition: Lattice fermions in a one-dimensional harmonic trap

    NASA Astrophysics Data System (ADS)

    Zhang, Yicheng; Vidmar, Lev; Rigol, Marcos

    2018-02-01

    We use quantum information measures to study the local quantum phase transition that occurs for trapped spinless fermions in one-dimensional lattices. We focus on the case of a harmonic confinement. The transition occurs upon increasing the characteristic density and results in the formation of a band-insulating domain in the center of the trap. We show that the ground-state bipartite entanglement entropy can be used as an order parameter to characterize this local quantum phase transition. We also study excited eigenstates by calculating the average von Neumann and second Renyi eigenstate entanglement entropies, and compare the results with the thermodynamic entropy and the mutual information of thermal states at the same energy density. While at low temperatures we observe a linear increase of the thermodynamic entropy with temperature at all characteristic densities, the average eigenstate entanglement entropies exhibit a strikingly different behavior as functions of temperature below and above the transition. They are linear in temperature below the transition but exhibit activated behavior above it. Hence, at nonvanishing energy densities above the ground state, the average eigenstate entanglement entropies carry fingerprints of the local quantum phase transition.

  15. Gas-liquid Phase Distribution and Void Fraction Measurements Using the MRI

    NASA Technical Reports Server (NTRS)

    Daidzic, N. E.; Schmidt, E.; Hasan, M. M.; Altobelli, S.

    2004-01-01

    We used a permanent-magnet MRI system to estimate the integral and spatially- and/or temporally-resolved void-fraction distributions and flow patterns in gas-liquid two-phase flows. Air was introduced at the bottom of the stagnant liquid column using an accurate and programmable syringe pump. Air flow rates were varied between 1 and 200 ml/min. The cylindrical non-conducting test tube in which two-phase flow was measured was placed in a 2.67 kGauss MRI with MRT spectrometer/imager. Roughly linear relationship has been obtained for the integral void-fraction, obtained by volume-averaging of the spatially-resolved signals, and the air flow rate in upward direction. The time-averaged spatially-resolved void fraction has also been obtained for the quasi-steady flow of air in a stagnant liquid column. No great accuracy is claimed as this was an exploratory proof-of-concept type of experiment. Preliminary results show that MRI a non-invasive and non-intrusive experimental technique can indeed provide a wealth of different qualitative and quantitative data and is especially well suited for averaged transport processes in adiabatic and diabatic multi-phase and/or multi-component flows.

  16. Secondary flow structure in a model curved artery: 3D morphology and circulation budget analysis

    NASA Astrophysics Data System (ADS)

    Bulusu, Kartik V.; Plesniak, Michael W.

    2015-11-01

    In this study, we examined the rate of change of circulation within control regions encompassing the large-scale vortical structures associated with secondary flows, i.e. deformed Dean-, Lyne- and Wall-type (D-L-W) vortices at planar cross-sections in a 180° curved artery model (curvature ratio, 1/7). Magnetic resonance velocimetry (MRV) and particle image velocimetry (PIV) experiments were performed independently, under the same physiological inflow conditions (Womersley number, 4.2) and using Newtonian blood-analog fluids. The MRV-technique performed at Stanford University produced phase-averaged, three-dimensional velocity fields. Secondary flow field comparisons of MRV-data to PIV-data at various cross-sectional planes and inflow phases were made. A wavelet-decomposition-based approach was implemented to characterize various secondary flow morphologies. We hypothesize that the persistence and decay of arterial secondary flow vortices is intrinsically related to the influence of the out-of-plane flow, tilting, in-plane convection and diffusion-related factors within the control regions. Evaluation of these factors will elucidate secondary flow structures in arterial hemodynamics. Supported by the National Science Foundation under Grant Number CBET-0828903, and GW Center for Biomimetics and Bioinspired Engineering (COBRE). The MRV data were acquired at Stanford University in collaboration with Christopher Elkins and John Eaton.

  17. Phytoplankton biodiversity changes in a shallow tropical reservoir during the hypertrophication process.

    PubMed

    Crossetti, L O; Bicudo, D C; Bicudo, C E M; Bini, L M

    2008-11-01

    Study aimed at evaluating phytoplankton biodiversity changes in a shallow tropical reservoir during its hypertrophication process. Samplings were carried out monthly during 8 consecutive years (1997-2004) in 5 depths. Conspicuous limnological changes in the reservoir derived from the presence and/or removal of the water hyacinth, characterized 3 different phases. Over the time series, reservoir changed from a typical polymictic eutrophic system to hypertrophic one, leading to a reduction of approximately 70 species (average 37%). Chlorophyceae accounted for the highest species richness (46%) among all algal classes and strictly followed total species richness variation. Internal feedback mechanisms intensification over phase III clearly promoted the sharp decrease in biodiversity. Highest decreases, mainly during springs, occurred simultaneously to the highest Cyanobacteria blooms. Increased turbidity due to heavy phytoplankton blooms suppressed all other algal groups, so that at the end of the present study even Cyanobacteria species richness decreased. Total dissolved phosphorous was included in most of the best selected models used to analyze the temporal patterns in species richness loss. Present data show that biodiversity loss following trophic change was not a single dimension of a single factor but, rather, a template of factors (e.g. light, stability) co-varying in consequence of the larger levels of biomass supported in the reservoir.

  18. Halophilic archaea cultivated from surface sterilized middle-late eocene rock salt are polyploid.

    PubMed

    Jaakkola, Salla T; Zerulla, Karolin; Guo, Qinggong; Liu, Ying; Ma, Hongling; Yang, Chunhe; Bamford, Dennis H; Chen, Xiangdong; Soppa, Jörg; Oksanen, Hanna M

    2014-01-01

    Live bacteria and archaea have been isolated from several rock salt deposits of up to hundreds of millions of years of age from all around the world. A key factor affecting their longevity is the ability to keep their genomic DNA intact, for which efficient repair mechanisms are needed. Polyploid microbes are known to have an increased resistance towards mutations and DNA damage, and it has been suggested that microbes from deeply buried rock salt would carry several copies of their genomes. Here, cultivable halophilic microbes were isolated from a surface sterilized middle-late Eocene (38-41 million years ago) rock salt sample, drilled from the depth of 800 m at Yunying salt mine, China. Eight unique isolates were obtained, which represented two haloarchaeal genera, Halobacterium and Halolamina. We used real-time PCR to show that our isolates are polyploid, with genome copy numbers of 11-14 genomes per cell in exponential growth phase. The ploidy level was slightly downregulated in stationary growth phase, but the cells still had an average genome copy number of 6-8. The polyploidy of halophilic archaea living in ancient rock salt might be a factor explaining how these organisms are able to overcome the challenge of prolonged survival during their entombment.

  19. Effect of annealing time, weight pressure and cobalt doping on the electrical and magnetic behavior of barium titanate

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Samuvel, K., E-mail: kssamuvel@gmail.com; Ramachandran, K., E-mail: ramach76@yahoo.com

    2016-05-06

    BaTi{sub 0.5}CO{sub 0.5}O{sub 3} (BTCO) nanoparticles were prepared by the solid state reaction technique using different starting materials and the microstructure examined by XRD, FESEM, BDS and VSM. X-ray diffraction and electron diffraction patterns showed that the nanoparticles were the tetragonal BTCO phase. The BTCO nanoparticles prepared from the starting materials of as prepared titanium-oxide, Cobalt -oxide and barium carbonate have spherical grain morphology, an average size of 65 nm and a fairly narrow size distribution. The nano-scale presence and the formation of the tetragonal perovskite phase as well as the crystallinity were detected using the mentioned techniques. Dielectric properties ofmore » the samples were measured at different frequencies. Broadband dielectric spectroscopy is applied to investigate the electrical properties of disordered perovskite-like ceramics in a wide temperature range. The doped BTCO samples exhibited low loss factor at 1 kHz and 1 MHz frequencies respectively.« less

  20. The influence of point defects on the thermal conductivity of AlN crystals

    NASA Astrophysics Data System (ADS)

    Rounds, Robert; Sarkar, Biplab; Alden, Dorian; Guo, Qiang; Klump, Andrew; Hartmann, Carsten; Nagashima, Toru; Kirste, Ronny; Franke, Alexander; Bickermann, Matthias; Kumagai, Yoshinao; Sitar, Zlatko; Collazo, Ramón

    2018-05-01

    The average bulk thermal conductivity of free-standing physical vapor transport and hydride vapor phase epitaxy single crystal AlN samples with different impurity concentrations is analyzed using the 3ω method in the temperature range of 30-325 K. AlN wafers grown by physical vapor transport show significant variation in thermal conductivity at room temperature with values ranging between 268 W/m K and 339 W/m K. AlN crystals grown by hydride vapor phase epitaxy yield values between 298 W/m K and 341 W/m K at room temperature, suggesting that the same fundamental mechanisms limit the thermal conductivity of AlN grown by both techniques. All samples in this work show phonon resonance behavior resulting from incorporated point defects. Samples shown by optical analysis to contain carbon-silicon complexes exhibit higher thermal conductivity above 100 K. Phonon scattering by point defects is determined to be the main limiting factor for thermal conductivity of AlN within the investigated temperature range.

  1. Technology Demonstration of the Zero Emissions Chromium Electroplating System

    DTIC Science & Technology

    2008-02-01

    Phase I trivalent chromium results ................................................................... 23 18 Phase II total chromium in PRD fluid results...0 xa B D F H J L Sam pies Figure 16. Phase II iron results. ERDC/CERL TR-05-35, Vol. 1 23 Trivalent Chromium Phase I Analysis for Phase I was...with the samples. Each sample was analyzed twice, and an average was computed. Figure 17 shows the results. ANAD has specified that Trivalent Chromium

  2. Effects of Vocal Fold Nodules on Glottal Cycle Measurements Derived from High-Speed Videoendoscopy in Children

    PubMed Central

    2016-01-01

    The goal of this study is to quantify the effects of vocal fold nodules on vibratory motion in children using high-speed videoendoscopy. Differences in vibratory motion were evaluated in 20 children with vocal fold nodules (5–11 years) and 20 age and gender matched typically developing children (5–11 years) during sustained phonation at typical pitch and loudness. Normalized kinematic features of vocal fold displacements from the mid-membranous vocal fold point were extracted from the steady-state high-speed video. A total of 12 kinematic features representing spatial and temporal characteristics of vibratory motion were calculated. Average values and standard deviations (cycle-to-cycle variability) of the following kinematic features were computed: normalized peak displacement, normalized average opening velocity, normalized average closing velocity, normalized peak closing velocity, speed quotient, and open quotient. Group differences between children with and without vocal fold nodules were statistically investigated. While a moderate effect size was observed for the spatial feature of speed quotient, and the temporal feature of normalized average closing velocity in children with nodules compared to vocally normal children, none of the features were statistically significant between the groups after Bonferroni correction. The kinematic analysis of the mid-membranous vocal fold displacement revealed that children with nodules primarily differ from typically developing children in closing phase kinematics of the glottal cycle, whereas the opening phase kinematics are similar. Higher speed quotients and similar opening phase velocities suggest greater relative forces are acting on vocal fold in the closing phase. These findings suggest that future large-scale studies should focus on spatial and temporal features related to the closing phase of the glottal cycle for differentiating the kinematics of children with and without vocal fold nodules. PMID:27124157

  3. Energy Dissipation in Ex-Vivo Porcine Liver during Electrosurgery

    PubMed Central

    Karaki, Wafaa; Akyildiz, Ali; De, Suvranu

    2017-01-01

    This paper explores energy dissipation in ex-vivo liver tissue during radiofrequency current excitation with application in electrosurgery. Tissue surface temperature for monopolar electrode configuration is measured using infrared thermometry. The experimental results are fitted to a finite element model for transient heat transfer taking into account energy storage and conduction in order to extract information about “apparent” specific heat, which encompasses storage and phase change. The average apparent specific heat determined for low temperatures is in agreement with published data. However, at temperatures approaching the boiling point of water, apparent specific heat increases by a factor of five, indicating that vaporization plays an important role in the energy dissipation through latent heat loss. PMID:27479955

  4. Wall Shear Stress, Wall Pressure and Near Wall Velocity Field Relationships in a Whirling Annular Seal

    NASA Technical Reports Server (NTRS)

    Morrison, Gerald L.; Winslow, Robert B.; Thames, H. Davis, III

    1996-01-01

    The mean and phase averaged pressure and wall shear stress distributions were measured on the stator wall of a 50% eccentric annular seal which was whirling in a circular orbit at the same speed as the shaft rotation. The shear stresses were measured using flush mounted hot-film probes. Four different operating conditions were considered consisting of Reynolds numbers of 12,000 and 24,000 and Taylor numbers of 3,300 and 6,600. At each of the operating conditions the axial distribution (from Z/L = -0.2 to 1.2) of the mean pressure, shear stress magnitude, and shear stress direction on the stator wall were measured. Also measured were the phase averaged pressure and shear stress. These data were combined to calculate the force distributions along the seal length. Integration of the force distributions result in the net forces and moments generated by the pressure and shear stresses. The flow field inside the seal operating at a Reynolds number of 24,000 and a Taylor number of 6,600 has been measured using a 3-D laser Doppler anemometer system. Phase averaged wall pressure and wall shear stress are presented along with phase averaged mean velocity and turbulence kinetic energy distributions located 0.16c from the stator wall where c is the seal clearance. The relationships between the velocity, turbulence, wall pressure and wall shear stress are very complex and do not follow simple bulk flow predictions.

  5. Power factor improvement in three-phase networks with unbalanced inductive loads using the Roederstein ESTAmat RPR power factor controller

    NASA Astrophysics Data System (ADS)

    Diniş, C. M.; Cunţan, C. D.; Rob, R. O. S.; Popa, G. N.

    2018-01-01

    The paper presents the analysis of a power factor with capacitors banks, without series coils, used for improving power factor for a three-phase and single-phase inductive loads. In the experimental measurements, to improve the power factor, the Roederstein ESTAmat RPR power factor controller can command up to twelve capacitors banks, while experimenting using only six capacitors banks. Six delta capacitors banks with approximately equal reactive powers were used for experimentation. The experimental measurements were carried out with a three-phase power quality analyser which worked in three cases: a case without a controller with all capacitors banks permanently parallel connected with network, and two other cases with power factor controller (one with setting power factor at 0.92 and the other one at 1). When performing experiments with the power factor controller, a current transformer was used to measure the current on one phase (at a more charged or less loaded phase).

  6. Closed-loop carrier phase synchronization techniques motivated by likelihood functions

    NASA Technical Reports Server (NTRS)

    Tsou, H.; Hinedi, S.; Simon, M.

    1994-01-01

    This article reexamines the notion of closed-loop carrier phase synchronization motivated by the theory of maximum a posteriori phase estimation with emphasis on the development of new structures based on both maximum-likelihood and average-likelihood functions. The criterion of performance used for comparison of all the closed-loop structures discussed is the mean-squared phase error for a fixed-loop bandwidth.

  7. Predictive capability of average Stokes polarimetry for simulation of phase multilevel elements onto LCoS devices.

    PubMed

    Martínez, Francisco J; Márquez, Andrés; Gallego, Sergi; Ortuño, Manuel; Francés, Jorge; Pascual, Inmaculada; Beléndez, Augusto

    2015-02-20

    Parallel-aligned (PA) liquid-crystal on silicon (LCoS) microdisplays are especially appealing in a wide range of spatial light modulation applications since they enable phase-only operation. Recently we proposed a novel polarimetric method, based on Stokes polarimetry, enabling the characterization of their linear retardance and the magnitude of their associated phase fluctuations or flicker, exhibited by many LCoS devices. In this work we apply the calibrated values obtained with this technique to show their capability to predict the performance of spatially varying phase multilevel elements displayed onto the PA-LCoS device. Specifically we address a series of multilevel phase blazed gratings. We analyze both their average diffraction efficiency ("static" analysis) and its associated time fluctuation ("dynamic" analysis). Two different electrical configuration files with different degrees of flicker are applied in order to evaluate the actual influence of flicker on the expected performance of the diffractive optical elements addressed. We obtain a good agreement between simulation and experiment, thus demonstrating the predictive capability of the calibration provided by the average Stokes polarimetric technique. Additionally, it is obtained that for electrical configurations with less than 30° amplitude for the flicker retardance, they may not influence the performance of the blazed gratings. In general, we demonstrate that the influence of flicker greatly diminishes when the number of quantization levels in the optical element increases.

  8. Microstructural Evolution of Al-1Fe (Weight Percent) Alloy During Accumulative Continuous Extrusion Forming

    NASA Astrophysics Data System (ADS)

    Wang, Xiang; Guan, Ren-Guo; Tie, Di; Shang, Ying-Qiu; Jin, Hong-Mei; Li, Hong-Chao

    2018-04-01

    As a new microstructure refining method, accumulative continuous extrusion forming (ACEF) cannot only refine metal matrix but also refine the phases that exist in it. In order to detect the refinements of grain and second phase during the process, Al-1Fe (wt pct) alloy was processed by ACEF, and the microstructural evolution was analyzed by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). Results revealed that the average grain size of Al-1Fe (wt pct) alloy decreased from 13 to 1.2 μm, and blocky Al3Fe phase with an average length of 300 nm was granulated to Al3Fe particle with an average diameter of 200 nm, after one pass of ACEF. Refinement of grain was attributed to continuous dynamic recrystallization (CDRX), and the granulation of Al3Fe phase included the spheroidization resulting from deformation heat and the fragmentation caused by the coupling effects of strain and thermal effect. The spheroidization worked in almost the entire deformation process, while the fragmentation required strain accumulation. However, fragmentation contributed more than spheroidization. Al3Fe particle stimulated the formation of substructure and retarded the migration of recrystallized grain boundary, but the effect of Al3Fe phase on refinement of grain could only be determined by the contrastive investigation of Al-1Fe (wt pct) alloy and pure Al.

  9. Experimental evidence for stochastic switching of supercooled phases in NdNiO3 nanostructures

    NASA Astrophysics Data System (ADS)

    Kumar, Devendra; Rajeev, K. P.; Alonso, J. A.

    2018-03-01

    A first-order phase transition is a dynamic phenomenon. In a multi-domain system, the presence of multiple domains of coexisting phases averages out the dynamical effects, making it nearly impossible to predict the exact nature of phase transition dynamics. Here, we report the metal-insulator transition in samples of sub-micrometer size NdNiO3 where the effect of averaging is minimized by restricting the number of domains under study. We observe the presence of supercooled metallic phases with supercooling of 40 K or more. The transformation from the supercooled metallic to the insulating state is a stochastic process that happens at different temperatures and times in different experimental runs. The experimental results are understood without incorporating material specific properties, suggesting that the behavior is of universal nature. The size of the sample needed to observe individual switching of supercooled domains, the degree of supercooling, and the time-temperature window of switching are expected to depend on the parameters such as quenched disorder, strain, and magnetic field.

  10. Design of admission medication reconciliation technology: a human factors approach to requirements and prototyping.

    PubMed

    Lesselroth, Blake J; Adams, Kathleen; Tallett, Stephanie; Wood, Scott D; Keeling, Amy; Cheng, Karen; Church, Victoria L; Felder, Robert; Tran, Hanna

    2013-01-01

    Our objectives were to (1) develop an in-depth understanding of the workflow and information flow in medication reconciliation, and (2) design medication reconciliation support technology using a combination of rapid-cycle prototyping and human-centered design. Although medication reconciliation is a national patient safety goal, limitations both of physical environment and in workflow can make it challenging to implement durable systems. We used several human factors techniques to gather requirements and develop a new process to collect a medication history at hospital admission. We completed an ethnography and time and motion analysis of pharmacists in order to illustrate the processes used to reconcile medications. We then used the requirements to design prototype multimedia software for collecting a bedside medication history. We observed how pharmacists incorporated the technology into their physical environment and documented usability issues. Admissions occurred in three phases: (1) list compilation, (2) order processing, and (3) team coordination. Current medication reconciliation processes at the hospital average 19 minutes to complete and do not include a bedside interview. Use of our technology during a bedside interview required an average of 29 minutes. The software represents a viable proof-of-concept to automate parts of history collection and enhance patient communication. However, we discovered several usability issues that require attention. We designed a patient-centered technology to enhance how clinicians collect a patient's medication history. By using multiple human factors methods, our research team identified system themes and design constraints that influence the quality of the medication reconciliation process and implementation effectiveness of new technology. Evidence-based design, human factors, patient-centered care, safety, technology.

  11. Multipartite entanglement characterization of a quantum phase transition

    NASA Astrophysics Data System (ADS)

    Costantini, G.; Facchi, P.; Florio, G.; Pascazio, S.

    2007-07-01

    A probability density characterization of multipartite entanglement is tested on the one-dimensional quantum Ising model in a transverse field. The average and second moment of the probability distribution are numerically shown to be good indicators of the quantum phase transition. We comment on multipartite entanglement generation at a quantum phase transition.

  12. Live cell refractometry using microfluidic devices.

    PubMed

    Lue, Niyom; Popescu, Gabriel; Ikeda, Takahiro; Dasari, Ramachandra R; Badizadegan, Kamran; Feld, Michael S

    2006-09-15

    Using Hilbert phase microscopy for extracting quantitative phase images, we measured the average refractive index associated with live cells in culture. To decouple the contributions to the phase signal from the cell refractive index and thickness, we confined the cells in microchannels. The results are confirmed by comparison with measurements of spherical cells in suspension.

  13. Optical implementation of spin squeezing

    NASA Astrophysics Data System (ADS)

    Ono, Takafumi; Sabines-Chesterking, Javier; Cable, Hugo; O'Brien, Jeremy L.; Matthews, Jonathan C. F.

    2017-05-01

    Quantum metrology enables estimation of optical phase shifts with precision beyond the shot-noise limit. One way to exceed this limit is to use squeezed states, where the quantum noise of one observable is reduced at the expense of increased quantum noise for its complementary partner. Because shot-noise limits the phase sensitivity of all classical states, reduced noise in the average value for the observable being measured allows for improved phase sensitivity. However, additional phase sensitivity can be achieved using phase estimation strategies that account for the full distribution of measurement outcomes. Here we experimentally investigate a model of optical spin-squeezing, which uses post-selection and photon subtraction from the state generated using a parametric downconversion photon source, and we investigate the phase sensitivity of this model. The Fisher information for all photon-number outcomes shows it is possible to obtain a quantum advantage of 1.58 compared to the shot-noise value for five-photon events, even though due to experimental imperfection, the average noise for the relevant spin-observable does not achieve sub-shot-noise precision. Our demonstration implies improved performance of spin squeezing for applications to quantum metrology.

  14. Decision-aided ICI mitigation with time-domain average approximation in CO-OFDM

    NASA Astrophysics Data System (ADS)

    Ren, Hongliang; Cai, Jiaxing; Ye, Xin; Lu, Jin; Cao, Quanjun; Guo, Shuqin; Xue, Lin-lin; Qin, Yali; Hu, Weisheng

    2015-07-01

    We introduce and investigate the feasibility of a novel iterative blind phase noise inter-carrier interference (ICI) mitigation scheme for coherent optical orthogonal frequency division multiplexing (CO-OFDM) systems. The ICI mitigation scheme is performed through the combination of frequency-domain symbol decision-aided estimation and the ICI phase noise time-average approximation. An additional initial decision process with suitable threshold is introduced in order to suppress the decision error symbols. Our proposed ICI mitigation scheme is proved to be effective in removing the ICI for a simulated CO-OFDM with 16-QAM modulation format. With the slightly high computational complexity, it outperforms the time-domain average blind ICI (Avg-BL-ICI) algorithm at a relatively wide laser line-width and high OSNR.

  15. Effects of growth phase on the membrane lipid composition of the thaumarchaeon Nitrosopumilus maritimus and their implications for archaeal lipid distributions in the marine environment

    NASA Astrophysics Data System (ADS)

    Elling, Felix J.; Könneke, Martin; Lipp, Julius S.; Becker, Kevin W.; Gagen, Emma J.; Hinrichs, Kai-Uwe

    2014-09-01

    The characteristic glycerol dibiphytanyl glycerol tetraether membrane lipids (GDGTs) of marine ammonia-oxidizing archaea (AOA) are widely used as biomarkers for studying their occurrence and distribution in marine environments and for reconstructing past sea surface temperatures using the TEX86 index. Despite an increasing use of GDGT biomarkers in microbial ecology and paleoceanography, the physiological and environmental factors influencing lipid composition in AOA, in particular the cyclization of GDGTs, remain unconstrained. We investigated the effect of metabolic state on the composition of intact polar and core lipids and the resulting TEX86 paleothermometer in pure cultures of the marine AOA Nitrosopumilus maritimus as a function of growth phase. The cellular lipid content ranged from 0.9 to 1.9 fg cell-1 and increased during growth but was lower in the stationary phases, indicating changes in average cell size in response to metabolic status. The relative abundances of monoglycosidic GDGTs increased from 27% in early growth phase to 60% in late stationary phase, while monohydroxylated GDGTs increased only slightly. The proportions of characteristic hexose-phosphohexose GDGTs were up to 7-fold higher during growth than in stationary phase, suggesting that they are valuable biomarkers for the metabolically active fraction of AOA assemblages in the environment. Methoxy archaeol was identified as novel, genuine archaeal lipid of yet unknown function; it is one of the most abundant single compounds in the lipidome of N. maritimus. TEX86 values of individual intact GDGTs and total GDGTs differed substantially, were generally lower during early and late growth phases than in stationary phase, and did not reflect growth temperature. Consequently, our results strongly suggest that biosynthesis is at least partially responsible for the systematic offsets in TEX86 values between different intact polar GDGT classes observed previously in environmental samples. Nevertheless, differences in degradation rates of intact polar GDGTs may influence the TEX86 index because the intact polar lipid precursors differ for individual core GDGTs and moreover their relative abundances change with growth stage, which may result in distinct release rates of core GDGTs from their polar precursors. Overall, our findings stress the need to accurately describe the factors influencing GDGT cyclization in thaumarchaea and thus paleotemperature reconstructions.

  16. [Treatment of severe intermittent claudication: ORACLE-PGE1 short term study. A randomised 40-week study. Evaluation of efficacy and costs].

    PubMed

    Cesarone, M R; Belcaro, G; Nicolaides, A N; Griffin, M; Geroulakos, G; Ramaswami, G; Cazaubon, M; Barsotti, A; Vasdekis, S; Christopoulos, D; Agus, G; Bavera, P; Mondani, P; Ippolito, E; Flenda, F

    2002-12-01

    The efficacy and cost of prostaglandin E1 (PGE1) in severe intermittent claudication was studied comparing a long-term protocol (LTP) with a short-term protocol (STP) in a randomised 40-week study. Phase 1 was a 2-week run-in phase (no treatment) for both protocols. In LTP, phase 2 was the main treatment phase. Treatment was performed with 2-hour infusions (60 micro g PGE1, 5 days each week for 4 weeks. In phase 3 (4-week interval period), PGE1 was administered twice a week (same dosage). In phase 4 (40 weeks), no PGE1 were used. In STP, phase 2 treatment was performed in two days by a 2-hour infusion (60 micro g PGE1 twice a day in 2 days). The same cycle was repeated every 4 weeks. A treadmill test was performed at inclusion, at the beginning of each phase and at the end of weeks 12, 16, 20 32 and 40. A progressive training plan (walking) and reduction in risk factors plan was used in both groups. Out of the 1276 included patients 1165 completed the study (606 in LTP group; 559 in the STP). Drop-outs were 111. The two groups were comparable in distribution, risk factors and smoking. Intention-to-treat analysis indicated an increase in pain free walking distance (PFWD). The absolute and percent increase in pain-free walking distance (PFWD) was comparable in both LTP and STP groups with a significative increase in TWD at 4 weeks. At 20 and 40 weeks increase was up to 219% in the LTP and 460% in the STP group (p<0.02). Comparable results concerning PFWD were obtained in the two groups. Both treatments were well tolerated. No side effect was observed. Local effects were observed in 8.5% of the treated subjects in the LTP and 4% in the STP. The average cost of the LTP protocol was 8786 Euro. For STP the costs was 946 (10.8% of LTP). For both protocols the cost of the infusion was 24% of the total for the LTP and 35% in the STP. Therefore 75% of the cost is not drug-related. In conclusion between-group-analysis favours STP considering walking distance and costs. Results indicate good efficacy and tolerability of PGE1 treatment particularly STP.

  17. Etudes diélectriques de la transition ferroélectrique induite par application d'un champ électrique dans les céramiques PbMg{1/3}Nb{2/3}O3 (PMN)

    NASA Astrophysics Data System (ADS)

    Chabin, M.; Malki, M.; Husson, E.; Morell, A.

    1994-07-01

    The evolution of the dielectric permittivity and loss factor under an external applied electric field has been studied in PbMg{1/3}Nb{2/3}O3 ceramics between 80 and 420 K. For a threshold field of 4 kV.cm^{-1}, it is possible to induce a ferroelectric transition from the average cubic phase to a macroscopically polar phase. The poling and depoling temperatures depend on the various combinations of thermal treatments and on the applied field strength. The transition between the nanopolar state and the macropolar state is discussed L'évolution de la permittivité diélectrique et du facteur de pertes diélectriques sous un champ électrique extérieur a été étudiée dans des céramiques de PbMg{1/3}Nb{2/3}O3 enre 80 et 420 K. Pour un champ de seuil de 4 kV.cm^{-1} il est possible d'induire une transition ferroélectrique de la phase cubique moyenne en une phase macroscopiquement polaire. Les températures de polarisation et de dépolarisation dépendent des différentes combinaisons de traitements thermiques et de la valeur du champ appliqué. La transition entre la phase constituée de nanodomaines polaires et la phase constituée de macrodomaines polaires est discutée.

  18. Effects of bottom water dissolved oxygen variability on copper and lead fractionation in the sediments across the oxygen minimum zone, western continental margin of India.

    PubMed

    Chakraborty, Parthasarathi; Chakraborty, Sucharita; Jayachandran, Saranya; Madan, Ritu; Sarkar, Arindam; Linsy, P; Nath, B Nagender

    2016-10-01

    This study describes the effect of varying bottom-water oxygen concentration on geochemical fractionation (operational speciation) of Cu and Pb in the underneath sediments across the oxygen minimum zone (Arabian Sea) in the west coast of India. Both, Cu and Pb were redistributed among the different binding phases of the sediments with changing dissolved oxygen level (from oxic to hypoxic and close to suboxic) in the bottom water. The average lability of Cu-sediment complexes gradually decreased (i.e., stability increased) with the decreasing dissolved oxygen concentrations of the bottom water. Decreasing bottom-water oxygen concentration increased Cu association with sedimentary organic matter. However, Pb association with Fe/Mn-oxyhydroxide phases in the sediments gradually decreased with the decreasing dissolved oxygen concentration of the overlying bottom water (due to dissolution of Fe/Mn oxyhydroxide phase). The lability of Pb-sediment complexes increased with the decreasing bottom-water oxygen concentration. This study suggests that bottom-water oxygen concentration is one of the key factors governing stability and lability of Cu and Pb complexes in the underneath sediment. Sedimentary organic matter and Fe/Mn oxyhydroxide binding phases were the major hosting phases for Cu and Pb respectively in the study area. Increasing lability of Pb-complexes in bottom sediments may lead to positive benthic fluxes of Pb at low oxygen environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Automated solid-phase extraction of phenolic acids using layered double hydroxide-alumina-polymer disks.

    PubMed

    Ghani, Milad; Palomino Cabello, Carlos; Saraji, Mohammad; Manuel Estela, Jose; Cerdà, Víctor; Turnes Palomino, Gemma; Maya, Fernando

    2018-01-26

    The application of layered double hydroxide-Al 2 O 3 -polymer mixed-matrix disks for solid-phase extraction is reported for the first time. Al 2 O 3 is embedded in a polymer matrix followed by an in situ metal-exchange process to obtain a layered double hydroxide-Al 2 O 3 -polymer mixed-matrix disk with excellent flow-through properties. The extraction performance of the prepared disks is evaluated as a proof of concept for the automated extraction using sequential injection analysis of organic acids (p-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, gallic acid) following an anion-exchange mechanism. After the solid-phase extraction, phenolic acids were quantified by reversed-phase high-performance liquid chromatography with diode-array detection using a core-shell silica-C18 stationary phase and isocratic elution (acetonitrile/0.5% acetic acid in pure water, 5:95, v/v). High sensitivity and reproducibility were obtained with limits of detection in the range of 0.12-0.25 μg/L (sample volume, 4 mL), and relative standard deviations between 2.9 and 3.4% (10 μg/L, n = 6). Enrichment factors of 34-39 were obtained. Layered double hydroxide-Al 2 O 3 -polymer mixed-matrix disks had an average lifetime of 50 extractions. Analyte recoveries ranged from 93 to 96% for grape juice and nonalcoholic beer samples. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. A new chemistry option in WRF-Chem v. 3.4 for the simulation of direct and indirect aerosol effects using VBS: evaluation against IMPACT-EUCAARI data

    NASA Astrophysics Data System (ADS)

    Tuccella, P.; Curci, G.; Grell, G. A.; Visconti, G.; Crumeyrolle, S.; Schwarzenboeck, A.; Mensah, A. A.

    2015-09-01

    A parameterization for secondary organic aerosol (SOA) production based on the volatility basis set (VBS) approach has been coupled with microphysics and radiative schemes in the Weather Research and Forecasting model with Chemistry (WRF-Chem) model. The new chemistry option called "RACM-MADE-VBS-AQCHEM" was evaluated on a cloud resolving scale against ground-based and aircraft measurements collected during the IMPACT-EUCAARI (Intensive Cloud Aerosol Measurement Campaign - European Integrated project on Aerosol Cloud Climate and Air quality interaction) campaign, and complemented with satellite data from MODIS. The day-to-day variability and the diurnal cycle of ozone (O3) and nitrogen oxides (NOx) at the surface are captured by the model. Surface aerosol mass concentrations of sulfate (SO4), nitrate (NO3), ammonium (NH4), and organic matter (OM) are simulated with correlations larger than 0.55. WRF-Chem captures the vertical profile of the aerosol mass concentration in both the planetary boundary layer (PBL) and free troposphere (FT) as a function of the synoptic condition, but the model does not capture the full range of the measured concentrations. Predicted OM concentration is at the lower end of the observed mass concentrations. The bias may be attributable to the missing aqueous chemistry processes of organic compounds and to uncertainties in meteorological fields. A key role could be played by assumptions on the VBS approach such as the SOA formation pathways, oxidation rate, and dry deposition velocity of organic condensable vapours. Another source of error in simulating SOA is the uncertainties in the anthropogenic emissions of primary organic carbon. Aerosol particle number concentration (condensation nuclei, CN) is overestimated by a factor of 1.4 and 1.7 within the PBL and FT, respectively. Model bias is most likely attributable to the uncertainties of primary particle emissions (mostly in the PBL) and to the nucleation rate. Simulated cloud condensation nuclei (CCN) are also overestimated, but the bias is more contained with respect to that of CN. The CCN efficiency, which is a characterization of the ability of aerosol particles to nucleate cloud droplets, is underestimated by a factor of 1.5 and 3.8 in the PBL and FT, respectively. The comparison with MODIS data shows that the model overestimates the aerosol optical thickness (AOT). The domain averages (for 1 day) are 0.38 ± 0.12 and 0.42 ± 0.10 for MODIS and WRF-Chem data, respectively. The droplet effective radius (Re) in liquid-phase clouds is underestimated by a factor of 1.5; the cloud liquid water path (LWP) is overestimated by a factor of 1.1-1.6. The consequence is the overestimation of average liquid cloud optical thickness (COT) from a few percent up to 42 %. The predicted cloud water path (CWP) in all phases displays a bias in the range +41-80 %, whereas the bias of COT is about 15 %. In sensitivity tests where we excluded SOA, the skills of the model in reproducing the observed patterns and average values of the microphysical and optical properties of liquid and all phase clouds decreases. Moreover, the run without SOA (NOSOA) shows convective clouds with an enhanced content of liquid and frozen hydrometers, and stronger updrafts and downdrafts. Considering that the previous version of WRF-Chem coupled with a modal aerosol module predicted very low SOA content (secondary organic aerosol model (SORGAM) mechanism) the new proposed option may lead to a better characterization of aerosol-cloud feedbacks.

  1. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yokelson, R. J.; Burling, I. R.; Gilman, J. B.

    Vegetative fuels commonly consumed in prescribed fires were collected from five locations in the southeastern and southwestern U.S. and burned in a series of 77 fires at the U.S. Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5) emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC), organic carbon (OC), and 38 elements. The trace gas emissions were measured with a large suite of state-of-the-art instrumentation including an open-path Fourier transform infrared (OP FTIR) spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS), proton-transfer ion-trap mass spectrometry (PIT-MS), negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), and gasmore » chromatography with MS detection (GC-MS). 204 trace gas species (mostly non-methane organic compounds (NMOC)) were identified and quantified with the above instruments. An additional 152 significant peaks in the unit mass resolution mass spectra were quantified, but either could not be identified or most of the signal at that molecular mass was unaccounted for by identifiable species. As phase II of this study, we conducted airborne and ground-based sampling of the emissions from real prescribed fires mostly in the same land management units where the fuels for the lab fires were collected. A broad variety, but smaller number of species (21 trace gas species and PM2.5) was measured on 14 fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. These extensive field measurements of emission factors (EF) for temperate biomass burning are useful both for modeling and to examine the representativeness of our lab fire EF. The lab/field EF ratio for the pine understory fuels was not statistically different from one, on average. However, our lab EF for “smoldering compounds” emitted by burning the semi-arid SW fuels should likely be increased by about a factor of 2.7 to better represent field fires. Based on the lab/field comparison, we present a table with emission factors for 365 pyrogenic species (including unidentified species) for 4 broad fuel types: pine understory, semi-arid shrublands, evergreen canopy, and duff. To our knowledge this is the most complete measurement of biomass burning emissions to date and it should enable improved representation of smoke in atmospheric models. The results provide important insights into the nature of smoke. For example, ~35% (range from 16-71%) of the mass of gas-phase NMOC species was attributed to the species that we could not identify. These unidentified species are likely not represented in most models, but some provision should be made for the fact that they will react in the atmosphere. In addition, the total mass of gas-phase NMOC divided by the mass of co-emitted PM2.5 averaged ~2.6 for the main fire types with a range from ~1.8-8.8. About 36-63% of the NMOC were likely semivolatile or of intermediate volatility. Thus, the gas-phase NMOC represent a large reservoir of potential precursors for secondary formation of organic aerosol. For the one fire in organic soil (Alaskan duff) about 28% of the emitted carbon was present as gas-phase NMOC in contrast to the other fuels for which NMOC accounted for only ~1-3% of emitted carbon. 71% of the mass of NMOC emitted by the smoldering duff was un-identified. The duff results highlight the need to learn more about the emissions from smoldering organic soils. The NMOC/“NOx-as-NO” ratio was consistently about ten for the main fire types when accounting for all NMOC, indicating strongly NOx-limited O3 production conditions. Finally, the fuel consumption per unit area was measured on 6 of the 14 prescribed fires and averaged 7.08 ± 2.09 (1) Mg ha-1.« less

  2. Relative phase of oscillations of cerebral oxy-hemoglobin and deoxy-hemoglobin concentrations during sleep

    NASA Astrophysics Data System (ADS)

    Pierro, Michele L.; Sassaroli, Angelo; Bergethon, Peter R.; Fantini, Sergio

    2012-02-01

    We present a near-infrared spectroscopy study of the instantaneous phase difference between spontaneous oscillations of cerebral deoxy-hemoglobin and oxy-hemoglobin concentrations ([Hb] and [HbO], respectively) in the low-frequency range, namely 0.04-0.12 Hz. We report phase measurements during the transitions between different sleep stages in a whole-night study of a human subject. We have found that the phase difference between [Hb] and [HbO] low-frequency oscillations tends to be greater in deep sleep (by ~96° on average) and REM sleep (by ~77° on average) compared to the awake state. In particular, we have observed progressive phase increases as the subject transitions from awake conditions into non-REM sleep stages N1, N2, and N3. Corresponding phase decreases were recorded in the reversed transitions from sleep stages N3 to N2, and N2 to awake. These results illustrate the physiological information content of phase measurements of [Hb] and [HbO] oscillations that reflect the different cerebral hemodynamic conditions of the different sleep stages, and that can find broader applicability in a wide range of near-infrared spectroscopy brain studies.

  3. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Miyasaka, Hiromasa; Harrison, Fiona A.; Fürst, Felix

    The Nuclear Spectroscopic Telescope Array hard X-ray telescope observed the transient Be/X-ray binary GS 0834–430 during its 2012 outburst—the first active state of this system observed in the past 19 yr. We performed timing and spectral analysis and measured the X-ray spectrum between 3-79 keV with high statistical significance. We find the phase-averaged spectrum to be consistent with that observed in many other magnetized, accreting pulsars. We fail to detect cyclotron resonance scattering features that would allow us to constrain the pulsar's magnetic field in either phase-averaged or phase-resolved spectra. Timing analysis shows a clearly detected pulse period of ∼12.29more » s in all energy bands. The pulse profiles show a strong, energy-dependent hard phase lag of up to 0.3 cycles in phase, or about 4 s. Such dramatic energy-dependent lags in the pulse profile have never before been reported in high-mass X-ray binary pulsars. Previously reported lags have been significantly smaller in phase and restricted to low energies (E < 10 keV). We investigate the possible mechanisms that might produce this energy-dependent pulse phase shift. We find the most likely explanation for this effect is a complex beam geometry.« less

  4. Normative Data for a User-friendly Paradigm for Pattern Electroretinogram Recording

    PubMed Central

    Porciatti, Vittorio; Ventura, Lori M.

    2009-01-01

    Purpose To provide normative data for a user-friendly paradigm for the pattern electroretinogram (PERG) optimized for glaucoma screening (PERGLA). Design Prospective nonrandomized case series. Participants Ninety-three normal subjects ranging in age between 22 and 85 years. Methods A circular black–white grating of 25° visual angle, reversing 16.28 times per second, was presented on a television monitor placed inside a Ganzfeld bowl. The PERG was recorded simultaneously from both eyes with undilated pupils by means of skin cup electrodes taped over the lower eyelids. Reference electrodes were taped on the ipsilateral temples. Electrophysiologic signals were conventionally amplified, filtered, and digitized. Six hundred artifact-free repetitions were averaged. The response component at the reversal frequency was isolated automatically by digital Fourier transforms and was expressed as a deviation from the age-corrected average. The procedure took approximately 4 minutes. Main Outcome Measures Pattern electroretinogram amplitude (μV) and phase (π rad); response variability (coefficient of variation [CV] = standard deviation [SD] / mean × 100) of amplitude and phase of 2 partial averages that build up the PERG waveform; amplitude (μV) of background noise waveform, obtained by multiplying alternate sweeps by +1 and −1; and interocular asymmetry (CV of amplitude and phase of the PERG of the 2 eyes). Results On average, the PERG has a signal-to-noise ratio of more than 13:1. The CVs of intrasession and intersession variabilities in amplitude and phase are lower than 10% and 2%, respectively, and do not depend on the operator. The CV of interocular asymmetries in amplitude and phase are 9.8±8.8% and 1.5±1.4%, respectively. The PERG amplitude and phase decrease with age. Residuals of linear regression lines have normal distribution, with an SD of 0.1 log units for amplitude and 0.019 log units for phase. Age-corrected confidence limits (P<0.05) are defined as ±2 SD of residuals. Conclusions The PERGLA paradigm yields responses as reliable as the best previously reported using standard protocols. The ease of execution and interpretation of results of PERGLA indicate a potential value for objective screening and follow-up of glaucoma. PMID:14711729

  5. Characterization of two-phase flow regimes in horizontal tubes using 81mKr tracer experiments.

    PubMed

    Oriol, Jean; Leclerc, Jean Pierre; Berne, Philippe; Gousseau, Georges; Jallut, Christian; Tochon, Patrice; Clement, Patrice

    2008-10-01

    The diagnosis of heat exchangers on duty with respect to flow mal-distributions needs the development of non-intrusive inlet-outlet experimental techniques in order to perform an online fault diagnosis. Tracer experiments are an example of such techniques. They can be applied to mono-phase heat exchangers but also to multi-phase ones. In this case, the tracer experiments are more difficult to perform. In order to check for the capabilities of tracer experiments to be used for the flow mal-distribution diagnosis in the case of multi-phase heat exchangers, we present here a preliminary study on the simplest possible system: two-phase flows in a horizontal tube. (81m)Kr is used as gas tracer and properly collimated NaI (TI) crystal scintillators as detectors. The specific shape of the tracer response allows two-phase flow regimes to be characterized. Signal analysis allows the estimation of the gas phase real average velocity and consequently of the liquid phase real average velocity as well as of the volumetric void fraction. These results are compared successfully to those obtained with liquid phase tracer experiments previously presented by Oriol et al. 2007. Characterization of the two-phase flow regimes and liquid dispersion in horizontal and vertical tubes using coloured tracer and no intrusive optical detector. Chem. Eng. Sci. 63(1), 24-34, as well as to those given by correlations from literature.

  6. Vibration testing and analysis using holography

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Time average holography is useful in recording steady state vibrational mode patterns. Phase relationships under steady state conditions are measured with real time holography and special phase shifting techniques. Data from Michelson interferometer verify vibration amplitudes from holographic data.

  7. A two-phase micromorphic model for compressible granular materials

    NASA Astrophysics Data System (ADS)

    Paolucci, Samuel; Li, Weiming; Powers, Joseph

    2009-11-01

    We introduce a new two-phase continuum model for compressible granular material based on micromorphic theory and treat it as a two-phase mixture with inner structure. By taking an appropriate number of moments of the local micro scale balance equations, the average phase balance equations result from a systematic averaging procedure. In addition to equations for mass, momentum and energy, the balance equations also include evolution equations for microinertia and microspin tensors. The latter equations combine to yield a general form of a compaction equation when the material is assumed to be isotropic. When non-linear and inertial effects are neglected, the generalized compaction equation reduces to that originally proposed by Bear and Nunziato. We use the generalized compaction equation to numerically model a mixture of granular high explosive and interstitial gas. One-dimensional shock tube and piston-driven solutions are presented and compared with experimental results and other known solutions.

  8. Sensitivity of a fibre scattered-light interferometer to external phase perturbations in an optical fibre

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Alekseev, A E; Potapov, V T; Gorshkov, B G

    2015-10-31

    Sensitivity of a fibre scattered-light interferometer to external phase perturbations is studied for the first time. An expression is derived for an average power of a useful signal at the interferometer output under external harmonic perturbations in a signal fibre of the interferometer. It is shown that the maximum sensitivity of the scattered-light interferometer depends on the dispersion of the interferogram intensity. An average signal-to-noise ratio is determined theoretically and experimentally at the output of the interferometer at different amplitudes of external perturbations. Using the measured dependences of the signal-to-noise ratio, the threshold sensitivity of the fibre scattered-light interferometer tomore » external phase perturbations is found. The results obtained can be used to optimise characteristics of optical time-domain reflectometers and to design individual phase-sensitive fibre-optic sensors. (laser applications and other topics in quantum electronics)« less

  9. Zernike phase-contrast electron cryotomography applied to marine cyanobacteria infected with cyanophages.

    PubMed

    Dai, Wei; Fu, Caroline; Khant, Htet A; Ludtke, Steven J; Schmid, Michael F; Chiu, Wah

    2014-11-01

    Advances in electron cryotomography have provided new opportunities to visualize the internal 3D structures of a bacterium. An electron microscope equipped with Zernike phase-contrast optics produces images with markedly increased contrast compared with images obtained by conventional electron microscopy. Here we describe a protocol to apply Zernike phase plate technology for acquiring electron tomographic tilt series of cyanophage-infected cyanobacterial cells embedded in ice, without staining or chemical fixation. We detail the procedures for aligning and assessing phase plates for data collection, and methods for obtaining 3D structures of cyanophage assembly intermediates in the host by subtomogram alignment, classification and averaging. Acquiring three or four tomographic tilt series takes ∼12 h on a JEM2200FS electron microscope. We expect this time requirement to decrease substantially as the technique matures. The time required for annotation and subtomogram averaging varies widely depending on the project goals and data volume.

  10. FRW cosmological models in Brans-Dicke theory of gravity with variable q and dynamical \\varLambda-term

    NASA Astrophysics Data System (ADS)

    Chand, Avtar; Mishra, R. K.; Pradhan, Anirudh

    2016-02-01

    Exact solution of modified Einstein's field equations are considered within the scope of spatially homogeneous and isotropic Fraidmann-Robertson-Walker (FRW) space-time filled with perfect fluid in the frame work of Brans-Dicke scalar-tensor theory of gravity. In this paper we have investigated the flat, open and closed FRW models and the effect of dynamic cosmological term on the evolution of the universe. Two types of FRW cosmological models are obtained by setting the power law between the scalar field φ and the scale factor a and deceleration parameter (DP) q as a time dependent. The concept of time dependent DP with some proper assumptions yield two type of the average scale factors (i) a(t)=[sinh(α t)]^{1/n} and (ii) a(t)=[t^{α}et]^{1/n}, α and n≠ 0 are arbitrary constants. In case (i), for 0 < n ≤ 1, it generates a class of accelerating models while for n > 1, the models of the universe exhibit phase transition from early decelerating to present accelerating phase and the transition redshift zt has been calculated and found to be in good agreement with the results from recent astrophysical observations. In case (ii), for n ≥ 2 and α = 1, we obtain a class of transit models of the universe from early decelerating to present accelerating phase. Taking into consideration the observational data, we conclude that the cosmological constant behaves as a positive decreasing function of time. The physical and geometric properties of the models are also discussed with the help of graphical presentations.

  11. Emission factors for gaseous and particulate pollutants from offshore diesel engine vessels in China

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Chen, Yingjun; Tian, Chongguo; Lou, Diming; Li, Jun; Zhang, Gan; Matthias, Volker

    2016-05-01

    Shipping emissions have significant influence on atmospheric environment as well as human health, especially in coastal areas and the harbour districts. However, the contribution of shipping emissions on the environment in China still need to be clarified especially based on measurement data, with the large number ownership of vessels and the rapid developments of ports, international trade and shipbuilding industry. Pollutants in the gaseous phase (carbon monoxide, sulfur dioxide, nitrogen oxides, total volatile organic compounds) and particle phase (particulate matter, organic carbon, elemental carbon, sulfates, nitrate, ammonia, metals) in the exhaust from three different diesel-engine-powered offshore vessels in China (350, 600 and 1600 kW) were measured in this study. Concentrations, fuel-based and power-based emission factors for various operating modes as well as the impact of engine speed on emissions were determined. Observed concentrations and emission factors for carbon monoxide, nitrogen oxides, total volatile organic compounds, and particulate matter were higher for the low-engine-power vessel (HH) than for the two higher-engine-power vessels (XYH and DFH); for instance, HH had NOx EF (emission factor) of 25.8 g kWh-1 compared to 7.14 and 6.97 g kWh-1 of DFH, and XYH, and PM EF of 2.09 g kWh-1 compared to 0.14 and 0.04 g kWh-1 of DFH, and XYH. Average emission factors for all pollutants except sulfur dioxide in the low-engine-power engineering vessel (HH) were significantly higher than that of the previous studies (such as 30.2 g kg-1 fuel of CO EF compared to 2.17 to 19.5 g kg-1 fuel in previous studies, 115 g kg-1 fuel of NOx EF compared to 22.3 to 87 g kg-1 fuel in previous studies and 9.40 g kg-1 fuel of PM EF compared to 1.2 to 7.6 g kg-1 fuel in previous studies), while for the two higher-engine-power vessels (DFH and XYH), most of the average emission factors for pollutants were comparable to the results of the previous studies, engine type was one of the most important influence factors for the differences. Emission factors for all three vessels were significantly different during different operating modes. Organic carbon and elemental carbon were the main components of particulate matter, while water-soluble ions and elements were present in trace amounts. The test inland ships and some test offshore vessels in China always had higher EFs for CO, NOx, and PM than previous studies. Besides, due to the significant influence of engine type on shipping emissions and that no accurate local EFs could be used in inventory calculation, much more measurement data for different vessels in China are still in urgent need. Best-fit engine speeds during actual operation should be based on both emission factors and economic costs.

  12. FEL system with homogeneous average output

    DOEpatents

    Douglas, David R.; Legg, Robert; Whitney, R. Roy; Neil, George; Powers, Thomas Joseph

    2018-01-16

    A method of varying the output of a free electron laser (FEL) on very short time scales to produce a slightly broader, but smooth, time-averaged wavelength spectrum. The method includes injecting into an accelerator a sequence of bunch trains at phase offsets from crest. Accelerating the particles to full energy to result in distinct and independently controlled, by the choice of phase offset, phase-energy correlations or chirps on each bunch train. The earlier trains will be more strongly chirped, the later trains less chirped. For an energy recovered linac (ERL), the beam may be recirculated using a transport system with linear and nonlinear momentum compactions M.sub.56, which are selected to compress all three bunch trains at the FEL with higher order terms managed.

  13. HeLa cells response to photodynamic treatment with Radachlorin at various irradiation parameters

    NASA Astrophysics Data System (ADS)

    Belashov, A. V.; Zhikhoreva, A. A.; Belyaeva, T. N.; Kornilova, E. S.; Petrov, N. V.; Salova, A. V.; Semenova, I. V.; Vasyutinskii, O. S.

    2017-07-01

    Measurements of average phase shifts introduced by living HeLa cells to probe wave front were carried out. Variations of this value were monitored in the course of morphological changes caused by photodynamic treatment at various irradiation doses. Observations of changes in living cells were also performed by means of far field optical microscopy and confocal fluorescent microscopy. Quantitative analysis of the data obtained shows that average phase shift introduced by the cells may either increase or decrease depending upon major parameters of the treatment.

  14. Figures of Merit for Magnetic Recording Media

    NASA Astrophysics Data System (ADS)

    Skomski, Ralph; Sellmyer, D. J.

    2007-03-01

    Since the first nucleation-field calculations for hard-soft nanostructures with multilayered [1] and arbitrary [2] geometries, exchange-spring magnets have attracted much attention in various areas of magnetism, including magnetic recording. Ultrahigh storage densities correspond to the strong-coupling limit, realized on small length scales and described by volume-averaged anisotropies. Second-order perturbation theory yields finite-size corrections that describe a partial decoupling of the phases. Since soft phases reduce the nucleation field, nanostructuring can be used to reduce the coercivity Hc while maintaining the energy barrier EB. However, the ratio EB/Hc is an ill-defined figure of merit, because the comparison with the Stoner-Wohlfarth model requires the introduction of a particle volume, as contrasted to an area. By using elongated particles with a continuous anisotropy gradient, it is possible to reduce the coercivity by a factor scaling as the bit size divided by the domain-wall width of the hard phase. However, with decreasing bit size this effect becomes less pronounced. In the strong-coupling limit, thermal stability yields a maximum storage density of order γ/kBT, where γ is the domain-wall energy of the hard phase. - This research is supported by NSF MRSEC, INSIC, and NCMN. [1] S. Nieber and H. Kronm"uller, phys. stat. sol. (b) 153, 367 (1989). [2] R. Skomski and J. M. D. Coey, Phys. Rev. B 48, 15812 (1993).

  15. 40 CFR 80.825 - How is the refinery or importer annual average toxics value determined?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... number of batches of gasoline produced or imported during the averaging period. i = Individual batch of... toxics value, Ti, of each batch of gasoline is determined using the Phase II Complex Model specified at...

  16. Project report : road weather information system phase II & IIb

    DOT National Transportation Integrated Search

    1997-09-15

    Data were collected on route choice and travel habits in the Lexington, Kentucky metropolitan area. The sample comprised 100 households, with the average household size 2.94 persons and with an average of 2.17 vehicles. This research project configur...

  17. Integration of Fixed and Flexible Route Public Transportation Systems, Phase II

    DOT National Transportation Integrated Search

    2012-01-01

    Conventional bus service (with fixed routes and schedules) has lower average cost than flexible bus service (with : demand-responsive routes) at high demand densities. At low demand densities flexible bus service has lower : average costs and provide...

  18. Real-world volatile organic compound emission rates from seated adults and children for use in indoor air studies.

    PubMed

    Stönner, C; Edtbauer, A; Williams, J

    2018-01-01

    Human beings emit many volatile organic compounds (VOCs) of both endogenous (internally produced) and exogenous (external source) origin. Here we present real-world emission rates of volatile organic compounds from cinema audiences (50-230 people) as a function of time in multiple screenings of three films. The cinema location and film selection allowed high-frequency measurement of human-emitted VOCs within a room flushed at a known rate so that emissions rates could be calculated for both adults and children. Gas-phase emission rates are analyzed as a function of time of day, variability during the film, and age of viewer. The average emission rates of CO 2 , acetone, and isoprene were lower (by a factor of ~1.2-1.4) for children under twelve compared to adults while for acetaldehyde emission rates were equivalent. Molecules influenced by exogenous sources such as decamethylcyclopentasiloxanes and methanol tended to decrease over the course of day and then rise for late evening screenings. These results represent average emission rates of people under real-world conditions and can be used in indoor air quality assessments and building design. Averaging over a large number of people generates emission rates that are less susceptible to individual behaviors. © 2017 The Authors. Indoor Air published by John Wiley & Sons Ltd.

  19. SU-G-JeP3-14: Positioning and Dosimetric Uncertainties in Image-Guided Radiation Therapy with Respiratory Gating

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ali, I; Hossain, S; Algan, O

    Purpose: To investigate quantitatively positioning and dosimetric uncertainties due to 4D-CT intra-phase motion in the internal-target-volume (ITV) associated with radiation therapy using respiratory-gating for patients setup with image-guidance-radiation-therapy (IGRT) using free-breathing or average-phase CT-images. Methods: A lung phantom with an embedded tissue-equivalent target is imaged with CT while it is stationary and moving. Four-sets of structures are outlined: (a) the actual target on CT-images of the stationary-target, (b) ITV on CT-images for the free-moving phantom, (c) ITV’s from the ten different phases (10–100%) and (d) ITV on the CT-images generated from combining 3 phases: 40%–50%–60%. The variations in volume, lengthmore » and center-position of the ITV’s and their effects on dosimetry during dose delivery for patients setup with image-guidance are investigated. Results: Intra-phase motion due to breathing affects the volume, center position and length of the ITVs from different respiratory-phases. The ITV’s vary by about 10% from one phase to another. The largest ITV is measured on the free breathing CT images and the smallest is on the stationary CT-images. The ITV lengths vary by about 4mm where it may shrink or elongated depending on the motion-phase. The center position of the ITV varies between the different motion-phases which shifts upto 10mm from the stationary-position which is nearly equal to motion-amplitude. This causes systematic shifts during dose delivery with beam gating using certain phases (40%–50%–60%) for patients setup with IGRT using free-breathing or average-phase CT-images. The dose coverage of the ITV depends on the margins used for treatment-planning-volume where margins larger than the motion-amplitudes are needed to ensure dose coverage of the ITV. Conclusion: Volume, length, and center position of the ITV’s change between the different motion phases. Large systematic shifts are induced by respiratory-gating with ITVs on certain phases when patients are setup with IGRT using free-breathing or average-phase CT-images.« less

  20. A Biomechanical Analysis of the Effects of Bouncing the Barbell in the Conventional Deadlift.

    PubMed

    Krajewski, Kellen; LeFavi, Robert; Riemann, Bryan

    2018-02-27

    The purpose of this study is to analyze biomechanical differences between the bounce and pause styles of deadlifting. Twenty physically active males performed deadlifts at their 75% one repetition maximum testing utilizing both pause and bounce techniques in a within-subjects randomized study design. The average peak height the barbell attained from the three bounce style repetitions was used to compute a compatible phase for analysis of the pause style repetitions. Net joint moment impulse (NJMI), work, average vertical ground reaction force (vGRF), vGRF impulse and phase time were computed for two phases, lift off to peak barbell height and the entire ascent. Additionally, the ankle, knee, hip, and trunk angles at the location of peak barbell height. During the lift off to peak barbell height phase, although each of the joints demonstrated significantly less NJMI and work during the bounce style, the hip joint was impacted the most. The average vGRF was greater for the bounce however the vGRF impulse was greater for the pause. The NJMI results for the ascent phase were similar to the lift off to peak barbell height phase, while work was significantly less for the bounce condition compared to the pause condition across all three joints. Strength and conditioning specialists utilizing the deadlift should be aware that the bounce technique does not allow the athlete to develop maximal force production in the early portion of the lift. Further analyses should focus on joint angles and potential vulnerability to injury when the barbell momentum generated from the bounce is lost.

  1. Rehabilitation needs and participation restriction in patients with cognitive disorder in the chronic phase of traumatic brain injury

    PubMed Central

    Sashika, Hironobu; Takada, Kaoruko; Kikuchi, Naohisa

    2017-01-01

    Abstract The purpose of this study was to clarify psychosocial factors/problems, social participation, quality of life (QOL), and rehabilitation needs in chronic-phase traumatic brain injury (TBI) patients with cognitive disorder discharged from the level-1 trauma center (L1-TC), and to inspect the effects of rehabilitation intervention to these subjects. A mixed-method research (cross-sectional and qualitative study) was conducted at an outpatient rehabilitation department. Inclusion criteria of subjects were transfer to the L1-TC due to TBI; acute-stage rehabilitation treatment received in the L1-TC from November 2006 to October 2011; age of ≥18 and <70 years at the time of injury; a score of 0–3 on the Modified Rankin Scale at discharge and that of 4–5 due to physical or severe aggressive behavioral comorbid disorders. Study details were sent, via mail, to 84 suitable candidates, of whom 36 replied. Thirty-one subjects (median age: 33.4 years; male: 17; and average time since injury: 48.1 months), who had consented to study participation, were participated. Cognitive function, social participation, QOL, psychosocial factors/problems, rehabilitation needs, and chronic-phase rehabilitation outcomes were evaluated using the Wechsler Adult Intelligence Scale, Third Edition, the Wechsler Memory Scale-Revised, the Zung Self-Rating Depression Scale, the Sydney Psychosocial Reintegration Scale, Version 2, and the Short Form 36, Version 2, qualitative analysis of semistructured interviews, etc. Participants were classified into achieved-social-participation (n = 11; employed: 8), difficult-social-participation (n = 12; unemployed: 8), and no-cognitive-dysfunction groups (n = 8; no social participation restriction). Relative to the achieved-social-participation group, the difficult-social-participation group showed greater injury and cognitive dysfunction and lower Sydney Psychosocial Reintegration Scale and Short Form 36 role/social component summary scores (64.9/49.1 vs 44.3/30.4, respectively, P < 0.05). Linear regression analysis showed that the social participation status was greatly affected by the later cognitive disorders and psychosocial factors/problems not by the severity of TBI. No changes were observed in these scores following chronic-phase rehabilitation intervention. Chronic-phase TBI with cognitive disorder led to rehabilitation needs, and improvement of subjects’ psychosocial problems and QOL was difficult. PMID:28121947

  2. Rehabilitation needs and participation restriction in patients with cognitive disorder in the chronic phase of traumatic brain injury.

    PubMed

    Sashika, Hironobu; Takada, Kaoruko; Kikuchi, Naohisa

    2017-01-01

    The purpose of this study was to clarify psychosocial factors/problems, social participation, quality of life (QOL), and rehabilitation needs in chronic-phase traumatic brain injury (TBI) patients with cognitive disorder discharged from the level-1 trauma center (L1-TC), and to inspect the effects of rehabilitation intervention to these subjects.A mixed-method research (cross-sectional and qualitative study) was conducted at an outpatient rehabilitation department.Inclusion criteria of subjects were transfer to the L1-TC due to TBI; acute-stage rehabilitation treatment received in the L1-TC from November 2006 to October 2011; age of ≥18 and <70 years at the time of injury; a score of 0-3 on the Modified Rankin Scale at discharge and that of 4-5 due to physical or severe aggressive behavioral comorbid disorders. Study details were sent, via mail, to 84 suitable candidates, of whom 36 replied. Thirty-one subjects (median age: 33.4 years; male: 17; and average time since injury: 48.1 months), who had consented to study participation, were participated. Cognitive function, social participation, QOL, psychosocial factors/problems, rehabilitation needs, and chronic-phase rehabilitation outcomes were evaluated using the Wechsler Adult Intelligence Scale, Third Edition, the Wechsler Memory Scale-Revised, the Zung Self-Rating Depression Scale, the Sydney Psychosocial Reintegration Scale, Version 2, and the Short Form 36, Version 2, qualitative analysis of semistructured interviews, etc.Participants were classified into achieved-social-participation (n = 11; employed: 8), difficult-social-participation (n = 12; unemployed: 8), and no-cognitive-dysfunction groups (n = 8; no social participation restriction). Relative to the achieved-social-participation group, the difficult-social-participation group showed greater injury and cognitive dysfunction and lower Sydney Psychosocial Reintegration Scale and Short Form 36 role/social component summary scores (64.9/49.1 vs 44.3/30.4, respectively, P < 0.05). Linear regression analysis showed that the social participation status was greatly affected by the later cognitive disorders and psychosocial factors/problems not by the severity of TBI. No changes were observed in these scores following chronic-phase rehabilitation intervention.Chronic-phase TBI with cognitive disorder led to rehabilitation needs, and improvement of subjects' psychosocial problems and QOL was difficult.

  3. Quantification of wall shear stress in large blood vessels using Lagrangian interpolation functions with cine phase-contrast magnetic resonance imaging.

    PubMed

    Cheng, Christopher P; Parker, David; Taylor, Charles A

    2002-09-01

    Arterial wall shear stress is hypothesized to be an important factor in the localization of atherosclerosis. Current methods to compute wall shear stress from magnetic resonance imaging (MRI) data do not account for flow profiles characteristic of pulsatile flow in noncircular vessel lumens. We describe a method to quantify wall shear stress in large blood vessels by differentiating velocity interpolation functions defined using cine phase-contrast MRI data on a band of elements in the neighborhood of the vessel wall. Validation was performed with software phantoms and an in vitro flow phantom. At an image resolution corresponding to in vivo imaging data of the human abdominal aorta, time-averaged, spatially averaged wall shear stress for steady and pulsatile flow were determined to be within 16% and 23% of the analytic solution, respectively. These errors were reduced to 5% and 8% with doubling in image resolution. For the pulsatile software phantom, the oscillation in shear stress was predicted to within 5%. The mean absolute error of circumferentially resolved shear stress for the nonaxisymmetric phantom decreased from 28% to 15% with a doubling in image resolution. The irregularly shaped phantom and in vitro investigation demonstrated convergence of the calculated values with increased image resolution. We quantified the shear stress at the supraceliac and infrarenal regions of a human abdominal aorta to be 3.4 and 2.3 dyn/cm2, respectively.

  4. Independence of amplitude-frequency and phase calibrations in an SSVEP-based BCI using stepping delay flickering sequences.

    PubMed

    Chang, Hsiang-Chih; Lee, Po-Lei; Lo, Men-Tzung; Lee, I-Hui; Yeh, Ting-Kuang; Chang, Chun-Yen

    2012-05-01

    This study proposes a steady-state visual evoked potential (SSVEP)-based brain-computer interface (BCI) independent of amplitude-frequency and phase calibrations. Six stepping delay flickering sequences (SDFSs) at 32-Hz flickering frequency were used to implement a six-command BCI system. EEG signals recorded from Oz position were first filtered within 29-35 Hz, segmented based on trigger events of SDFSs to obtain SDFS epochs, and then stored separately in epoch registers. An epoch-average process suppressed the inter-SDFS interference. For each detection point, the latest six SDFS epochs in each epoch register were averaged and the normalized power of averaged responses was calculated. The visual target that induced the maximum normalized power was identified as the visual target. Eight subjects were recruited in this study. All subjects were requested to produce the "563241" command sequence four times. The averaged accuracy, command transfer interval, and information transfer rate (mean ± std.) values for all eight subjects were 97.38 ± 5.97%, 3.56 ± 0.68 s, and 42.46 ± 11.17 bits/min, respectively. The proposed system requires no calibration in either the amplitude-frequency characteristic or the reference phase of SSVEP which may provide an efficient and reliable channel for the neuromuscular disabled to communicate with external environments.

  5. Wavelet assessment of cerebrospinal compensatory reserve and cerebrovascular pressure reactivity

    NASA Astrophysics Data System (ADS)

    Latka, M.; Turalska, M.; Kolodziej, W.; Latka, D.; West, B.

    2006-03-01

    We employ complex continuous wavelet transforms to develop a consistent mathematical framework capable of quantifying both cerebrospinal compensatory reserve and cerebrovascular pressure--reactivity. The wavelet gain, defined as the frequency dependent ratio of time averaged wavelet coefficients of intracranial (ICP) and arterial blood pressure (ABP) fluctuations, characterizes the dampening of spontaneous arterial blood oscillations. This gain is introduced as a novel measure of cerebrospinal compensatory reserve. For a group of 10 patients who died as a result of head trauma (Glasgow Outcome Scale GOS =1) the average gain is 0.45 calculated at 0.05 Hz significantly exceeds that of 16 patients with favorable outcome (GOS=2): with gain of 0.24 with p=4x10-5. We also study the dynamics of instantaneous phase difference between the fluctuations of the ABP and ICP time series. The time-averaged synchronization index, which depends upon frequency, yields the information about the stability of the phase difference and is used as a cerebrovascular pressure--reactivity index. The average phase difference for GOS=1 is close to zero in sharp contrast to the mean value of 30^o for patients with GOS=2. We hypothesize that in patients who died the impairment of cerebral autoregulation is followed by the break down of residual pressure reactivity.

  6. 25 CFR 39.230 - How will the provisions of this subpart be phased in?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... SCHOOL EQUALIZATION PROGRAM Administrative Procedures, Student Counts, and Verifications Phase-in Period... rolling average of ADM for each school and for the entire Bureau-funded school system will be phased-in as shown in the following table. Time period How OIEP must calculate ADM (a) First school year after May 31...

  7. 26 CFR 1.861-13T - Transition rules for interest expenses (temporary regulations).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...-in fraction is the general phase-in amount over the current year average debt level of the affiliated... pro rata by the relative amount of interest expense that is directly allocated. (b) General phase-in... does not exceed the general phase-in amount, as defined in paragraph (b)(2) of this section. (2...

  8. 26 CFR 1.861-13T - Transition rules for interest expenses (temporary regulations).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...-in fraction is the general phase-in amount over the current year average debt level of the affiliated... pro rata by the relative amount of interest expense that is directly allocated. (b) General phase-in... does not exceed the general phase-in amount, as defined in paragraph (b)(2) of this section. (2...

  9. [Concentrations and influencing factors of gaseous polycyclic aromatic hydrocarbons in residential air in Beijing].

    PubMed

    Wei, Zhi-cheng; Chang, Biao; Qiu, Wei-xun; Wang, Yi; Wu, Shi-min; Xing, Bao-shan; Liu, Wen-xin; Tao, Shu

    2007-09-01

    7 gas phase PAHs components in indoor air collected from 38 families were investigated by modified passive air samplers in Beijing areas during the local heating and non-heating seasons, and the influencing factors were discussed as well. The analytical results indicate that the gasous PAHs in local indoor air are dominated by 2 and 3 rings compounds, the mean concentrations for the 7 individual gaseous components range from 1 to 40 ng/m3, and the average concentration of total gaseous PAHs is about 100 ng/m3. There is no significant difference in total gaseous PAHs concentrations between the heating and the non-heating seasons, while some apparent seasonal changes occur in ACY and FLA concentrations. Compared with heating season, contribution of 2 rings compounds decreases while the proportions of 3 and 4 rings species increase during the non-heating season. Based on household activity questionnaires and actual analytical concentrations, the main influencing factors accounted for gaseous PAHs in indoor air, identified by multifactor analysis of variance, include cigarette smoking, use of moth ball, intensity of draft, cuisine frequency and built age.

  10. A software to measure phase-velocity dispersion from ambient-noise correlations and its application to the SNSN data

    NASA Astrophysics Data System (ADS)

    Sadeghisorkhani, Hamzeh; Gudmundsson, Ólafur

    2017-04-01

    Graphical software for phase-velocity dispersion measurements of surface waves in noise-correlation traces, called GSpecDisp, is presented. It is an interactive environment for the measurements and presentation of the results. It measures phase-velocity dispersion curves in the frequency domain based on matching of the real part of the cross-correlation spectrum with the appropriate Bessel function. The inputs are time-domain cross-correlations in SAC format. It can measure two types of phase-velocity dispersion curves; 1- average phase-velocity of a region, and 2- single-pair phase velocity. The average phase-velocity dispersion curve of a region can be used as a reference curve to automatically select the dispersion curves from each single-pair cross-correlation in that region. It also allows the users to manually refine the selections. Therefore, no prior knowledge is needed for an unknown region. GSpecDisp can measure the phase velocity of Rayleigh and Love waves from all possible components of the noise correlation tensor, including diagonal and off-diagonal components of the tensor. First, we explain how GSpecDisp is applied to measure phase-velocity dispersion curves. Then, we demonstrate measurement results on synthetic and real data from the Swedish National Seismic Network (SNSN). We compare the results with two other methods of phase-velocity dispersion measurements. Finally, we compare phase-velocity dispersion curves of Rayleigh waves obtained from different components of the correlation tensor.

  11. Performance prediction using geostatistics and window reservoir simulation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fontanilla, J.P.; Al-Khalawi, A.A.; Johnson, S.G.

    1995-11-01

    This paper is the first window model study in the northern area of a large carbonate reservoir in Saudi Arabia. It describes window reservoir simulation with geostatistics to model uneven water encroachment in the southwest producing area of the northern portion of the reservoir. In addition, this paper describes performance predictions that investigate the sweep efficiency of the current peripheral waterflood. A 50 x 50 x 549 (240 m. x 260 m. x 0.15 m. average grid block size) geological model was constructed with geostatistics software. Conditional simulation was used to obtain spatial distributions of porosity and volume of dolomite.more » Core data transforms were used to obtain horizontal and vertical permeability distributions. Simple averaging techniques were used to convert the 549-layer geological model to a 50 x 50 x 10 (240 m. x 260 m. x 8 m. average grid block size) window reservoir simulation model. Flux injectors and flux producers were assigned to the outermost grid blocks. Historical boundary flux rates were obtained from a coarsely-ridded full-field model. Pressure distribution, water cuts, GORs, and recent flowmeter data were history matched. Permeability correction factors and numerous parameter adjustments were required to obtain the final history match. The permeability correction factors were based on pressure transient permeability-thickness analyses. The prediction phase of the study evaluated the effects of infill drilling, the use of artificial lifts, workovers, horizontal wells, producing rate constraints, and tight zone development to formulate depletion strategies for the development of this area. The window model will also be used to investigate day-to-day reservoir management problems in this area.« less

  12. Long-term response of total ozone content at different latitudes of the Northern and Southern Hemispheres caused by solar activity during 1958-2006 (results of regression analysis)

    NASA Astrophysics Data System (ADS)

    Krivolutsky, Alexei A.; Nazarova, Margarita; Knyazeva, Galina

    Solar activity influences on atmospheric photochemical system via its changebale electromag-netic flux with eleven-year period and also by energetic particles during solar proton event (SPE). Energetic particles penetrate mostly into polar regions and induce additional produc-tion of NOx and HOx chemical compounds, which can destroy ozone in photochemical catalytic cycles. Solar irradiance variations cause in-phase variability of ozone in accordance with photo-chemical theory. However, real ozone response caused by these two factors, which has different physical nature, is not so clear on long-term time scale. In order to understand the situation multiply linear regression statistical method was used. Three data series, which covered the period 1958-2006, have been used to realize such analysis: yearly averaged total ozone at dif-ferent latitudes (World Ozone Data Centre, Canada, WMO); yearly averaged proton fluxes with E¿ 10 MeV ( IMP, GOES, METEOR satellites); yearly averaged numbers of solar spots (Solar Data). Then, before the analysis, the data sets of ozone deviations from the mean values for whole period (1958-2006) at each latitudinal belt were prepared. The results of multiply regression analysis (two factors) revealed rather complicated time-dependent behavior of ozone response with clear negative peaks for the years of strong SPEs. The magnitudes of such peaks on annual mean basis are not greater than 10 DU. The unusual effect -positive response of ozone to solar proton activity near both poles-was discovered by statistical analysis. The pos-sible photochemical nature of found effect is discussed. This work was supported by Russian Science Foundation for Basic Research (grant 09-05-009949) and by the contract 1-6-08 under Russian Sub-Program "Research and Investigation of Antarctica".

  13. Analysis of high mass resolution PTR-TOF mass spectra from 1,3,5-trimethylbenzene (TMB) environmental chamber experiments

    NASA Astrophysics Data System (ADS)

    Müller, M.; Graus, M.; Wisthaler, A.; Hansel, A.; Metzger, A.; Dommen, J.; Baltensperger, U.

    2011-09-01

    A series of 1,3,5-trimethylbenzene (TMB) photo-oxidation experiments was performed in the 27-m3 Paul Scherrer Institute environmental chamber under various NOx conditions. A University of Innsbruck prototype high resolution Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-TOF) was used for measurements of gas and particulate phase organics. The gas phase mass spectrum displayed ~200 ion signals during the TMB photo-oxidation experiments. Molecular formulas CNmHnNoOp were determined and ion signals were separated and grouped according to their C, O and N numbers. This allowed to determine the time evolution of the O:C ratio and of the average carbon oxidation state OSC of the reaction mixture. Both quantities were compared with master chemical mechanism (MCMv3.1) simulations. The O:C ratio in the particle phase was about twice the O:C ratio in the gas phase. Average carbon oxidation states of secondary organic aerosol (SOA) samples OSCSOA were in the range of -0.34 to -0.31, in agreement with expected average carbon oxidation states of fresh SOA (OSC = -0.5 - 0).

  14. Analysis of high mass resolution PTR-TOF mass spectra from 1,3,5-trimethylbenzene (TMB) environmental chamber experiments

    NASA Astrophysics Data System (ADS)

    Müller, M.; Graus, M.; Wisthaler, A.; Hansel, A.; Metzger, A.; Dommen, J.; Baltensperger, U.

    2012-01-01

    A series of 1,3,5-trimethylbenzene (TMB) photo-oxidation experiments was performed in the 27-m3 Paul Scherrer Institute environmental chamber under various NOx conditions. A University of Innsbruck prototype high resolution Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-TOF) was used for measurements of gas and particulate phase organics. The gas phase mass spectrum displayed ~200 ion signals during the TMB photo-oxidation experiments. Molecular formulas CmHnNoOp were determined and ion signals were separated and grouped according to their C, O and N numbers. This allowed to determine the time evolution of the O:C ratio and of the average carbon oxidation state OSC of the reaction mixture. Both quantities were compared with master chemical mechanism (MCMv3.1) simulations. The O:C ratio in the particle phase was about twice the O:C ratio in the gas phase. Average carbon oxidation states of secondary organic aerosol (SOA) samples OSCSOA were in the range of -0.34 to -0.31, in agreement with expected average carbon oxidation states of fresh SOA (OSC = -0.5-0).

  15. Development of High-Fill-Factor Large-Aperture Micromirrors for Agile Optical Phased Arrays

    DTIC Science & Technology

    2010-02-28

    Final Project Report Contract/Grant Title: Development of High-Fill-Factor Large-Aperture Micromirrors for Agile Optical Phased Arrays...factor (HFF) micromirror array (MMA) has been proposed, fabricated and tested. Optical-phased-array (OPA) beam steering based on the HFF MMA has also...electrically tuned to multiple 2. 1. Background High-fill-factor (HFF) micromirror arrays (MMAs) can form optical phased arrays (OPAs) for laser beam

  16. The X-ray absorption spectrum of 4U1700-37 and its implications for the stellar wind of the companion HD153919

    NASA Technical Reports Server (NTRS)

    White, N. E.; Kallman, T. R.; Swank, J. H.

    1982-01-01

    The first high resolution non-dispersive 2-60 KeV X-ray spectra of 4U1700-37 is presented. The continuum is typical of that found from X-ray pulsars; that is a flat power law between 2 and 10 keV and, beyond 10 keV, an exponential decay of characteristic energy varying between 10 and 20 keV. No X-ray pulsations were detected between 160 ms and 6 min with an amplitude greater than approximately 2%. The absorption measured at binary phases approximately 0.72 is comparable to that expected from the stellar wind of the primary. The gravitational capture of material in the wind is found to be more than enough to power the X-ray source. The increase in the average absorption after phi o approximately 0.5 is confirmed. The minimum level of adsorption is a factor of 2 or 3 lower than that reported by previous observers, which may be related to a factor of approximately 10 decline in the average X-ray luminosity over the same interval. Short term approximately 50% variations in adsorption are seen for the first time which appear to be loosely correlated with approximately 10 min flickering activity in the X-ray flux. These most likely originate from inhomogeneities in the stellar wind of the primary.

  17. Gait Phase Recognition for Lower-Limb Exoskeleton with Only Joint Angular Sensors

    PubMed Central

    Liu, Du-Xin; Wu, Xinyu; Du, Wenbin; Wang, Can; Xu, Tiantian

    2016-01-01

    Gait phase is widely used for gait trajectory generation, gait control and gait evaluation on lower-limb exoskeletons. So far, a variety of methods have been developed to identify the gait phase for lower-limb exoskeletons. Angular sensors on lower-limb exoskeletons are essential for joint closed-loop controlling; however, other types of sensors, such as plantar pressure, attitude or inertial measurement unit, are not indispensable.Therefore, to make full use of existing sensors, we propose a novel gait phase recognition method for lower-limb exoskeletons using only joint angular sensors. The method consists of two procedures. Firstly, the gait deviation distances during walking are calculated and classified by Fisher’s linear discriminant method, and one gait cycle is divided into eight gait phases. The validity of the classification results is also verified based on large gait samples. Secondly, we build a gait phase recognition model based on multilayer perceptron and train it with the phase-labeled gait data. The experimental result of cross-validation shows that the model has a 94.45% average correct rate of set (CRS) and an 87.22% average correct rate of phase (CRP) on the testing set, and it can predict the gait phase accurately. The novel method avoids installing additional sensors on the exoskeleton or human body and simplifies the sensory system of the lower-limb exoskeleton. PMID:27690023

  18. Electron backscatter diffraction studies of focused ion beam induced phase transformation in cobalt

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jones, H.G., E-mail: helen.jones@npl.co.uk

    A focused ion beam microscope was used to induce cubic to hexagonal phase transformation in a cobalt alloy, of similar composition to that of the binder phase in a hardmetal, in a controlled manner at 0°, 45° and 80° ion incident angles. The cobalt had an average grain size of ~ 20 μm, allowing multiple orientations to be studied, exposed to a range of doses between 6 × 10{sup 7} and 2 × 10{sup 10} ions/μm{sup 2}. Electron backscatter diffraction (EBSD) was used to determine the original and induced phase orientations, and area fractions, before and after the ion beammore » exposure. On average, less phase transformation was observed at higher incident angles and after lower ion doses. However there was an orientation effect where grains with an orientation close to (111) planes were most susceptible to phase transformation, and (101) the least, where grains partially and fully transformed at varying ion doses. - Highlights: •Ion-induced phase change in FCC cobalt was observed at multiple incidence angles. •EBSD was used to study the relationship between grain orientation and transformation. •Custom software analysed ion dose and phase change with respect to grain orientation. •A predictive capability of ion-induced phase change in cobalt was enabled.« less

  19. Phase Inversion: Inferring Solar Subphotospheric Flow and Other Asphericity from the Distortion of Acoustic Waves

    NASA Technical Reports Server (NTRS)

    Gough, Douglas; Merryfield, William J.; Toomre, Juri

    1998-01-01

    A method is proposed for analyzing an almost monochromatic train of waves propagating in a single direction in an inhomogeneous medium that is not otherwise changing in time. An effective phase is defined in terms of the Hilbert transform of the wave function, which is related, via the JWKB approximation, to the spatial variation of the background state against which the wave is propagating. The contaminating effect of interference between the truly monochromatic components of the train is eliminated using its propagation properties. Measurement errors, provided they are uncorrelated, are manifest as rapidly varying noise; although that noise can dominate the raw phase-processed signal, it can largely be removed by low-pass filtering. The intended purpose of the analysis is to determine the distortion of solar oscillations induced by horizontal structural variation and material flow. It should be possible to apply the method directly to sectoral modes. The horizontal phase distortion provides a measure of longitudinally averaged properties of the Sun in the vicinity of the equator, averaged also in radius down to the depth to which the modes penetrate. By combining such averages from different modes, the two-dimensional variation can be inferred by standard inversion techniques. After taking due account of horizontal refraction, it should be possible to apply the technique also to locally sectoral modes that propagate obliquely to the equator and thereby build a network of lateral averages at each radius, from which the full three-dimensional structure of the Sun can, in principle, be determined as an inverse Radon transform.

  20. Analysis of phase II studies on targeted agents and subsequent phase III trials: what are the predictors for success?

    PubMed

    Chan, John K; Ueda, Stefanie M; Sugiyama, Valerie E; Stave, Christopher D; Shin, Jacob Y; Monk, Bradley J; Sikic, Branimir I; Osann, Kathryn; Kapp, Daniel S

    2008-03-20

    To identify the characteristics of phase II studies that predict for subsequent "positive" phase III trials (those that reached the proposed primary end points of study or those wherein the study drug was superior to the standard regimen investigating targeted agents in advanced tumors. We identified all phase III clinical trials of targeted therapies against advanced cancers published from 1985 to 2005. Characteristics of the preceding phase II studies were reviewed to identify predictive factors for success of the subsequent phase III trial. Data were analyzed using the chi(2) test and logistic regression models. Of 351 phase II studies, 167 (47.6%) subsequent phase III trials were positive and 184 (52.4%) negative. Phase II studies from multiple rather than single institutions were more likely to precede a successful trial (60.4% v 39.4%; P < .001). Positive phase II results were more likely to lead to a successful phase III trial (50.8% v 22.5%; P = .003). The percentage of successful trials from pharmaceutical companies was significantly higher compared with academic, cooperative groups, and research institutes (89.5% v 44.2%, 45.2%, and 46.3%, respectively; P = .002). On multivariate analysis, these factors and shorter time interval between publication of phase II results and III study publication were independent predictive factors for a positive phase III trial. In phase II studies of targeted agents, multiple- versus single-institution participation, positive phase II trial, pharmaceutical company-based trials, and shorter time period between publication of phase II to phase III trial were independent predictive factors of success in a phase III trial. Investigators should be cognizant of these factors in phase II studies before designing phase III trials.

  1. Ionic liquid phases with comprehensive two-dimensional gas chromatography of fatty acid methyl esters.

    PubMed

    Pojjanapornpun, Siriluck; Nolvachai, Yada; Aryusuk, Kornkanok; Kulsing, Chadin; Krisnangkura, Kanit; Marriott, Philip J

    2018-02-17

    New generation inert ionic liquid (iIL) GC columns IL60i, IL76i and IL111i, comprising phosphonium or imidazolium cationic species, were investigated for separation of fatty acid methyl esters (FAME). In general, the iIL phases provide comparable retention times to their corresponding conventional columns, with only minor selectivity differences. The average tailing factors and peak widths were noticeably improved (reduced) for IL60i and IL76i, while they were slightly improved for IL111i. Inert IL phase columns were coupled with conventional IL columns in comprehensive two-dimensional GC (GC × GC) with a solid-state modulator which offers variable modulation temperature (T M ), programmable T M during analysis and trapping stationary phase material during the trap/release (modulation) process, independent of oven T and column sets. Although IL phases are classified as polar, relative polarity of the two phases comprising individual GC × GC column sets permits combination of less-polar IL/polar IL and polar IL/less-polar IL column sets; it was observed that a polar/less-polar column set provided better separation of FAME. A higher first dimension ( 1 D) phase polarity combined with a lower 2 D phase polarity, for instance 1 D IL111i with 2 D IL59 gave the best result; the greater difference in 1 D/ 2 D phase polarity results in increasing occupancy of peak area in the 2D space. The IL111i/IL59 column set was selected for analysis of fatty acids in fat and oil products (butter, margarine, fish oil and canola oil). Compared with the conventional IL111, IL111i showed reduced column bleed which makes this more suited to GC × GC analysis of FAME. The proposed method offers a fast profiling approach with good repeatability of analysis of FAME.

  2. Detecting macroeconomic phases in the Dow Jones Industrial Average time series

    NASA Astrophysics Data System (ADS)

    Wong, Jian Cheng; Lian, Heng; Cheong, Siew Ann

    2009-11-01

    In this paper, we perform statistical segmentation and clustering analysis of the Dow Jones Industrial Average (DJI) time series between January 1997 and August 2008. Modeling the index movements and log-index movements as stationary Gaussian processes, we find a total of 116 and 119 statistically stationary segments respectively. These can then be grouped into between five and seven clusters, each representing a different macroeconomic phase. The macroeconomic phases are distinguished primarily by their volatilities. We find that the US economy, as measured by the DJI, spends most of its time in a low-volatility phase and a high-volatility phase. The former can be roughly associated with economic expansion, while the latter contains the economic contraction phase in the standard economic cycle. Both phases are interrupted by a moderate-volatility market correction phase, but extremely-high-volatility market crashes are found mostly within the high-volatility phase. From the temporal distribution of various phases, we see a high-volatility phase from mid-1998 to mid-2003, and another starting mid-2007 (the current global financial crisis). Transitions from the low-volatility phase to the high-volatility phase are preceded by a series of precursor shocks, whereas the transition from the high-volatility phase to the low-volatility phase is preceded by a series of inverted shocks. The time scale for both types of transitions is about a year. We also identify the July 1997 Asian Financial Crisis to be the trigger for the mid-1998 transition, and an unnamed May 2006 market event related to corrections in the Chinese markets to be the trigger for the mid-2007 transition.

  3. Dynamic Cerebral Autoregulation is Preserved During Acute Head-down Tilt

    DTIC Science & Technology

    2003-06-27

    relationship of mean arterial pressure to mean cerebral blood flow velocity transfer function gain at the high and low frequencies, respectively; TCD-PHASE...HF and TCD-PHASE-LF, phase angle between mean arterial pressure and mean cerebral blood flow veloc- ity at high and low frequencies, respectively...arterial pressure and mean ce- rebral blood flow oscillations decrease from low- to high -frequency ranges. Average phase angles were 68° at low frequencies

  4. Large improvement of the electrical impedance of imaging and high-intensity focused ultrasound (HIFU) phased arrays using multilayer piezoelectric ceramics coupled in lateral mode.

    PubMed

    Song, Junho; Lucht, Benjamin; Hynynen, Kullervo

    2012-07-01

    With a change in phased-array configuration from one dimension to two, the electrical impedance of the array elements is substantially increased because of their decreased width (w)-to-thickness (t) ratio. The most common way to compensate for this impedance increase is to employ electrical matching circuits at a high cost of fabrication complexity and effort. In this paper, we introduce a multilayer lateral-mode coupling method for phased-array construction. The direct comparison showed that the electrical impedance of a single-layer transducer driven in thickness mode is 1/(n²(1/(w/t))²) times that of an n-layer lateral mode transducer. A large reduction of the electrical impedance showed the impact and benefit of the lateral-mode coupling method. A one-dimensional linear 32-element 770-kHz imaging array and a 42-element 1.45-MHz high-intensity focused ultrasound (HIFU) phased array were fabricated. The averaged electrical impedances of each element were measured to be 58 Ω at the maximum phase angle of -1.2° for the imaging array and 105 Ω at 0° for the HIFU array. The imaging array had a center frequency of 770 kHz with an averaged -6-dB bandwidth of approximately 52%. For the HIFU array, the averaged maximum surface acoustic intensity was measured to be 32.8 W/cm² before failure.

  5. Cost-effectiveness of the U.S. Geological Survey stream-gaging program in Indiana

    USGS Publications Warehouse

    Stewart, J.A.; Miller, R.L.; Butch, G.K.

    1986-01-01

    Analysis of the stream gaging program in Indiana was divided into three phases. The first phase involved collecting information concerning the data need and the funding source for each of the 173 surface water stations in Indiana. The second phase used alternate methods to produce streamflow records at selected sites. Statistical models were used to generate stream flow data for three gaging stations. In addition, flow routing models were used at two of the sites. Daily discharges produced from models did not meet the established accuracy criteria and, therefore, these methods should not replace stream gaging procedures at those gaging stations. The third phase of the study determined the uncertainty of the rating and the error at individual gaging stations, and optimized travel routes and frequency of visits to gaging stations. The annual budget, in 1983 dollars, for operating the stream gaging program in Indiana is $823,000. The average standard error of instantaneous discharge for all continuous record gaging stations is 25.3%. A budget of $800,000 could maintain this level of accuracy if stream gaging stations were visited according to phase III results. A minimum budget of $790,000 is required to operate the gaging network. At this budget, the average standard error of instantaneous discharge would be 27.7%. A maximum budget of $1 ,000,000 was simulated in the analysis and the average standard error of instantaneous discharge was reduced to 16.8%. (Author 's abstract)

  6. Forced free-shear layer measurements

    NASA Technical Reports Server (NTRS)

    Leboeuf, Richard L.

    1994-01-01

    Detailed three-dimensional three-component phase averaged measurements of the spanwise and streamwise vorticity formation and evolution in acoustically forced plane free-shear flows have been obtained. For the first time, phase-averaged measurements of all three velocity components have been obtained in both a mixing layer and a wake on three-dimensional grids, yielding the spanwise and streamwise vorticity distributions without invoking Taylor's hypothesis. Initially, two-frequency forcing was used to phase-lock the roll-up and first pairing of the spanwise vortical structures in a plane mixing layer. The objective of this study was to measure the near-field vortical structure morphology in a mixing layer with 'natural' laminar initial boundary layers. For the second experiment the second and third subharmonics of the fundamental roll-up frequency were added to the previous two-frequency forcing in order to phase-lock the roll-up and first three pairings of the spanwise rollers in the mixing layer. The objective of this study was to determine the details of spanwise scale changes observed in previous time-averaged measurements and flow visualization of unforced mixing layers. For the final experiment, single-frequency forcing was used to phase-lock the Karman vortex street in a plane wake developing from nominally two-dimensional laminar initial boundary layers. The objective of this study was to compare measurements of the three-dimensional structure in a wake developing from 'natural' initial boundary layers to existing models of wake vortical structure.

  7. Learning curves for single incision and conventional laparoscopic right hemicolectomy: a multidimensional analysis.

    PubMed

    Park, Yoonah; Yong, Yuen Geng; Yun, Seong Hyeon; Jung, Kyung Uk; Huh, Jung Wook; Cho, Yong Beom; Kim, Hee Cheol; Lee, Woo Yong; Chun, Ho-Kyung

    2015-05-01

    This study aimed to compare the learning curves and early postoperative outcomes for conventional laparoscopic (CL) and single incision laparoscopic (SIL) right hemicolectomy (RHC). This retrospective study included the initial 35 cases in each group. Learning curves were evaluated by the moving average of operative time, mean operative time of every five consecutive cases, and cumulative sum (CUSUM) analysis. The learning phase was considered overcome when the moving average of operative times reached a plateau, and when the mean operative time of every five consecutive cases reached a low point and subsequently did not vary by more than 30 minutes. Six patients with missing data in the CL RHC group were excluded from the analyses. According to the mean operative time of every five consecutive cases, learning phase of SIL and CL RHC was completed between 26 and 30 cases, and 16 and 20 cases, respectively. Moving average analysis revealed that approximately 31 (SIL) and 25 (CL) cases were needed to complete the learning phase, respectively. CUSUM analysis demonstrated that 10 (SIL) and two (CL) cases were required to reach a steady state of complication-free performance, respectively. Postoperative complications rate was higher in SIL than in CL group, but the difference was not statistically significant (17.1% vs. 3.4%). The learning phase of SIL RHC is longer than that of CL RHC. Early oncological outcomes of both techniques were comparable. However, SIL RHC had a statistically insignificant higher complication rate than CL RHC during the learning phase.

  8. Integration of coastal inundation modeling from storm tides to individual waves

    NASA Astrophysics Data System (ADS)

    Li, Ning; Roeber, Volker; Yamazaki, Yoshiki; Heitmann, Troy W.; Bai, Yefei; Cheung, Kwok Fai

    2014-11-01

    Modeling of storm-induced coastal inundation has primarily focused on the surge generated by atmospheric pressure and surface winds with phase-averaged effects of the waves as setup. Through an interoperable model package, we investigate the role of phase-resolving wave processes in simulation of coastal flood hazards. A spectral ocean wave model describes generation and propagation of storm waves from deep to intermediate water, while a non-hydrostatic storm-tide model has the option to couple with a spectral coastal wave model for computation of phase-averaged processes in a near-shore region. The ocean wave and storm-tide models can alternatively provide the wave spectrum and the surface elevation as the boundary and initial conditions for a nested Boussinesq model. Additional surface-gradient terms in the Boussinesq equations maintain the quasi-steady, non-uniform storm tide for modeling of phase-resolving surf and swash-zone processes as well as combined tide, surge, and wave inundation. The two nesting schemes are demonstrated through a case study of Hurricane Iniki, which made landfall on the Hawaiian Island of Kauai in 1992. With input from a parametric hurricane model and global reanalysis and tidal datasets, the two approaches produce comparable significant wave heights and phase-averaged surface elevations in the surf zone. The nesting of the Boussinesq model provides a seamless approach to augment the inundation due to the individual waves in matching the recorded debris line along the coast.

  9. SU-E-J-226: Propagation of Pancreas Target Contours On Respiratory Correlated CT Images Using Deformable Image Registration

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, F; Yorke, E; Mageras, G

    2014-06-01

    Purpose: Respiratory Correlated CT (RCCT) scans to assess intra-fraction motion among pancreatic cancer patients undergoing radiotherapy allow for dose sparing of normal tissues, in particular for the duodenum. Contour propagation of the gross tumor volume (GTV) from one reference respiratory phase to 9 other phases is time consuming. Deformable image registration (DIR) has been successfully used for high contrast disease sites but lower contrast for pancreatic tumors may compromise accuracy. This study evaluates the accuracy of Fast Free Form (FFF) registration-based contour propagation of the GTV on RCCT scans of pancreas cancer patients. Methods: Twenty-four pancreatic cancer patients were retrospectivelymore » studied; 20 had tumors in the pancreatic head/neck, 4 in the body/tail. Patients were simulated with RCCT and images were sorted into 10 respiratory phases. A radiation oncologist manually delineated the GTV for 5 phases (0%, 30%, 50%, 70% and 90%). The FFF algorithm was used to map deformations between the EE (50%) phase and each of the other 4 phases. The resultant deformation fields served to propagate GTV contours from EE to the other phases. The Dice Similarity Coefficient (DSC), which measures agreement between the DIR-propagated and manually-delineated GTVs, was used to quantitatively examine DIR accuracy. Results: Average DSC over all scans and patients is 0.82 and standard deviation is 0.09 (DSC range 0.97–0.57). For GTV volumes above and below the median volume of 20.2 cc, a Wilcoxon rank-sum test shows significantly different DSC (p=0.0000002). For the GTVs above the median volume, average +/− SD is 0.85 +/− 0.07; and for the GTVs below, the average +/− SD is 0.75 +/−0.08. Conclusion: For pancreatic tumors, the FFF DIR algorithm accurately propagated the GTV between the images in different phases of RCCT, with improved performance for larger tumors.« less

  10. Evaluation of 4-dimensional Computed Tomography to 4-dimensional Cone-Beam Computed Tomography Deformable Image Registration for Lung Cancer Adaptive Radiation Therapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Balik, Salim; Weiss, Elisabeth; Jan, Nuzhat

    2013-06-01

    Purpose: To evaluate 2 deformable image registration (DIR) algorithms for the purpose of contour mapping to support image-guided adaptive radiation therapy with 4-dimensional cone-beam CT (4DCBCT). Methods and Materials: One planning 4D fan-beam CT (4DFBCT) and 7 weekly 4DCBCT scans were acquired for 10 locally advanced non-small cell lung cancer patients. The gross tumor volume was delineated by a physician in all 4D images. End-of-inspiration phase planning 4DFBCT was registered to the corresponding phase in weekly 4DCBCT images for day-to-day registrations. For phase-to-phase registration, the end-of-inspiration phase from each 4D image was registered to the end-of-expiration phase. Two DIR algorithms—smallmore » deformation inverse consistent linear elastic (SICLE) and Insight Toolkit diffeomorphic demons (DEMONS)—were evaluated. Physician-delineated contours were compared with the warped contours by using the Dice similarity coefficient (DSC), average symmetric distance, and false-positive and false-negative indices. The DIR results are compared with rigid registration of tumor. Results: For day-to-day registrations, the mean DSC was 0.75 ± 0.09 with SICLE, 0.70 ± 0.12 with DEMONS, 0.66 ± 0.12 with rigid-tumor registration, and 0.60 ± 0.14 with rigid-bone registration. Results were comparable to intraobserver variability calculated from phase-to-phase registrations as well as measured interobserver variation for 1 patient. SICLE and DEMONS, when compared with rigid-bone (4.1 mm) and rigid-tumor (3.6 mm) registration, respectively reduced the average symmetric distance to 2.6 and 3.3 mm. On average, SICLE and DEMONS increased the DSC to 0.80 and 0.79, respectively, compared with rigid-tumor (0.78) registrations for 4DCBCT phase-to-phase registrations. Conclusions: Deformable image registration achieved comparable accuracy to reported interobserver delineation variability and higher accuracy than rigid-tumor registration. Deformable image registration performance varied with the algorithm and the patient.« less

  11. The effect of dry and wet deposition of condensable vapors on secondary organic aerosols concentrations over the continental US

    NASA Astrophysics Data System (ADS)

    Knote, C.; Hodzic, A.; Jimenez, J. L.

    2015-01-01

    The effect of dry and wet deposition of semi-volatile organic compounds (SVOCs) in the gas phase on the concentrations of secondary organic aerosol (SOA) is reassessed using recently derived water solubility information. The water solubility of SVOCs was implemented as a function of their volatility distribution within the WRF-Chem regional chemistry transport model, and simulations were carried out over the continental United States for the year 2010. Results show that including dry and wet removal of gas-phase SVOCs reduces annual average surface concentrations of anthropogenic and biogenic SOA by 48 and 63% respectively over the continental US. Dry deposition of gas-phase SVOCs is found to be more effective than wet deposition in reducing SOA concentrations (-40 vs. -8% for anthropogenics, and -52 vs. -11% for biogenics). Reductions for biogenic SOA are found to be higher due to the higher water solubility of biogenic SVOCs. The majority of the total mass of SVOC + SOA is actually deposited via the gas phase (61% for anthropogenics and 76% for biogenics). Results are sensitive to assumptions made in the dry deposition scheme, but gas-phase deposition of SVOCs remains crucial even under conservative estimates. Considering reactivity of gas-phase SVOCs in the dry deposition scheme was found to be negligible. Further sensitivity studies where we reduce the volatility of organic matter show that consideration of gas-phase SVOC removal still reduces average SOA concentrations by 31% on average. We consider this a lower bound for the effect of gas-phase SVOC removal on SOA concentrations. A saturation effect is observed for Henry's law constants above 108 M atm-1, suggesting an upper bound of reductions in surface level SOA concentrations by 60% through removal of gas-phase SVOCs. Other models that do not consider dry and wet removal of gas-phase SVOCs would hence overestimate SOA concentrations by roughly 50%. Assumptions about the water solubility of SVOCs made in some current modeling systems (H* = H* (CH3COOH); H* = 105 M atm-1; H* = H* (HNO3)) still lead to an overestimation of 35%/25%/10% compared to our best estimate.

  12. Using Contingency Management Procedures to Reduce At-Risk Drinking in Heavy Drinkers

    PubMed Central

    Dougherty, Donald M.; Lake, Sarah L.; Hill-Kapturczak, Nathalie; Liang, Yuanyuan; Karns, Tara E.; Mullen, Jillian; Roache, John D.

    2017-01-01

    Background Treatments for alcohol use disorders typically have been abstinence-based, but harm reduction approaches that encourage drinkers to alter their drinking behavior to reduce the probability of alcohol-related consequences, have gained in popularity. The current study used a contingency management procedure to determine its effectiveness in reducing alcohol consumption among heavy drinkers. Methods Eighty non-treatment-seeking heavy drinkers (ages 21–54, M = 30.20) who did not meet diagnostic criteria for alcohol dependence participated in the study. The study had three phases: 1) an Observation phase (4 weeks) where participants drank normally; 2) a Contingency Management phase (12 weeks) where participants were paid $50 weekly for not exceeding low levels of alcohol consumption as measured by transdermal alcohol concentrations, < 0.03 g/dL; and 3) a Follow-up phase (12 weeks) where participants (n = 66) returned monthly for 3 months to self-report drinking after the contingencies were removed. Transdermal alcohol monitors were used to verify meeting contingency requirements; all other analyses were conducted on self-reported alcohol use. Results On average 42.3% of participants met the contingency criteria and were paid an average of $222 during the Contingency Management phase, with an average $1998 in total compensation throughout the study. Compared to the Observation phase, the percent of any self-reported drinking days significantly decreased from 59.9% to 40.0% in the Contingency Management and 32.0% in the Follow-up phases. The percent of self-reported heavy drinking days reported also significantly decreased from 42.4% in the Observation phase to 19.7% in the Contingency Management phase, which was accompanied by a significant increase in percent days of self-reported no (from 40.1% to 60.0%) and low level drinking (from 9.9% to 15.4%). Self-reported reductions in drinking either persisted, or became more pronounced, during the Follow-up phase. Conclusions Contingency management was associated with a reduction in self-reported episodes of heavy drinking among non-treatment-seeking heavy drinkers. These effects persisted even after incentives were removed, indicating the potential utility of contingency management as a therapeutic intervention to reduce harmful patterns of drinking. PMID:25833033

  13. Time Averaged Transmitter Power and Exposure to Electromagnetic Fields from Mobile Phone Base Stations

    PubMed Central

    Bürgi, Alfred; Scanferla, Damiano; Lehmann, Hugo

    2014-01-01

    Models for exposure assessment of high frequency electromagnetic fields from mobile phone base stations need the technical data of the base stations as input. One of these parameters, the Equivalent Radiated Power (ERP), is a time-varying quantity, depending on communication traffic. In order to determine temporal averages of the exposure, corresponding averages of the ERP have to be available. These can be determined as duty factors, the ratios of the time-averaged power to the maximum output power according to the transmitter setting. We determine duty factors for UMTS from the data of 37 base stations in the Swisscom network. The UMTS base stations sample contains sites from different regions of Switzerland and also different site types (rural/suburban/urban/hotspot). Averaged over all regions and site types, a UMTS duty factor F ≈ 0.32 ± 0.08 for the 24 h-average is obtained, i.e., the average output power corresponds to about a third of the maximum power. We also give duty factors for GSM based on simple approximations and a lower limit for LTE estimated from the base load on the signalling channels. PMID:25105551

  14. OPERATIONAL CHARACTERISTICS OF THE ARMOUR FISSION GAS GAMMA FACILITY

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Terrell, C.W.; McElroy, W.N.

    1958-10-31

    As the reactor power level is changed frequently, the radiation levels in the gamma facility fluctuate. Data are presented to show the power dependency of the gamma dose rate and the manner of growth and decay. Additional data show the dependercy of the equilibrium gamma activity on the foel temperature and total system pressure. The final phase of the work is directed toward determining an average gamma energy by attenuation measurements with various thicknesses of several materials. The neutrou flux associated with the gas phase activity is determined by foil measurement. From the measurements of dose rate and average gammamore » energy, calculations to determine the number of curies of gas phase decay gamma activity per watt of reactor power are presented. (auth)« less

  15. Robust electroencephalogram phase estimation with applications in brain-computer interface systems.

    PubMed

    Seraj, Esmaeil; Sameni, Reza

    2017-03-01

    In this study, a robust method is developed for frequency-specific electroencephalogram (EEG) phase extraction using the analytic representation of the EEG. Based on recent theoretical findings in this area, it is shown that some of the phase variations-previously associated to the brain response-are systematic side-effects of the methods used for EEG phase calculation, especially during low analytical amplitude segments of the EEG. With this insight, the proposed method generates randomized ensembles of the EEG phase using minor perturbations in the zero-pole loci of narrow-band filters, followed by phase estimation using the signal's analytical form and ensemble averaging over the randomized ensembles to obtain a robust EEG phase and frequency. This Monte Carlo estimation method is shown to be very robust to noise and minor changes of the filter parameters and reduces the effect of fake EEG phase jumps, which do not have a cerebral origin. As proof of concept, the proposed method is used for extracting EEG phase features for a brain computer interface (BCI) application. The results show significant improvement in classification rates using rather simple phase-related features and a standard K-nearest neighbors and random forest classifiers, over a standard BCI dataset. The average performance was improved between 4-7% (in absence of additive noise) and 8-12% (in presence of additive noise). The significance of these improvements was statistically confirmed by a paired sample t-test, with 0.01 and 0.03 p-values, respectively. The proposed method for EEG phase calculation is very generic and may be applied to other EEG phase-based studies.

  16. Molecular gas in low-metallicity starburst galaxies:. Scaling relations and the CO-to-H2 conversion factor

    NASA Astrophysics Data System (ADS)

    Amorín, R.; Muñoz-Tuñón, C.; Aguerri, J. A. L.; Planesas, P.

    2016-04-01

    Context. Tracing the molecular gas-phase in low-mass star-forming galaxies becomes extremely challenging due to significant UV photo-dissociation of CO molecules in their low-dust, low-metallicity ISM environments. Aims: We aim to study the molecular content and the star-formation efficiency of a representative sample of 21 blue compact dwarf galaxies (BCDs), previously characterized on the basis of their spectrophotometric properties. Methods: We present CO (1-0) and (2-1) observations conducted at the IRAM-30m telescope. These data are further supplemented with additional CO measurements and multiwavelength ancillary data from the literature. We explore correlations between the derived CO luminosities and several galaxy-averaged properties. Results: We detect CO emission in seven out of ten BCDs observed. For two galaxies these are the first CO detections reported so far. We find the molecular content traced by CO to be correlated with the stellar and Hi masses, star formation rate (SFR) tracers, the projected size of the starburst, and its gas-phase metallicity. BCDs appear to be systematically offset from the Schmidt-Kennicutt (SK) law, showing lower average gas surface densities for a given ΣSFR, and therefore showing extremely low (≲0.1 Gyr) H2 and H2 +Hi depletion timescales. The departure from the SK law is smaller when considering H2 +Hi rather than H2 only, and is larger for BCDs with lower metallicity and higher specific SFR. Thus, the molecular fraction (ΣH2/ ΣHI) and CO depletion timescale (ΣH2/ ΣSFR) of BCDs is found to be strongly correlated with metallicity. Using this, and assuming that the empirical correlation found between the specific SFR and galaxy-averaged H2 depletion timescale of more metal-rich galaxies extends to lower masses, we derive a metallicity-dependent CO-to-H2 conversion factor αCO,Z ∝ (Z/Z⊙)- y, with y = 1.5(±0.3)in qualitative agreement with previous determinations, dust-based measurements, and recent model predictions. Consequently, our results suggest that in vigorously star-forming dwarfs the fraction of H2 traced by CO decreases by a factor of about 40 from Z ~ Z⊙ to Z ~ 0.1 Z⊙, leading to a strong underestimation of the H2 mass in metal-poor systems when a Galactic αCO,MW is considered. Adopting our metallicity-dependent conversion factor αCO,Z we find that departures from the SK law are partially resolved. Conclusions: Our results suggest that starbursting dwarfs have shorter depletion gas timescales and lower molecular fractions compared to normal late-type disc galaxies, even accounting for the molecular gas not traced by CO emission in metal-poor environments, raising additional constraints to model predictions. Based on observations carried out with the IRAM 30m Telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).

  17. Single-drop reactive extraction/extractive reaction with forced convective diffusion and interphase mass transfer

    NASA Technical Reports Server (NTRS)

    Kleinman, Leonid S.; Reed, X. B., Jr.

    1995-01-01

    An algorithm has been developed for the forced convective diffusion-reaction problem for convection inside and outside a droplet by a recirculating flow field hydrodynamically coupled at the droplet interface with an external flow field that at infinity becomes a uniform streaming flow. The concentration field inside the droplet is likewise coupled with that outside by boundary conditions at the interface. A chemical reaction can take place either inside or outside the droplet or reactions can take place in both phases. The algorithm has been implemented and results are shown here for the case of no reaction and for the case of an external first order reaction, both for unsteady behavior. For pure interphase mass transfer, concentration isocontours, local and average Sherwood numbers, and average droplet concentrations have been obtained as a function of the physical properties and external flow field. For mass transfer enhanced by an external reaction, in addition to the above forms of results, we present the enhancement factor, with the results now also depending upon the (dimensionless) rate of reaction.

  18. The 27-28 October 1986 FIRE IFO cirrus case study - Cloud optical properties determined by High Spectral Resolution Lidar

    NASA Technical Reports Server (NTRS)

    Grund, C. J.; Eloranta, E. W.

    1990-01-01

    The High Spectral Resolution Lidar (HSRL) was operated from a roof-top site in Madison, Wisconsin. The transmitter configuration used to acquire the case study data produces about 50 mW of ouput power and achieved eye-safe, direct optical depth, and backscatter cross section measurements with 10 min averaging times. A new continuously pumped, injection seeded, frequency doubled Nd:YAG laser transmitter reduces time-averaging constraints by a factor of about 10, while improving the aerosol-molecular signal separation capabilities and wavelength stability of the instrument. The cirrus cloud backscatter-phase functions have been determined for the October 27-28, 1986 segment of the HSRL FIRE dataset. Features exhibiting backscatter cross sections ranging over four orders of magnitude have been observed within this 33 h period. During this period, cirrus clouds were observed with optical thickness ranging from 0.01 to 1.4. The altitude relationship between cloud top and bottom boundaries and the optical center of the cloud is influenced by the type of formation observed.

  19. Calibration and field application of passive sampling for episodic exposure to polar organic pesticides in streams.

    PubMed

    Fernández, Diego; Vermeirssen, Etiënne L M; Bandow, Nicole; Muñoz, Katherine; Schäfer, Ralf B

    2014-11-01

    Rainfall-triggered runoff is a major driver of pesticide input in streams. Only few studies have examined the suitability of passive sampling to quantify such episodic exposures. In this study, we used Empore™ styrene-divinylbenzene reverse phase sulfonated disks (SDB disks) and event-driven water samples (EDS) to assess exposure to 15 fungicides and 4 insecticides in 17 streams in a German vineyard area during 4 rainfall events. We also conducted a microcosm experiment to determine the SDB-disk sampling rates and provide a free-software solution to derive sampling rates under time-variable exposure. Sampling rates ranged from 0.26 to 0.77 L d(-1) and time-weighted average (TWA) concentrations from 0.05 to 2.11 μg/L. The 2 sampling systems were in good agreement and EDS exceeded TWA concentrations on average by a factor of 3. Our study demonstrates that passive sampling is suitable to quantify episodic exposures from polar organic pesticides. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Multi-phase-fluid discrimination with local fibre-optical probes: I. Liquid/liquid flows

    NASA Astrophysics Data System (ADS)

    Fordham, E. J.; Holmes, A.; Ramos, R. T.; Simonian, S.; Huang, S.-M.; Lenn, C. P.

    1999-12-01

    We demonstrate the use of a novel design of fibre-optical sensor (or `local probe') for immiscible-fluid discrimination in multi-phase flows. These probes are made from standard silica fibres with plane oblique facets polished at the fibre tip, with various surface treatments, including a crucial one for wettability control. Total internal reflection is used to distinguish drops, bubbles or other regions of fluid in multi-phase flows, on the basis of refractive-index contrast. Such probes have quasi-binary outputs; we demonstrate in this paper their use in distinguishing water from oil (kerosene) in oil/water two-phase flows and compare the results with those obtained from a simple cleaved fibre relying on the (small) difference in Fresnel reflectivity for discrimination. Quantitative accuracy is demonstrated by comparison of profiles, across a pipe diameter, of local, time-averaged volume fractions (`hold-ups'), with pipe-averaged hold-ups determined from a carefully calibrated gradio-manometer in a fully developed region of the flow. Companion papers deal with the sensors used and results achieved in gas/liquid flows and three-phase flows.

  1. Frequency downconversion and phase noise in MIT.

    PubMed

    Watson, S; Williams, R J; Griffiths, H; Gough, W; Morris, A

    2002-02-01

    High-frequency (3-30 MHz) operation of MIT systems offers advantages in terms of the larger induced signal amplitudes compared to systems operating in the low- or medium-frequency ranges. Signal distribution at HF, however, presents difficulties, in particular with isolation and phase stability. It is therefore valuable to translate received signals to a lower frequency range through heterodyne downconversion, a process in which relative signal amplitude and phase information is in theory retained. Measurement of signal amplitude and phase is also simplified at lower frequencies. The paper presents details of measurements on a direct phase measurement system utilizing heterodyne downconversion and compares the relative performance of three circuit configurations. The 100-sample average precision of a circuit suitable for use as a receiver within an MIT system was 0.008 degrees for input amplitude -21 dBV. As the input amplitude was reduced from -21 to -72 dBV variation in the measured phase offset was observed, with the offset varying by 1.8 degrees. The precision of the circuit deteriorated with decreasing input amplitude, but was found to provide a 100-sample average precision of <0.022 degrees down to an input amplitude of -60 dBV. The characteristics of phase noise within the system are discussed.

  2. Theory of inhomogeneous quantum systems. III. Variational wave functions for Fermi fluids

    NASA Astrophysics Data System (ADS)

    Krotscheck, E.

    1985-04-01

    We develop a general variational theory for inhomogeneous Fermi systems such as the electron gas in a metal surface, the surface of liquid 3He, or simple models of heavy nuclei. The ground-state wave function is expressed in terms of two-body correlations, a one-body attenuation factor, and a model-system Slater determinant. Massive partial summations of cluster expansions are performed by means of Born-Green-Yvon and hypernetted-chain techniques. An optimal single-particle basis is generated by a generalized Hartree-Fock equation in which the two-body correlations screen the bare interparticle interaction. The optimization of the pair correlations leads to a state-averaged random-phase-approximation equation and a strictly microscopic determination of the particle-hole interaction.

  3. Figure correction of multilayer coated optics

    DOEpatents

    Chapman; Henry N. , Taylor; John S.

    2010-02-16

    A process is provided for producing near-perfect optical surfaces, for EUV and soft-x-ray optics. The method involves polishing or otherwise figuring the multilayer coating that has been deposited on an optical substrate, in order to correct for errors in the figure of the substrate and coating. A method such as ion-beam milling is used to remove material from the multilayer coating by an amount that varies in a specified way across the substrate. The phase of the EUV light that is reflected from the multilayer will be affected by the amount of multilayer material removed, but this effect will be reduced by a factor of 1-n as compared with height variations of the substrate, where n is the average refractive index of the multilayer.

  4. Phase averaging method for the modeling of the multiprobe and cutaneous cryosurgery

    NASA Astrophysics Data System (ADS)

    E Shilnikov, K.; Kudryashov, N. A.; Y Gaiur, I.

    2017-12-01

    In this paper we consider the problem of planning and optimization of the cutaneous and multiprobe cryosurgery operations. An explicit scheme based on the finite volume approximation of phase averaged Pennes bioheat transfer model is applied. The flux relaxation method is used for the stability improvement of scheme. Skin tissue is considered as strongly inhomogeneous media. Computerized planning tool is tested on model cryotip-based and cutaneous cryosurgery problems. For the case of cutaneous cryosurgery the method of an additional freezing element mounting is studied as an approach to optimize the cellular necrosis front propagation.

  5. Primary and secondary precipitates in a hierarchical-precipitate-strengthened ferritic alloy

    DOE PAGES

    Song, Gian; Sun, Zhiqian; Poplawsky, Jonathan D.; ...

    2017-02-27

    The microstructures of a hierarchical-precipitate-strengthened ferritic alloy are characterized, using transmission-electron microscopy (TEM) and atom-probe tomography (APT). The alloy shows duplex precipitates. The primary precipitate with an average edge length of 90 nm consists of NiAl- and Ni2TiAl-type phases, while the secondary precipitate with an average radius of 2 nm is a NiAl-type phase. Based on the APT results, the volume fractions of the primary and secondary precipitates were calculated, using the lever rule to be 17.3 and 2.3 %, respectively.

  6. [Estimation of average traffic emission factor based on synchronized incremental traffic flow and air pollutant concentration].

    PubMed

    Li, Run-Kui; Zhao, Tong; Li, Zhi-Peng; Ding, Wen-Jun; Cui, Xiao-Yong; Xu, Qun; Song, Xian-Feng

    2014-04-01

    On-road vehicle emissions have become the main source of urban air pollution and attracted broad attentions. Vehicle emission factor is a basic parameter to reflect the status of vehicle emissions, but the measured emission factor is difficult to obtain, and the simulated emission factor is not localized in China. Based on the synchronized increments of traffic flow and concentration of air pollutants in the morning rush hour period, while meteorological condition and background air pollution concentration retain relatively stable, the relationship between the increase of traffic and the increase of air pollution concentration close to a road is established. Infinite line source Gaussian dispersion model was transformed for the inversion of average vehicle emission factors. A case study was conducted on a main road in Beijing. Traffic flow, meteorological data and carbon monoxide (CO) concentration were collected to estimate average vehicle emission factors of CO. The results were compared with simulated emission factors of COPERT4 model. Results showed that the average emission factors estimated by the proposed approach and COPERT4 in August were 2.0 g x km(-1) and 1.2 g x km(-1), respectively, and in December were 5.5 g x km(-1) and 5.2 g x km(-1), respectively. The emission factors from the proposed approach and COPERT4 showed close values and similar seasonal trends. The proposed method for average emission factor estimation eliminates the disturbance of background concentrations and potentially provides real-time access to vehicle fleet emission factors.

  7. An effective method to accurately calculate the phase space factors for β - β - decay

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Neacsu, Andrei; Horoi, Mihai

    2016-01-01

    Accurate calculations of the electron phase space factors are necessary for reliable predictions of double-beta decay rates and for the analysis of the associated electron angular and energy distributions. Here, we present an effective method to calculate these phase space factors that takes into account the distorted Coulomb field of the daughter nucleus, yet it allows one to easily calculate the phase space factors with good accuracy relative to the most exact methods available in the recent literature.

  8. Do 16 Polycyclic Aromatic Hydrocarbons Represent PAH Air Toxicity?

    PubMed Central

    Samburova, Vera; Zielinska, Barbara; Khlystov, Andrey

    2017-01-01

    Estimation of carcinogenic potency based on analysis of 16 polycyclic aromatic hydrocarbons (PAHs) ranked by U.S. Environmental Protection Agency (EPA) is the most popular approach within scientific and environmental air quality management communities. The majority of PAH monitoring projects have been focused on particle-bound PAHs, ignoring the contribution of gas-phase PAHs to the toxicity of PAH mixtures in air samples. In this study, we analyzed the results of 13 projects in which 88 PAHs in both gas and particle phases were collected from different sources (biomass burning, mining operation, and vehicle emissions), as well as in urban air. The aim was to investigate whether 16 particle-bound U.S. EPA priority PAHs adequately represented health risks of inhalation exposure to atmospheric PAH mixtures. PAH concentrations were converted to benzo(a)pyrene-equivalent (BaPeq) toxicity using the toxic equivalency factor (TEF) approach. TEFs of PAH compounds for which such data is not available were estimated using TEFs of close isomers. Total BaPeq toxicities (∑88BaPeq) of gas- and particle-phase PAHs were compared with BaPeq toxicities calculated for the 16 particle-phase EPA PAH (∑16EPABaPeq). The results showed that 16 EPA particle-bound PAHs underrepresented the carcinogenic potency on average by 85.6% relative to the total (gas and particle) BaPeq toxicity of 88 PAHs. Gas-phase PAHs, like methylnaphthalenes, may contribute up to 30% of ∑88BaPeq. Accounting for other individual non-EPA PAHs (i.e., benzo(e)pyrene) and gas-phase PAHs (i.e., naphthalene, 1- and 2-methylnaphthalene) will make the risk assessment of PAH-containing air samples significantly more accurate. PMID:29051449

  9. Sensitivity of tumor motion simulation accuracy to lung biomechanical modeling approaches and parameters.

    PubMed

    Tehrani, Joubin Nasehi; Yang, Yin; Werner, Rene; Lu, Wei; Low, Daniel; Guo, Xiaohu; Wang, Jing

    2015-11-21

    Finite element analysis (FEA)-based biomechanical modeling can be used to predict lung respiratory motion. In this technique, elastic models and biomechanical parameters are two important factors that determine modeling accuracy. We systematically evaluated the effects of lung and lung tumor biomechanical modeling approaches and related parameters to improve the accuracy of motion simulation of lung tumor center of mass (TCM) displacements. Experiments were conducted with four-dimensional computed tomography (4D-CT). A Quasi-Newton FEA was performed to simulate lung and related tumor displacements between end-expiration (phase 50%) and other respiration phases (0%, 10%, 20%, 30%, and 40%). Both linear isotropic and non-linear hyperelastic materials, including the neo-Hookean compressible and uncoupled Mooney-Rivlin models, were used to create a finite element model (FEM) of lung and tumors. Lung surface displacement vector fields (SDVFs) were obtained by registering the 50% phase CT to other respiration phases, using the non-rigid demons registration algorithm. The obtained SDVFs were used as lung surface displacement boundary conditions in FEM. The sensitivity of TCM displacement to lung and tumor biomechanical parameters was assessed in eight patients for all three models. Patient-specific optimal parameters were estimated by minimizing the TCM motion simulation errors between phase 50% and phase 0%. The uncoupled Mooney-Rivlin material model showed the highest TCM motion simulation accuracy. The average TCM motion simulation absolute errors for the Mooney-Rivlin material model along left-right, anterior-posterior, and superior-inferior directions were 0.80 mm, 0.86 mm, and 1.51 mm, respectively. The proposed strategy provides a reliable method to estimate patient-specific biomechanical parameters in FEM for lung tumor motion simulation.

  10. Sensitivity of Tumor Motion Simulation Accuracy to Lung Biomechanical Modeling Approaches and Parameters

    PubMed Central

    Tehrani, Joubin Nasehi; Yang, Yin; Werner, Rene; Lu, Wei; Low, Daniel; Guo, Xiaohu

    2015-01-01

    Finite element analysis (FEA)-based biomechanical modeling can be used to predict lung respiratory motion. In this technique, elastic models and biomechanical parameters are two important factors that determine modeling accuracy. We systematically evaluated the effects of lung and lung tumor biomechanical modeling approaches and related parameters to improve the accuracy of motion simulation of lung tumor center of mass (TCM) displacements. Experiments were conducted with four-dimensional computed tomography (4D-CT). A Quasi-Newton FEA was performed to simulate lung and related tumor displacements between end-expiration (phase 50%) and other respiration phases (0%, 10%, 20%, 30%, and 40%). Both linear isotropic and non-linear hyperelastic materials, including the Neo-Hookean compressible and uncoupled Mooney-Rivlin models, were used to create a finite element model (FEM) of lung and tumors. Lung surface displacement vector fields (SDVFs) were obtained by registering the 50% phase CT to other respiration phases, using the non-rigid demons registration algorithm. The obtained SDVFs were used as lung surface displacement boundary conditions in FEM. The sensitivity of TCM displacement to lung and tumor biomechanical parameters was assessed in eight patients for all three models. Patient-specific optimal parameters were estimated by minimizing the TCM motion simulation errors between phase 50% and phase 0%. The uncoupled Mooney-Rivlin material model showed the highest TCM motion simulation accuracy. The average TCM motion simulation absolute errors for the Mooney-Rivlin material model along left-right (LR), anterior-posterior (AP), and superior-inferior (SI) directions were 0.80 mm, 0.86 mm, and 1.51 mm, respectively. The proposed strategy provides a reliable method to estimate patient-specific biomechanical parameters in FEM for lung tumor motion simulation. PMID:26531324

  11. Do 16 Polycyclic Aromatic Hydrocarbons Represent PAH Air Toxicity?

    PubMed

    Samburova, Vera; Zielinska, Barbara; Khlystov, Andrey

    2017-08-15

    Estimation of carcinogenic potency based on analysis of 16 polycyclic aromatic hydrocarbons (PAHs) ranked by U.S. Environmental Protection Agency (EPA) is the most popular approach within scientific and environmental air quality management communities. The majority of PAH monitoring projects have been focused on particle-bound PAHs, ignoring the contribution of gas-phase PAHs to the toxicity of PAH mixtures in air samples. In this study, we analyzed the results of 13 projects in which 88 PAHs in both gas and particle phases were collected from different sources (biomass burning, mining operation, and vehicle emissions), as well as in urban air. The aim was to investigate whether 16 particle-bound U.S. EPA priority PAHs adequately represented health risks of inhalation exposure to atmospheric PAH mixtures. PAH concentrations were converted to benzo(a)pyrene-equivalent (BaPeq) toxicity using the toxic equivalency factor (TEF) approach. TEFs of PAH compounds for which such data is not available were estimated using TEFs of close isomers. Total BaPeq toxicities (∑ 88 BaPeq) of gas- and particle-phase PAHs were compared with BaPeq toxicities calculated for the 16 particle-phase EPA PAH (∑ 16EPA BaPeq). The results showed that 16 EPA particle-bound PAHs underrepresented the carcinogenic potency on average by 85.6% relative to the total (gas and particle) BaPeq toxicity of 88 PAHs. Gas-phase PAHs, like methylnaphthalenes, may contribute up to 30% of ∑ 88 BaPeq. Accounting for other individual non-EPA PAHs (i.e., benzo(e)pyrene) and gas-phase PAHs (i.e., naphthalene, 1- and 2-methylnaphthalene) will make the risk assessment of PAH-containing air samples significantly more accurate.

  12. Risk Assessment Related to Atmospheric Polycyclic Aromatic Hydrocarbons in Gas and Particle Phases near Industrial Sites

    PubMed Central

    Ramírez, Noelia; Cuadras, Anna; Marcé, Rosa Maria

    2011-01-01

    Background: Inhalation is one of the main means of human exposure to polycyclic aromatic hydrocarbons (PAHs) because of their ubiquitous presence in the atmosphere. However, most studies have considered only PAHs found in the particle phase and have omitted the contribution of the gas-phase PAHs to the risk. Objective: We estimated the lifetime lung cancer risk from PAH exposure by inhalation in people living next to the largest chemical site in Southern Europe and the Mediterranean area. Methods: We determined 18 PAHs in the atmospheric gas and particle phase. We monitored the PAHs for 1 year in three locations near the chemical site in different seasons. We used toxic equivalence factors to calculate benzo[a]pyrene (BaP) equivalents (BaP-eq) for individual PAHs and applied the World Health Organization unit risk (UR) for BaP (UR = 8.7 × 10–5) to estimate lifetime cancer risks due to PAH exposures. Results: We observed some spatial and seasonal variability in PAH concentrations. The contribution of gas-phase PAHs to the total BaP-eq value was between 34% and 86%. The total estimated average lifetime lung cancer risk due to PAH exposure in the study area was 1.2 × 10–4. Conclusions: The estimated risk was higher than values recommended by the World Health Organization and U.S. Environmental Protection Agency but lower than the threshold value of 10–3 that is considered an indication of definite risk according to similar risk studies. The results also showed that risk may be underestimated if the contributions of gas-phase PAHs are not considered. PMID:21478082

  13. Layered Na‐Ion Cathodes with Outstanding Performance Resulting from the Synergetic Effect of Mixed P‐ and O‐Type Phases

    PubMed Central

    Keller, Marlou

    2015-01-01

    Herein, the synthesis of new quaternary layered Na‐based oxides of the type NaxMnyNizFe0.1Mg0.1O2 (0.67≤ x ≤ 1.0; 0.5≤ y ≤ 0.7; 0.1≤ z ≤ 0.3) is described. The synthesis can be tuned to obtain P2‐ and O3‐type as well as mixed P‐/O‐type phases as demonstrated by structural, morphological, and electrochemical properties characterization. Although all materials show good electrochemical performance, the simultaneous presence of the P‐ and O‐type phases is found to have a synergetic effect resulting in outstanding performance of the mixed phase material as a sodium‐ion cathode. The mixed P3/P2/O3‐type material, having an average elemental composition of Na0.76Mn0.5Ni0.3Fe0.1Mg0.1O2, overcomes the specific drawbacks associated with the P2‐ and O3‐type materials, allowing the outstanding electrochemical performance. In detail, the mixed phase material is able to deliver specific discharge capacities of up to 155 mAh g−1 (18 mA g−1) in the potential range of 2.0–4.3 V. In the narrower potential range of 2.5–4.3 V the material exhibits high average discharge potential (3.4 V versus Na/Na+), exceptional average coulombic efficiencies (>99.9%), and extraordinary capacity retention (90.2% after 601 cycles). The unexplored class of P‐/O‐type mixed phases introduces new perspectives for the development of layered positive electrode materials and powerful Na‐ion batteries. PMID:27134617

  14. Home Circadian Phase Assessments with Measures of Compliance Yield Accurate Dim Light Melatonin Onsets.

    PubMed

    Burgess, Helen J; Wyatt, James K; Park, Margaret; Fogg, Louis F

    2015-06-01

    There is a need for the accurate assessment of circadian phase outside of the clinic/laboratory, particularly with the gold standard dim light melatonin onset (DLMO). We tested a novel kit designed to assist in saliva sampling at home for later determination of the DLMO. The home kit includes objective measures of compliance to the requirements for dim light and half-hourly saliva sampling. Participants were randomized to one of two 10-day protocols. Each protocol consisted of two back-to-back home and laboratory phase assessments in counterbalanced order, separated by a 5-day break. Laboratory or participants' homes. Thirty-five healthy adults, age 21-62 y. N/A. Most participants received at least one 30-sec epoch of light > 50 lux during the home phase assessments (average light intensity 4.5 lux), but on average for < 9 min of the required 8.5 h. Most participants collected every saliva sample within 5 min of the scheduled time. Ninety-two percent of home DLMOs were not affected by light > 50 lux or sampling errors. There was no significant difference between the home and laboratory DLMOs (P > 0.05); on average the home DLMOs occurred 9.6 min before the laboratory DLMOs. The home DLMOs were highly correlated with the laboratory DLMOs (r = 0.91, P < 0.001). Participants were reasonably compliant to the home phase assessment procedures. The good agreement between the home and laboratory dim light melatonin onsets (DLMOs) demonstrates that including objective measures of light exposure and sample timing during home saliva sampling can lead to accurate home DLMOs. Circadian Phase Assessments at Home, http://clinicaltrials.gov/show/NCT01487252, NCT01487252. © 2015 Associated Professional Sleep Societies, LLC.

  15. Analysis of the nutritional management practices in intensive care: Identification of needs for improvement.

    PubMed

    Lázaro-Martín, N I; Catalán-González, M; García-Fuentes, C; Terceros-Almanza, L; Montejo-González, J C

    2015-12-01

    To analyze the nutritional management practices in Intensive Care (ICU) to detect the need for improvement actions. Re-evaluate the process after implementation of improvement actions. Prospective observational study in 3 phases: 1) observation; 2) analysis, proposal development and dissemination; 3) analysis of the implementation. ICU of a hospital of high complexity. Adult ICU forecast more than 48h of artificial nutrition. Parenteral nutrition (PN), enteral nutrition (EN) (type, average effective volume, complications) and average nutritional ratio. A total of 229 patients (phase 1: 110, phase 3: 119). After analyzing the initial results, were proposed: increased use and precocity of EN, increased protein intake, nutritional monitoring effectiveness and increased supplementary indication NP. The measures were broadcast at specific meetings. During phase 3 more patients received EN (55.5 vs. 78.2%, P=.001), with no significant difference in the start time (1.66 vs. 2.33 days), duration (6.82 vs. 10,12 days) or complications (37,7 vs. 47,3%).Use of hyperproteic diets was higher in phase 3 (0 vs. 13.01%, P<.05). The use of NP was similar (48.2 vs. 48,7%) with a tendency to a later onset in phase 3 (1.25±1.25 vs. 2.45±3.22 days). There were no significant differences in the average nutritional ratio (0.56±0.28 vs. 0.61±0.27, P=.56). The use of EN and the protein intake increased, without appreciating effects on other improvement measures. Other methods appear to be necessary for the proper implementation of improvement measures. Copyright © 2015 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

  16. Influence of heat-treated Al-Si coating on the weldability and microstructural inhomogeneity for hot stamped steel resistance nut projection welds

    NASA Astrophysics Data System (ADS)

    Chun, Eun-Joon; Lim, Sung-Sang; Kim, Young-Tae; Nam, Ki-Sung; Kim, Young-Min; Park, Young-Whan; Murugan, Siva Prasad; Park, Yeong-Do

    2018-03-01

    Resistance nut projection weldability of Al-Si coated hot stamped steel (HSS) was investigated under the viewpoint of weldable current range and joint strength (pull-out load). The microstructural inhomogeneities in the welds were also studied in order to elucidate the factors affecting the joint strength of the welds. The weldability of the given Al-Si coated HSS was compared with the weldability of an identical HSS without the Al-Si coating (Al-Si coating was polished out) and Zn coated dual phase steel. The weldable current range of Al-Si coated HSS was found to be narrower than that of the other materials. Furthermore, the average pull-out load within the weldable current range of the Al-Si coated HSS was the lowest among the three materials. The reason for poor weld mechanical property of the Al-Si coated hot-stamped steel was attributed to the microstructural inhomogeneities such as unmixed Al-Si coating layer at the edge of the nugget and the second phase Fe3(Al, Si) intermetallic compound. The formation of Fe3(Al, Si) phase was attributed to the solidification segregation of Al and Si during the weld solidification and was confirmed with the numerical analysis of solidification segregation.

  17. Rotational broadening and conservation of angular momentum in post-extreme horizontal branch stars

    NASA Astrophysics Data System (ADS)

    Fontaine, G.; Latour, M.

    2018-06-01

    We show that the recent realization that isolated post-extreme horizontal branch (post-EHB) stars are generally characterized by rotational broadening with values of V rot sini between 25 and 30 km s-1 can be explained as a natural consequence of the conservation of angular momentum from the previous He-core burning phase on the EHB. The progenitors of these evolved objects, the EHB stars, are known to be slow rotators with an average value of V rot sini of 7.7 km s-1. This implies significant spin-up between the EHB and post-EHB phases. Using representative evolutionary models of hot subdwarf stars, we demonstrate that angular momentum conservation in uniformly rotating structures (rigid-body rotation) boosts that value of the projected equatorial rotation speed by a factor 3.6 by the time the model has reached the region of the surface gravity-effective temperature plane where the newly-studied post-EHB objects are found. This is exactly what is needed to account for their observed atmospheric broadening. We note that the decrease of the moment of inertia causing the spin-up is mostly due to the redistribution of matter that produces more centrally-condensed structures in the post-EHB phase of evolution, not to the decrease of the radius per se.

  18. Anisotropic scattering of discrete particle arrays.

    PubMed

    Paul, Joseph S; Fu, Wai Chong; Dokos, Socrates; Box, Michael

    2010-05-01

    Far-field intensities of light scattered from a linear centro-symmetric array illuminated by a plane wave of incident light are estimated at a series of detector angles. The intensities are computed from the superposition of E-fields scattered by the individual array elements. An average scattering phase function is used to model the scattered fields of individual array elements. The nature of scattering from the array is investigated using an image (theta-phi plot) of the far-field intensities computed at a series of locations obtained by rotating the detector angle from 0 degrees to 360 degrees, corresponding to each angle of incidence in the interval [0 degrees 360 degrees]. The diffraction patterns observed from the theta-Phi plot are compared with those for isotropic scattering. In the absence of prior information on the array geometry, the intensities corresponding to theta-Phi pairs satisfying the Bragg condition are used to estimate the phase function. An algorithmic procedure is presented for this purpose and tested using synthetic data. The relative error between estimated and theoretical values of the phase function is shown to be determined by the mean spacing factor, the number of elements, and the far-field distance. An empirical relationship is presented to calculate the optimal far-field distance for a given specification of the percentage error.

  19. Interpretation of solution scattering data from lipid nanodiscs

    DOE PAGES

    Graziano, Vito; Miller, Lisa; Yang, Lin

    2018-02-01

    The structural information contained in solution scattering data from empty lipid nanodiscs is examined in the context of a multi-component geometric model. X-ray scattering data were collected on nanodiscs of different compositions at scattering vector magnitudes up to 2.0 Å −1 . Through the calculation of the partial form factor for each of the nanodisc components before the isotropic average, structural parameters in the model were correlated to the features observed in the X-ray scattering data and to the corresponding distance distribution function. It is shown that, in general, the features at ∼0.3–0.6 Å −1 in the scattering data correlate to themore » bilayer structure. The data also support the argument that the elliptical shape of nanodiscs found in model fitting is physical, rather than an artefact due to the nanodisc size distribution. The lipid chain packing peak at ∼1.5 Å −1 is visible in the data and reflects the lipid bilayer phase transition. The shape change in the distance distribution function across the phase transition suggests that the nanodiscs are more circular in the fluid phase. The implication of these findings for model fitting of empty and protein-loaded nanodiscs is discussed.« less

  20. Variability of ionospheric TEC during solar and geomagnetic minima (2008 and 2009): external high speed stream drivers

    NASA Astrophysics Data System (ADS)

    Verkhoglyadova, O. P.; Tsurutani, B. T.; Mannucci, A. J.; Mlynczak, M. G.; Hunt, L. A.; Runge, T.

    2013-02-01

    We study solar wind-ionosphere coupling through the late declining phase/solar minimum and geomagnetic minimum phases during the last solar cycle (SC23) - 2008 and 2009. This interval was characterized by sequences of high-speed solar wind streams (HSSs). The concomitant geomagnetic response was moderate geomagnetic storms and high-intensity, long-duration continuous auroral activity (HILDCAA) events. The JPL Global Ionospheric Map (GIM) software and the GPS total electron content (TEC) database were used to calculate the vertical TEC (VTEC) and estimate daily averaged values in separate latitude and local time ranges. Our results show distinct low- and mid-latitude VTEC responses to HSSs during this interval, with the low-latitude daytime daily averaged values increasing by up to 33 TECU (annual average of ~20 TECU) near local noon (12:00 to 14:00 LT) in 2008. In 2009 during the minimum geomagnetic activity (MGA) interval, the response to HSSs was a maximum of ~30 TECU increases with a slightly lower average value than in 2008. There was a weak nighttime ionospheric response to the HSSs. A well-studied solar cycle declining phase interval, 10-22 October 2003, was analyzed for comparative purposes, with daytime low-latitude VTEC peak values of up to ~58 TECU (event average of ~55 TECU). The ionospheric VTEC changes during 2008-2009 were similar but ~60% less intense on average. There is an evidence of correlations of filtered daily averaged VTEC data with Ap index and solar wind speed. We use the infrared NO and CO2 emission data obtained with SABER on TIMED as a proxy for the radiation balance of the thermosphere. It is shown that infrared emissions increase during HSS events possibly due to increased energy input into the auroral region associated with HILDCAAs. The 2008-2009 HSS intervals were ~85% less intense than the 2003 early declining phase event, with annual averages of daily infrared NO emission power of ~ 3.3 × 1010 W and 2.7 × 1010 W in 2008 and 2009, respectively. The roles of disturbance dynamos caused by high-latitude winds (due to particle precipitation and Joule heating in the auroral zones) and of prompt penetrating electric fields (PPEFs) in the solar wind-ionosphere coupling during these intervals are discussed. A correlation between geoeffective interplanetary electric field components and HSS intervals is shown. Both PPEF and disturbance dynamo mechanisms could play important roles in solar wind-ionosphere coupling during prolonged (up to days) external driving within HILDCAA intervals.

  1. Smoke and fire characteristics for cerrado and deforestation burns in Brazil: BASE-B experiment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ward, D.E.; Susott, R.A.; Babbitt, R.E.

    1992-09-20

    Fires of the tropical forests and savannas are a major source of particulate matter and trace gases affecting the atmosphere globally. A paucity of quantitative information exists for these ecosystems with respect to fuel biomass, smoke emissions, and fire behavior conditions affecting the release of emissions. Five test fires were performed during August and September 1990 in the cerrado (savannalike region) in central Brazil (three fires) and tropical moist forest (two fires) in the eastern Amazon. This paper details the gases released, the ratios of the gases to each other and to particulate matter, fuel loads and the fraction consumedmore » (combustion factors), and the fire behavior associated with biomass consumption. Models are presented for evaluating emission factors for CH{sub 4}, CO{sub 2}, CO, H{sub 2}, and particles less than 2.5 {mu}m diameter (PM2.5) as a function of combustion efficiency. The ratio of carbon released as CO{sub 2} (combustion efficiency) for the cerrado fires averaged 0.94 and for the deforestation fires it decreased from 0.88 for the flaming phase to <0.80 during the smoldering phase of combustion. For tropical ecosystems, emissions of most products of incomplete combustion are projected to be lower than previous estimates for savanna ecosystems and somewhat higher for fires used for deforestation purposes. 59 refs., 9 figs., 10 tabs.« less

  2. Market-driven automotive industry compliance with fuel economy and greenhouse gas standards: Analysis based on consumer choice

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xie, Fei; Lin, Zhenhong

    This paper explored factors that affect market-driven compliance with both Corporate Average Fuel Economy (CAFE) and greenhouse gas (GHG) standards (together called the National Program) in the United States for phase I 2012–2016 and phase II 2017–2025. We considered a consumer-choice-based simulation approach, using the MA3T model, to estimate the market acceptance of fuel efficiency (FE) technologies and alternative fuel technologies as reflected by new sales of light-duty vehicle (LDV). Because both full and extremely low FE valuations are common in the literature, we use a moderate assumption of a 10-year perceived vehicle lifetime at a 7% annual discount ratemore » in the baseline and include both extreme views (5 years and 15 years) in the sensitivity analysis. The study focuses on market-driven compliance and therefore excludes manufacturers’ cross-subsidization. The model results suggest that the LDV industry is able to comply with both standards even without cross-subsidization and with projected high technology cost, mainly thanks to the multiple credit programs and technology advancements. The compliance robustness, while encouraging, however is based on moderate market assumptions, such as Annual Energy Outlook 2016 Reference oil price projection and moderate FE consumer valuation. Finally, sensitivity analysis results reveal two significant risk factors for compliance: low oil prices and consumers’ FE undervaluation.« less

  3. Market-driven automotive industry compliance with fuel economy and greenhouse gas standards: Analysis based on consumer choice

    DOE PAGES

    Xie, Fei; Lin, Zhenhong

    2017-06-09

    This paper explored factors that affect market-driven compliance with both Corporate Average Fuel Economy (CAFE) and greenhouse gas (GHG) standards (together called the National Program) in the United States for phase I 2012–2016 and phase II 2017–2025. We considered a consumer-choice-based simulation approach, using the MA3T model, to estimate the market acceptance of fuel efficiency (FE) technologies and alternative fuel technologies as reflected by new sales of light-duty vehicle (LDV). Because both full and extremely low FE valuations are common in the literature, we use a moderate assumption of a 10-year perceived vehicle lifetime at a 7% annual discount ratemore » in the baseline and include both extreme views (5 years and 15 years) in the sensitivity analysis. The study focuses on market-driven compliance and therefore excludes manufacturers’ cross-subsidization. The model results suggest that the LDV industry is able to comply with both standards even without cross-subsidization and with projected high technology cost, mainly thanks to the multiple credit programs and technology advancements. The compliance robustness, while encouraging, however is based on moderate market assumptions, such as Annual Energy Outlook 2016 Reference oil price projection and moderate FE consumer valuation. Finally, sensitivity analysis results reveal two significant risk factors for compliance: low oil prices and consumers’ FE undervaluation.« less

  4. Examination of Rotating Spoke Instability in a Cross-Field Discharge

    DTIC Science & Technology

    2013-07-08

    leader), L. Balika, J. Vaudolon EMAU R. Schneider, K. Matyash PPPL Y. Raitses, A. Diallo, Y. Shi Distribution A: Approved for public...the spoke. The project was originally divided into three successive phases, namely: Phase 1: Time-averaged LIF study on the CHT at PPPL Phase 2...Time-resolved LIF study on the CHT at ICARE Phase 3: Time-resolved LIF study on a 2 kW HT at PPPL (Optional) Distribution A: Approved for public

  5. Organic carbon at a remote site of the western Mediterranean Basin: sources and chemistry during the ChArMEx SOP2 field experiment

    NASA Astrophysics Data System (ADS)

    Michoud, Vincent; Sciare, Jean; Sauvage, Stéphane; Dusanter, Sébastien; Léonardis, Thierry; Gros, Valérie; Kalogridis, Cerise; Zannoni, Nora; Féron, Anaïs; Petit, Jean-Eudes; Crenn, Vincent; Baisnée, Dominique; Sarda-Estève, Roland; Bonnaire, Nicolas; Marchand, Nicolas; Langley DeWitt, H.; Pey, Jorge; Colomb, Aurélie; Gheusi, François; Szidat, Sonke; Stavroulas, Iasonas; Borbon, Agnès; Locoge, Nadine

    2017-07-01

    The ChArMEx (Chemistry and Aerosols Mediterranean Experiments) SOP2 (special observation period 2) field campaign took place from 15 July to 5 August 2013 in the western Mediterranean Basin at Ersa, a remote site in Cape Corse. During the campaign more than 80 volatile organic compounds (VOCs), including oxygenated species, were measured by different online and offline techniques. At the same time, an exhaustive description of the chemical composition of fine aerosols was performed with an aerosol chemical speciation monitor (ACSM). Low levels of anthropogenic VOCs (typically tens to hundreds of parts per trillion for individual species) and black carbon (0.1-0.9 µg m-3) were observed, while significant levels of biogenic species (peaking at the ppb level) were measured. Furthermore, secondary oxygenated VOCs (OVOCs) largely dominated the VOC speciation during the campaign, while organic matter (OM) dominated the aerosol chemical composition, representing 55 % of the total mass of non-refractory PM1 on average (average of 3.74 ± 1.80 µg m-3), followed by sulfate (27 %, 1.83 ± 1.06 µg m-3), ammonium (13 %, 0.90 ± 0.55 µg m-3) and nitrate (5 %, 0.31 ± 0.18 µg m-3). Positive matrix factorization (PMF) and concentration field (CF) analyses were performed on a database containing 42 VOCs (or grouped VOCs), including OVOCs, to identify the covariation factors of compounds that are representative of primary emissions or chemical transformation processes. A six-factor solution was found for the PMF analysis, including a primary and secondary biogenic factor correlated with temperature and exhibiting a clear diurnal profile. In addition, three anthropogenic factors characterized by compounds with various lifetimes and/or sources have been identified (long-lived, medium-lived and short-lived anthropogenic factors). The anthropogenic nature of these factors was confirmed by the CF analysis, which identified potential source areas known for intense anthropogenic emissions (north of Italy and southeast of France). Finally, a factor characterized by OVOCs of both biogenic and anthropogenic origin was found. This factor was well correlated with submicron organic aerosol (OA) measured by an aerosol chemical speciation monitor (ACSM), highlighting the close link between OVOCs and organic aerosols; the latter is mainly associated (96 %) with the secondary OA fraction. The source apportionment of OA measured by ACSM led to a three-factor solution identified as hydrogen-like OA (HOA), semi-volatile oxygenated OA (SV-OOA) and low volatility OOA (LV-OOA) for averaged mass concentrations of 0.13, 1.59 and 1.92 µg m-3, respectively. A combined analysis of gaseous PMF factors with inorganic and organic fractions of aerosols helped distinguish between anthropogenic continental and biogenic influences on the aerosol- and gas-phase compositions.

  6. A Phase I proof-of-concept and safety trial of sildenafil to treat cerebral vasospasm following subarachnoid hemorrhage.

    PubMed

    Washington, Chad W; Derdeyn, Colin P; Dhar, Rajat; Arias, Eric J; Chicoine, Michael R; Cross, DeWitte T; Dacey, Ralph G; Han, Byung Hee; Moran, Christopher J; Rich, Keith M; Vellimana, Ananth K; Zipfel, Gregory J

    2016-02-01

    Studies show that phosphodiesterase-V (PDE-V) inhibition reduces cerebral vasospasm (CVS) and improves outcomes after experimental subarachnoid hemorrhage (SAH). This study was performed to investigate the safety and effect of sildenafil (an FDA-approved PDE-V inhibitor) on angiographic CVS in SAH patients. A2-phase, prospective, nonrandomized, human trial was implemented. Subarachnoid hemorrhage patients underwent angiography on Day 7 to assess for CVS. Those with CVS were given 10 mg of intravenous sildenafil in the first phase of the study and 30 mg in the second phase. In both, angiography was repeated 30 minutes after infusion. Safety was assessed by monitoring neurological examination findings and vital signs and for the development of adverse reactions. For angiographic assessment, in a blinded fashion, pre- and post-sildenafil images were graded as "improvement" or "no improvement" in CVS. Unblinded measurements were made between pre- and post-sildenafil angiograms. Twelve patients received sildenafil; 5 patients received 10 mg and 7 received 30 mg. There were no adverse reactions. There was no adverse effect on heart rate or intracranial pressure. Sildenafil resulted in a transient decline in mean arterial pressure, an average of 17% with a return to baseline in an average of 18 minutes. Eight patients (67%) were found to have a positive angiographic response to sildenafil, 3 (60%) in the low-dose group and 5 (71%) in the high-dose group. The largest degree of vessel dilation was an average of 0.8 mm (range 0-2.1 mm). This corresponded to an average percentage increase in vessel diameter of 62% (range 0%-200%). The results from this Phase I safety and proof-of-concept trial assessing the use of intravenous sildenafil in patients with CVS show that sildenafil is safe and well tolerated in the setting of SAH. Furthermore, the angiographic data suggest that sildenafil has a positive impact on human CVS.

  7. A preliminary evaluation of nearhore extreme sea level and wave models for fringing reef environments

    NASA Astrophysics Data System (ADS)

    Hoeke, R. K.; Reyns, J.; O'Grady, J.; Becker, J. M.; Merrifield, M. A.; Roelvink, J. A.

    2016-02-01

    Oceanic islands are widely perceived as vulnerable to sea level rise and are characterized by steep nearshore topography and fringing reefs. In such settings, near shore dynamics and (non-tidal) water level variability tends to be dominated by wind-wave processes. These processes are highly sensitive to reef morphology and roughness and to regional wave climate. Thus sea level extremes tend to be highly localized and their likelihood can be expected to change in the future (beyond simple extrapolation of sea level rise scenarios): e.g. sea level rise may increase the effective mean depth of reef crests and flats and ocean acidification and/or increased temperatures may lead to changes in reef structure. The problem is sufficiently complex that analytic or numerical approaches are necessary to estimate current hazards and explore potential future changes. In this study, we evaluate the capacity of several analytic/empirical approaches and phase-averaged and phase-resolved numerical models at sites in the insular tropical Pacific. We consider their ability to predict time-averaged wave setup and instantaneous water level exceedance probability (or dynamic wave run-up) as well as computational cost; where possible, we compare the model results with in situ observations from a number of previous studies. Preliminary results indicate analytic approaches are by far the most computationally efficient, but tend to perform poorly when alongshore straight and parallel morphology cannot be assumed. Phase-averaged models tend to perform well with respect to wave setup in such situations, but are unable to predict processes related to individual waves or wave groups, such as infragravity motions or wave run-up. Phase-resolved models tend to perform best, but come at high computational cost, an important consideration when exploring possible future scenarios. A new approach of combining an unstructured computational grid with a quasi-phase averaged approach (i.e. only phase resolving motions below a frequency cutoff) shows promise as a good compromise between computational efficiency and resolving processes such as wave runup and overtopping in more complex bathymetric situations.

  8. Conditional sampling technique to test the applicability of the Taylor hypothesis for the large-scale coherent structures

    NASA Technical Reports Server (NTRS)

    Hussain, A. K. M. F.

    1980-01-01

    Comparisons of the distributions of large scale structures in turbulent flow with distributions based on time dependent signals from stationary probes and the Taylor hypothesis are presented. The study investigated an area in the near field of a 7.62 cm circular air jet at a Re of 32,000, specifically having coherent structures through small-amplitude controlled excitation and stable vortex pairing in the jet column mode. Hot-wire and X-wire anemometry were employed to establish phase averaged spatial distributions of longitudinal and lateral velocities, coherent Reynolds stress and vorticity, background turbulent intensities, streamlines and pseudo-stream functions. The Taylor hypothesis was used to calculate spatial distributions of the phase-averaged properties, with results indicating that the usage of the local time-average velocity or streamwise velocity produces large distortions.

  9. Characterization of optical turbulence in a jet engine exhaust with Shack-Hartmenn wavefront sensor

    NASA Astrophysics Data System (ADS)

    Deron, R.; Mendez, F.

    2008-10-01

    Airborne laser countermeasure applications (DIRCM) are hampered by the turbulence of jet engine exhaust. The effects of this source of perturbation on optical propagation have still to be documented and analyzed in order to get a better insight into the different mechanisms of the plume perturbations and also to validate CFD/LES codes. For that purpose, wave front sensing has been used as a non-intrusive optical technique to provide unsteady and turbulent optical measurements through a plume of a jet engine installed at a fixed point on the ground. The experiment has been implemented in October 2007 along with other optical measuring techniques at Volvo Aero Corporation (Trollhättan, Sweden). This study is part of a European research programme dealing with DIRCM issues. The Shack- Hartmann (SH) wave front sensing technique was employed. It consisted of 64 x 64 lenslets coupled to a 1024x1024 pixel Dalsa CCD sensor working at a sampling rate of 40 Hz. A 15 ns pulsed laser synchronized with the SH sensor enabled "freezing" turbulence in each SH image. The ability of the technique to substract a reference permitted a simple calibration procedure to ensure accurate and reliable measurements despite vibration environment. Instantaneous phases are reconstructed using Fourier techniques so as to obtain a better spatial resolution against turbulent effects. Under any given plume condition, overall tilt aberration prevails. Phase power spectra derived from phase statistics are drawn according to the plume main axis and to normal axis. They compare favorably well to the decaying Kolmogorov power law on a useful high spatial frequency range. Averaged phases are also decomposed into Zernike polynomials to analyze optical mode behavior according to engine status and to plume abscissa. With overall tilt removed, turbulent DSP's amplitude drops by a factor of 30 to 40 and mean aberrations by a factor of 10 from an abscissa 1 meter to another 3.5 meters away from the engine nozzle, due to quite different turbulent conditions.

  10. Numerical experiments on breaking waves on contrasting beaches using a two-phase flow approach

    NASA Astrophysics Data System (ADS)

    Bakhtyar, R.; Barry, D. A.; Kees, C. E.

    2012-11-01

    A mechanistic understanding of beach environments needs to account for interactions of oceanic forcing and beach materials, in particular the role of waves on the evolution of the beach profile. A fully coupled two-phase flow model was used to simulate nearshore fluid-sediment turbulent flow in the cross-shore direction. It includes the Reynolds-Averaged Navier-Stokes equations and turbulent stress closures for each phase, and accounts for inter-granular stresses. The model has previously been validated using laboratory-scale data, so the results are likely more reliable for that scale. It was used to simulate wave breaking and the ensuing hydrodynamics and sediment transport processes in the surf/swash zones. Numerical experiments were conducted to investigate the effects of varying beach and wave characteristics (e.g., beach slope, sediment grain size, wave periods and heights) on the foreshore profile changes. Spilling and plunging breakers occur on dissipative and intermediate beaches, respectively. The impact of these wave/beach types on nearshore zone hydrodynamics and beach morphology was determined. The numerical results showed that turbulent kinetic energy, sediment concentrations and transport rate are greater on intermediate than on dissipative beaches. The results confirmed that wave energy, beach grain size and bed slope are main factors for sediment transport and beach morphodynamics. The location of the maximum sediment transport is near the breaking point for both beach types. Coarse- and fine-sand beaches differ significantly in their erosive characteristics (e.g., foreshore profile evolutions are erosive and accretionary on the fine and coarse sand beaches, respectively). In addition, a new parameter (based on main driving factors) is proposed that can characterize the sediment transport in the surf and swash zones. The results are consistent with existing physical observations, suggesting that the two-phase flow model is suitable for the simulation of hyper-concentrated mixed water-sediment flows in the nearshore. The model thus has potential as a useful tool for investigating interactions between nearshore hydrodynamics and beach morphology.

  11. Scattering from phase-separated vesicles. I. An analytical form factor for multiple static domains

    DOE PAGES

    Heberle, Frederick A.; Anghel, Vinicius N. P.; Katsaras, John

    2015-08-18

    This is the first in a series of studies considering elastic scattering from laterally heterogeneous lipid vesicles containing multiple domains. Unique among biophysical tools, small-angle neutron scattering can in principle give detailed information about the size, shape and spatial arrangement of domains. A general theory for scattering from laterally heterogeneous vesicles is presented, and the analytical form factor for static domains with arbitrary spatial configuration is derived, including a simplification for uniformly sized round domains. The validity of the model, including series truncation effects, is assessed by comparison with simulated data obtained from a Monte Carlo method. Several aspects ofmore » the analytical solution for scattering intensity are discussed in the context of small-angle neutron scattering data, including the effect of varying domain size and number, as well as solvent contrast. Finally, the analysis indicates that effects of domain formation are most pronounced when the vesicle's average scattering length density matches that of the surrounding solvent.« less

  12. Validation of an interior noise prediction model for a composite cylinder

    NASA Technical Reports Server (NTRS)

    Beyer, Todd B.; Grosveld, Ferdinand W.

    1987-01-01

    An acoustic modal analysis has been performed in the cavity of a composite cylinder model of an aircraft fuselage. The filament wound, composite shell is 12 feet long and 5.5 feet in diameter. A one-half-in. thick plywood floor is attached to the shell 69 deg from the vertical centerline through the bottom of the shell. The acoustic modal frequencies were obtained from a sound pressure level and phase survey conducted throughout the interior volume bounded by the floor, endcaps and stiffened shell, while being excited by white noise from a loudspeaker source. The measured acoustic resonance frequencies and mode shapes compare well with analytical predictions from the Propeller Aircraft Interior Noise (PAIN) model. Details of the theory and derivation of the acoustic characteristics have been included. Reverberation time measurements, using the integrated impulse technique, have been performed to determine acoustic loss factors. These measured loss factors have been input to the PAIN program in order to more accurately predict the space-averaged interior noise of the composite cylinder.

  13. The MXB1916-053/4U1915-05: Burst properties and constraints on a 50 minute binary secondary

    NASA Technical Reports Server (NTRS)

    Swank, J. H.; Taam, R. E.; White, N. E.

    1983-01-01

    Results are presented from OSO-8 and HEAO-1 A2 observations of 34 bursts from the X-ray burster MXB1916-053/4U1915-05 recently discovered to show a 50 minute binary period. While 11 burst previously reported all had similar light curves, 22 observed two years later show a factor of 3 range of peak fluxes and decay times between 3 and 20 s. Recurrence times between successive bursts vary between 3 and 6 hours. A ratio of steady flux to average burst flux of equiv 120 is developed. A burst observed with the HEAO-1 A2 experiment showed an initial temperature rise to a peak black body temperature of equiv 3 keV followed by the cooling typical of type I bursts. The burst was unusual in that the apparent projected size of a blackbody source increased by a factor of 3 during the cooling phase.

  14. Development and Initial Validation of the Five-Factor Model Adolescent Personality Questionnaire (FFM-APQ).

    PubMed

    Rogers, Mary E; Glendon, A Ian

    2018-01-01

    This research reports on the 4-phase development of the 25-item Five-Factor Model Adolescent Personality Questionnaire (FFM-APQ). The purpose was to develop and determine initial evidence for validity of a brief adolescent personality inventory using a vocabulary that could be understood by adolescents up to 18 years old. Phase 1 (N = 48) consisted of item generation and expert (N = 5) review of items; Phase 2 (N = 179) involved item analyses; in Phase 3 (N = 496) exploratory factor analysis assessed the underlying structure; in Phase 4 (N = 405) confirmatory factor analyses resulted in a 25-item inventory with 5 subscales.

  15. Speckle phase near random surfaces

    NASA Astrophysics Data System (ADS)

    Chen, Xiaoyi; Cheng, Chuanfu; An, Guoqiang; Han, Yujing; Rong, Zhenyu; Zhang, Li; Zhang, Meina

    2018-03-01

    Based on Kirchhoff approximation theory, the speckle phase near random surfaces with different roughness is numerically simulated. As expected, the properties of the speckle phase near the random surfaces are different from that in far field. In addition, as scattering distances and roughness increase, the average fluctuations of the speckle phase become larger. Unusually, the speckle phase is somewhat similar to the corresponding surface topography. We have performed experiments to verify the theoretical simulation results. Studies in this paper contribute to understanding the evolution of speckle phase near a random surface and provide a possible way to identify a random surface structure based on its speckle phase.

  16. Stick-Jump (SJ) Evaporation of Strongly Pinned Nanoliter Volume Sessile Water Droplets on Quick Drying, Micropatterned Surfaces.

    PubMed

    Debuisson, Damien; Merlen, Alain; Senez, Vincent; Arscott, Steve

    2016-03-22

    We present an experimental study of stick-jump (SJ) evaporation of strongly pinned nanoliter volume sessile water droplets drying on micropatterned surfaces. The evaporation is studied on surfaces composed of photolithographically micropatterned negative photoresist (SU-8). The micropatterning of the SU-8 enables circular, smooth, trough-like features to be formed which causes a very strong pinning of the three phase (liquid-vapor-solid) contact line of an evaporating droplet. This is ideal for studying SJ evaporation as it contains sequential constant contact radius (CCR) evaporation phases during droplet evaporation. The evaporation was studied in nonconfined conditions, and forced convection was not used. Micropatterned concentric circles were defined having an initial radius of 1000 μm decreasing by a spacing ranging from 500 to 50 μm. The droplet evaporates, successively pinning and depinning from circle to circle. For each pinning radius, the droplet contact angle and volume are observed to decrease quasi-linearly with time. The experimental average evaporation rates were found to decrease with decreasing pining radii. In contrast, the experimental average evaporation flux is found to increase with decreasing droplet radii. The data also demonstrate the influence of the initial contact angle on evaporation rate and flux. The data indicate that the total evaporation time of a droplet depends on the specific micropattern spacing and that the total evaporation time on micropatterned surfaces is always less than on flat, homogeneous surfaces. Although the surface patterning is observed to have little effect on the average droplet flux-indicating that the underlying evaporation physics is not significantly changed by the patterning-the total evaporation time is considerably modified by patterning, up to a factor or almost 2 compared to evaporation on a flat, homogeneous surface. The closely spaced concentric circle pinning maintains a large droplet radius and small contact angle from jump to jump; the result is a large evaporation rate leading to faster evaporation.

  17. 78 FR 77098 - Submission for OMB Review; Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ...: Regular submission (extension of a current information collection). Number of Respondents: 1,800. Average... Trustees in more efficiently carrying out the restoration planning phase of Natural Resource Damage... requiring restoration, during the restoration planning phase of the NRDA process. Affected Public: Not-for...

  18. [Drying characteristics and apparent change of sludge granules during drying].

    PubMed

    Ma, Xue-Wen; Weng, Huan-Xin; Zhang, Jin-Jun

    2011-08-01

    Three different weight grades of sludge granules (2.5, 5, 10 g) were dried at constant temperature of 100, 200, 300, 400 and 500 degrees C, respectively. Then characteristics of weight loss and change of apparent form during sludge drying were analyzed. Results showed that there were three stages during sludge drying at 100-200 degrees C: acceleration phase, constant-rate phase, and falling-rate phase. At 300-500 degrees C, there were no constant-rate phase, but due to lots of cracks generated at sludge surface, average drying rates were still high. There was a quadratic nonlinear relationship between average drying rate and drying temperature. At 100-200 degrees C, drying processes of different weight grade sludge granules were similar. At 300-500 degrees C, drying processes of same weight grade of sludge granules were similar. Little organic matter decomposed till sludge burning at 100-300 degrees C, while some organic matter began to decompose at the beginning of sludge drying at 400-500 degrees C.

  19. Design Considerations for Fusible Heat Sink

    NASA Technical Reports Server (NTRS)

    Cognata, Thomas J.; Leimkuehler, Thomas O.; Sheth, Rubik B.

    2011-01-01

    Traditionally radiator designs are based off a passive or flow through design depending on vehicle requirements. For cyclical heat loads, a novel idea of combining a full flow through radiator to a phase change material is currently being investigated. The flow through radiator can be designed for an average heat load while the phase change material can be used as a source of supplemental heat rejections when vehicle heat loads go above the average load. Furthermore, by using water as the phase change material, harmful radiation protection can be provided to the crew. This paper discusses numerous trades conducted to understand the most optimal fusible heat sink design for a particular heat load. Trades include configuration concepts, amount of phase change needed for supplemental heat rejection, and the form of interstitial material needed for optimal performance. These trades were used to culminate to a fusible heat sink design. The paper will discuss design parameters taken into account to develop an engineering development unit.

  20. Zernike Phase Contrast Electron Cryo-Tomography Applied to Marine Cyanobacteria Infected with Cyanophages

    PubMed Central

    Dai, Wei; Fu, Caroline; Khant, Htet A.; Ludtke, Steven J.; Schmid, Michael F.; Chiu, Wah

    2015-01-01

    Advances in electron cryo-tomography have provided a new opportunity to visualize the internal 3D structures of a bacterium. An electron microscope equipped with Zernike phase contrast optics produces images with dramatically increased contrast compared to images obtained by conventional electron microscopy. Here we describe a protocol to apply Zernike phase plate technology for acquiring electron tomographic tilt series of cyanophage-infected cyanobacterial cells embedded in ice, without staining or chemical fixation. We detail the procedures for aligning and assessing phase plates for data collection, and methods to obtain 3D structures of cyanophage assembly intermediates in the host, by subtomogram alignment, classification and averaging. Acquiring three to four tomographic tilt series takes approximately 12 h on a JEM2200FS electron microscope. We expect this time requirement to decrease substantially as the technique matures. Time required for annotation and subtomogram averaging varies widely depending on the project goals and data volume. PMID:25321408

  1. Learning Curve of the Application of Huang Three-Step Maneuver in a Laparoscopic Spleen-Preserving Splenic Hilar Lymphadenectomy for Advanced Gastric Cancer

    PubMed Central

    Huang, Ze-Ning; Huang, Chang-Ming; Zheng, Chao-Hui; Li, Ping; Xie, Jian-Wei; Wang, Jia-Bin; Lin, Jian-Xian; Lu, Jun; Chen, Qi-Yue; Cao, Long-long; Lin, Mi; Tu, Ru-Hong

    2016-01-01

    Abstract To investigate the learning curve of the application of Huang 3-step maneuver, which was summarized and proposed by our center for the treatment of advanced upper gastric cancer. From April 2012 to March 2013, 130 consecutive patients who underwent a laparoscopic spleen-preserving splenic hilar lymphadenectomy (LSPL) by a single surgeon who performed Huang 3-step maneuver were retrospectively analyzed. The learning curve was analyzed based on the moving average (MA) method and the cumulative sum method (CUSUM). Surgical outcomes, short-term outcomes, and follow-up results before and after learning curve were contrastively analyzed. A stepwise multivariate logistic regression was used for a multivariable analysis to determine the factors that affect the operative time using Huang 3-step maneuver. Based on the CUSUM, the learning curve for Huang 3-step maneuver was divided into phase 1 (cases 1–40) and phase 2 (cases 41–130). The dissection time (DT) (P < 0.001), blood loss (BL) (P < 0.001), and number of vessels injured in phase 2 were significantly less than those in phase 1. There were no significant differences in the clinicopathological characteristics, short-term outcomes, or major postoperative complications between the learning curve phases. Univariate and multivariate analyses revealed that body mass index (BMI), short gastric vessels (SGVs), splenic hilar artery (SpA) type, and learning curve phase were significantly associated with DT. In the entire group, 124 patients were followed for a median time of 23.0 months (range, 3–30 months). There was no significant difference in the survival curve between phases. AUGC patients with a BMI less than 25 kg/m2, a small number of SGVs, and a concentrated type of SpA are ideal candidates for surgeons who are in phase 1 of the learning curve. PMID:27043698

  2. The Influence of Footwear on the Modular Organization of Running.

    PubMed

    Santuz, Alessandro; Ekizos, Antonis; Janshen, Lars; Baltzopoulos, Vasilios; Arampatzis, Adamantios

    2017-01-01

    For most of our history, we predominantly ran barefoot or in minimalist shoes. The advent of modern footwear, however, might have introduced alterations in the motor control of running. The present study investigated shod and barefoot running under the perspective of the modular organization of muscle activation, in order to help addressing the neurophysiological factors underlying human locomotion. On a treadmill, 20 young and healthy inexperienced barefoot runners ran shod and barefoot at preferred speed (2.8 ± 0.4 m/s). Fundamental synergies, containing the time-dependent activation coefficients (motor primitives) and the time-invariant muscle weightings (motor modules), were extracted from 24 ipsilateral electromyographic activities using non-negative matrix factorization. In shod running, the average foot strike pattern was a rearfoot strike, while in barefoot running it was a mid-forefoot strike. In both conditions, five fundamental synergies were enough to describe as many gait cycle phases: weight acceptance, propulsion, arm swing, early swing and late swing. We found the motor primitives to be generally shifted earlier in time during the stance-related phases and later in the swing-related ones in barefoot running. The motor primitive describing the propulsion phase was significantly of shorter duration (peculiarity confirmed by the analysis of the spinal motor output). The arm swing primitive, instead, was significantly wider in the barefoot condition. The motor modules demonstrated analogous organization with some significant differences in the propulsion, arm swing and late swing synergies. Other than to the trivial absence of shoes, the differences might be deputed to the lower ankle gear ratio (and the consequent increased system instability) and to the higher recoil capabilities of the longitudinal foot arch during barefoot compared to shod running.

  3. The Influence of Footwear on the Modular Organization of Running

    PubMed Central

    Santuz, Alessandro; Ekizos, Antonis; Janshen, Lars; Baltzopoulos, Vasilios; Arampatzis, Adamantios

    2017-01-01

    For most of our history, we predominantly ran barefoot or in minimalist shoes. The advent of modern footwear, however, might have introduced alterations in the motor control of running. The present study investigated shod and barefoot running under the perspective of the modular organization of muscle activation, in order to help addressing the neurophysiological factors underlying human locomotion. On a treadmill, 20 young and healthy inexperienced barefoot runners ran shod and barefoot at preferred speed (2.8 ± 0.4 m/s). Fundamental synergies, containing the time-dependent activation coefficients (motor primitives) and the time-invariant muscle weightings (motor modules), were extracted from 24 ipsilateral electromyographic activities using non-negative matrix factorization. In shod running, the average foot strike pattern was a rearfoot strike, while in barefoot running it was a mid-forefoot strike. In both conditions, five fundamental synergies were enough to describe as many gait cycle phases: weight acceptance, propulsion, arm swing, early swing and late swing. We found the motor primitives to be generally shifted earlier in time during the stance-related phases and later in the swing-related ones in barefoot running. The motor primitive describing the propulsion phase was significantly of shorter duration (peculiarity confirmed by the analysis of the spinal motor output). The arm swing primitive, instead, was significantly wider in the barefoot condition. The motor modules demonstrated analogous organization with some significant differences in the propulsion, arm swing and late swing synergies. Other than to the trivial absence of shoes, the differences might be deputed to the lower ankle gear ratio (and the consequent increased system instability) and to the higher recoil capabilities of the longitudinal foot arch during barefoot compared to shod running. PMID:29213246

  4. 42 CFR 422.252 - Terminology.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... a nationally average risk profile for the factors described in § 422.308(c), and this amount is... risk profile for the risk factors CMS applies to payment calculations as set forth at § 422.308(c) of... eligible beneficiary with a nationally average risk profile for the risk factors CMS applies to payment...

  5. Influences of misalignment of control mirror of axisymmetric-structural CO2 laser on phase locking.

    PubMed

    Xu, Yonggen; Li, Yude; Qiu, Yi; Feng, Ting; Fu, Fuxing; Guo, Wei

    2008-11-20

    Based on the principle of phase locking of an axisymmetric-fold combination CO2 laser under the normal state condition, the mechanisms of phase locking are analyzed when the control mirror is misaligned. Then the overlapping rate (OR) of the mode volume is introduced: the main influences on phase locking are the OR, the average life of the light wave, the root mean square phase error, and the mode coupling coefficient; these influences on phase locking are studied. The distribution of the light intensity reflects the effect of phase locking. It is shown that the misaligned angle has little influence on the phase locking if it is within tolerance.

  6. Determination of vapor pressures for nonpolar and semipolar organic compounds from gas chromatographic retention data

    USGS Publications Warehouse

    Hinckley, D.A.; Bidleman, T.F.; Foreman, W.T.; Tuschall, J.R.

    1990-01-01

    Vapor pressures for nonpolar and moderately polar organochlorine, pyrethroid, and organophosphate insecticides, phthalate esters, and organophosphate flame retardants were determined by capillary gas chromatography (GC). Organochlorines and polycyclic aromatic hydrocarbons with known liquid-phase vapor pressures (P??L) (standard compounds) were chromatographed along with two reference compounds n-C20 (elcosane) and p,p???-DDT on a 1.0-m-long poly(dimethylsiloxane) bonded-phase (BP-1) column to determine their vapor pressures by GC (P??GC). A plot of log P??L vs log P??GC for standard compounds was made to establish a correlation between measured and literature values, and this correlation was then used to compute P??L of test compounds from their measured P??GC. P??L of seven major components of technical chlordane, endosulfan and its metabolites, ??-hexachlorocyclohexane, mirex, and two components of technical toxaphene were determined by GC. This method provides vapor pressures within a factor of 2 of average literature values for nonpolar compounds, similar to reported interlaboratory precisions of vapor pressure determinations. GC tends to overestimate vapor pressures of moderately polar compounds. ?? 1990 American Chemical Society.

  7. [Influence of the time factor on hospitalised patient's opinion].

    PubMed

    Santiñà, Manuel; Ascaso, Carlos; Escaramís, Georgia; Prat, Andreu; Asenjo, Miguel A

    2003-11-01

    An important controversy at the time of studying the perceived quality is which is the best time to know the patient's opinion. The objective of this work was to find out whether this opinion is different at the time of discharge and one month later. We included patients who were discharged between October 1999 and March 2000. We designed a specific opinion survey with 44 items. The survey was administered at the time of discharge. Individuals who responded to the first survey were sent the same one by e-mail 30 days after the discharge. The first survey was responded by 1,061 subjects and the second one by 485 (45.71%). Overall, answers from subjects who responded the survey in both phases showed a 65% agreement rate and a 35% disagreement rate. On the other hand, 84% of questions showed answers with a low agreement's Kappa index, while 6% had a good agreement. Globally considered, the average satisfaction expressed by subjects was equivalent in the two phases of the study, yet the individual degree of satisfaction varied.

  8. Determination of acidic herbicides in surface water by solid-phase extraction followed by capillary zone electrophoresis.

    PubMed

    Qin, Weidong; Wei, Hongping; Li, Sam Fong Yau

    2002-08-01

    A rapid solid-phase extraction-capillary zone electrophoresis (CZE) method for determining 2,4-dichlorophenoxyacetic acid, 4-(2,4-dichlorophenoxy) butyric acid, and 2,4,5-trichlorophenoxyacetic acid in real water samples is described. Factors affecting the recoveries and detection of the targets are investigated. With samples being acidified to pH 2 and salted by sodium sulfate to 2% (w/w), an average recovery of greater than 85% is obtained using ethyl acetate as the eluent on an octadecylsilane-bonded silica cartridge. A running buffer of 5 mM sodium tetraborate in a water-acetonitrile mixture (70:30, v/v) adjusted to pH 9 is employed in the CZE analysis, and the targets can be analyzed within 7 min with good reproducibility and acceptable sensitivity. The method is suitable for detecting herbicide residues of sub-parts-per-billion levels in surface water. A local pond water is analyzed, and the concentrations of 2,4-dichlorophenoxyacetic acid and 4-(2,4-dichlorophenoxy) butyric acid are detected to be 0.27 +/- 0.03 ppb and 0.61 +/- 0.08 ppb, respectively.

  9. A facile in vitro model to study rapid mineralization in bone tissues.

    PubMed

    Deegan, Anthony J; Aydin, Halil M; Hu, Bin; Konduru, Sandeep; Kuiper, Jan Herman; Yang, Ying

    2014-09-16

    Mineralization in bone tissue involves stepwise cell-cell and cell-ECM interaction. Regulation of osteoblast culture microenvironments can tailor osteoblast proliferation and mineralization rate, and the quality and/or quantity of the final calcified tissue. An in vitro model to investigate the influencing factors is highly required. We developed a facile in vitro model in which an osteoblast cell line and aggregate culture (through the modification of culture well surfaces) were used to mimic intramembranous bone mineralization. The effect of culture environments including culture duration (up to 72 hours for rapid mineralization study) and aggregates size (monolayer culture as control) on mineralization rate and mineral quantity/quality were examined by osteogenic gene expression (PCR) and mineral markers (histological staining, SEM-EDX and micro-CT). Two size aggregates (on average, large aggregates were 745 μm and small 79 μm) were obtained by the facile technique with high yield. Cells in aggregate culture generated visible and quantifiable mineralized matrix within 24 hours, whereas cells in monolayer failed to do so by 72 hours. The gene expression of important ECM molecules for bone formation including collagen type I, alkaline phosphatase, osteopontin and osteocalcin, varied temporally, differed between monolayer and aggregate cultures, and depended on aggregate size. Monolayer specimens stayed in a proliferation phase for the first 24 hours, and remained in matrix synthesis up to 72 hours; whereas the small aggregates were in the maturation phase for the first 24 and 48 hour cultures and then jumped to a mineralization phase at 72 hours. Large aggregates were in a mineralization phase at all these three time points and produced 36% larger bone nodules with a higher calcium content than those in the small aggregates after just 72 hours in culture. This study confirms that aggregate culture is sufficient to induce rapid mineralization and that aggregate size determines the mineralization rate. Mineral content depended on aggregate size and culture duration. Thus, our culture system may provide a good model to study regulation factors at different development phases of the osteoblastic lineage.

  10. Feasibility of semiautomated MR volumetry using gadoxetic acid-enhanced MRI at hepatobiliary phase for living liver donors.

    PubMed

    Lee, Jeongjin; Kim, Kyoung Won; Kim, So Yeon; Kim, Bohyoung; Lee, So Jung; Kim, Hyoung Jung; Lee, Jong Seok; Lee, Moon Gyu; Song, Gi-Won; Hwang, Shin; Lee, Sung-Gyu

    2014-09-01

    To assess the feasibility of semiautomated MR volumetry using gadoxetic acid-enhanced MRI at the hepatobiliary phase compared with manual CT volumetry. Forty potential live liver donor candidates who underwent MR and CT on the same day, were included in our study. Semiautomated MR volumetry was performed using gadoxetic acid-enhanced MRI at the hepatobiliary phase. We performed the quadratic MR image division for correction of the bias field inhomogeneity. With manual CT volumetry as the reference standard, we calculated the average volume measurement error of the semiautomated MR volumetry. We also calculated the mean of the number and time of the manual editing, edited volume, and total processing time. The average volume measurement errors of the semiautomated MR volumetry were 2.35% ± 1.22%. The average values of the numbers of editing, operation times of manual editing, edited volumes, and total processing time for the semiautomated MR volumetry were 1.9 ± 0.6, 8.1 ± 2.7 s, 12.4 ± 8.8 mL, and 11.7 ± 2.9 s, respectively. Semiautomated liver MR volumetry using hepatobiliary phase gadoxetic acid-enhanced MRI with the quadratic MR image division is a reliable, easy, and fast tool to measure liver volume in potential living liver donors. Copyright © 2013 Wiley Periodicals, Inc.

  11. Far field and wavefront characterization of a high-power semiconductor laser for free space optical communications

    NASA Technical Reports Server (NTRS)

    Cornwell, Donald M., Jr.; Saif, Babak N.

    1991-01-01

    The spatial pointing angle and far field beamwidth of a high-power semiconductor laser are characterized as a function of CW power and also as a function of temperature. The time-averaged spatial pointing angle and spatial lobe width were measured under intensity-modulated conditions. The measured pointing deviations are determined to be well within the pointing requirements of the NASA Laser Communications Transceiver (LCT) program. A computer-controlled Mach-Zehnder phase-shifter interferometer is used to characterize the wavefront quality of the laser. The rms phase error over the entire pupil was measured as a function of CW output power. Time-averaged measurements of the wavefront quality are also made under intensity-modulated conditions. The measured rms phase errors are determined to be well within the wavefront quality requirements of the LCT program.

  12. Tissue refractometry using Hilbert phase microscopy.

    PubMed

    Lue, Niyom; Bewersdorf, Joerg; Lessard, Mark D; Badizadegan, Kamran; Dasari, Ramachandra R; Feld, Michael S; Popescu, Gabriel

    2007-12-15

    We present, for the first time to our knowledge, quantitative phase images associated with unstained 5 mum thick tissue slices of mouse brain, spleen, and liver. The refractive properties of the tissue are retrieved in terms of the average refractive index and its spatial variation. We find that the average refractive index varies significantly with tissue type, such that the brain is characterized by the lowest value and the liver by the highest. The spatial power spectra of the phase images reveal power law behavior with different exponents for each tissue type. This approach opens a new possibility for stain-free characterization of tissues, where the diagnostic power is provided by the intrinsic refractive properties of the biological structure. We present results obtained for liver tissue affected by a lysosomal storage disease and show that our technique can quantify structural changes during this disease development.

  13. Experimental comparisons of hypothesis test and moving average based combustion phase controllers.

    PubMed

    Gao, Jinwu; Wu, Yuhu; Shen, Tielong

    2016-11-01

    For engine control, combustion phase is the most effective and direct parameter to improve fuel efficiency. In this paper, the statistical control strategy based on hypothesis test criterion is discussed. Taking location of peak pressure (LPP) as combustion phase indicator, the statistical model of LPP is first proposed, and then the controller design method is discussed on the basis of both Z and T tests. For comparison, moving average based control strategy is also presented and implemented in this study. The experiments on a spark ignition gasoline engine at various operating conditions show that the hypothesis test based controller is able to regulate LPP close to set point while maintaining the rapid transient response, and the variance of LPP is also well constrained. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Cells of pea (Pisum sativum) that differentiate from G2 phase have extrachromosomal DNA.

    PubMed Central

    Van't Hof, J; Bjerknes, C A

    1982-01-01

    Velocity sedimentation in an alkaline sucrose gradient of newly replicated chromosomal DNA revealed the presence of extrachromosomal DNA that was not replicated by differentiating cells in the elongation zone. The extrachromosomal DNA had a number average molecular weight of 12 X 10(6) to 15 X 10(6) and a weight average molecular weight of 25 X 10(6), corresponding to about 26 X 10(6) and 50 X 10(6) daltons, respectively, of double-stranded DNA. The molecules were stable, lasting at least 72 h after being formed. Concurrent measurements by velocity sedimentation, autoradiography, and cytophotometry of isolated nuclei indicated that the extrachromosomal molecules were associated with root-tip cells that stopped dividing and differentiated from G2 phase but not with those that stopped dividing and differentiated from G1 phase. PMID:7110135

  15. Topography and refractometry of sperm cells using spatial light interference microscopy

    NASA Astrophysics Data System (ADS)

    Liu, Lina; Kandel, Mikhail E.; Rubessa, Marcello; Schreiber, Sierra; Wheeler, Mathew B.; Popescu, Gabriel

    2018-02-01

    Characterization of spermatozoon viability is a common test in treating infertility. Recently, it has been shown that label-free, phase-sensitive imaging can provide a valuable alternative for this type of assay. We employ spatial light interference microscopy (SLIM) to perform high-accuracy single-cell phase imaging and decouple the average thickness and refractive index information for the population. This procedure was enabled by quantitative-phase imaging cells on media of two different refractive indices and using a numerical tool to remove the curvature from the cell tails. This way, we achieved ensemble averaging of topography and refractometry of 100 cells in each of the two groups. The results show that the thickness profile of the cell tail goes down to 150 nm and the refractive index can reach values of 1.6 close to the head.

  16. Porous and Phase Change Nanomaterials For Photonic Applications

    DTIC Science & Technology

    2014-08-28

    two phase composite material can be considered as a single effective medium with a characteristic dielectric constant that is a weighted average of...reported that a phase transition could be trig- gered by electrical stimuli using a short current pulse to heat the material past the critical 12 29...in effective index, or phase ∆φ . When placed inside an optical cavity, such as an ultra-compact micro -ring resonator (R = 1.5 µm, Fig. 5.1.b), a short

  17. Variability of radon and thoron equilibrium factors in indoor environment of Garhwal Himalaya.

    PubMed

    Prasad, Mukesh; Rawat, Mukesh; Dangwal, Anoop; Kandari, Tushar; Gusain, G S; Mishra, Rosaline; Ramola, R C

    2016-01-01

    The measurements of radon, thoron and their progeny concentrations have been carried out in the dwellings of Uttarkashi and Tehri districts of Garhwal Himalaya, India using LR-115 detector based pin-hole dosimeter and DRPS/DTPS techniques. The equilibrium factors for radon, thoron and their progeny were calculated by using the values measured with these techniques. The average values of equilibrium factor between radon and its progeny have been found to be 0.44, 0.39, 0.39 and 0.28 for rainy, autumn, winter and summer seasons, respectively. For thoron and its progeny, the average values of equilibrium factor have been found to be 0.04, 0.04, 0.04 and 0.03 for rainy, autumn, winter and summer seasons, respectively. The equilibrium factor between radon and its progeny has been found to be dependent on the seasonal changes. However, the equilibrium factor for thoron and progeny has been found to be same for rainy, autumn and winter seasons but slightly different for summer season. The annual average equilibrium factors for radon and thoron have been found to vary from 0.23 to 0.80 with an average of 0.42 and from 0.01 to 0.29 with an average of 0.07, respectively. The detailed discussion of the measurement techniques and the explanation for the results obtained is given in the paper. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. SU-C-210-03: Impact of Breathing Irregularities On Gated Treatments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schiuma, D; Arheit, M; Schmelzer, P

    2015-06-15

    Purpose: To evaluate the effect of breathing irregularities on target location in gated treatments using amplitude and phase gating. Methods: 111 breathing patterns acquired using RPM system were categorized based on period and amplitude STD as regular (STD period ≤ 0.5 s, STD amplitude ≤ 1.5 mm), medium (0.5 s < STD period ≤ 1 s, 1.5 mm < STD amplitude ≤ 3 mm) and irregular (STD period > 1 s, STD amplitude > 3 mm). One pattern representative of the average defined population was selected per category and corresponding target motion reproduced using Quasar Respiratory Motion Phantom. Phantom inmore » motion underwent 4D-CT scan with phase reconstruction. Gated window was defined at end of exhale and DRRs reconstructed in treatment planning at 40% (beam on) and 60% phase (beam off). Target location uncertainty was assessed by comparing gated kV triggered images continuously acquired at beam on/off on a True Beam 2.0 with corresponding DRRs. Results: Average target uncertainty with amplitude gating was in [0.4 – 1.9] mm range for the different scenarios with maximum STD of 1.2 mm for the irregular pattern. Average target uncertainty with phase gating was [1.1 – 2.2] mm for regular and medium patterns, while it increased to [3.6 – 9.6] mm for the irregular pattern. Live gated motion was stable with amplitude gating, while increasing with phase gating for the irregular pattern. Treatment duration range was [68 – 160] s with amplitude and [70 – 74] s with phase gating. Conclusion: Breathing irregularities were found to affect gated treatments only when using phase gating. For regular and medium patterns no significant difference was found between the two gating strategies. Amplitude gating ensured stable gated motion within the different patterns, thus reducing intra-fraction target location variability for the irregular pattern and resulting in longer treatment duration.« less

  19. Home Circadian Phase Assessments with Measures of Compliance Yield Accurate Dim Light Melatonin Onsets

    PubMed Central

    Burgess, Helen J.; Wyatt, James K.; Park, Margaret; Fogg, Louis F.

    2015-01-01

    Study Objectives: There is a need for the accurate assessment of circadian phase outside of the clinic/laboratory, particularly with the gold standard dim light melatonin onset (DLMO). We tested a novel kit designed to assist in saliva sampling at home for later determination of the DLMO. The home kit includes objective measures of compliance to the requirements for dim light and half-hourly saliva sampling. Design: Participants were randomized to one of two 10-day protocols. Each protocol consisted of two back-to-back home and laboratory phase assessments in counterbalanced order, separated by a 5-day break. Setting: Laboratory or participants' homes. Participants: Thirty-five healthy adults, age 21–62 y. Interventions: N/A. Measurements and Results: Most participants received at least one 30-sec epoch of light > 50 lux during the home phase assessments (average light intensity 4.5 lux), but on average for < 9 min of the required 8.5 h. Most participants collected every saliva sample within 5 min of the scheduled time. Ninety-two percent of home DLMOs were not affected by light > 50 lux or sampling errors. There was no significant difference between the home and laboratory DLMOs (P > 0.05); on average the home DLMOs occurred 9.6 min before the laboratory DLMOs. The home DLMOs were highly correlated with the laboratory DLMOs (r = 0.91, P < 0.001). Conclusions: Participants were reasonably compliant to the home phase assessment procedures. The good agreement between the home and laboratory dim light melatonin onsets (DLMOs) demonstrates that including objective measures of light exposure and sample timing during home saliva sampling can lead to accurate home DLMOs. Clinical Trial Registration: Circadian Phase Assessments at Home, http://clinicaltrials.gov/show/NCT01487252, NCT01487252. Citation: Burgess HJ, Wyatt JK, Park M, Fogg LF. Home circadian phase assessments with measures of compliance yield accurate dim light melatonin onsets. SLEEP 2015;38(6):889–897. PMID:25409110

  20. CENTRAL CAROLINA VEHICLE PARTICULATE EMISSION STUDY (FINAL REPORT)

    EPA Science Inventory

    A study to characterize the exhaust emissions from a light-duty fleet of in-use vehicles representative of central North Carolina was conducted in 1999 during both a winter phase (February) and a summer phase (June - July). Summer temperatures averaged 78 F, while the winter te...

  1. Precise Orbit Determination of the GOCE Re-Entry Phase

    NASA Astrophysics Data System (ADS)

    Gini, Francesco; Otten, Michiel; Springer, Tim; Enderle, Werner; Lemmens, Stijn; Flohrer, Tim

    2015-03-01

    During the last days of the GOCE mission, after the GOCE spacecraft ran out of fuel, it slowly decayed before finally re-entering the atmosphere on the 11th November 2013. As an integrated part of the AOCS, GOCE carried a GPS receiver that was in operations during the re-entry phase. This feature provided a unique opportunity for Precise Orbit Determination (POD) analysis. As part of the activities carried out by the Navigation Support Office (HSO-GN) at ESOC, precise ephemerides of the GOCE satellite have been reconstructed for the entire re-entry phase based on the available GPS observations of the onboard LAGRANGE receiver. All the data available from the moment the thruster was switched off on the 21st of October 2013 to the last available telemetry downlink on the 10th November 2013 have been processed, for a total of 21 daily arcs. For this period a dedicated processing sequence has been defined and implemented within the ESA/ESOC NAvigation Package for Earth Observation Satellites (NAPEOS) software. The computed results show a post-fit RMS of the GPS undifferenced carrier phase residuals (ionospheric-free linear combination) between 6 and 14 mm for the first 16 days which then progressively increases up to about 80 mm for the last available days. An orbit comparison with the Precise Science Orbits (PSO) generated at the Astronomical Institute of the University of Bern (AIUB, Bern, Switzerland) shows an average difference around 9 cm for the first 8 daily arcs and progressively increasing up to 17 cm for the following days. During this reentry phase (21st of October - 10th November 2013) a substantial drop in the GOCE altitude is observed, starting from about 230 km to 130 km where the last GPS measurements were taken. During this orbital decay an increment of a factor of 100 in the aerodynamic acceleration profile is observed. In order to limit the mis-modelling of the non-gravitational forces (radiation pressure and aerodynamic effects) the newly developed software ARPA (Aerodynamics and Radiation Pressure Analysis) has been adopted to compute the forces acting on GOCE. An overview of the software techniques and the results of its implementation is presented in this paper. The use of the ARPA modelling leads to an average reduction of the carrier phase post-fit RMS of about 2 mm and decrement of the difference with the PSO orbits of more than 1 cm.

  2. Learning curves for single incision and conventional laparoscopic right hemicolectomy: a multidimensional analysis

    PubMed Central

    Park, Yoonah; Yong, Yuen Geng; Jung, Kyung Uk; Huh, Jung Wook; Cho, Yong Beom; Kim, Hee Cheol; Lee, Woo Yong; Chun, Ho-Kyung

    2015-01-01

    Purpose This study aimed to compare the learning curves and early postoperative outcomes for conventional laparoscopic (CL) and single incision laparoscopic (SIL) right hemicolectomy (RHC). Methods This retrospective study included the initial 35 cases in each group. Learning curves were evaluated by the moving average of operative time, mean operative time of every five consecutive cases, and cumulative sum (CUSUM) analysis. The learning phase was considered overcome when the moving average of operative times reached a plateau, and when the mean operative time of every five consecutive cases reached a low point and subsequently did not vary by more than 30 minutes. Results Six patients with missing data in the CL RHC group were excluded from the analyses. According to the mean operative time of every five consecutive cases, learning phase of SIL and CL RHC was completed between 26 and 30 cases, and 16 and 20 cases, respectively. Moving average analysis revealed that approximately 31 (SIL) and 25 (CL) cases were needed to complete the learning phase, respectively. CUSUM analysis demonstrated that 10 (SIL) and two (CL) cases were required to reach a steady state of complication-free performance, respectively. Postoperative complications rate was higher in SIL than in CL group, but the difference was not statistically significant (17.1% vs. 3.4%). Conclusion The learning phase of SIL RHC is longer than that of CL RHC. Early oncological outcomes of both techniques were comparable. However, SIL RHC had a statistically insignificant higher complication rate than CL RHC during the learning phase. PMID:25960990

  3. A Novel Equation-of-State to Model Microemulsion Phase Behavior for Enhanced Oil Recovery Application

    NASA Astrophysics Data System (ADS)

    Ghosh, Soumyadeep

    Surfactant-polymer (SP) floods have significant potential to recover waterflood residual oil in shallow oil reservoirs. A thorough understanding of surfactant-oil-brine phase behavior is critical to the design of chemical EOR floods. While considerable progress has been made in developing surfactants and polymers that increase the potential of a chemical enhanced oil recovery (EOR) project, very little progress has been made to predict phase behavior as a function of formulation variables such as pressure, temperature, and oil equivalent alkane carbon number (EACN). The empirical Hand's plot is still used today to model the microemulsion phase behavior with little predictive capability as these and other formulation variables change. Such models could lead to incorrect recovery predictions and improper flood designs. Reservoir crudes also contain acidic components (primarily naphthenic acids), which undergo neutralization to form soaps in the presence of alkali. The generated soaps perform synergistically with injected synthetic surfactants to mobilize waterflood residual oil in what is termed alkali-surfactant-polymer (ASP) flooding. The addition of alkali, however, complicates the measurement and prediction of the microemulsion phase behavior that forms with acidic crudes. In this dissertation, we account for pressure changes in the hydrophilic-lipophilic difference (HLD) equation. This new HLD equation is coupled with the net-average curvature (NAC) model to predict phase volumes, solubilization ratios, and microemulsion phase transitions (Winsor II-, III, and II+). This dissertation presents the first modified HLD-NAC model to predict microemulsion phase behavior for live crudes, including optimal solubilization ratio and the salinity width of the three-phase Winsor III region at different temperatures and pressures. This new equation-of-state-like model could significantly aid the design and forecast of chemical floods where key variables change dynamically, and in screening of potential candidate reservoirs for chemical EOR. The modified HLD-NAC model is also extended here for ASP flooding. We use an empirical equation to calculate the acid distribution coefficient from the molecular structure of the soap. Key HLD-NAC parameters like optimum salinities and optimum solubilization ratios are calculated from soap mole fraction weighted equations. The model is tuned to data from phase behavior experiments with real crudes to demonstrate the procedure. We also examine the ability of the new model to predict fish plots and activity charts that show the evolution of the three-phase region. The modified HLD-NAC equations are then made dimensionless to develop important microemulsion phase behavior relationships and for use in tuning the new model to measured data. Key dimensionless groups that govern phase behavior and their effects are identified and analyzed. A new correlation was developed to predict optimum solubilization ratios at different temperatures, pressures and oil EACN with an average relative error of 10.55%. The prediction of optimum salinities with the modified HLD approach resulted in average relative errors of 2.35%. We also present a robust method to precisely determine optimum salinities and optimum solubilization ratios from salinity scan data with average relative errors of 1.17% and 2.44% for the published data examined.

  4. Explaining variation in hospice visit intensity for routine home care.

    PubMed

    Stearns, Sally C; Sheingold, Steven; Zuckerman, Rachael B

    2014-01-01

    Medicare pays a flat per diem rate by level of hospice service without case-mix adjustment, although previous research shows that visit intensity varies considerably over the course of hospice episodes. Concerns pertain to the inherent financial incentives for routine home care, the most frequently used level, and whether payment efficiency can be improved using case-mix adjustment. The aim of this study was to assess variation in hospice visit intensity during hospice episodes by patient, hospice, and episode characteristics to inform policy discussions regarding hospice payment methods. This observational study used Medicare claims for hospice episodes in 2010. Multiple observations were constructed per episode phase (eg, days 1-14, 15-30, etc.). Episode phase and observed characteristics were regressed on average routine home care visit intensity per day; patient and hospice fixed effects controlled for unobserved characteristics. Visit intensity was constructed using national wages to weight visits by provider type. Observed patient characteristics included age, sex, race, diagnoses, venue of care, use of other hospice levels of care, and discharge status; hospice characteristics included ownership, affiliation, size, and urban/state location. Visit intensity varied substantially by episode phase. This pattern was largely invariant to observed patient and hospice characteristics, which explained <4% of variation in visit intensity per day after adjusting for episode phase. Unobserved patient characteristics explained approximately 85% of remaining variation. These results show that case-mix adjustment based on commonly observed factors would only minimally improve hospice payment methodology.

  5. The Bolocam Galactic Plane Survey. XIV. Physical Properties of Massive Starless and Star-forming Clumps

    NASA Astrophysics Data System (ADS)

    Svoboda, Brian E.; Shirley, Yancy L.; Battersby, Cara; Rosolowsky, Erik W.; Ginsburg, Adam G.; Ellsworth-Bowers, Timothy P.; Pestalozzi, Michele R.; Dunham, Miranda K.; Evans, Neal J., II; Bally, John; Glenn, Jason

    2016-05-01

    We sort 4683 molecular clouds between 10° < ℓ < 65° from the Bolocam Galactic Plane Survey based on observational diagnostics of star formation activity: compact 70 μm sources, mid-IR color-selected YSOs, H2O and CH3OH masers, and UCH II regions. We also present a combined NH3-derived gas kinetic temperature and H2O maser catalog for 1788 clumps from our own GBT 100 m observations and from the literature. We identify a subsample of 2223 (47.5%) starless clump candidates (SCCs), the largest and most robust sample identified from a blind survey to date. Distributions of flux density, flux concentration, solid angle, kinetic temperature, column density, radius, and mass show strong (>1 dex) progressions when sorted by star formation indicator. The median SCC is marginally subvirial (α ˜ 0.7) with >75% of clumps with known distance being gravitationally bound (α < 2). These samples show a statistically significant increase in the median clump mass of ΔM ˜ 170-370 M ⊙ from the starless candidates to clumps associated with protostars. This trend could be due to (I) mass growth of the clumps at \\dot{M}˜ 200{--}440 M ⊙ Myr-1 for an average freefall 0.8 Myr timescale, (II) a systematic factor of two increase in dust opacity from starless to protostellar phases, and/or (III) a variation in the ratio of starless to protostellar clump lifetime that scales as ˜M -0.4. By comparing to the observed number of CH3OH maser containing clumps, we estimate the phase lifetime of massive (M > 103 M ⊙) starless clumps to be 0.37 ± 0.08 Myr (M/103 M ⊙)-1 the majority (M < 450 M ⊙) have phase lifetimes longer than their average freefall time.

  6. A half-century of production-phase greenhouse gas emissions from food loss & waste in the global food supply chain.

    PubMed

    Porter, Stephen D; Reay, David S; Higgins, Peter; Bomberg, Elizabeth

    2016-11-15

    Research on loss & waste of food meant for human consumption (FLW) and its environmental impact typically focuses on a single or small number of commodities in a specific location and point in time. However, it is unclear how trends in global FLW and potential for climate impact have evolved. Here, by utilising the Food and Agriculture Organization's food balance sheet data, we expand upon existing literature. Firstly, we provide a differentiated (by commodity, country and supply chain stage) bottom-up approach; secondly, we conduct a 50-year longitudinal analysis of global FLW and its production-phase greenhouse gas (GHG) emissions; and thirdly, we trace food wastage and its associated emissions through the entire food supply chain. Between 1961 and 2011 the annual amount of FLW by mass grew a factor of three - from 540Mt to 1.6Gt; associated production-phase (GHG) emissions more than tripled (from 680Mt to 2.2Gt CO2e). A 44% increase in global average per capita FLW emissions was also identified - from 225kg CO2e in 1961 to 323kg CO2e in 2011. The regional weighting within this global average changing markedly over time; in 1961 developed countries accounted for 48% of FLW and less than a quarter (24%) in 2011. The largest increases in FLW-associated GHG emissions were from developing economies, specifically China and Latin America - primarily from increasing losses in fruit and vegetables. Over the period examined, cumulatively such emissions added almost 68Gt CO2e to the atmospheric GHG stock; an amount the rough equivalent of two years of emissions from all anthropogenic sources at present rates. Building up from the most granular data available, this study highlights the growth in the climate burden of FLW emissions, and thus the need to improve efficiency in food supply chains to mitigate future emissions. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Multiple oxygen and sulfur isotope compositions of secondary atmospheric sulfate in the city of Wuhan, central China

    NASA Astrophysics Data System (ADS)

    Li, X.; Bao, H.; Zhou, A.; Wang, D.

    2012-12-01

    Secondary atmospheric sulfate (SAS) is the oxidation product and sink for sulfur gases of biological, volcanic, and anthropogenic origins on Earth. SAS can be produced from gas-phase OH-radical oxidation and five aqueous-phase chemical reactions including aqueous-phase S (IV) oxidation reactions by H2O2, O3, oxygen catalyzed by Fe3+ and Mn2+, and methyle hydrogen peroxide and peroxyacetic acid. The tropospheric sulfur oxidation pathway is therefore determined by cloud-water pH, dissolved [Fe2+] or [Mn2+] content, S emission rate, meteorological condition, and other factors. The S isotope composition is a good tracer for the source while the O isotopes, especially the triple O isotope compositions are a good tracer for S oxidation pathway. Jerkins and Bao (2006) provided the first set of multiple stable isotope compositions (δ34S, δ18O and Δ17O) for SAS collected from bulk atmosphere in Baton Rouge in the relatively rural southern USA. Their study revealed a long-tern average Δ17O value of ~+0.7‰ for SAS, and speculated that much of the Earth mid-latitudes may have a similar average SAS Δ17O value. Additional sampling campaign at different sites is necessarily for constructing and testing models on sulfur oxidation and transport in the troposphere. A total of 33 sulfate samples were collected from bulk atmospheric deposition over a 950-day period from May 2009 to December 2011 in the city of Wuhan, Hubei Province, China. Differing from Baton Rouge, Wuhan is an industrial metropolis with a population of 9.8 million and a high particulate matter content (115 μg/m3). It also has a subtropical monsoon climate, with rainwater pH at ~5.3 year-around. The rainwater ion concentrations have seasonal variations, typically low in summer and high in winter. The anions are dominated by SO42-, at an average concentration of 8.5 mg/L. There is little sulfate contribution from sea-salt (SS) sulfate or dusts in Wuhan. The isotopic compositions for bulk atmospheric sulfate range from 0.00‰ to 1.02‰ for the Δ17O, 8.0‰ to 17.8‰ for the δ18O, and 2.1‰ to 24.1‰ for the δ34S. No apparent correlation is found among Δ17O, δ18O, or δ34S values. No significant temporal pattern exists for the Δ17O over the collection period. The positive Δ17O values for SAS have a time-weighted average of 0.52 ± 0.23‰, lower than the average in Baton Rouge, raising the possibility that the high particulate matter content in Wuhan may have played a role in promoting S oxidation via surface and/or Fe(III)-catalyzed pathways that do not generate positive 17O anomaly in product sulfate. The average Δ17O value also supports the assertion that the long-term average Δ17O value for SAS in the mid-latitude sites fall within a range (0.6~0.8‰) that is much lower than that in polar areas. The SAS δ18O values in Wuhan lie within the range reported for other sites (+5.0‰ to +19.6‰), with a time-weighted average value of 12.0 ± 2.3‰. Not counting three outlier (>13‰), the δ34S values are at a narrow range with a time-weighted average of +4.5 ±1.3‰ (n=30), which is higher than those from Baton Rouge but is typical for the heavily populated regions in China.

  8. A Study of the Relationships between Indicators of Georgia Alternative School Effectiveness and Measures of Student Success as Perceived by Alternative School Administrators

    ERIC Educational Resources Information Center

    Obleton, Eddie V.

    2010-01-01

    The purpose of this study was to investigate the relationships between Georgia alternative school administrators' perceptions of student success factors and the three domains of essential elements of effective alternative schools. The success factors included: dropout rate, average grade point average (GPA), average absences per student,…

  9. The effect of shot noise on the start up of the fundamental and harmonics in free-electron lasers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Freund, H. P.; Miner, W. H. Jr.; Giannessi, L.

    2008-12-15

    The problem of radiation start up in free-electron lasers (FELs) is important in the simulation of virtually all FEL configurations including oscillators and amplifiers in both seeded master oscillator power amplifier (MOPA) and self-amplified spontaneous emission (SASE) modes. Both oscillators and SASE FELs start up from spontaneous emission due to shot noise on the electron beam, which arises from the random fluctuations in the phase distribution of the electrons. The injected power in a MOPA is usually large enough to overwhelm the shot noise. However, this noise must be treated correctly in order to model the initial start up ofmore » the harmonics. In this paper, we discuss and compare two different shot noise models that are implemented in both one-dimensional wiggler-averaged (PERSEO) and non-wiggler-averaged (MEDUSA1D) simulation codes, and a three-dimensional non-wiggler-averaged (MEDUSA) formulation. These models are compared for examples describing both SASE and MOPA configurations in one dimension, in steady-state, and time-dependent simulations. Remarkable agreement is found between PERSEO and MEDUSA1D for the evolution of the fundamental and harmonics. In addition, three-dimensional correction factors have been included in the MEDUSA1D and PERSEO, which show reasonable agreement with MEDUSA for a sample MOPA in steady-state and time-dependent simulations.« less

  10. Machine-Learning Inspired Seismic Phase Detection for Aftershocks of the 2008 MW7.9 Wenchuan Earthquake

    NASA Astrophysics Data System (ADS)

    Zhu, L.; Li, Z.; Li, C.; Wang, B.; Chen, Z.; McClellan, J. H.; Peng, Z.

    2017-12-01

    Spatial-temporal evolution of aftershocks is important for illumination of earthquake physics and for rapid response of devastative earthquakes. To improve aftershock catalogs of the 2008 MW7.9 Wenchuan earthquake in Sichuan, China, Alibaba cloud and China Earthquake Administration jointly launched a seismological contest in May 2017 [Fang et al., 2017]. This abstract describes how we handle this problem in this competition. We first used Short-Term Average/Long-Term Average (STA/LTA) and Kurtosis function to obtain over 55000 candidate phase picks (P or S). Based on Signal to Noise Ratio (SNR), about 40000 phases (P or S) are selected. So far, these 40000 phases have a hit rate of 40% among the manually picks. The causes include that 1) there exist false picks (neither P nor S); 2) some P and S arrivals are mis-labeled. To improve our results, we correlate the 40000 phases over continuous waveforms to obtain the phases missed by during the first pass. This results in 120,000 events. After constructing an affinity matrix based on the cross-correlation for newly detected phases, subspace clustering methods [Vidal 2011] are applied to group those phases into separated subspaces. Initial results show good agreement between empirical and clustered labels of P phases. Half of the empirical S phases are clustered into the P phase cluster. This may be a combined effect of 1) mislabeling isolated P phases to S phases and 2) clustering errors due to a small incomplete sample pool. Phases that were falsely detected in the initial results can be also teased out. To better characterize P and S phases, our next step is to apply subspace clustering methods directly to the waveforms, instead of using the cross-correlation coefficients of detected phases. After that, supervised learning, e.g., a convolutional neural network, can be employed to improve the pick accuracy. Updated results will be presented at the meeting.

  11. Correlations between water-soluble organic aerosol and water vapor: a synergistic effect from biogenic emissions?

    PubMed

    Hennigan, Christopher J; Bergin, Michael H; Weber, Rodney J

    2008-12-15

    Ground-based measurements of meteorological parameters and water-soluble organic carbon in the gas(WSOCg) and particle (WSOCp) phases were carried out in Atlanta, Georgia, from May to September 2007. Fourteen separate events were observed throughout the summer in which WSOCp and water vapor concentrations were highly correlated (average WSOCp-water vapor r = 0.92); however, for the entire summer, no well-defined relationship existed between the two. The correlation events, which lasted on average 19 h, were characterized by a wide range of WSOCp and water vapor concentrations. Several hypotheses for the correlation are explored, including heterogeneous liquid phase SOA formation and the co-emission of biogenic VOCs and water vapor. The data provide supporting evidence for contributions from both and suggest the possibility of a synergistic effect between the co-emission of water vapor and VOCs from biogenic sources on SOA formation. Median WSOCp concentrations were also correlated with elemental carbon (EC), although this correlation extended over the entire summer. Despite the emission of water vapor from anthropogenic mobile sources and the WSOCp-EC correlation, mobile sources were not considered a potential cause for the WSOCp-water vapor correlations because of their low contribution to the water vapor budget. Meteorology could perhaps have influenced the WSOCp-EC correlation, but other factors are implicated as well. Overall, the results suggest that the temperature-dependent co-emission of water vapor through evapotranspiration and SOA precursor-VOCs by vegetation may be an important process contributing to SOA in some environments.

  12. Mexican American Adolescents’ Gender Role Attitude Development: The Role of Adolescents’ Gender and Nativity and Parents’ Gender Role Attitudes

    PubMed Central

    Updegraff, Kimberly A.; McHale, Susan M.; Zeiders, Katharine H.; Umaña-Taylor, Adriana J.; Perez-Brena, Norma J.; Wheeler, Lorey A.; Rodríguez De Jesús, Sue A.

    2014-01-01

    Gender development has long term implications for education and career endeavors and family formation behaviors, but we know very little about the role of sociocultural factors in developmental and individual differences. In this study, we investigated one domain of gender development, gender role attitudes, in Mexican American adolescents (N = 246; 51% female), using four phases of longitudinal data across eight years. Data were collected when adolescents averaged 12.51 years (SD = 0.58), 14.64 years (SD = 0.59), 17.72 years (SD = 0.57), and 19.60 years of age (SD = 0.66). Mothers’ and fathers’ gender role attitudes also were assessed in Phases 1, 3, and 4. Findings revealed that gender attitude development varied as a function of the interaction between adolescents’ nativity and gender. Among Mexico-born adolescents, females exhibited significant declines in traditional attitudes from early to late adolescence, but males’ attitudes were stable over time. U.S.-born females and males, in contrast, did not differ in their gender attitude trajectories. Examining the links between mothers’, fathers’, and adolescents’ gender role attitudes revealed within-person associations between mothers’ and adolescents’ gender role attitudes: on occasions when mothers reported more traditional attitudes relative to their own cross-time average, adolescents also reported more traditional attitudes than usual. In addition, fathers’ more traditional gender role attitudes were associated with daughters’, but not sons’, more traditional gender role attitudes at the between-person level. The discussion focuses on the interpretation of Mexican American adolescents’ gender role attitude development from a cultural ecological perspective. PMID:24777649

  13. Selecting a proper design period for heliostat field layout optimization using Campo code

    NASA Astrophysics Data System (ADS)

    Saghafifar, Mohammad; Gadalla, Mohamed

    2016-09-01

    In this paper, different approaches are considered to calculate the cosine factor which is utilized in Campo code to expand the heliostat field layout and maximize its annual thermal output. Furthermore, three heliostat fields containing different number of mirrors are taken into consideration. Cosine factor is determined by considering instantaneous and time-average approaches. For instantaneous method, different design days and design hours are selected. For the time average method, daily time average, monthly time average, seasonally time average, and yearly time averaged cosine factor determinations are considered. Results indicate that instantaneous methods are more appropriate for small scale heliostat field optimization. Consequently, it is proposed to consider the design period as the second design variable to ensure the best outcome. For medium and large scale heliostat fields, selecting an appropriate design period is more important. Therefore, it is more reliable to select one of the recommended time average methods to optimize the field layout. Optimum annual weighted efficiency for heliostat fields (small, medium, and large) containing 350, 1460, and 3450 mirrors are 66.14%, 60.87%, and 54.04%, respectively.

  14. Geographic Variation in Mentally Unhealthy Days: Air Pollution and Altitude Perspectives.

    PubMed

    Ha, Hoehun

    2017-09-01

    Ha, Hoehun. Geographic variation in mentally unhealthy days: air pollution and altitude perspectives. High Alt Med Biol. 18:258-266, 2017. Mental health incorporates our emotional, psychological, and social well-being and it is critical at each phase of life, from youth and preadulthood through adulthood. We assessed the association between mentally unhealthy days (MUDs), air pollutant concentrations, and altitude on the basis of cross-county studies. Data on poor mental health days for the United States were based on health-related telephone surveys conducted by the Behavioral Risk Factor Surveillance System (BRFSS). Average annual regional air pollution data were obtained from Center for Disease Control and Prevention (CDC) WONDER Environmental data, and altitude data were collected from the U.S. Geological Survey (USGS). In the data set (across 2589 U.S. counties for 2011), even after accounting for potential confounding variables and multicollinearity, a significant association between altitude, air pollution, and poor mental health days was found, explaining that poor mental health days increase with increasing air pollution concentrations and with decreasing altitude (R 2  = 0.663, p < 0.001). Controlling for socioeconomic (e.g., education and employment) and social (including social relationship and crime) factors did not change these findings. In this study, we found that counties with lower air pollution and higher altitude had significantly lower average number of MUDs reported within the past 30 days. This association has not been reported before in the literature. These findings suggest a need for further investigation into the extent that air quality and altitude may serve as significant factors for mental health and have major implications in our understanding of the etiology of mental health by medical professionals.

  15. Modeling of the influence of humidity on H1N1 flu in China

    NASA Astrophysics Data System (ADS)

    PEI, Y.; Tian, H.; Xu, B.

    2015-12-01

    In 2009, a heavy Flu hit the whole world. It was caused by the virus H1N1. The influenza first broke out in Mexico in March and the United States in April, 2009. The World Health Organization (WHO) announced that the H1N1 influenza became pandemic, alert to a warning phase of six. By the end of 2011, 181302 H1N1 cases were reported in mainland China. To improve our understanding on the impact of environmental factors on the disease transmission, we constructed an SIR (Susceptible - Infectious - Recovered) model incorporating environmental factors. It was found that the absolute humidity was a dominant environmental factor. The study interpolated the humidity data monitored with 340 weather stations from 1951 to 2011 in mainland China. First, the break point of the trend for the absolutely humidity was detected by the BFAST (Break For Additive Season and Trend) method. Then, the SIR model with and without the absolutely humidity incorporated in the model was built and tested. Finally, the results with the two scenarios were compared. Results indicate that lower absolutely humidity may promote the transmission of the H1N1 cases. The calculated basic reproductive number ranges from 1.65 to 3.66 with a changing absolute humidity. This is consistent with the former study result with basic reproductive number ranging from 2.03 to 4.18. The average recovery duration was estimated to be 5.7 days. The average duration to get immunity from the influenza is 399.02 days. A risk map is also produced to illustrate the model results.

  16. Closed-Loop Adaptive Optics Control in Strong Atmospheric Turbulence

    DTIC Science & Technology

    2008-09-01

    115 7.1.1 Kalman estimation of anisoplanatic Zernike tilt . . . . 115 7.1.2 An improved temporally phase-shifted design . . . . . 115 7.1.3...5 7. Shack-Hartmann lenslet diagram [40] . . . . . . . . . . . . . . . . . . 9 8. Determining phase tilt from a S-H WFS [8...wavefront prior to it encountering the WFS. In this system a non- deformable mirror known as a fast-steering mirror (FSM) corrects the tilt (average phase

  17. Pacing the phasing of leg and arm movements in breaststroke swimming to minimize intra-cyclic velocity fluctuations

    PubMed Central

    Roerdink, Melvyn; Huibers, Alja V.; Evers, Lotte L. W.; Beek, Peter J.

    2017-01-01

    In swimming propelling efficiency is partly determined by intra-cyclic velocity fluctuations. The higher these fluctuations are at a given average swimming velocity, the less efficient is the propulsion. This study explored whether the leg-arm coordination (i.e. phase relation ϕ) within the breaststroke cycle can be influenced with acoustic pacing, and whether the so induced changes are accompanied by changes in intra-cyclic velocity fluctuations. Twenty-six participants were asked to couple their propulsive leg and arm movements to a double-tone metronome beat and to keep their average swimming velocity constant over trials. The metronome imposed five different phase relations ϕi (90, 135, 180, 225 and 270°) of leg-arm coordination. Swimmers adjusted their technique under the influence of the metronome, but failed to comply to the velocity requirement for ϕ = 90 and 135°. For imposed ϕ = 180, 225 and 270°, the intra-cyclic velocity fluctuations increased with increasing ϕ, while average swimming velocity did not differ. This suggests that acoustic pacing may be used to adjust ϕ and thereby performance of breaststroke swimming given the dependence of propelling efficiency on ϕ. PMID:29023496

  18. Novel Gyroscopic Mounting for Crystal Oscillators to Increase Short and Medium Term Stability under Highly Dynamic Conditions.

    PubMed

    Abedi, Maryam; Jin, Tian; Sun, Kewen

    2015-06-17

    In this paper, a gyroscopic mounting method for crystal oscillators to reduce the impact of dynamic loads on their output stability has been proposed. In order to prove the efficiency of this mounting approach, each dynamic load-induced instability has been analyzed in detail. A statistical study has been performed on the elevation angle of the g-sensitivity vector of Stress Compensated-cut (SC-cut) crystals. The analysis results show that the proposed gyroscopic mounting method gives good performance for host vehicle attitude changes. A phase noise improvement of 27 dB maximum and 5.7 dB on average can be achieved in the case of steady state loads, while under sinusoidal vibration conditions, the maximum and average phase noise improvement are as high as 24 dB and 7.5 dB respectively. With this gyroscopic mounting method, random vibration-induced phase noise instability is reduced 30 dB maximum and 8.7 dB on average. Good effects are apparent for crystal g-sensitivity vectors with low elevation angle φ and azimuthal angle β. under highly dynamic conditions, indicating the probability that crystal oscillator instability will be significantly reduced by using the proposed mounting approach.

  19. Pacing the phasing of leg and arm movements in breaststroke swimming to minimize intra-cyclic velocity fluctuations.

    PubMed

    van Houwelingen, Josje; Roerdink, Melvyn; Huibers, Alja V; Evers, Lotte L W; Beek, Peter J

    2017-01-01

    In swimming propelling efficiency is partly determined by intra-cyclic velocity fluctuations. The higher these fluctuations are at a given average swimming velocity, the less efficient is the propulsion. This study explored whether the leg-arm coordination (i.e. phase relation ϕ) within the breaststroke cycle can be influenced with acoustic pacing, and whether the so induced changes are accompanied by changes in intra-cyclic velocity fluctuations. Twenty-six participants were asked to couple their propulsive leg and arm movements to a double-tone metronome beat and to keep their average swimming velocity constant over trials. The metronome imposed five different phase relations ϕi (90, 135, 180, 225 and 270°) of leg-arm coordination. Swimmers adjusted their technique under the influence of the metronome, but failed to comply to the velocity requirement for ϕ = 90 and 135°. For imposed ϕ = 180, 225 and 270°, the intra-cyclic velocity fluctuations increased with increasing ϕ, while average swimming velocity did not differ. This suggests that acoustic pacing may be used to adjust ϕ and thereby performance of breaststroke swimming given the dependence of propelling efficiency on ϕ.

  20. Sequential dome-collapse nuées ardentes analyzed from broadband seismic data, Merapi Volcano, Indonesia

    USGS Publications Warehouse

    Brodscholl, A.; Kirbani, S.B.; Voight, B.

    2000-01-01

    The broadband data were evaluated using the assumption that avalanches with the same source areas and descent paths exhibit a linear relation between source volume and recorded seismic-amplitude envelope area. A result of the analysis is the determination of the volume of selected individual events. From the field surveys, the total volume of the collapsed dome lava is 2.6 Mm3. Discounting the volumetric influence of rockfalls, the average size of the 44 nuées ardentes is therefore about 60,000 m3. The largest collapse event at 10:54 is estimated to involve 260,000 m3, based on an analysis of the seismicity. The remaining 23 phase I events averaged 60,000 m3, with the total volume of all phase I events accounting for 63% of the unstable dome. The 20 phase II events comprised 37% of the total volume and averaged 47,000 m3. The methods described here can be put to practical use in real-time monitoring situations. Broadband data were essential in this study primarily because of the wide dynamic range.

  1. Coadding Techniques for Image-based Wavefront Sensing for Segmented-mirror Telescopes

    NASA Technical Reports Server (NTRS)

    Smith, Scott; Aronstein, David; Dean, Bruce; Acton, Scott

    2007-01-01

    Image-based wavefront sensing algorithms are being used to characterize optical performance for a variety of current and planned astronomical telescopes. Phase retrieval recovers the optical wavefront that correlates to a series of diversity-defocused point-spread functions (PSFs), where multiple frames can be acquired at each defocus setting. Multiple frames of data can be coadded in different ways; two extremes are in "image-plane space," to average the frames for each defocused PSF and use phase retrieval once on the averaged images, or in "pupil-plane space," to use phase retrieval on every set of PSFs individually and average the resulting wavefronts. The choice of coadd methodology is particularly noteworthy for segmented-mirror telescopes that are subject to noise that causes uncorrelated motions between groups of segments. Using data collected on and simulations of the James Webb Space Telescope Testbed Telescope (TBT) commissioned at Ball Aerospace, we show how different sources of noise (uncorrelated segment jitter, turbulence, and common-mode noise) and different parts of the optical wavefront, segment and global aberrations, contribute to choosing the coadd method. Of particular interest, segment piston is more accurately recovered in "image-plane space" coadding, while segment tip/tilt is recovered in "pupil-plane space" coadding.

  2. Characterizing cycle-to-cycle variations of the shedding cycle in the turbulent wake of a normal flat plate using generalized phase averages

    NASA Astrophysics Data System (ADS)

    Martinuzzi, Robert

    2016-11-01

    Quasi-periodic vortex shedding in the turbulent wake of a thin-flat plate placed normal to a uniform stream at Reynolds number of 6700 is investigated based on Particle Image Velocimetry experiments. The wake structure and vortex formation are characterized using a generalized phase average (GPA), a refinement of the triple decomposition of Reynolds and Hussain (1970) incorporating elements of mean-field theory (Stuart, 1958). The resulting analysis highlights the importance of cycle-to-cycle variations in characterizing vortex formation, wake topology and the residual turbulent Reynolds Stresses. For example, it is shown that during high-amplitude cycles vorticity is strongly concentrated within the well-organized shed vortices, whereas during low-amplitude cycles the shed vortices are highly distorted resulting in significant modulation of the shedding frequency. It is found that high-amplitude cycles contribute more to the coherent Reynolds stress field while the low-amplitude cycles contribute to the residual stress field. It is further shown that traditional phase-averaging techniques lead to an over-estimation of the residual stress field. Natural Sciences and Engineering Research Council of Canada.

  3. Distributed Sensor Fusion for Scalar Field Mapping Using Mobile Sensor Networks.

    PubMed

    La, Hung Manh; Sheng, Weihua

    2013-04-01

    In this paper, autonomous mobile sensor networks are deployed to measure a scalar field and build its map. We develop a novel method for multiple mobile sensor nodes to build this map using noisy sensor measurements. Our method consists of two parts. First, we develop a distributed sensor fusion algorithm by integrating two different distributed consensus filters to achieve cooperative sensing among sensor nodes. This fusion algorithm has two phases. In the first phase, the weighted average consensus filter is developed, which allows each sensor node to find an estimate of the value of the scalar field at each time step. In the second phase, the average consensus filter is used to allow each sensor node to find a confidence of the estimate at each time step. The final estimate of the value of the scalar field is iteratively updated during the movement of the mobile sensors via weighted average. Second, we develop the distributed flocking-control algorithm to drive the mobile sensors to form a network and track the virtual leader moving along the field when only a small subset of the mobile sensors know the information of the leader. Experimental results are provided to demonstrate our proposed algorithms.

  4. Prevalence and correlates of delayed sleep phase in high school students.

    PubMed

    Saxvig, Ingvild W; Pallesen, Ståle; Wilhelmsen-Langeland, Ane; Molde, Helge; Bjorvatn, Bjørn

    2012-02-01

    To investigate prevalence and correlates of delayed sleep phase, characterized by problems falling asleep in the evening and rising at adequate times in the morning, in a large sample of Norwegian high school students. A randomized sample of 1285 high school students (aged 16-19 years) participated in an internet based study answering questions about sleep habits, height, weight, smoking, alcohol use, school grades, and anxiety and depression symptoms. Delayed sleep phase was operationalized as difficulties falling asleep before 2 a.m. at least three nights per week together with much or very much difficulty waking up in the morning. The results show a prevalence of delayed sleep phase of 8.4%. In all, 68% of these students (5.7% of the total sample) also reported problems advancing their sleep period as well as one daytime consequence (oversleeping at least two days a week or experiencing much/very much sleepiness at school). Delayed sleep phase was associated with lower average school grades, smoking, alcohol usage, and elevated anxiety and depression scores. Delayed sleep phase appears to be common amongst Norwegian adolescents and is associated with negative outcomes such as lower average school grades, smoking, alcohol usage, and elevated anxiety and depression scores. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. ESTIMATION OF SHEAR STRESS WORKING ON SUBMERGED HOLLOW FIBRE MEMBRANE BY CFD METHOD IN MBRs

    NASA Astrophysics Data System (ADS)

    Zaw, Hlwan Moe; Li, Tairi; Nagaoka, Hiroshi

    This study was conducted to evaluate shear stress working on submerged hollow fibre membrane by CFD (Computation Fluid Dynamics) method in MBRs. Shear stress on hollow fibre membrane caused by aeration was measured directly using a two-direction load sensor. The measurement of water-phase flow velocity was done also by using laser doppler velocimeter. It was confirmed that the shear stress was possible to be evaluated from the water-phase flow velocityby the result of comparison of time average shear stress actually measured with one hollow fibre membrane and the one calculated by the water-phase flow velocity. In the estimation of the water-phase flow velocity using the CFD method, time average water-phase flow velocity estimated by consideration of the fluid resistance of the membrane module nearly coincided with the measured values, and it was shown that it was possible to be estimated also within the membrane module. Moreover, the measured shear stress and drag force well coincided with the values calculated from the estimated water-phase flow velocity outside of membrane module and in the center of membrane module, and it was suggested that the shear stress on the hollow fibre membrane could be estimated by the CFD method in MBRs.

  6. Measurement of regional compliance using 4DCT images for assessment of radiation treatment1

    PubMed Central

    Zhong, Hualiang; Jin, Jian-yue; Ajlouni, Munther; Movsas, Benjamin; Chetty, Indrin J.

    2011-01-01

    Purpose: Radiation-induced damage, such as inflammation and fibrosis, can compromise ventilation capability of local functional units (alveoli) of the lung. Ventilation function as measured with ventilation images, however, is often complicated by the underlying mechanical variations. The purpose of this study is to present a 4DCT-based method to measure the regional ventilation capability, namely, regional compliance, for the evaluation of radiation-induced lung damage. Methods: Six 4DCT images were investigated in this study: One previously used in the generation of a POPI model and the other five acquired at Henry Ford Health System. A tetrahedral geometrical model was created and scaled to encompass each of the 4DCT image domains. Image registrations were performed on each of the 4DCT images using a multiresolution Demons algorithm. The images at the end of exhalation were selected as a reference. Images at other exhalation phases were registered to the reference phase. For the POPI-modeled patient, each of these registration instances was validated using 40 landmarks. The displacement vector fields (DVFs) were used first to calculate the volumetric variation of each tetrahedron, which represents the change in the air volume. The calculated results were interpolated to generate 3D ventilation images. With the computed DVF, a finite element method (FEM) framework was developed to compute the stress images of the lung tissue. The regional compliance was then defined as the ratio of the ventilation and stress values and was calculated for each phase. Based on iterative FEM simulations, the potential range of the mechanical parameters for the lung was determined by comparing the model-computed average stress to the clinical reference value of airway pressure. The effect of the parameter variations on the computed stress distributions was estimated using Pearson correlation coefficients. Results: For the POPI-modeled patient, five exhalation phases from the start to the end of exhalation were denoted by Pi, i=1,…,5, respectively. The average lung volume variation relative to the reference phase (P5) was reduced from 18% at P1 to 4.8% at P4. The average stress at phase Pi was 1.42, 1.34, 0.74, and 0.28 kPa, and the average regional compliance was 0.19, 0.20, 0.20, and 0.24 for i=1,…,4, respectively. For the other five patients, their average Rv value at the end-inhalation phase was 21.1%, 19.6%, 22.4%, 22.5%, and 18.8%, respectively, and the regional compliance averaged over all six patients is 0.2. For elasticity parameters chosen from the potential parameter range, the resultant stress distributions were found to be similar to each other with Pearson correlation coefficients greater than 0.81. Conclusions: A 4DCT-based mechanical model has been developed to calculate the ventilation and stress images of the lung. The resultant regional compliance represents the lung’s elasticity property and is potentially useful in correlating regions of lung damage with radiation dose following a course of radiation therapy. PMID:21520868

  7. Measurement of regional compliance using 4DCT images for assessment of radiation treatment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhong Hualiang; Jin Jianyue; Ajlouni, Munther

    2011-03-15

    Purpose: Radiation-induced damage, such as inflammation and fibrosis, can compromise ventilation capability of local functional units (alveoli) of the lung. Ventilation function as measured with ventilation images, however, is often complicated by the underlying mechanical variations. The purpose of this study is to present a 4DCT-based method to measure the regional ventilation capability, namely, regional compliance, for the evaluation of radiation-induced lung damage. Methods: Six 4DCT images were investigated in this study: One previously used in the generation of a POPI model and the other five acquired at Henry Ford Health System. A tetrahedral geometrical model was created and scaledmore » to encompass each of the 4DCT image domains. Image registrations were performed on each of the 4DCT images using a multiresolution Demons algorithm. The images at the end of exhalation were selected as a reference. Images at other exhalation phases were registered to the reference phase. For the POPI-modeled patient, each of these registration instances was validated using 40 landmarks. The displacement vector fields (DVFs) were used first to calculate the volumetric variation of each tetrahedron, which represents the change in the air volume. The calculated results were interpolated to generate 3D ventilation images. With the computed DVF, a finite element method (FEM) framework was developed to compute the stress images of the lung tissue. The regional compliance was then defined as the ratio of the ventilation and stress values and was calculated for each phase. Based on iterative FEM simulations, the potential range of the mechanical parameters for the lung was determined by comparing the model-computed average stress to the clinical reference value of airway pressure. The effect of the parameter variations on the computed stress distributions was estimated using Pearson correlation coefficients. Results: For the POPI-modeled patient, five exhalation phases from the start to the end of exhalation were denoted by P{sub i}, i=1,...,5, respectively. The average lung volume variation relative to the reference phase (P{sub 5}) was reduced from 18% at P{sub 1} to 4.8% at P{sub 4}. The average stress at phase P{sub i} was 1.42, 1.34, 0.74, and 0.28 kPa, and the average regional compliance was 0.19, 0.20, 0.20, and 0.24 for i=1,...,4, respectively. For the other five patients, their average R{sub v} value at the end-inhalation phase was 21.1%, 19.6%, 22.4%, 22.5%, and 18.8%, respectively, and the regional compliance averaged over all six patients is 0.2. For elasticity parameters chosen from the potential parameter range, the resultant stress distributions were found to be similar to each other with Pearson correlation coefficients greater than 0.81. Conclusions: A 4DCT-based mechanical model has been developed to calculate the ventilation and stress images of the lung. The resultant regional compliance represents the lung's elasticity property and is potentially useful in correlating regions of lung damage with radiation dose following a course of radiation therapy.« less

  8. Three phase power factor controller

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1984-01-01

    A power control circuit for a three phase induction motor is described. Power factors for the three phases are summed to provide a control signal, and this control signal is particularly filtered and then employed to control the duty cycle of each phase of input power to the motor.

  9. THE EFFECT OF METASTABLE EQUILIBRIUM STATES ON THE PARTITIONING OF NITRATE BETWEEN THE GAS AND AEROSOL PHASES. (R824793)

    EPA Science Inventory

    With the aid of three atmospheric aerosol equilibrium models, we quantify the effect of metastable equilibrium states (efflorescence branch) in comparison to stable (deliquescence branch) on the partitioning of total nitrate between the gas and aerosol phases. On average, efflore...

  10. Can Pearlite form Outside of the Hultgren Extrapolation of the Ae3 and Acm Phase Boundaries?

    NASA Astrophysics Data System (ADS)

    Aranda, M. M.; Rementeria, R.; Capdevila, C.; Hackenberg, R. E.

    2016-02-01

    It is usually assumed that ferrous pearlite can form only when the average austenite carbon concentration C 0 lies between the extrapolated Ae3 ( γ/ α) and Acm ( γ/ θ) phase boundaries (the "Hultgren extrapolation"). This "mutual supersaturation" criterion for cooperative lamellar nucleation and growth is critically examined from a historical perspective and in light of recent experiments on coarse-grained hypoeutectoid steels which show pearlite formation outside the Hultgren extrapolation. This criterion, at least as interpreted in terms of the average austenite composition, is shown to be unnecessarily restrictive. The carbon fluxes evaluated from Brandt's solution are sufficient to allow pearlite growth both inside and outside the Hultgren Extrapolation. As for the feasibility of the nucleation events leading to pearlite, the only criterion is that there are some local regions of austenite inside the Hultgren Extrapolation, even if the average austenite composition is outside.

  11. Stable fiber-optic time transfer by active radio frequency phase locking.

    PubMed

    Yin, Feifei; Wu, Zhongle; Dai, Yitang; Ren, Tianpeng; Xu, Kun; Lin, Jintong; Tang, Geshi

    2014-05-15

    In this Letter we demonstrate a fiber link capable of stable time signal transfer utilizing our active long-distance radio frequency (RF) stabilization technology. Taking advantage of the chromatic dispersion in optical fiber, our scheme compensates dynamically the link delay variation by tuning the optical carrier wavelength to phase lock a round-trip RF reference. Since the time signal and the RF reference are carried by the same optical carrier, a highly stable time transfer is achieved at the same time. Experimentally, we demonstrate a stability of the time signal transfer over 50-km fiber with a time deviation of 40 ps at 1-s average and 2.3 ps at 1000-s average. The performance of the RF reference delivery is also tested, with an Allan deviation of 2×10(-15) at 1000-s average. According to our proposal, a simultaneous stable time and frequency transfer is expected.

  12. The effects of noise in cardiac diffusion tensor imaging and the benefits of averaging complex data.

    PubMed

    Scott, Andrew D; Nielles-Vallespin, Sonia; Ferreira, Pedro F; McGill, Laura-Ann; Pennell, Dudley J; Firmin, David N

    2016-05-01

    There is growing interest in cardiac diffusion tensor imaging (cDTI), but, unlike other diffusion MRI applications, there has been little investigation of the effects of noise on the parameters typically derived. One method of mitigating noise floor effects when there are multiple image averages, as in cDTI, is to average the complex rather than the magnitude data, but the phase contains contributions from bulk motion, which must be removed first. The effects of noise on the mean diffusivity (MD), fractional anisotropy (FA), helical angle (HA) and absolute secondary eigenvector angle (E2A) were simulated with various diffusion weightings (b values). The effect of averaging complex versus magnitude images was investigated. In vivo cDTI was performed in 10 healthy subjects with b = 500, 1000, 1500 and 2000 s/mm(2). A technique for removing the motion-induced component of the image phase present in vivo was implemented by subtracting a low-resolution copy of the phase from the original images before averaging the complex images. MD, FA, E2A and the transmural gradient in HA were compared for un-averaged, magnitude- and complex-averaged reconstructions. Simulations demonstrated an over-estimation of FA and MD at low b values and an under-estimation at high b values. The transition is relatively signal-to-noise ratio (SNR) independent and occurs at a higher b value for FA (b = 1000-1250 s/mm(2)) than MD (b ≈ 250 s/mm(2)). E2A is under-estimated at low and high b values with a transition at b ≈ 1000 s/mm(2), whereas the bias in HA is comparatively small. The under-estimation of FA and MD at high b values is caused by noise floor effects, which can be mitigated by averaging the complex data. Understanding the parameters of interest and the effects of noise informs the selection of the optimal b values. When complex data are available, they should be used to maximise the benefit from the acquisition of multiple averages. The combination of complex data is also a valuable step towards segmented acquisitions. Copyright © 2016 John Wiley & Sons, Ltd.

  13. Radiation exposure of German aircraft crews under the impact of solar cycle 23 and airline business factors.

    PubMed

    Frasch, Gerhard; Kammerer, Lothar; Karofsky, Ralf; Schlosser, Andrea; Stegemann, Ralf

    2014-12-01

    The exposure of German aircraft crews to cosmic radiation varies both with solar activity and operational factors of airline business. Data come from the German central dose registry and cover monthly exposures of up to 37,000 German aircraft crewmembers that were under official monitoring. During the years 2004 to 2009 of solar cycle 23 (i.e., in the decreasing phase of solar activity), the annual doses of German aircraft crews increased by an average of 20%. Decreasing solar activity allows more galactic radiation to reach the atmosphere, increasing high-altitude doses. The rise results mainly from the less effective protection from the solar wind but also from airline business factors. Both cockpit and cabin personnel differ in age-dependent professional and social status. This status determines substantially the annual effective dose: younger cabin personnel and the elder pilots generally receive higher annual doses than their counterparts. They also receive larger increases in their annual dose when the solar activity decreases. The doses under this combined influence of solar activity and airline business factors result in a maximum of exposure for German aircrews for this solar cycle. With the increasing solar activity of the current solar cycle 24, the doses are expected to decrease again.

  14. Parameters effective on estimating a nonstationary mixed-phase wavelet using cumulant matching approach

    NASA Astrophysics Data System (ADS)

    Vosoughi, Ehsan; Javaherian, Abdolrahim

    2018-01-01

    Seismic inversion is a process performed to remove the effects of propagated wavelets in order to recover the acoustic impedance. To obtain valid velocity and density values related to subsurface layers through the inversion process, it is highly essential to perform reliable wavelet estimation such as cumulant matching approach. For this purpose, the seismic data were windowed in this work in such a way that two consecutive windows were only one sample apart. Also, we did not consider any fixed wavelet for any window and let the phase of each wavelet rotate in each sample in the window. Comparing the fourth order cumulant of the whitened trace and fourth-order moment of the all-pass operator in each window generated a cost function that should be minimized with a non-linear optimization method. In this regard, parameters effective on the estimation of the nonstationary mixed-phase wavelets were tested over the created nonstationary seismic trace at 0.82 s and 1.6 s. Besides, we compared the consequences of each parameter on estimated wavelets at two mentioned times. The parameters studied in this work are window length, taper type, the number of iteration, signal-to-noise ratio, bandwidth to central frequency ratio, and Q factor. The results show that applying the optimum values of the effective parameters, the average correlation of the estimated mixed-phase wavelets with the original ones is about 87%. Moreover, the effectiveness of the proposed approach was examined on a synthetic nonstationary seismic section with variable Q factor values alongside the time and offset axis. Eventually, the cumulant matching method was applied on a cross line of the migrated data from a 3D data set of an oilfield in the Persian Gulf. Also, the effect of the wrong Q estimation on the estimated mixed-phase wavelet was considered on the real data set. It is concluded that the accuracy of the estimated wavelet relied on the estimated Q and more than 10% error in the estimated value of Q is acceptable. Eventually, an 88% correlation was found between the estimated mixed-phase wavelets and the original ones for three horizons. The estimated wavelets applied to the data and the result of deconvolution processes was presented.

  15. Evaporation of Liquid Droplet in Nano and Micro Scales from Statistical Rate Theory.

    PubMed

    Duan, Fei; He, Bin; Wei, Tao

    2015-04-01

    The statistical rate theory (SRT) is applied to predict the average evaporation flux of liquid droplet after the approach is validated in the sessile droplet experiments of the water and heavy water. The steady-state experiments show a temperature discontinuity at the evaporating interface. The average evaporation flux is evaluated by individually changing the measurement at a liquid-vapor interface, including the interfacial liquid temperature, the interfacial vapor temperature, the vapor-phase pressure, and the droplet size. The parameter study shows that a higher temperature jump would reduce the average evaporation flux. The average evaporation flux can significantly be influenced by the interfacial liquid temperature and the vapor-phase pressure. The variation can switch the evaporation into condensation. The evaporation flux is found to remain relative constant if the droplet is larger than a micro scale, while the smaller diameters in nano scale can produce a much higher evaporation flux. In addition, a smaller diameter of droplets with the same liquid volume has a larger surface area. It is suggested that the evaporation rate increases dramatically as the droplet shrinks into nano size.

  16. Velocity of mist droplets and suspending gas imaged separately

    NASA Astrophysics Data System (ADS)

    Kuethe, Dean O.; McBride, Amber; Altobelli, Stephen A.

    2012-03-01

    Nuclear Magnetic Resonance Images (MRIs) of the velocity of water droplets and velocity of the suspending gas, hexafluoroethane, are presented for a vertical and horizontal mist pipe flow. In the vertical flow, the upward velocity of the droplets is clearly slower than the upward velocity of the gas. The average droplet size calculated from the average falling velocity in the upward flow is larger than the average droplet size of mist drawn from the top of the pipe measured with a multi-stage aerosol impactor. Vertical flow concentrates larger particles because they have a longer transit time through the pipe. In the horizontal flow there is a gravity-driven circulation with high-velocity mist in the lower portion of the pipe and low-velocity gas in the upper portion. MRI has the advantages that it can image both phases and that it is unperturbed by optical opacity. A drawback is that the droplet phase of mist is difficult to image because of low average spin density and because the signal from water coalesced on the pipe walls is high. To our knowledge these are the first NMR images of mist.

  17. Analysis of the covariance function and aperture averaged fluctuations of irradiance to calculate Cn2

    NASA Astrophysics Data System (ADS)

    Cauble, Galen D.; Wayne, David T.

    2017-09-01

    The growth of optical communication has created a need to correctly characterize the atmospheric channel. Atmospheric turbulence along a given channel can drastically affect optical communication signal quality. One means of characterizing atmospheric turbulence is through measurement of the refractive index structure parameter, Cn2. When calculating Cn2 from the scintillation index, σΙ2,the point aperture scintillation index is required. Direct measurement of the point aperture scintillation index is difficult at long ranges due to the light collecting abilities of small apertures. When aperture size is increased past the atmospheric correlation width, aperture averaging decreases the scintillation index below that of the point aperture scintillation index. While the aperture averaging factor can be calculated from theory, it does not often agree with experimental results. Direct measurement of the aperture averaging factor via the pupil plane irradiance covariance function allows conversion from the aperture averaged scintillation index to the point aperture scintillation index. Using a finite aperture, camera, and detector, the aperture averaged scintillation index and aperture averaging factor are measured in parallel and the point aperture scintillation index is calculated. A new instrument built by SSC Pacific was used to collect scintillation data at the Townes Institute Science and Technology Experimentation Facility (TISTEF). This new instrument's data was then compared to BLS900 data. The results show that direct measurement of the aperture averaging factor is achievable using a camera and matches well with groundtruth instrumentation.

  18. Design and Measurement of a Digital Phase Locked BWO for Accurately Extracting the Quality Factors in a Biconcave Resonator System

    NASA Astrophysics Data System (ADS)

    Gao, Yuanci; Charles, Jones R.; Yu, Guofen; Jyotsna, Dutta M.

    2012-03-01

    A long loop phase locked backward-wave oscillator (BWO) for a high quality factor resonator system operating at D-band frequencies (130-170GHz) was described, the phase noise of the phased locked BWO was analyzed and measured at typical frequencies. When it used with a high quality factor open resonator for measuring the quality factor of simple harmonic resonators based on the magnitude transfer characteristic, this system has proven to be capable of accurate measuring the quality factor as high as 0.8 million with an uncertainty of less than 1.3% (Lorentzian fitting) at typical frequencies in the range of 130GHz-170GHz.

  19. The effect of dry and wet deposition of condensable vapors on secondary organic aerosols concentrations over the continental US

    DOE PAGES

    Knote, C.; Hodzic, A.; Jimenez, J. L.

    2015-01-06

    The effect of dry and wet deposition of semi-volatile organic compounds (SVOCs) in the gas phase on the concentrations of secondary organic aerosol (SOA) is reassessed using recently derived water solubility information. The water solubility of SVOCs was implemented as a function of their volatility distribution within the WRF-Chem regional chemistry transport model, and simulations were carried out over the continental United States for the year 2010. Results show that including dry and wet removal of gas-phase SVOCs reduces annual average surface concentrations of anthropogenic and biogenic SOA by 48 and 63% respectively over the continental US. Dry deposition ofmore » gas-phase SVOCs is found to be more effective than wet deposition in reducing SOA concentrations (−40 vs. −8% for anthropogenics, and −52 vs. −11% for biogenics). Reductions for biogenic SOA are found to be higher due to the higher water solubility of biogenic SVOCs. The majority of the total mass of SVOC + SOA is actually deposited via the gas phase (61% for anthropogenics and 76% for biogenics). Results are sensitive to assumptions made in the dry deposition scheme, but gas-phase deposition of SVOCs remains crucial even under conservative estimates. Considering reactivity of gas-phase SVOCs in the dry deposition scheme was found to be negligible. Further sensitivity studies where we reduce the volatility of organic matter show that consideration of gas-phase SVOC removal still reduces average SOA concentrations by 31% on average. We consider this a lower bound for the effect of gas-phase SVOC removal on SOA concentrations. A saturation effect is observed for Henry's law constants above 10 8 M atm −1, suggesting an upper bound of reductions in surface level SOA concentrations by 60% through removal of gas-phase SVOCs. Other models that do not consider dry and wet removal of gas-phase SVOCs would hence overestimate SOA concentrations by roughly 50%. Assumptions about the water solubility of SVOCs made in some current modeling systems ( H * = H * (CH 3COOH); H * = 10 5 M atm −1; H * = H * (HNO 3)) still lead to an overestimation of 35%/25%/10% compared to our best estimate.« less

  20. Using contingency management procedures to reduce at-risk drinking in heavy drinkers.

    PubMed

    Dougherty, Donald M; Lake, Sarah L; Hill-Kapturczak, Nathalie; Liang, Yuanyuan; Karns, Tara E; Mullen, Jillian; Roache, John D

    2015-04-01

    Treatments for alcohol use disorders typically have been abstinence based, but harm reduction approaches that encourage drinkers to alter their drinking behavior to reduce the probability of alcohol-related consequences, have gained in popularity. This study used a contingency management procedure to determine its effectiveness in reducing alcohol consumption among heavy drinkers. Eighty-two nontreatment-seeking heavy drinkers (ages 21 to 54, M = 30.20) who did not meet diagnostic criteria for alcohol dependence participated in the study. The study had 3 phases: (i) an Observation phase (4 weeks) where participants drank normally; (ii) a Contingency Management phase (12 weeks) where participants were paid $50 weekly for not exceeding low levels of alcohol consumption as measured by transdermal alcohol concentrations, <0.03 g/dl; and (iii) a Follow-up phase (12 weeks) where participants (n = 66) returned monthly for 3 months to self-report drinking after the contingencies were removed. Transdermal alcohol monitors were used to verify meeting contingency requirements; all other analyses were conducted on self-reported alcohol use. On average 42.3% of participants met the contingency criteria and were paid an average of $222 during the Contingency Management phase, with an average $1,998 in total compensation throughout the study. Compared to the Observation phase, the percent of any self-reported drinking days significantly decreased from 59.9 to 40.0% in the Contingency Management and 32.0% in the Follow-up phases. The percent of self-reported heavy drinking days reported also significantly decreased from 42.4% in the Observation phase to 19.7% in the Contingency Management phase, which was accompanied by a significant increase in percent days of self-reported no (from 40.1 to 60.0%) and low-level drinking (from 9.9 to 15.4%). Self-reported reductions in drinking either persisted, or became more pronounced, during the Follow-up phase. Contingency management was associated with a reduction in self-reported episodes of heavy drinking among nontreatment-seeking heavy drinkers. These effects persisted even after incentives were removed, indicating the potential utility of contingency management as a therapeutic intervention to reduce harmful patterns of drinking. Copyright © 2015 by the Research Society on Alcoholism.

  1. Correction of Motion Artifacts From Shuttle Mode Computed Tomography Acquisitions for Body Perfusion Imaging Applications.

    PubMed

    Ghosh, Payel; Chandler, Adam G; Altinmakas, Emre; Rong, John; Ng, Chaan S

    2016-01-01

    The aim of this study was to investigate the feasibility of shuttle-mode computed tomography (CT) technology for body perfusion applications by quantitatively assessing and correcting motion artifacts. Noncontrast shuttle-mode CT scans (10 phases, 2 nonoverlapping bed locations) were acquired from 4 patients on a GE 750HD CT scanner. Shuttling effects were quantified using Euclidean distances (between-phase and between-bed locations) of corresponding fiducial points on the shuttle and reference phase scans (prior to shuttle mode). Motion correction with nonrigid registration was evaluated using sum-of-squares differences and distances between centers of segmented volumes of interest on shuttle and references images. Fiducial point analysis showed an average shuttling motion of 0.85 ± 1.05 mm (between-bed) and 1.18 ± 1.46 mm (between-phase), respectively. The volume-of-interest analysis of the nonrigid registration results showed improved sum-of-squares differences from 2950 to 597, between-bed distance from 1.64 to 1.20 mm, and between-phase distance from 2.64 to 1.33 mm, respectively, averaged over all cases. Shuttling effects introduced during shuttle-mode CT acquisitions can be computationally corrected for body perfusion applications.

  2. Multipoint entanglement in disordered systems

    NASA Astrophysics Data System (ADS)

    Magán, Javier M.; Paganelli, Simone; Oganesyan, Vadim

    2017-02-01

    We develop an approach to characterize excited states of disordered many-body systems using spatially resolved structures of entanglement. We show that the behavior of the mutual information (MI) between two parties of a many-body system can signal a qualitative difference between thermal and localized phases - MI is finite in insulators while it approaches zero in the thermodynamic limit in the ergodic phase. Related quantities, such as the recently introduced Codification Volume (CV), are shown to be suitable to quantify the correlation length of the system. These ideas are illustrated using prototypical non-interacting wavefunctions of localized and extended particles and then applied to characterize states of strongly excited interacting spin chains. We especially focus on evolution of spatial structure of quantum information between high temperature diffusive and many-body localized (MBL) phases believed to exist in these models. We study MI as a function of disorder strength both averaged over the eigenstates and in time-evolved product states drawn from continuously deformed family of initial states realizable experimentally. As expected, spectral and time-evolved averages coincide inside the ergodic phase and differ significantly outside. We also highlight dispersion among the initial states within the localized phase - some of these show considerable generation and delocalization of quantum information.

  3. Twist-averaged boundary conditions for nuclear pasta Hartree-Fock calculations

    DOE PAGES

    Schuetrumpf, B.; Nazarewicz, W.

    2015-10-21

    Nuclear pasta phases, present in the inner crust of neutron stars, are associated with nucleonic matter at subsaturation densities arranged in regular shapes. Those complex phases, residing in a layer which is approximately 100-m thick, impact many features of neutron stars. Theoretical quantum-mechanical simulations of nuclear pasta are usually carried out in finite three-dimensional boxes assuming periodic boundary conditions. The resulting solutions are affected by spurious finite-size effects. To remove spurious finite-size effects, it is convenient to employ twist-averaged boundary conditions (TABC) used in condensed matter, nuclear matter, and lattice quantum chromodynamics applications. In this work, we study the effectivenessmore » of TABC in the context of pasta phase simulations within nuclear density functional theory. We demonstrated that by applying TABC reliable results can be obtained from calculations performed in relatively small volumes. By studying various contributions to the total energy, we gain insights into pasta phases in mid-density range. Future applications will include the TABC extension of the adaptive multiresolution 3D Hartree-Fock solver and Hartree-Fock-Bogoliubov TABC applications to superfluid pasta phases and complex nucleonic topologies as in fission.« less

  4. Systematic Review of Prognostic Factors for Return to Work in Workers with Sub Acute and Chronic Low Back Pain.

    PubMed

    Steenstra, Ivan A; Munhall, Claire; Irvin, Emma; Oranye, Nelson; Passmore, Steven; Van Eerd, Dwayne; Mahood, Quenby; Hogg-Johnson, Sheilah

    2017-09-01

    Purpose We systematically reviewed the evidence on factors that predict duration of sick leave in workers after 6 weeks low back pain (LBP) related sick leave. We hypothesized that different factors affect the duration of the leave depending on the time away from work. Methods The review occurred in seven phases: (1) developing the central question, (2) conducting the literature search, (3) identifying relevant publications, (4) quality appraisal, (5) data extraction, (6) evidence synthesis, and (7) knowledge translation. We searched for studies that reported episodes of LBP and sick leave that lasted more than 6 weeks. All included studies reported at least one prognostic factor where return to work was the outcome. Results We identified twenty-two relevant publications. The impact of pain, functional status and radiating pain seems to change with duration of work disability. Workers' recovery expectations remain important after 6 weeks. Modified duties are rarely studied in later phases of work disability. Depression/mental health did not appear to be an important factor in later phases. Workplace physical factors remain important. There is insufficient evidence that pain catastrophising and fear avoidance are predictive factors in later phases. There was moderate evidence for age in the later phases. Functional capacity and claim related factors were supported by some evidence. Discusion Physical demands in the workplace are preventing workers from getting back to work in a timely fashion across phases. The psychosocial work environment is understudied in later phases. Overall, we cannot conclude that prognostic factors change over time.

  5. Investigating different computed tomography techniques for internal target volume definition.

    PubMed

    Yoganathan, S A; Maria Das, K J; Subramanian, V Siva; Raj, D Gowtham; Agarwal, Arpita; Kumar, Shaleen

    2017-01-01

    The aim of this work was to evaluate the various computed tomography (CT) techniques such as fast CT, slow CT, breath-hold (BH) CT, full-fan cone beam CT (FF-CBCT), half-fan CBCT (HF-CBCT), and average CT for delineation of internal target volume (ITV). In addition, these ITVs were compared against four-dimensional CT (4DCT) ITVs. Three-dimensional target motion was simulated using dynamic thorax phantom with target insert of diameter 3 cm for ten respiration data. CT images were acquired using a commercially available multislice CT scanner, and the CBCT images were acquired using On-Board-Imager. Average CT was generated by averaging 10 phases of 4DCT. ITVs were delineated for each CT by contouring the volume of the target ball; 4DCT ITVs were generated by merging all 10 phases target volumes. Incase of BH-CT, ITV was derived by boolean of CT phases 0%, 50%, and fast CT target volumes. ITVs determined by all CT and CBCT scans were significantly smaller (P < 0.05) than the 4DCT ITV, whereas there was no significant difference between average CT and 4DCT ITVs (P = 0.17). Fast CT had the maximum deviation (-46.1% ± 20.9%) followed by slow CT (-34.3% ± 11.0%) and FF-CBCT scans (-26.3% ± 8.7%). However, HF-CBCT scans (-12.9% ± 4.4%) and BH-CT scans (-11.1% ± 8.5%) resulted in almost similar deviation. On the contrary, average CT had the least deviation (-4.7% ± 9.8%). When comparing with 4DCT, all the CT techniques underestimated ITV. In the absence of 4DCT, the HF-CBCT target volumes with appropriate margin may be a reasonable approach for defining the ITV.

  6. Regionalized life cycle impact assessment of air pollution on the global scale: Damage to human health and vegetation

    NASA Astrophysics Data System (ADS)

    van Zelm, Rosalie; Preiss, Philipp; van Goethem, Thomas; Van Dingenen, Rita; Huijbregts, Mark

    2016-06-01

    We developed regionalized characterization factors (CFs) for human health damage from particulate matter (PM2.5) and ozone, and for damage to vegetation from ozone, at the global scale. These factors can be used in the impact assessment phase of an environmental life cycle assessment. CFs express the overall damage of a certain pollutant per unit of emission of a precursor, i.e. primary PM2.5, nitrogen oxides (NOx), ammonia (NH3), sulfur dioxide (SO2) and non-methane volatile organic compounds (NMVOCs). The global chemical transport model TM5 was used to calculate intake fractions of PM2.5 and ozone for 56 world regions covering the whole globe. Furthermore, region-specific effect and damage factors were derived, using mortality rates, background concentrations and years of life lost. The emission-weighted world average CF for primary PM2.5 emissions is 629 yr kton-1, varying up to 3 orders of magnitude over the regions. Larger CFs were obtained for emissions in central Asia and Europe, and smaller factors in Australia and South America. The world average CFs for PM2.5 from secondary aerosols, i.e. NOx, NH3, and SO2, is 67.2 to 183.4 yr kton-1. We found that the CFs for ozone human health damage are 2-4 orders of magnitude lower compared to the CFs for damage due to primary PM2.5 and PM2.5 precursor emissions. Human health damage due to the priority air pollutants considered in this study was 1.7·10-2 yr capita-1 worldwide in year 2010, with primary PM2.5 emissions as the main contributor (62%). The emission-weighted world average CF for ecosystem damage due to ozone was 2.5 km2 yr kton-1 for NMVOCs and 8.7 m2 yr kg-1 for NOx emissions, varying 2-3 orders of magnitude over the regions. Ecosystem damage due to the priority air pollutants considered in this study was 1.6·10-4 km2 capita-1 worldwide in 2010, with NOx as the main contributor (72%). The spatial range in CFs stresses the importance of including spatial variation in life cycle impact assessment of priority air pollutants.

  7. Detrending Algorithms in Large Time Series: Application to TFRM-PSES Data

    NASA Astrophysics Data System (ADS)

    del Ser, D.; Fors, O.; Núñez, J.; Voss, H.; Rosich, A.; Kouprianov, V.

    2015-07-01

    Certain instrumental effects and data reduction anomalies introduce systematic errors in photometric time series. Detrending algorithms such as the Trend Filtering Algorithm (TFA; Kovács et al. 2004) have played a key role in minimizing the effects caused by these systematics. Here we present the results obtained after applying the TFA, Savitzky & Golay (1964) detrending algorithms, and the Box Least Square phase-folding algorithm (Kovács et al. 2002) to the TFRM-PSES data (Fors et al. 2013). Tests performed on these data show that by applying these two filtering methods together the photometric RMS is on average improved by a factor of 3-4, with better efficiency towards brighter magnitudes, while applying TFA alone yields an improvement of a factor 1-2. As a result of this improvement, we are able to detect and analyze a large number of stars per TFRM-PSES field which present some kind of variability. Also, after porting these algorithms to Python and parallelizing them, we have improved, even for large data samples, the computational performance of the overall detrending+BLS algorithm by a factor of ˜10 with respect to Kovács et al. (2004).

  8. Changes in Depressive Symptoms in the Context of Disablement Processes: Role of Demographic Characteristics, Cognitive Function, Health, and Social Support

    PubMed Central

    Gerstorf, Denis; Ram, Nilam; Malmberg, Bo

    2012-01-01

    Objectives. Gerontological research suggests that depressive symptoms show antecedent and consequent relations with late-life disability. Less is known, however, about how depressive symptoms change with the progression of disability-related processes and what factors moderate such changes. Methods. We applied multiphase growth models to longitudinal data pooled across 4 Swedish studies of very old age (N = 779, M age = 86 years at disability onset, 64% women) to describe change in depressive symptoms prior to disability onset, at or around disability onset (the measurement wave at which assistance in personal activities of daily living was first recorded), and postdisability onset. Results. Results indicate that, on average, depressive symptoms slightly increase with approaching disability, increase at onset, and decline in the postdisability phase. Age, study membership, being a woman, and multimorbidity were related to depressive symptoms, but social support emerged as the most powerful predictor of level and change in depressive symptoms. Discussion. Our findings are consistent with conceptual notions implicating disability-related factors as key contributors to late-life change and suggest that contextual and psychosocial factors play a pivotal role for how well people adapt to late-life challenges. PMID:21821838

  9. Relationships of feeding behaviors with average daily gain, dry matter intake, and residual feed intake in Red Angus-sired cattle.

    PubMed

    McGee, M; Welch, C M; Ramirez, J A; Carstens, G E; Price, W J; Hall, J B; Hill, R A

    2014-11-01

    Feeding behavior has the potential to enhance prediction of feed intake and to improve understanding of the relationships between behavior, DMI, ADG, and residual feed intake (RFI) in beef cattle. Two cohorts, born in 2009 and 2010, the progeny of Red Angus bulls (n = 58 heifers and n = 53 steers), were evaluated during the growing phase, and the latter group of steers was also evaluated during the finishing phase. All behavior analyses were based on 7 feeding behavior traits (bunk visit frequency, bunk visit duration [BVDUR], feed bout frequency, feed bout duration, meal frequency, meal duration, and average meal intake) and their relationships with ADG, DMI, and RFI. During the growing phase, feeding duration traits were most indicative of DMI with positive correlations between BVDUR and DMI for cohort 1 steers, growing phase (n = 28, r = 0.52, P = 0.00); cohort 2 steers, growing phase (n = 25, r = 0.44, P = 0.01); and cohort 2 heifers, growing phase (n = 29, r = 0.28 P = 0.05). There were similar trends toward correlation of BVDUR and RFI for both steer groups and cohort 1 heifers, growing phase (C1HG; n = 29; r = 0.27, P = 0.06; r = 0.30, P = 0.07; and r = 0.26, P = 0.08, respectively). Feed bout frequency was correlated with ADG in C1HG and in cohort 2 steers, finishing phase (r = -0.31, P = 0.04, and r = 0.43, P = 0.01, respectively). Feed bout duration was correlated with ADG in heifer groups (r = 0.29 and r = 0.28, P = 0.05 for both groups) and DMI for all growing phase animals (r = 0.29 to 0.55, P ≤ 0.05 for all groups). Evaluation of growing vs. finishing phase steer groups suggests that all behaviors, RFI, and DMI, but not ADG, are correlated through the growing and finishing phases (P ≤ 0.01 for all variables excluding ADG), implying that feeding behaviors determined during the growing phase are strong predictors of DMI in either life stage. Sire maintenance energy EPD effects (measured as high or low groups) on progeny feeding behaviors revealed a difference in meal duration with a tendency to differ in average meal intake (P = 0.01 and P = 0.07, respectively). Feeding behavior duration traits may be useful predictors of DMI in Red Angus cattle.

  10. Quantitative Measures of Chaotic Charged Particle Dynamics in the Magnetotail

    NASA Astrophysics Data System (ADS)

    Holland, D. L.; Martin, R. F., Jr.; Burris, C.

    2017-12-01

    It has long been noted that the motion of charged particles in magnetotail-like magnetic fields is chaotic, however, efforts to quantify the degree of chaos have had conflicting conclusions. In this paper we re-examine the question by focusing on quantitative measures of chaos. We first examine the percentage of orbits that enter the chaotic region of phase space and the average trapping time of those particles. We then examine the average exponential divergence rate (AEDR) of the chaotic particles between their first and last crossing of the mid-plane. We show that at resonant energies where the underlying phase space has a high degree of symmetry, only a small number of particle enter the chaotic region, but they are trapped for long periods of time and the time asymptotic value of the AEDR is very close to the average value of the AEDR. At the off-resonant energies where the phase space is highly asymmetric, the majority of the particle enter the chaotic region for fairly short periods of time and the time asymptotic value of the AEDR is much smaller than the average value. The root cause is that in the resonant case, the longest-lived orbits tend interact with the current many times and sample the entire chaotic region, whereas in the non-resonant case the longest-lived orbits only interact with the current sheet a small number of times but have very long mirrorings where the motion is nearly regular. Additionally we use an ad-hoc model where we model the current sheet as a Lorentz scattering system with each interaction with the current sheet being considered as a "collision". We find that the average kick per collision is greatest at off-resonant energies. Finally, we propose a chaos parameter as the product of the AEDR times the average chaotic particle trapping time times the percentage of orbits that are chaotic. We find that this takes on peak values at the resonant energies.

  11. [Papillary muscle rupture complicating acute myocardial infarction--treatment with mitral valve replacement and coronary bypass surgery in acute phase].

    PubMed

    Kyo, S; Miyamoto, N; Yokote, Y; Ueda, K; Takamoto, S; Omoto, R

    1996-06-01

    Complete rupture of a papillary muscle following acute myocardial infarction is a severe complication that is typically associated with acute left ventricular failure, pulmonary edema, and relentless clinical deterioration. The reported mortality rates without surgical intervention is almost 90%, therefore, prompt operation without prolonged attempts at medical stabilization is the key to decrease operative mortality. Although the complete coronary revascularization in conjunction with mitral valve replacement is advocated in the western medical academic society, there is only a few case of conjunct surgery has been reported in Japan. Three successful cases of conjunct surgery of mitral valve replacement and coronary complete revascularization in acute phase within one week from the onset of acute myocardial infarction (AMI) are described. There were one male and two female patients with an average age of 60-year-old (range 48-67), who developed cardiogenic shock and admitted to our hospital. The average interval between onset of AMI and the appearance of mitral regurgitation (MR) was 38 hours, and that of the appearance of MR and admission was 40 hours. Surgeries were performed within 26 hours (average 13 hours) after admission. The mitral valve was replaced with a mechanical valve (St. Jude Medical Valve) and a complete coronary revasculatization was done using saphenous vein graft. The average period of operation time and aortic cross clamping time were 6 hours 22 minutes and 109 minutes respectively. The average number of coronary grafting was 2.3 (range 1-3). Postoperative recovery from cardiogenic shock was uneventful in all three patients. The average periods of ICU stay and hospital stay were 5 days and 43 days respectively. All patients have regained their social activities with mean follow up period of 52 months. Since ischemic heart disease remains the leading cause of death in such patients, it is suggested that complete coronary revascularization should be performed immediately in conjunction with valve replacement even in the acute phase after onset of AMI.

  12. Effective phase function of light scattered at small angles by polydisperse particulate media

    NASA Astrophysics Data System (ADS)

    Turcu, I.

    2008-06-01

    Particles with typical dimensions higher than the light wavelength and relative refraction indexes close to one, scatter light mainly in the forward direction where the scattered light intensity has a narrow peak. For particulate media accomplishing these requirements the light scattered at small angles in a far-field detecting set-up can be described analytically by an effective phase function (EPF) even in the multiple scattering regime. The EPF model which was built for monodispersed systems has been extended to polydispersed media. The main ingredients consist in the replacement of the single particle phase function and of the optical thickness with their corresponding averaged values. Using a Gamma particle size distribution (PSD) as a testing model, the effect of polydispersity was systematically investigated. The increase of the average radius or/and of the PSD standard deviation leads to the decrease of the angular spreading of the small angle scattered light.

  13. Topography and refractometry of sperm cells using spatial light interference microscopy.

    PubMed

    Liu, Lina; Kandel, Mikhail E; Rubessa, Marcello; Schreiber, Sierra; Wheeler, Mathew B; Popescu, Gabriel

    2018-02-01

    Characterization of spermatozoon viability is a common test in treating infertility. Recently, it has been shown that label-free, phase-sensitive imaging can provide a valuable alternative for this type of assay. We employ spatial light interference microscopy (SLIM) to perform high-accuracy single-cell phase imaging and decouple the average thickness and refractive index information for the population. This procedure was enabled by quantitative-phase imaging cells on media of two different refractive indices and using a numerical tool to remove the curvature from the cell tails. This way, we achieved ensemble averaging of topography and refractometry of 100 cells in each of the two groups. The results show that the thickness profile of the cell tail goes down to 150 nm and the refractive index can reach values of 1.6 close to the head. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  14. Tissue refractometry using Hilbert phase microscopy

    PubMed Central

    Lue, Niyom; Bewersdorf, Joerg; Lessard, Mark D.; Badizadegan, Kamran; Dasari, Ramachandra R.; Feld, Michael S.; Popescu, Gabriel

    2009-01-01

    We present, for the first time to our knowledge, quantitative phase images associated with unstained 5 μm thick tissue slices of mouse brain, spleen, and liver. The refractive properties of the tissue are retrieved in terms of the average refractive index and its spatial variation. We find that the average refractive index varies significantly with tissue type, such that the brain is characterized by the lowest value and the liver by the highest. The spatial power spectra of the phase images reveal power law behavior with different exponents for each tissue type. This approach opens a new possibility for stain-free characterization of tissues, where the diagnostic power is provided by the intrinsic refractive properties of the biological structure. We present results obtained for liver tissue affected by a lysosomal storage disease and show that our technique can quantify structural changes during this disease development. PMID:18087529

  15. Allantoin as a solid phase adsorbent for removing endotoxins.

    PubMed

    Vagenende, Vincent; Ching, Tim-Jang; Chua, Rui-Jing; Gagnon, Pete

    2013-10-04

    In this study we present a simple and robust method for removing endotoxins from protein solutions by using crystals of the small-molecule compound 2,5-dioxo-4-imidazolidinyl urea (allantoin) as a solid phase adsorbent. Allantoin crystalline powder is added to a protein solution at supersaturated concentrations, endotoxins bind and undissolved allantoin crystals with bound endotoxins are removed by filtration or centrifugation. This method removes an average of 99.98% endotoxin for 20 test proteins. The average protein recovery is ∼80%. Endotoxin binding is largely independent of pH, conductivity, reducing agent and various organic solvents. This is consistent with a hydrogen-bond based binding mechanism. Allantoin does not affect protein activity and stability, and the use of allantoin as a solid phase adsorbent provides better endotoxin removal than anion exchange, polymixin affinity and biological affinity methods for endotoxin clearance. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Structure, thermal expansion coefficient and phase stability of La2(Zr0.7Ce0.3)2O7 studied by molecular dynamic simulation and experiment

    NASA Astrophysics Data System (ADS)

    Che, JunWei; Liu, XiangYang; Wang, XueZhi; Liang, GongYing

    2018-04-01

    This paper presents structure, thermal expansion coefficient and phase stability of La2(Zr0.7Ce0.3)2O7 (LZ7C3) ceramic by both theoretical and experimental results. It was found out that LZ7C3 powders had a pyrochlore structure after being heat-treated at temperatures higher than 1473 K or higher according to XRD and TEM results. The calculated average thermal expansion coefficient (TEC) was 7.12 × 10-6 K-1, which is a little smaller than experiment result, but changes of calculated average TECs of LZ, YSZ and LZ7C3 had the same trend with experimental results. Finally, the radial distribution function (RDF) was calculated to study the phase stability of LZ7C3.

  17. Phase Transition in Protocols Minimizing Work Fluctuations

    NASA Astrophysics Data System (ADS)

    Solon, Alexandre P.; Horowitz, Jordan M.

    2018-05-01

    For two canonical examples of driven mesoscopic systems—a harmonically trapped Brownian particle and a quantum dot—we numerically determine the finite-time protocols that optimize the compromise between the standard deviation and the mean of the dissipated work. In the case of the oscillator, we observe a collection of protocols that smoothly trade off between average work and its fluctuations. However, for the quantum dot, we find that as we shift the weight of our optimization objective from average work to work standard deviation, there is an analog of a first-order phase transition in protocol space: two distinct protocols exchange global optimality with mixed protocols akin to phase coexistence. As a result, the two types of protocols possess qualitatively different properties and remain distinct even in the infinite duration limit: optimal-work-fluctuation protocols never coalesce with the minimal-work protocols, which therefore never become quasistatic.

  18. Incremental Value of Repeated Risk Factor Measurements for Cardiovascular Disease Prediction in Middle-Aged Korean Adults: Results From the NHIS-HEALS (National Health Insurance System-National Health Screening Cohort).

    PubMed

    Cho, In-Jeong; Sung, Ji Min; Chang, Hyuk-Jae; Chung, Namsik; Kim, Hyeon Chang

    2017-11-01

    Increasing evidence suggests that repeatedly measured cardiovascular disease (CVD) risk factors may have an additive predictive value compared with single measured levels. Thus, we evaluated the incremental predictive value of incorporating periodic health screening data for CVD prediction in a large nationwide cohort with periodic health screening tests. A total of 467 708 persons aged 40 to 79 years and free from CVD were randomly divided into development (70%) and validation subcohorts (30%). We developed 3 different CVD prediction models: a single measure model using single time point screening data; a longitudinal average model using average risk factor values from periodic screening data; and a longitudinal summary model using average values and the variability of risk factors. The development subcohort included 327 396 persons who had 3.2 health screenings on average and 25 765 cases of CVD over 12 years. The C statistics (95% confidence interval [CI]) for the single measure, longitudinal average, and longitudinal summary models were 0.690 (95% CI, 0.682-0.698), 0.695 (95% CI, 0.687-0.703), and 0.752 (95% CI, 0.744-0.760) in men and 0.732 (95% CI, 0.722-0.742), 0.735 (95% CI, 0.725-0.745), and 0.790 (95% CI, 0.780-0.800) in women, respectively. The net reclassification index from the single measure model to the longitudinal average model was 1.78% in men and 1.33% in women, and the index from the longitudinal average model to the longitudinal summary model was 32.71% in men and 34.98% in women. Using averages of repeatedly measured risk factor values modestly improves CVD predictability compared with single measurement values. Incorporating the average and variability information of repeated measurements can lead to great improvements in disease prediction. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02931500. © 2017 American Heart Association, Inc.

  19. Cavity-enhanced eigenmode and angular hybrid multiplexing in holographic data storage systems.

    PubMed

    Miller, Bo E; Takashima, Yuzuru

    2016-12-26

    Resonant optical cavities have been demonstrated to improve energy efficiencies in Holographic Data Storage Systems (HDSS). The orthogonal reference beams supported as cavity eigenmodes can provide another multiplexing degree of freedom to push storage densities toward the limit of 3D optical data storage. While keeping the increased energy efficiency of a cavity enhanced reference arm, image bearing holograms are multiplexed by orthogonal phase code multiplexing via Hermite-Gaussian eigenmodes in a Fe:LiNbO3 medium with a 532 nm laser at two Bragg angles. We experimentally confirmed write rates are enhanced by an average factor of 1.1, and page crosstalk is about 2.5%. This hybrid multiplexing opens up a pathway to increase storage density while minimizing modification of current angular multiplexing HDSS.

  20. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Stassi, D.; Ma, H.; Schmidt, T. G., E-mail: taly.gilat-schmidt@marquette.edu

    Purpose: Reconstructing a low-motion cardiac phase is expected to improve coronary artery visualization in coronary computed tomography angiography (CCTA) exams. This study developed an automated algorithm for selecting the optimal cardiac phase for CCTA reconstruction. The algorithm uses prospectively gated, single-beat, multiphase data made possible by wide cone-beam imaging. The proposed algorithm differs from previous approaches because the optimal phase is identified based on vessel image quality (IQ) directly, compared to previous approaches that included motion estimation and interphase processing. Because there is no processing of interphase information, the algorithm can be applied to any sampling of image phases, makingmore » it suited for prospectively gated studies where only a subset of phases are available. Methods: An automated algorithm was developed to select the optimal phase based on quantitative IQ metrics. For each reconstructed slice at each reconstructed phase, an image quality metric was calculated based on measures of circularity and edge strength of through-plane vessels. The image quality metric was aggregated across slices, while a metric of vessel-location consistency was used to ignore slices that did not contain through-plane vessels. The algorithm performance was evaluated using two observer studies. Fourteen single-beat cardiac CT exams (Revolution CT, GE Healthcare, Chalfont St. Giles, UK) reconstructed at 2% intervals were evaluated for best systolic (1), diastolic (6), or systolic and diastolic phases (7) by three readers and the algorithm. Pairwise inter-reader and reader-algorithm agreement was evaluated using the mean absolute difference (MAD) and concordance correlation coefficient (CCC) between the reader and algorithm-selected phases. A reader-consensus best phase was determined and compared to the algorithm selected phase. In cases where the algorithm and consensus best phases differed by more than 2%, IQ was scored by three readers using a five point Likert scale. Results: There was no statistically significant difference between inter-reader and reader-algorithm agreement for either MAD or CCC metrics (p > 0.1). The algorithm phase was within 2% of the consensus phase in 15/21 of cases. The average absolute difference between consensus and algorithm best phases was 2.29% ± 2.47%, with a maximum difference of 8%. Average image quality scores for the algorithm chosen best phase were 4.01 ± 0.65 overall, 3.33 ± 1.27 for right coronary artery (RCA), 4.50 ± 0.35 for left anterior descending (LAD) artery, and 4.50 ± 0.35 for left circumflex artery (LCX). Average image quality scores for the consensus best phase were 4.11 ± 0.54 overall, 3.44 ± 1.03 for RCA, 4.39 ± 0.39 for LAD, and 4.50 ± 0.18 for LCX. There was no statistically significant difference (p > 0.1) between the image quality scores of the algorithm phase and the consensus phase. Conclusions: The proposed algorithm was statistically equivalent to a reader in selecting an optimal cardiac phase for CCTA exams. When reader and algorithm phases differed by >2%, image quality as rated by blinded readers was statistically equivalent. By detecting the optimal phase for CCTA reconstruction, the proposed algorithm is expected to improve coronary artery visualization in CCTA exams.« less

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