WorldWideScience

Sample records for broadening distribution comparisons

  1. Proton Lateral Broadening Distribution Comparisons Between GRNTRN, MCNPX, and Laboratory Beam Measurements

    Science.gov (United States)

    Mertens, Christopher J.; Moyers, Michael F.; Walker, Steven A.; Tweed, John

    2010-01-01

    Recent developments in NASA s deterministic High charge (Z) and Energy TRaNsport (HZETRN) code have included lateral broadening of primary ion beams due to small-angle multiple Coulomb scattering, and coupling of the ion-nuclear scattering interactions with energy loss and straggling. This new version of HZETRN is based on Green function methods, called GRNTRN, and is suitable for modeling transport with both space environment and laboratory boundary conditions. Multiple scattering processes are a necessary extension to GRNTRN in order to accurately model ion beam experiments, to simulate the physical and biological-effective radiation dose, and to develop new methods and strategies for light ion radiation therapy. In this paper we compare GRNTRN simulations of proton lateral broadening distributions with beam measurements taken at Loma Linda University Proton Therapy Facility. The simulated and measured lateral broadening distributions are compared for a 250 MeV proton beam on aluminum, polyethylene, polystyrene, bone substitute, iron, and lead target materials. The GRNTRN results are also compared to simulations from the Monte Carlo MCNPX code for the same projectile-target combinations described above.

  2. A scheme comparison of Autler-Townes based slow light in inhomogeneously broadened quantum dot media

    DEFF Research Database (Denmark)

    Hansen, Per Lunnemann; Mørk, Jesper

    2010-01-01

    We propose a method to achieve significant optical signal delays exploiting the effect of Autler–Townes splitting (ATS) in an inhomogeneously broadened quantum dot medium. The absorption and slowdown effects are compared for three schemes i.e., Ξ, V, and Λ, corresponding to different excitation c...

  3. Determination of the Ion Velocity Distribution in a Rotating Plasma from Measurements of Doppler Broadening

    DEFF Research Database (Denmark)

    Jørgensen, L. W.; Sillesen, Alfred Hegaard

    1979-01-01

    The Doppler-broadened profile of the He II 4685.75 AA line was measured along a chord in a rotating plasma, transverse to the magnetic field. Using a single-particle orbit picture, the corresponding velocity spectrum of ions confirm the measurements, so it can be concluded that the single......-particle orbit picture is valid for the discharge period under investigation, except for the first few microseconds during breakdown when a strong interaction between plasma and remaining neutral gas takes place by Alfvens critical velocity mechanism. A simple relation is given between the measured half...

  4. [The reconstruction of welding arc 3D electron density distribution based on Stark broadening].

    Science.gov (United States)

    Zhang, Wang; Hua, Xue-Ming; Pan, Cheng-Gang; Li, Fang; Wang, Min

    2012-10-01

    The three-dimensional electron density is very important for welding arc quality control. In the present paper, Side-on characteristic line profile was collected by a spectrometer, and the lateral experimental data were approximated by a polynomial fitting. By applying an Abel inversion technique, the authors obtained the radial intensity distribution at each wavelength and thus constructed a profile for the radial positions. The Fourier transform was used to separate the Lorentz linear from the spectrum reconstructed, thus got the accurate Stark width. And we calculated the electronic density three-dimensional distribution of the TIG welding are plasma.

  5. Aerosol indirect effect from turbulence-induced broadening of cloud-droplet size distributions

    Energy Technology Data Exchange (ETDEWEB)

    Chandrakar, Kamal Kant; Cantrell, Will; Chang, Kelken; Ciochetto, David; Niedermeier, Dennis; Ovchinnikov, Mikhail; Shaw, Raymond A.; Yang, Fan

    2016-11-28

    The influence of aerosol concentration on cloud droplet size distribution is investigated in a laboratory chamber that enables turbulent cloud formation through moist convection. The experiments allow steady-state microphysics to be achieved, with aerosol input balanced by cloud droplet growth and fallout. As aerosol concentration is increased the cloud droplet mean diameter decreases as expected, but the width of the size distribution also decreases sharply. The aerosol input allows for cloud generation in the limiting regimes of fast microphysics (τc < τt) for high aerosol concentration, and slow microphysics (τc > τt) for low aerosol concentration; here, τc is the phase relaxation time and τt is the turbulence correlation time. The increase in the width of the droplet size distribution for the low aerosol limit is consistent with larger variability of supersaturation due to the slow microphysical response. A stochastic differential equation for supersaturation predicts that the standard deviation of the squared droplet radius should increase linearly with a system time scale defined as τs-1c-1 + τt-1, and the measurements are in excellent agreement with this finding. This finding underscores the importance of droplet size dispersion for the aerosol indirect effect: increasing aerosol concentration not only suppresses precipitation formation through reduction of the mean droplet diameter, but perhaps more importantly, through narrowing of the droplet size distribution due to reduced supersaturation fluctuations. Supersaturation fluctuations in the low aerosol / slow microphysics limit are likely of leading importance for precipitation formation.

  6. Linewidth broadening in a distributed feedback laser integrated with a semiconductor optical amplifier

    DEFF Research Database (Denmark)

    Champagne, A.; Camel, J.; Maciejko, R.

    2002-01-01

    The problem of the linewidth degradation in systems using distributed-feedback lasers together with strained-layer multi-quantum-well semiconductor optical amplifiers (SOAs) is examined. A modified expression for the linewidth in the case of antireflection-coated SOA output facets is derived and ...... and simulation results are given in the case of output facets with a nonvanishing reflectivity. A numerical model combining finite-element calculations in the transverse x-y plane and a longitudinal model based on the Green's function method is used for that purpose....

  7. Distributed Wind Policy Comparison Tool

    Energy Technology Data Exchange (ETDEWEB)

    None

    2011-12-01

    Power through Policy: 'Best Practices' for Cost-Effective Distributed Wind is a U.S. Department of Energy (DOE)-funded project to identify distributed wind technology policy best practices and to help policymakers, utilities, advocates, and consumers examine their effectiveness using a pro forma model. Incorporating a customized feed from the Database of State Incentives for Renewables and Efficiency (DSIRE), the Web-based Distributed Wind Policy Comparison Tool (Policy Tool) is designed to assist state, local, and utility officials in understanding the financial impacts of different policy options to help reduce the cost of distributed wind technologies. The Policy Tool can be used to evaluate the ways that a variety of federal and state policies and incentives impact the economics of distributed wind (and subsequently its expected market growth). It also allows policymakers to determine the impact of policy options, addressing market challenges identified in the U.S. DOE’s '20% Wind Energy by 2030' report and helping to meet COE targets.

  8. Broadening of Distribution of Trap States in PbS Quantum Dot Field-Effect Transistors with High-k Dielectrics.

    Science.gov (United States)

    Nugraha, Mohamad I; Häusermann, Roger; Watanabe, Shun; Matsui, Hiroyuki; Sytnyk, Mykhailo; Heiss, Wolfgang; Takeya, Jun; Loi, Maria A

    2017-02-08

    We perform a quantitative analysis of the trap density of states (trap DOS) in PbS quantum dot field-effect transistors (QD-FETs), which utilize several polymer gate insulators with a wide range of dielectric constants. With increasing gate dielectric constant, we observe increasing trap DOS close to the lowest unoccupied molecular orbital (LUMO) of the QDs. In addition, this increase is also consistently followed by broadening of the trap DOS. We rationalize that the increase and broadening of the spectral trap distribution originate from dipolar disorder as well as polaronic interactions, which are appearing at strong dielectric polarization. Interestingly, the increased polaron-induced traps do not show any negative effect on the charge carrier mobility in our QD devices at the highest applied gate voltage, giving the possibility to fabricate efficient low-voltage QD devices without suppressing carrier transport.

  9. The distribution of interlaboratory comparison data

    DEFF Research Database (Denmark)

    Heydorn, Kaj

    2008-01-01

    The distribution of mutually consistent results from interlaboratory comparisons is expected to be leptokurtic, and readers are warned against accepting conclusions based on simulations assuming normality....

  10. A comparison between different X-ray diffraction line broadening analysis methods for nanocrystalline ball-milled FCC powders

    Energy Technology Data Exchange (ETDEWEB)

    Soleimanian, V. [Shahrekord University, Department of Physics, Faculty of Sciences, P.O. Box 115, Shahrekord (Iran, Islamic Republic of); Shahrekord University, Nanotechnology Research Center, Shahrekord (Iran, Islamic Republic of); Mojtahedi, M. [Pooya Gharb Branch of University of Applied Science and Technology, Department of Materials Engineering, Kermanshah (Iran, Islamic Republic of)

    2015-06-15

    The microstructural characteristics of aluminum, copper and nickel powders are investigated using different X-ray diffraction line broadening analysis approaches. Prior to analysis, the powders were ball-milled to produce a nanocrystalline structure with high density of probable types of lattice defects. A variety of methods, including Scherrer, Williamson-Smallman, Williamson-Hall, Warren-Averbach, modified Williamson-Hall, modified Warren-Averbach, Rietveld refinement and whole powder pattern modeling (WPPM) approaches are applied. In this way, microstructural characteristics such as crystallite size, microstrain, dislocation density, effective outer cut-off radius of dislocations and the probability of twining and stacking faults are calculated. On the other hand, the results of conventional and advanced line broadening analysis methods are compared. It is revealed that the density of linear and planar defects in the mechanically deformed aluminum powder is significantly smaller than that of copper and nickel, as well as the level of anisotropic strain broadening. Moreover, the WPPM procedure provided a better profile fitting with more accurate results. (orig.)

  11. Calibrating and Controlling the Quantum Efficiency Distribution of Inhomogeneously Broadened Quantum Rods by Using a Mirror Ball

    DEFF Research Database (Denmark)

    Hansen, Per Lunnemann; Rabouw, Freddy T.; van Dijk-Moes, Relinde J. A.

    2013-01-01

    -in-rod emitters. The emitters are of large current interest due to their improved stability and reduced blinking. We retrieve a room-temperature ensemble average quantum efficiency of 0.87 ± 0.08 at a mean lifetime around 20 ns. We confirm a log-normal distribution of decay rates as often assumed in literature...

  12. Distributed Wind Policy Comparison Tool Guidebook

    Energy Technology Data Exchange (ETDEWEB)

    2011-11-01

    Power through Policy: 'Best Practices' for Cost-Effective Distributed Wind is a U.S. Department of Energy (DOE)-funded project to identify distributed wind technology policy best practices and to help policymakers, utilities, advocates, and consumers examine their effectiveness using a pro forma model. Incorporating a customized feed from the Database of State Incentives for Renewables and Efficiency (DSIRE), the Web-based Distributed Wind Policy Comparison Tool (Policy Tool) is designed to assist state, local, and utility officials in understanding the financial impacts of different policy options to help reduce the cost of distributed wind technologies. The Policy Tool can be used to evaluate the ways that a variety of federal and state policies and incentives impact the economics of distributed wind (and subsequently its expected market growth). It also allows policymakers to determine the impact of policy options, addressing market challenges identified in the U.S. DOE's '20% Wind Energy by 2030' report and helping to meet COE targets.

  13. comparison of estimation methods for fitting weibull distribution

    African Journals Online (AJOL)

    Tersor

    QuercusroburL.) stands in northwest Spain with the beta distribution. Investigación Agraria: Sistemasy Recursos Forestales 17(3):. 271-281. COMPARISON OF ESTIMATION METHODS FOR FITTING WEIBULL DISTRIBUTION TO THE NATURAL ...

  14. Does interest broaden or narrow attentional scope?

    Science.gov (United States)

    Sung, Billy; Yih, Jennifer

    2015-08-10

    Theory proposes that interest is a positive emotion that may either broaden attention to facilitate processing of new information, or narrow attention to preserve engagement with new information. To our knowledge, no research has directly examined the effect of interest on attentional scope. Across four experiments, we show that traits associated with the propensity to experience interest-specifically, trait curiosity and internal boredom proneness-are associated with a narrower scope of attention. We also find that, instead of broadening, interest actually narrows attentional scope in comparison to a neutral state and awe. Challenging the conventional notion that all positive emotions broaden cognition and attention, our findings suggest that specific emotions influence attention in ways that extend beyond a general emotional valence effect.

  15. Nonlocal inhomogeneous broadening in plasmonic nanoparticle ensembles

    DEFF Research Database (Denmark)

    Tserkezis, Christos; Maack, Johan Rosenkrantz; Liu, Z.

    )] or realistic noble metals, following sharp or smooth size distribution functions around an ensemble mean value, and identify examples where inhomogeneous broadening can be significant. We also explain how its role becomes less important in most experimentally accessible situations, provided that all...

  16. Power broadening and collision broadening of gas laser transitions

    NARCIS (Netherlands)

    Bolwijn, P.T.; Alkemade, C.T.J.

    1967-01-01

    From measured tuning characteristics of the amplitude of laser power modulation in single-mode operation, power broadening as well as collision broadening of the laser transition is shown to be relatively important and can be studied separately. It is also found that the d.c. laser power is

  17. Lifetime broadening in angle-resolved photoemission

    Science.gov (United States)

    McLean, A. B.; Mitchell, C. E. J.; Hill, I. G.

    1994-08-01

    The register line formalism of angle-resolved photoemission is applied to the special case where electrons are excited from sp surface states. By considering lifetime broadening alone, it is demonstrated that it is possible to explain why photoemission linewidths increase as the initial states disperse towards the Fermi level. Favourable comparisons are made between the theory and with measurements of the surface state widths on Cu(111) and Al(001).

  18. Comparison between Different Air Distribution Systems

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    The aim of an air conditioning system is to remove excess heat in a room and replace room air with fresh air to obtain a high air quality. It is not sufficient to remove heat and contaminated air, it is also necessary to distribute and control the air movement in the room to create thermal comfort...... in the occupied zone. Most air distribution systems are based on mixing ventilation with ceiling or wall-mounted diffusers or on displacement ventilation with wall-mounted low velocity diffusers. New principles for room air distribution were introduced during the last decades, as the textile terminals mounted...... in the ceiling and radial diffusers with swirling flow also mounted in the ceiling. This paper addresses five air distribution systems in all, namely mixing ventilation from a wallmounted terminal, mixing ventilation from a ceiling-mounted diffuser, mixing ventilation from a ceiling-mounted diffuser...

  19. Comparison of sparse point distribution models

    DEFF Research Database (Denmark)

    Erbou, Søren Gylling Hemmingsen; Vester-Christensen, Martin; Larsen, Rasmus

    2010-01-01

    This paper compares several methods for obtaining sparse and compact point distribution models suited for data sets containing many variables. These are evaluated on a database consisting of 3D surfaces of a section of the pelvic bone obtained from CT scans of 33 porcine carcasses. The superior m...... in slaughterhouses....

  20. Broadening nanotechnology's impact on development

    NARCIS (Netherlands)

    Beumer, K.|info:eu-repo/dai/nl/344382710

    2016-01-01

    Discussions about nanotechnology and development focus on applications that directly address the needs of the world’s poor. Nanotechnology can certainly make an impact in the fight against global poverty, but we need to broaden our imagination.

  1. Broadening nanotechnology's impact on development

    Science.gov (United States)

    Beumer, Koen

    2016-05-01

    Discussions about nanotechnology and development focus on applications that directly address the needs of the world's poor. Nanotechnology can certainly make an impact in the fight against global poverty, but we need to broaden our imagination.

  2. Generalized Poisson distribution: the property of mixture of Poisson and comparison with negative binomial distribution.

    Science.gov (United States)

    Joe, Harry; Zhu, Rong

    2005-04-01

    We prove that the generalized Poisson distribution GP(theta, eta) (eta > or = 0) is a mixture of Poisson distributions; this is a new property for a distribution which is the topic of the book by Consul (1989). Because we find that the fits to count data of the generalized Poisson and negative binomial distributions are often similar, to understand their differences, we compare the probability mass functions and skewnesses of the generalized Poisson and negative binomial distributions with the first two moments fixed. They have slight differences in many situations, but their zero-inflated distributions, with masses at zero, means and variances fixed, can differ more. These probabilistic comparisons are helpful in selecting a better fitting distribution for modelling count data with long right tails. Through a real example of count data with large zero fraction, we illustrate how the generalized Poisson and negative binomial distributions as well as their zero-inflated distributions can be discriminated.

  3. Solar Wind Strahl Broadening by Self-Generated Plasma Waves

    Science.gov (United States)

    Pavan, J.; Vinas, A. F.; Yoon, P. H.; Ziebell, L. F.; Gaelzer, R.

    2013-01-01

    This Letter reports on the results of numerical simulations which may provide a possible explanation for the strahl broadening during quiet solar conditions. The relevant processes involved in the broadening are due to kinetic quasi-linear wave-particle interaction. Making use of static analytical electron distribution in an inhomogeneous field, it is found that self-generated electrostatic waves at the plasma frequency, i.e., Langmuir waves, are capable of scattering the strahl component, resulting in energy and pitch-angle diffusion that broadens its velocity distribution significantly. The present theoretical results provide an alternative or complementary explanation to the usual whistler diffusion scenario, suggesting that self-induced electrostatic waves at the plasma frequency might play a key role in broadening the solar wind strahl during quiet solar conditions.

  4. SOLAR WIND STRAHL BROADENING BY SELF-GENERATED PLASMA WAVES

    Energy Technology Data Exchange (ETDEWEB)

    Pavan, J.; Gaelzer, R. [UFPEL, Pelotas (Brazil); Vinas, A. F. [NASA GSFC, Greenbelt, MD 20771 (United States); Yoon, P. H. [IPST, UMD, College Park, MD (United States); Ziebell, L. F., E-mail: joel.pavan@ufpel.edu.br, E-mail: rudi@ufpel.edu.br, E-mail: adolfo.vinas@nasa.gov, E-mail: yoonp@umd.edu, E-mail: luiz.ziebell@ufrgs.br [UFRGS, Porto Alegre (Brazil)

    2013-06-01

    This Letter reports on the results of numerical simulations which may provide a possible explanation for the strahl broadening during quiet solar conditions. The relevant processes involved in the broadening are due to kinetic quasi-linear wave-particle interaction. Making use of static analytical electron distribution in an inhomogeneous field, it is found that self-generated electrostatic waves at the plasma frequency, i.e., Langmuir waves, are capable of scattering the strahl component, resulting in energy and pitch-angle diffusion that broadens its velocity distribution significantly. The present theoretical results provide an alternative or complementary explanation to the usual whistler diffusion scenario, suggesting that self-induced electrostatic waves at the plasma frequency might play a key role in broadening the solar wind strahl during quiet solar conditions.

  5. Spectral shapes of Ar-broadened HCl lines in the fundamental band by classical molecular dynamics simulations and comparison with experiments

    Energy Technology Data Exchange (ETDEWEB)

    Tran, H., E-mail: ha.tran@lisa.u-pec.fr [Laboratoire Interuniversitaire des Systèmes Atmosphériques, UMR CNRS 7583, Université Paris Est Créteil, Université Paris Diderot, Institut Pierre-Simon Laplace, 94010 Créteil Cedex (France); Domenech, J.-L. [Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas, (IEM-CSIC), Serrano 123, 28006 Madrid (Spain)

    2014-08-14

    Spectral shapes of isolated lines of HCl perturbed by Ar are investigated for the first time using classical molecular dynamics simulations (CMDS). Using reliable intermolecular potentials taken from the literature, these CMDS provide the time evolution of the auto-correlation function of the dipole moment, whose Fourier-Laplace transform leads to the absorption spectrum. In order to test these calculations, room temperature spectra of various lines in the fundamental band of HCl diluted in Ar are measured, in a large pressure range, with a difference-frequency laser spectrometer. Comparisons between measured and calculated spectra show that the CMDS are able to predict the large Dicke narrowing effect on the shape of HCl lines and to satisfactorily reproduce the shapes of HCl spectra at different pressures and for various rotational quantum numbers.

  6. Muscle Distribution in Farm Animals: Comparison Between Goats ...

    African Journals Online (AJOL)

    animals~ However, there has been limited study,. 01lmJscl~/4istribution of g~ats and comparison. *CoITcsponding anthor. , data with otller species:'is even more scanty. The aIm of the,ph:sent stitdy was to compare muscle distribution of goats with that of other. , species of farm animals. ''''",'. Materials and Method. • ._ ' _ ,.

  7. Comparison of aerosol size distribution in coastal and oceanic environments

    NARCIS (Netherlands)

    Kusmierczyk-Michulec, J.T.; Eijk, A.M.J. van

    2006-01-01

    The results of applying the empirical orthogonal functions (EOF) method to decomposition and approximation of aerosol size distributions are presented. A comparison was made for two aerosol data sets, representing coastal and oceanic environments. The first data set includes measurements collected

  8. A comparison of queueing, cluster and distributed computing systems

    Science.gov (United States)

    Kaplan, Joseph A.; Nelson, Michael L.

    1993-01-01

    Using workstation clusters for distributed computing has become popular with the proliferation of inexpensive, powerful workstations. Workstation clusters offer both a cost effective alternative to batch processing and an easy entry into parallel computing. However, a number of workstations on a network does not constitute a cluster. Cluster management software is necessary to harness the collective computing power. A variety of cluster management and queuing systems are compared: Distributed Queueing Systems (DQS), Condor, Load Leveler, Load Balancer, Load Sharing Facility (LSF - formerly Utopia), Distributed Job Manager (DJM), Computing in Distributed Networked Environments (CODINE), and NQS/Exec. The systems differ in their design philosophy and implementation. Based on published reports on the different systems and conversations with the system's developers and vendors, a comparison of the systems are made on the integral issues of clustered computing.

  9. Hydrogen Stark Broadened Brackett lines

    Directory of Open Access Journals (Sweden)

    C. Stehlé

    2010-01-01

    Full Text Available Stark-broadened lines of the hydrogen Brackett series are computed for the conditions of stellar atmospheres and circumstellar envelopes. The computation is performed within the Model Microfield Method, which includes the ion dynamic effects and makes the bridge between the impact limit at low density and the static limit at high density and in the line wings. The computation gives the area normalized line shape, from the line core up to the static line wings.

  10. Understanding Doppler Broadening of Gamma Rays

    Energy Technology Data Exchange (ETDEWEB)

    Rawool-Sullivan, Mohini [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sullivan, John P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-07-03

    Doppler-broadened gamma ray peaks are observed routinely in the collection and analysis of gamma-ray spectra. If not recognized and understood, the appearance of Doppler broadening can complicate the interpretation of a spectrum and the correct identification of the gamma ray-emitting material. We have conducted a study using a simulation code to demonstrate how Doppler broadening arises and provide a real-world example in which Doppler broadening is found. This report describes that study and its results.

  11. Practical comparison of distributed ledger technologies for IoT

    Science.gov (United States)

    Red, Val A.

    2017-05-01

    Existing distributed ledger implementations - specifically, several blockchain implementations - embody a cacophony of divergent capabilities augmenting innovations of cryptographic hashes, consensus mechanisms, and asymmetric cryptography in a wide variety of applications. Whether specifically designed for cryptocurrency or otherwise, several distributed ledgers rely upon modular mechanisms such as consensus or smart contracts. These components, however, can vary substantially among implementations; differences involving proof-of-work, practical byzantine fault tolerance, and other consensus approaches exemplify distinct distributed ledger variations. Such divergence results in unique combinations of modules, performance, latency, and fault tolerance. As implementations continue to develop rapidly due to the emerging nature of blockchain technologies, this paper encapsulates a snapshot of sensor and internet of things (IoT) specific implementations of blockchain as of the end of 2016. Several technical risks and divergent approaches preclude standardization of a blockchain for sensors and IoT in the foreseeable future; such issues will be assessed alongside the practicality of IoT applications among Hyperledger, Iota, and Ethereum distributed ledger implementations suggested for IoT. This paper contributes a comparison of existing distributed ledger implementations intended for practical sensor and IoT utilization. A baseline for characterizing distributed ledger implementations in the context of IoT and sensors is proposed. Technical approaches and performance are compared considering IoT size, weight, and power limitations. Consensus and smart contracts, if applied, are also analyzed for the respective implementations' practicality and security. Overall, the maturity of distributed ledgers with respect to sensor and IoT applicability will be analyzed for enterprise interoperability.

  12. Wind Power Forecasting Error Distributions: An International Comparison

    DEFF Research Database (Denmark)

    Hodge, Bri-Mathias; Lew, Debra; Milligan, Michael

    2012-01-01

    Wind power forecasting is essential for greater penetration of wind power into electricity systems. Because no wind forecasting system is perfect, a thorough understanding of the errors that may occur is a critical factor for system operation functions, such as the setting of operating reserve...... levels. This paper provides an international comparison of the distribution of wind power forecasting errors from operational systems, based on real forecast data. The paper concludes with an assessment of similarities and differences between the errors observed in different locations....

  13. How can model comparison help improving species distribution models?

    Directory of Open Access Journals (Sweden)

    Emmanuel Stephan Gritti

    Full Text Available Today, more than ever, robust projections of potential species range shifts are needed to anticipate and mitigate the impacts of climate change on biodiversity and ecosystem services. Such projections are so far provided almost exclusively by correlative species distribution models (correlative SDMs. However, concerns regarding the reliability of their predictive power are growing and several authors call for the development of process-based SDMs. Still, each of these methods presents strengths and weakness which have to be estimated if they are to be reliably used by decision makers. In this study we compare projections of three different SDMs (STASH, LPJ and PHENOFIT that lie in the continuum between correlative models and process-based models for the current distribution of three major European tree species, Fagussylvatica L., Quercusrobur L. and Pinussylvestris L. We compare the consistency of the model simulations using an innovative comparison map profile method, integrating local and multi-scale comparisons. The three models simulate relatively accurately the current distribution of the three species. The process-based model performs almost as well as the correlative model, although parameters of the former are not fitted to the observed species distributions. According to our simulations, species range limits are triggered, at the European scale, by establishment and survival through processes primarily related to phenology and resistance to abiotic stress rather than to growth efficiency. The accuracy of projections of the hybrid and process-based model could however be improved by integrating a more realistic representation of the species resistance to water stress for instance, advocating for pursuing efforts to understand and formulate explicitly the impact of climatic conditions and variations on these processes.

  14. Comparison of Measured Dark Current Distributions with Calculated Damage Energy Distributions in HgCdTe

    Science.gov (United States)

    Marshall, C. J.; Marshall, P. W.; Howe, C. L.; Reed, R. A.; Weller, R. A.; Mendenhall, M.; Waczynski, A.; Ladbury, R.; Jordan, T. M.

    2007-01-01

    This paper presents a combined Monte Carlo and analytic approach to the calculation of the pixel-to-pixel distribution of proton-induced damage in a HgCdTe sensor array and compares the results to measured dark current distributions after damage by 63 MeV protons. The moments of the Coulombic, nuclear elastic and nuclear inelastic damage distributions were extracted from Monte Carlo simulations and combined to form a damage distribution using the analytic techniques first described in [1]. The calculations show that the high energy recoils from the nuclear inelastic reactions (calculated using the Monte Carlo code MCNPX [2]) produce a pronounced skewing of the damage energy distribution. While the nuclear elastic component (also calculated using the MCNPX) contributes only a small fraction of the total nonionizing damage energy, its inclusion in the shape of the damage across the array is significant. The Coulombic contribution was calculated using MRED [3-5], a Geant4 [4,6] application. The comparison with the dark current distribution strongly suggests that mechanisms which are not linearly correlated with nonionizing damage produced according to collision kinematics are responsible for the observed dark current increases. This has important implications for the process of predicting the on-orbit dark current response of the HgCdTe sensor array.

  15. Combustion technology overview. [the use of broadened property aircraft fuels

    Science.gov (United States)

    Niedzwiecki, R. W.

    1980-01-01

    An overview of combustor technology developments required for use of broadened property fuels in jet aircraft is presented. The intent of current investigations is to determine the extent to which fuel properties can be varied, to obtain a data base of combustion - fuel quality effects, and to determine the trade-offs associated with broadened property fuels. Subcomponents of in-service combustors such as fuel injectors and liners, as well as air distributions and stoichiometry, are being altered to determine the extent to which fuel flexibility can be extended. Finally, very advanced technology consisting of new combustor concepts is being evolved to optimize the fuel flexibility of gas turbine combustors.

  16. Comparison of Drop Size Distribution Measurements by Impact and Optical Disdrometers.

    Science.gov (United States)

    Tokay, Ali; Kruger, Anton; Krajewski, Witold F.

    2001-11-01

    Simultaneous observations made with optical- and impact-type disdrometers were analyzed to broaden knowledge of these instruments. These observations were designed to test how accurately they measure drop size distributions (DSDs). The instruments' use in determining radar rainfall relations such as that between reflectivity and rainfall rate also was analyzed. A unique set of instruments, including two video and one Joss-Waldvogel disdrometer along with eight tipping-bucket rain gauges, was operated within a small area of about 100 × 50 m2 during a 2-month-long field campaign in central Florida. The disdrometers were evaluated by comparing their rain totals with the rain gauges. Both disdrometers underestimated the rain totals, but the video disdrometers had higher readings, resulting in a better agreement with the gauges. The disdrometers underreported small- to medium-size drops, which most likely caused the underestimation of rain totals. However, more medium-size drops were measured by the video disdrometer, thus producing higher rain rates for that instrument. The comparison of DSDs, averaged at different timescales, showed good agreement between the two types of disdrometers. A continuous increase in the number of drops toward smaller sizes was only evident in the video disdrometers at rain rates above 20 mm h1. Otherwise, the concentration of small drops remained the same or decreased to the smallest measurable size. The Joss-Waldvogel disdrometer severely underestimated only at very small drop size (diameter 0.5 mm). Beyond the Joss-Waldvogel disdrometer measurement limit were very large drops that fell during heavy and extreme rain intensities. The derived parameters of exponential and gamma distributions reflect the good agreement between the disdrometers' DSD measurements. The parameters of fitted distributions were close to each other, especially when all the coincident measurements were averaged. The low concentrations of very large drops observed by

  17. Systematic comparison of trip distribution laws and models

    CERN Document Server

    Lenormand, Maxime; Ramasco, José J

    2016-01-01

    Trip distribution laws are basic for the travel demand characterization needed in transport and urban planning. Several approaches have been considered in the last years. One of them is the so-called gravity law, in which the number of trips is assumed to be related to the population at origin and destination and to decrease with the distance. The mathematical expression of this law resembles Newton's law of gravity, which explains its name. Another popular approach is inspired by the theory of intervening opportunities and it has been concreted into the so-called radiation models. Individuals are supposed to travel until they find a job opportunity, so the population and jobs spatial distributions naturally lead to a trip flow network. In this paper, we perform a thorough comparison between the gravity and the radiation approaches in their ability at estimating commuting flows. We test the gravity and the radiation laws against empirical trip data at different scales and coming from different countries. Diff...

  18. Stark broadening data for stellar plasma research.

    Science.gov (United States)

    Dimitrijević, M. S.

    Results of an effort to provide to astrophysicists and physicists an as much as possible complete set of Stark broadening parameters needed for stellar opacity calculations, stellar atmosphere modelling, abundance determinations and diagnostics of different plasmas in astrophysics, physics and plasma technology, are presented. Stark broadening has been considered within the semiclassical perturbation, and the modified semiempirical approaches.

  19. Comparisons of Particulate Size Distributions from Multiple Combustion Strategies

    Science.gov (United States)

    Zhang, Yizhou

    In this study, a comparison of particle size distribution (PSD) measurements from eight different combustion strategies was conducted at four different load-speed points. The PSDs were measured using a scanning mobility particle sizer (SMPS) together with a condensation particle counter (CPC). To study the influence of volatile particles, PSD measurements were performed with and without a volatile particle remover (thermodenuder, TD) at both low and high dilution ratios. The common engine platform utilized in the experiment helps to eliminate the influence of background particulate and ensures similarity in dilution conditions. The results show a large number of volatile particles were present under LDR sample conditions for most of the operating conditions. The use of a TD, especially when coupled with HDR, was demonstrated to be effective at removing volatile particles and provided consistent measurements across all combustion strategies. The PSD comparison showed that gasoline premixed combustion strategies such as HCCI and GCI generally have low PSD magnitudes for particle sizes greater than the Particle Measurement Programme (PMP) cutoff diameter (23 nm), and the PSDs were highly nuclei-mode particle dominated. The strategies using diesel as the only fuel (DLTC and CDC) generally showed the highest particle number emissions for particles larger than 23 nm and had accumulation-mode particle dominated PSDs. A consistent correlation between the increase of the direct-injection of diesel fuel and a higher fraction of accumulation-mode particles was observed over all combustion strategies. A DI fuel substitution study and injector nozzle geometry study were conducted to better understand the correlation between PSD shape and DI fueling. It was found that DI fuel properties has a clear impact on PSD behavior for CDC and NG DPI. Fuel with lower density and lower sooting tendency led to a nuclei-mode particle dominated PSD shape. For NG RCCI, accumulation

  20. Exciton broadening in WS2/graphene heterostructures

    Science.gov (United States)

    Hill, Heather M.; Rigosi, Albert F.; Raja, Archana; Chernikov, Alexey; Roquelet, Cyrielle; Heinz, Tony F.

    2017-11-01

    We have used optical spectroscopy to observe spectral broadening of WS2 exciton reflectance peaks in heterostructures of monolayer WS2 capped with mono- to few-layer graphene. The broadening is found to be similar for the A and B excitons and on the order of 5-10 meV. No strong dependence on the number of graphene layers was observed within experimental uncertainty. The broadening can be attributed to charge- and energy-transfer processes between the two materials, providing an observed lower bound for the corresponding time scales of 65 fs.

  1. Collisional broadening of angular correlations in a multiphase transport model

    Science.gov (United States)

    Edmonds, Terrence; Li, Qingfeng; Wang, Fuqiang

    2017-10-01

    Systematic comparisons of jetlike correlation data to radiative and collisional energy loss model calculations are essential to extract transport properties of the quark-gluon medium created in relativistic heavy ion collisions. This paper presents a transport study of collisional broadening of jetlike correlations, by following parton-parton collision history in a multiphase transport (AMPT) model. The correlation shape is studied as functions of the number of parton-parton collisions suffered by a high transverse momentum probe parton (Ncoll) and the azimuth of the probe relative to the reaction plane (ϕfin.probe). Correlation is found to broaden with increasing Ncoll and ϕfin.probe from in- to out-of-plane direction. This study provides a transport model reference for future jet-medium interaction studies.

  2. Spectral broadening in narrow linewidth, continuous-wave high power fiber amplifiers

    Science.gov (United States)

    Feng, Yujun; Wang, Xiaojun; Ke, Weiwei; Sun, Yinhong; Zhang, Kai; Ma, Yi; Li, Tenglong; Wang, Yanshan; Wu, Juan

    2017-11-01

    We present an investigation on the spectrum broadening in continuous-wave, sub-nanometer linewidth high power fiber amplifiers caused by the multiple four-wave mixing (FWM) process. The spectrum broadening employing two different types of narrow linewidth seeds, including the multi-longitudinal-mode seed and the broadened single frequency seed generated by high speed phase modulation, is studied. It is shown both theoretically and experimentally that the multi-longitudinal-mode seed experiences serious spectrum broadening induced by the FWM among various longitudinal modes, while the modulated seed can maintain the spectrum profile during the amplifying process even with some noise fluctuation. The different broadening results are mainly caused by the random phase distribution of the multiple waves. It is further explained by an exact solution of the degenerate FWM with three waves. The theoretical predictions on the spectrum and power dependence of the output laser linewidth are in quantitative agreement with the experimental results up to kilowatt.

  3. Stark broadening parameter tables for In II

    Directory of Open Access Journals (Sweden)

    Dimitrijević M.S.

    2000-01-01

    Full Text Available Electron-, proton-, and ionized helium-impact broadening parameter tables for In II spectral lines, are presented as a function of the temperature and the perturber density. Calculations have been performed within the semiclassical perturbation approach.

  4. Broadening the concept of marketing.

    Science.gov (United States)

    Kotler, P; Levy, S J

    1969-01-01

    Marketing in business is the task of finding and stimulating buyers for a firms's output. Product development, pricing, distribution, and communication are the mainstays of marketing, while progressive firms also develop new products and chart the trends and changes in people's needs and desires. Marketing can either apply its knowledge to social problems and organizations or remain in a narrowly defined business activity. Every organization has basically the same functions: personnel management, production, income, and promotion, which are using modern marketing skills in commercial sectors. Suppliers and consumers are needed by all organizations. In Canada a group wished to promote an antismoking campaign but they had little money compared to the tobacco companies. This group used modern marketing techniques to combat their lack of funds and found many ways, e.g., books, articles. A business firm uses a multitude of marketing tools to sell its product. Nonbusiness organizations frequently do not integrate their programs the way the businesses place all activities under one marketing vice president and department. Astute marketing depends on continuous feedback from consumers and suppliers. They are dependent upon up-to-the-minute research that tells them about changes in the environment and moves of competitors. Nonbusiness organizations are often casual about the research upon which they base their vital decisions.

  5. Immunity of intersubband polaritons to inhomogeneous broadening

    Science.gov (United States)

    Manceau, J.-M.; Biasiol, G.; Tran, N. L.; Carusotto, I.; Colombelli, R.

    2017-12-01

    We demonstrate that intersubband (ISB) polaritons are robust to inhomogeneous effects originating from the presence of multiple quantum wells (MQWs). In a series of samples that exhibit mid-infrared ISB absorption transitions with broadenings varying by a factor of 5 (from 4 to 20 meV), we observed polariton linewidths always lying in the 4 to 7 meV range only. We experimentally verified the dominantly inhomogeneous origin of the broadening of the ISB transition, and that the linewidth reduction effect of the polariton modes persists up to room-temperature. This immunity to inhomogeneous broadening is a direct consequence of the coupling of the large number of ISB oscillators to a single photonic mode. It is a precious tool to gauge the natural linewidth of the ISB plasmon that is otherwise masked in such MQWs system, and is also beneficial in view of perspective applications such as intersubband polariton lasers.

  6. Analysis and Comparison of Typical Models within Distribution Network Design

    DEFF Research Database (Denmark)

    Jørgensen, Hans Jacob; Larsen, Allan; Madsen, Oli B.G.

    Efficient and cost effective transportation and logistics plays a vital role in the supply chains of the modern world’s manufacturers. Global distribution of goods is a very complicated matter as it involves many different distinct planning problems. The focus of this presentation is to demonstrate...... a number of important issues which have been identified when addressing the Distribution Network Design problem from a modelling angle. More specifically, we present an analysis of the research which has been performed in utilizing operational research in developing and optimising distribution systems....

  7. Line broadening in the PXRD patterns of layered hydroxides: The ...

    Indian Academy of Sciences (India)

    Common among the disorders are stacking faults, which broaden the ℎ0ℓ/0ℓ reflections. Interstratification selectively broadens the 00ℓ reflections and turbostratic disorder broadens the 0ℓ reflections. The line broadening caused by structural disorder has to be discounted before estimates of particle size are made by ...

  8. Implementing Distributed Operations: A Comparison of Two Deep Space Missions

    Science.gov (United States)

    Mishkin, Andrew; Larsen, Barbara

    2006-01-01

    Two very different deep space exploration missions--Mars Exploration Rover and Cassini--have made use of distributed operations for their science teams. In the case of MER, the distributed operations capability was implemented only after the prime mission was completed, as the rovers continued to operate well in excess of their expected mission lifetimes; Cassini, designed for a mission of more than ten years, had planned for distributed operations from its inception. The rapid command turnaround timeline of MER, as well as many of the operations features implemented to support it, have proven to be conducive to distributed operations. These features include: a single science team leader during the tactical operations timeline, highly integrated science and engineering teams, processes and file structures designed to permit multiple team members to work in parallel to deliver sequencing products, web-based spacecraft status and planning reports for team-wide access, and near-elimination of paper products from the operations process. Additionally, MER has benefited from the initial co-location of its entire operations team, and from having a single Principal Investigator, while Cassini operations have had to reconcile multiple science teams distributed from before launch. Cassini has faced greater challenges in implementing effective distributed operations. Because extensive early planning is required to capture science opportunities on its tour and because sequence development takes significantly longer than sequence execution, multiple teams are contributing to multiple sequences concurrently. The complexity of integrating inputs from multiple teams is exacerbated by spacecraft operability issues and resource contention among the teams, each of which has their own Principal Investigator. Finally, much of the technology that MER has exploited to facilitate distributed operations was not available when the Cassini ground system was designed, although later adoption

  9. Comparison of Deterministic and Probabilistic Radial Distribution Systems Load Flow

    Science.gov (United States)

    Gupta, Atma Ram; Kumar, Ashwani

    2017-08-01

    Distribution system network today is facing the challenge of meeting increased load demands from the industrial, commercial and residential sectors. The pattern of load is highly dependent on consumer behavior and temporal factors such as season of the year, day of the week or time of the day. For deterministic radial distribution load flow studies load is taken as constant. But, load varies continually with a high degree of uncertainty. So, there is a need to model probable realistic load. Monte-Carlo Simulation is used to model the probable realistic load by generating random values of active and reactive power load from the mean and standard deviation of the load and for solving a Deterministic Radial Load Flow with these values. The probabilistic solution is reconstructed from deterministic data obtained for each simulation. The main contribution of the work is: Finding impact of probable realistic ZIP load modeling on balanced radial distribution load flow. Finding impact of probable realistic ZIP load modeling on unbalanced radial distribution load flow. Compare the voltage profile and losses with probable realistic ZIP load modeling for balanced and unbalanced radial distribution load flow.

  10. Comparison of Deterministic and Probabilistic Radial Distribution Systems Load Flow

    Science.gov (United States)

    Gupta, Atma Ram; Kumar, Ashwani

    2017-12-01

    Distribution system network today is facing the challenge of meeting increased load demands from the industrial, commercial and residential sectors. The pattern of load is highly dependent on consumer behavior and temporal factors such as season of the year, day of the week or time of the day. For deterministic radial distribution load flow studies load is taken as constant. But, load varies continually with a high degree of uncertainty. So, there is a need to model probable realistic load. Monte-Carlo Simulation is used to model the probable realistic load by generating random values of active and reactive power load from the mean and standard deviation of the load and for solving a Deterministic Radial Load Flow with these values. The probabilistic solution is reconstructed from deterministic data obtained for each simulation. The main contribution of the work is: Finding impact of probable realistic ZIP load modeling on balanced radial distribution load flow. Finding impact of probable realistic ZIP load modeling on unbalanced radial distribution load flow. Compare the voltage profile and losses with probable realistic ZIP load modeling for balanced and unbalanced radial distribution load flow.

  11. Doppler broadening effects in plasmonic quantum dots

    Science.gov (United States)

    Alves, R. A.; Silva, Nuno A.; Costa, J. C.; Gomes, M.; Guerreiro, A.

    2017-08-01

    In this paper we analyse the effects of the Doppler shift on the optical response of a nanoplasmonic system. Through the development of a simplified model based on the Hydrodynamic Drude model we analyse the response of a quantum dot embed in a moving fluid, predicting the Doppler broadening and the shift of the spectral line.

  12. Broadening Our View of Linguistic Diversity

    Science.gov (United States)

    O'Neal, Debra; Ringler, Marjorie

    2010-01-01

    The definition of English language learners needs to be broadened to include the marginalized dialects of English. Not all native speakers speak Standard English, and even those who do need to learn Academic English to succeed in school. By using strategies developed for ELLs, teachers can help all students become fluent in the language of school.

  13. A comparison of graphical design techniques for parallel, distributed software

    NARCIS (Netherlands)

    M. Polman (Mark); M.R. van Steen

    1994-01-01

    textabstractWe have compared three graphical design techniques, OMT, ADL, and PARSE, on their suitability for the development of parallel/distributed applications. Our method has been to use all three of them in modeling one, existing, application: a backup facility running within the Andrew File

  14. Comparison of thermal cracking and hydro-cracking yield distributions

    Energy Technology Data Exchange (ETDEWEB)

    Romero, S.; Sayles, S. [KBC Advanced Technologies Inc., Houston, TX (United States)

    2009-07-01

    Operators of bitumen upgraders are faced with the challenge of obtaining maximum performance from existing equipment whose performance is already pushed to the limits. The main constraint is the primary upgrader processes, notably coking and hydrocracking. Under the current economic conditions, funding for new equipment is difficult. However, changes can be made to optimize unit performance by better understanding the basic kinetics in thermal cracking and hydrocracking. This paper reviewed the yield distribution differences between thermal cracking and hydrocracking to provide insight into the basic components of operational changes. The objective was to compare yields, product quality distributions and the elemental balances. The opportunities to increase production and improve performance were then analyzed quantitatively within the existing unit equipment limits. tabs., figs.

  15. Analysis and Comparison of Typical Models within Distribution Network Design

    DEFF Research Database (Denmark)

    Jørgensen, Hans Jacob; Larsen, Allan; Madsen, Oli B.G.

    This paper investigates the characteristics of typical optimisation models within Distribution Network Design. During the paper fourteen models known from the literature will be thoroughly analysed. Through this analysis a schematic approach to categorisation of distribution network design models...... for educational purposes. Furthermore, the paper can be seen as a practical introduction to network design modelling as well as a being an art manual or recipe when constructing such a model....... are covered in the categorisation include fixed vs. general networks, specialised vs. general nodes, linear vs. nonlinear costs, single vs. multi commodity, uncapacitated vs. capacitated activities, single vs. multi modal and static vs. dynamic. The models examined address both strategic and tactical planning...

  16. A Comparison of Generalized Hyperbolic Distribution Models for Equity Returns

    Directory of Open Access Journals (Sweden)

    Virginie Konlack Socgnia

    2014-01-01

    Full Text Available We discuss the calibration of the univariate and multivariate generalized hyperbolic distributions, as well as their hyperbolic, variance gamma, normal inverse Gaussian, and skew Student’s t-distribution subclasses for the daily log-returns of seven of the most liquid mining stocks listed on the Johannesburg Stocks Exchange. To estimate the model parameters from historic distributions, we use an expectation maximization based algorithm for the univariate case and a multicycle expectation conditional maximization estimation algorithm for the multivariate case. We assess the goodness of fit statistics using the log-likelihood, the Akaike information criterion, and the Kolmogorov-Smirnov distance. Finally, we inspect the temporal stability of parameters and note implications as criteria for distinguishing between models. To better understand the dependence structure of the stocks, we fit the MGHD and subclasses to both the stock returns and the two leading principal components derived from the price data. While the MGHD could fit both data subsets, we observed that the multivariate normality of the stock return residuals, computed by removing shared components, suggests that the departure from normality can be explained by the structure in the common factors.

  17. Software Comparison for Renewable Energy Deployment in a Distribution Network

    Energy Technology Data Exchange (ETDEWEB)

    Gao, David Wenzhong [Alternative Power Innovations, LLC, Sharonville, OH (United States); Muljadi, Eduard [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, Mackay [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-02-22

    The main objective of this report is to evaluate different software options for performing robust distributed generation (DG) power system modeling. The features and capabilities of four simulation tools, OpenDSS, GridLAB-D, CYMDIST, and PowerWorld Simulator, are compared to analyze their effectiveness in analyzing distribution networks with DG. OpenDSS and GridLAB-D, two open source software, have the capability to simulate networks with fluctuating data values. These packages allow the running of a simulation each time instant by iterating only the main script file. CYMDIST, a commercial software, allows for time-series simulation to study variations on network controls. PowerWorld Simulator, another commercial tool, has a batch mode simulation function through the 'Time Step Simulation' tool, which obtains solutions for a list of specified time points. PowerWorld Simulator is intended for analysis of transmission-level systems, while the other three are designed for distribution systems. CYMDIST and PowerWorld Simulator feature easy-to-use graphical user interfaces (GUIs). OpenDSS and GridLAB-D, on the other hand, are based on command-line programs, which increase the time necessary to become familiar with the software packages.

  18. A Comparison of Distribution Free and Non-Distribution Free Factor Analysis Methods

    Science.gov (United States)

    Ritter, Nicola L.

    2012-01-01

    Many researchers recognize that factor analysis can be conducted on both correlation matrices and variance-covariance matrices. Although most researchers extract factors from non-distribution free or parametric methods, researchers can also extract factors from distribution free or non-parametric methods. The nature of the data dictates the method…

  19. Comparison of Multi Disk Exponential Gas Distribution vs. Single Disk

    Science.gov (United States)

    Rao, Erica; O'Brien, James

    2013-04-01

    In fitting galactic rotation curves to data, most standard theories make use of a single exponential disk approximation of the gas distribution to account for the HI synthesis data observed at various radio telescope facilities. We take a sample of surface brightness profiles from The HI Nearby Galaxy Survey (THINGS), and apply both single disk exponentials and Multi-Disk exponentials, and use these various models to see how the modelling procedure changes the Newtonian prediction of the mass of the galaxy. Since the missing mass problem has not been fully explained in large spiral galaxies, different modelling procedures could account for some of the missing matter.

  20. Physician assistant specialty choice: Distribution, salaries, and comparison with physicians.

    Science.gov (United States)

    Morgan, Perri; Everett, Christine M; Humeniuk, Katherine M; Valentin, Virginia L

    2016-07-01

    To describe trends in physician assistant (PA) specialty distribution, compare these trends with physicians, and quantify the relationship of PA specialty prevalence with both PA and physician salary. PA specialty and salary data were obtained from the 2013 American Academy of PAs' Annual Survey; physician specialty and salary data from the American Medical Association Physician Masterfile and the Medical Group Management Association. Analyses included descriptive statistics and linear regression. The proportion of PAs working in primary care decreased from 50% in 1997 to 30% in 2013. Substantial growth in PA proportions occurred in surgical and medical subspecialties. Regression models showed a higher prevalence of PAs in specialties with higher PA salary, higher physician salary, and higher physician-to-PA salary ratio (P<0.05). PAs are moving toward subspecialty practice. Our study suggests that demand for PAs may be an important factor driving the trend toward specialization.

  1. A comparison of parameter estimations of the Poisson-generalised Lindley distribution

    Science.gov (United States)

    Denthet, Sunthree

    2017-11-01

    In this paper, the Poisson-generalised Lindley distribution is presented. It is obtained by mixing the Poisson distribution with a generalised Lindley distribution. This distribution is an alternative distribution for count data with over-distribution. We apply two methods of parameter estimation, maximum likelihood estimation and method of moment, to estimate the parameters. The Monte Carlo simulation study is conducted for efficiency comparison between two methods of estimation based on root of mean squared error. The study exposes that method of moment is highly efficient with maximum likelihood estimation when the model is decreasing or bimodal model. Finally, the proposed distribution is applied to real data sets,but the result based on p-value of the discrete Anderson-Daring test show that maximum likelihood estimation can be hight efficiency for fitting data set.

  2. Secure distributed genome analysis for GWAS and sequence comparison computation

    Science.gov (United States)

    2015-01-01

    Background The rapid increase in the availability and volume of genomic data makes significant advances in biomedical research possible, but sharing of genomic data poses challenges due to the highly sensitive nature of such data. To address the challenges, a competition for secure distributed processing of genomic data was organized by the iDASH research center. Methods In this work we propose techniques for securing computation with real-life genomic data for minor allele frequency and chi-squared statistics computation, as well as distance computation between two genomic sequences, as specified by the iDASH competition tasks. We put forward novel optimizations, including a generalization of a version of mergesort, which might be of independent interest. Results We provide implementation results of our techniques based on secret sharing that demonstrate practicality of the suggested protocols and also report on performance improvements due to our optimization techniques. Conclusions This work describes our techniques, findings, and experimental results developed and obtained as part of iDASH 2015 research competition to secure real-life genomic computations and shows feasibility of securely computing with genomic data in practice. PMID:26733307

  3. Experimental comparison of PV-smoothing controllers using distributed generators

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Jay Dean; Ellis, Abraham; Denda, Atsushi; Morino, Kimio; Hawkins, John N.; Arellano, Brian; Shinji, Takao; Ogata, Takao; Tadokoro, Masayuki

    2014-02-01

    The power output variability of photovoltaic systems can affect local electrical grids in locations with high renewable energy penetrations or weak distribution or transmission systems. In those rare cases, quick controllable generators (e.g., energy storage systems) or loads can counteract the destabilizing effects by compensating for the power fluctuations. Previously, control algorithms for coordinated and uncoordinated operation of a small natural gas engine-generator (genset) and a battery for smoothing PV plant output were optimized using MATLAB/Simulink simulations. The simulations demonstrated that a traditional generation resource such as a natural gas genset in combination with a battery would smooth the photovoltaic output while using a smaller battery state of charge (SOC) range and extending the life of the battery. This paper reports on the experimental implementation of the coordinated and uncoordinated controllers to verify the simulations and determine the differences in the controllers. The experiments were performed with the PNM PV and energy storage Prosperity site and a gas engine-generator located at the Aperture Center at Mesa Del Sol in Albuquerque, New Mexico. Two field demonstrations were performed to compare the different PV smoothing control algorithms: (1) implementing the coordinated and uncoordinated controls while switching off a subsection of the PV array at precise times on successive clear days, and (2) comparing the results of the battery and genset outputs for the coordinated control on a high variability day with simulations of the coordinated and uncoordinated controls. It was found that for certain PV power profiles the SOC range of the battery may be larger with the coordinated control, but the total amp-hours through the battery-which approximates battery wear-will always be smaller with the coordinated control.

  4. A distributional approach to obtain adjusted comparisons of proportions of a population at risk

    Directory of Open Access Journals (Sweden)

    Odile Sauzet

    2016-06-01

    Full Text Available Abstract Background Dichotomisation of continuous data has statistical drawbacks such as loss of power but may be useful in epidemiological research to define high risk individuals. Methods We extend a methodology for the presentation of comparison of proportions derived from a comparison of means for a continuous outcome to reflect the relationship between a continuous outcome and covariates in a linear (mixed model without losing statistical power. The so called “distributional method” is described and using perinatal data for illustration, results from the distributional method are compared to those of logistic regression and to quantile regression for three different outcomes. Results Estimates obtained using the distributional method for the comparison of proportions are consistently more precise than those obtained using logistic regression. For one of the three outcomes the estimates obtained from the distributional method and from logistic regression disagreed highlighting that the relationships between outcome and covariate differ conceptually between the two models. Conclusion When an outcome follows the required condition of distribution shift between exposure groups, the results of a linear regression model can be followed by the corresponding comparison of proportions at risk. This dual approach provides more precise estimates than logistic regression thus avoiding the drawback of the usual dichotomisation of continuous outcomes.

  5. Smart Grid communication middleware comparison distributed control comparison for the internet of things

    DEFF Research Database (Denmark)

    Petersen, Bo Søborg; Bindner, Henrik W.; Poulsen, Bjarne

    2017-01-01

    Communication between Distributed Energy Resources (DERs) is necessary to efficiently solve the intermittency issues caused by renewable energy, using DER power grid auxiliary services, primarily load shifting and shedding. The middleware used for communication determines which services are possi...

  6. Smart grid communication comparison: Distributed control middleware and serialization comparison for the Internet of Things

    DEFF Research Database (Denmark)

    Petersen, Bo Søborg; Bindner, Henrik W.; Poulsen, Bjarne

    2017-01-01

    To solve the problems caused by intermittent renewable energy production, communication between Distributed Energy Resources (DERs) and system operators is necessary. The communication middleware and serialization used for communication are essential to ensure delivery of the messages within the ...

  7. Correlation function and electronic spectral line broadening in relativistic plasmas

    Directory of Open Access Journals (Sweden)

    Douis S.

    2013-01-01

    Full Text Available The electrons dynamics and the time autocorrelation function Cee(t for the total electric microfield of the electrons on positive charge impurity embedded in a plasma are considered when the relativistic dynamic of the electrons is taken into account. We have, at first, built the effective potential governing the electrons dynamics. This potential obeys a nonlinear integral equation that we have solved numerically. Regarding the electron broadening of the line in plasma, we have found that when the plasma parameters change, the amplitude of the collision operator changes in the same way as the time integral of Cee(t. The electron-impurity interaction is taken at first time as screened Deutsh interaction and at the second time as Kelbg interaction. Comparisons of all interesting quantities are made with respect to the previous interactions as well as between classical and relativistic dynamics of electrons.

  8. Line Broadening in White Dwarf Photospheres

    Science.gov (United States)

    Winget, D. E.

    2012-06-01

    White dwarfs are the simplest stars with the simplest surface chemical compositions known. Spectroscopically we detect only hydrogen in surfaces of the vast majority of these stars. The remainders are of various types, including stars with surfaces of nearly pure helium and some apparently massive stars with carbon and oxygen at the photosphere. We will examine the potential offered by the white dwarf stars in the context of both astrophysics and physics. This potential includes studying cosmochronology--establishing the age and evolutionary history of our galaxy and an independent lower limit on the age of the universe, constraining the properties of axions and WIMPS in the context of dark matter models, constraining dark energy by establishing the properties of the massive progenitors of type Ia supernovae, studying nucleosynthesis from their internal composition structure, and crystallization in dense Coulomb plasmas, among many others. Realizing this tremendous scientific potential depends on the determination of two boundary conditions for each star: the surface gravity and effective temperature. To do this, we must establish the photospheric plasma conditions, density and temperature, using observations of the stellar absorption spectra. Our understanding of line broadening appears to be an obstacle, at present. We will discuss the evidence for past theoretical inadequacies in line broadening theory and the hope for recent and future calculations. We will discuss how the experiments underway on the Z-facility at Sandia National Laboratories --where we can create macroscopic uniform plasmas under white dwarf photospheric conditions--will provide the benchmarks for improving our understanding of line broadening under white dwarf photospheric plasma conditions. These experiments will guide future theory and improve our understanding of the white dwarf stars and, through them, the contents and evolution of the cosmos.

  9. Latest data on distribution of the Pygmy Owl (Glaucidium passerinum) in Bulgaria and Slovakia including population density comparison

    National Research Council Canada - National Science Library

    Samuel Pacenovský; Peter Shurulinkov

    2008-01-01

      Latest data on distribution of the Pygmy Owl ([Glaucidium passerinum]) in Bulgaria and Slovakia including population density comparison The authors provide an outline of actual knowledge on the distribution of the Pygmy Owl...

  10. Temporal scalability comparison of the H.264/SVC and distributed video codec

    DEFF Research Database (Denmark)

    Huang, Xin; Ukhanova, Ann; Belyaev, Evgeny

    2009-01-01

    The problem of the multimedia scalable video streaming is a current topic of interest. There exist many methods for scalable video coding. This paper is focused on the scalable extension of H.264/AVC (H.264/SVC) and distributed video coding (DVC). The paper presents an efficiency comparison of SVC...

  11. Observation of plasmon line broadening in single gold nanorods

    Science.gov (United States)

    Qiu, Le; Larson, Timothy A.; Smith, Danielle; Vitkin, Edward; Modell, Mark D.; Korgel, Brian A.; Sokolov, Konstantin V.; Hanlon, Eugene B.; Itzkan, Irving; Perelman, Lev T.

    2008-10-01

    Attempts to realize the important potential of gold nanorods as extremely bright molecular markers have been limited by the broad spectroscopic linewidths usually observed. We identify the origin of this broadening as inhomogeneous broadening due to the extreme sensitivity of the surface plasmon resonance to the nanorod aspect ratio. Using confocal light scattering spectroscopic microscopy, we observed the narrow homogeneously broadened plasmon lines of single gold nanorods and obtained the first quantitative measurements of this homogeneous broadening. We show that homogeneous broadening can be predicted from first principals.

  12. Line broadening in a photoionization spectrometer due to elastic electron--atom collisions

    Energy Technology Data Exchange (ETDEWEB)

    Butikov, E.I.; Mishchenko, E.D.; Tumarkin, Y.N.

    1984-02-01

    Line broadening in a photoionization spectrometer due to elastic collisions between photoelectrons and atoms of the working gas is considered. Expressions are obtained for the stationary electron energy distribution function and for the initial part of the current-voltage characteristic in the case of monochromatic ionizing radiation for intensities of the retarding field close to the initial photoelectron energy.

  13. Phonon broadening in high entropy alloys

    Science.gov (United States)

    Körmann, Fritz; Ikeda, Yuji; Grabowski, Blazej; Sluiter, Marcel H. F.

    2017-09-01

    Refractory high entropy alloys feature outstanding properties making them a promising materials class for next-generation high-temperature applications. At high temperatures, materials properties are strongly affected by lattice vibrations (phonons). Phonons critically influence thermal stability, thermodynamic and elastic properties, as well as thermal conductivity. In contrast to perfect crystals and ordered alloys, the inherently present mass and force constant fluctuations in multi-component random alloys (high entropy alloys) can induce significant phonon scattering and broadening. Despite their importance, phonon scattering and broadening have so far only scarcely been investigated for high entropy alloys. We tackle this challenge from a theoretical perspective and employ ab initio calculations to systematically study the impact of force constant and mass fluctuations on the phonon spectral functions of 12 body-centered cubic random alloys, from binaries up to 5-component high entropy alloys, addressing the key question of how chemical complexity impacts phonons. We find that it is crucial to include both mass and force constant fluctuations. If one or the other is neglected, qualitatively wrong results can be obtained such as artificial phonon band gaps. We analyze how the results obtained for the phonons translate into thermodynamically integrated quantities, specifically the vibrational entropy. Changes in the vibrational entropy with increasing the number of elements can be as large as changes in the configurational entropy and are thus important for phase stability considerations. The set of studied alloys includes MoTa, MoTaNb, MoTaNbW, MoTaNbWV, VW, VWNb, VWTa, VWNbTa, VTaNbTi, VWNbTaTi, HfZrNb, HfMoTaTiZr.

  14. Near-surface wind speed statistical distribution: comparison between ECMWF System 4 and ERA-Interim

    Science.gov (United States)

    Marcos, Raül; Gonzalez-Reviriego, Nube; Torralba, Verónica; Cortesi, Nicola; Young, Doo; Doblas-Reyes, Francisco J.

    2017-04-01

    In the framework of seasonal forecast verification, knowing whether the characteristics of the climatological wind speed distribution, simulated by the forecasting systems, are similar to the observed ones is essential to guide the subsequent process of bias adjustment. To bring some light about this topic, this work assesses the properties of the statistical distributions of 10m wind speed from both ERA-Interim reanalysis and seasonal forecasts of ECMWF system 4. The 10m wind speed distribution has been characterized in terms of the four main moments of the probability distribution (mean, standard deviation, skewness and kurtosis) together with the coefficient of variation and goodness of fit Shapiro-Wilks test, allowing the identification of regions with higher wind variability and non-Gaussian behaviour at monthly time-scales. Also, the comparison of the predicted and observed 10m wind speed distributions has been measured considering both inter-annual and intra-seasonal variability. Such a comparison is important in both climate research and climate services communities because it provides useful climate information for decision-making processes and wind industry applications.

  15. Particle size distributions by transmission electron microscopy: an interlaboratory comparison case study.

    Science.gov (United States)

    Rice, Stephen B; Chan, Christopher; Brown, Scott C; Eschbach, Peter; Han, Li; Ensor, David S; Stefaniak, Aleksandr B; Bonevich, John; Vladár, András E; Hight Walker, Angela R; Zheng, Jiwen; Starnes, Catherine; Stromberg, Arnold; Ye, Jia; Grulke, Eric A

    2013-11-01

    This paper reports an interlaboratory comparison that evaluated a protocol for measuring and analysing the particle size distribution of discrete, metallic, spheroidal nanoparticles using transmission electron microscopy (TEM). The study was focused on automated image capture and automated particle analysis. NIST RM8012 gold nanoparticles (30 nm nominal diameter) were measured for area-equivalent diameter distributions by eight laboratories. Statistical analysis was used to (1) assess the data quality without using size distribution reference models, (2) determine reference model parameters for different size distribution reference models and non-linear regression fitting methods and (3) assess the measurement uncertainty of a size distribution parameter by using its coefficient of variation. The interlaboratory area-equivalent diameter mean, 27.6 nm ± 2.4 nm (computed based on a normal distribution), was quite similar to the area-equivalent diameter, 27.6 nm, assigned to NIST RM8012. The lognormal reference model was the preferred choice for these particle size distributions as, for all laboratories, its parameters had lower relative standard errors (RSEs) than the other size distribution reference models tested (normal, Weibull and Rosin-Rammler-Bennett). The RSEs for the fitted standard deviations were two orders of magnitude higher than those for the fitted means, suggesting that most of the parameter estimate errors were associated with estimating the breadth of the distributions. The coefficients of variation for the interlaboratory statistics also confirmed the lognormal reference model as the preferred choice. From quasi-linear plots, the typical range for good fits between the model and cumulative number-based distributions was 1.9 fitted standard deviations less than the mean to 2.3 fitted standard deviations above the mean. Automated image capture, automated particle analysis and statistical evaluation of the data and fitting coefficients provide a

  16. Particle size distributions by transmission electron microscopy: an interlaboratory comparison case study

    Science.gov (United States)

    Rice, Stephen B; Chan, Christopher; Brown, Scott C; Eschbach, Peter; Han, Li; Ensor, David S; Stefaniak, Aleksandr B; Bonevich, John; Vladár, András E; Hight Walker, Angela R; Zheng, Jiwen; Starnes, Catherine; Stromberg, Arnold; Ye, Jia; Grulke, Eric A

    2015-01-01

    This paper reports an interlaboratory comparison that evaluated a protocol for measuring and analysing the particle size distribution of discrete, metallic, spheroidal nanoparticles using transmission electron microscopy (TEM). The study was focused on automated image capture and automated particle analysis. NIST RM8012 gold nanoparticles (30 nm nominal diameter) were measured for area-equivalent diameter distributions by eight laboratories. Statistical analysis was used to (1) assess the data quality without using size distribution reference models, (2) determine reference model parameters for different size distribution reference models and non-linear regression fitting methods and (3) assess the measurement uncertainty of a size distribution parameter by using its coefficient of variation. The interlaboratory area-equivalent diameter mean, 27.6 nm ± 2.4 nm (computed based on a normal distribution), was quite similar to the area-equivalent diameter, 27.6 nm, assigned to NIST RM8012. The lognormal reference model was the preferred choice for these particle size distributions as, for all laboratories, its parameters had lower relative standard errors (RSEs) than the other size distribution reference models tested (normal, Weibull and Rosin–Rammler–Bennett). The RSEs for the fitted standard deviations were two orders of magnitude higher than those for the fitted means, suggesting that most of the parameter estimate errors were associated with estimating the breadth of the distributions. The coefficients of variation for the interlaboratory statistics also confirmed the lognormal reference model as the preferred choice. From quasi-linear plots, the typical range for good fits between the model and cumulative number-based distributions was 1.9 fitted standard deviations less than the mean to 2.3 fitted standard deviations above the mean. Automated image capture, automated particle analysis and statistical evaluation of the data and fitting coefficients provide a

  17. Pan-European comparison of candidate distributions for climatological drought indices, SPI and SPEI

    Science.gov (United States)

    Stagge, James; Tallaksen, Lena; Gudmundsson, Lukas; Van Loon, Anne; Stahl, Kerstin

    2013-04-01

    Drought indices are vital to objectively quantify and compare drought severity, duration, and extent across regions with varied climatic and hydrologic regimes. The Standardized Precipitation Index (SPI), a well-reviewed meterological drought index recommended by the WMO, and its more recent water balance variant, the Standardized Precipitation-Evapotranspiration Index (SPEI) both rely on selection of univariate probability distributions to normalize the index, allowing for comparisons across climates. The SPI, considered a universal meteorological drought index, measures anomalies in precipitation, whereas the SPEI measures anomalies in climatic water balance (precipitation minus potential evapotranspiration), a more comprehensive measure of water availability that incorporates temperature. Many reviewers recommend use of the gamma (Pearson Type III) distribution for SPI normalization, while developers of the SPEI recommend use of the three parameter log-logistic distribution, based on point observation validation. Before the SPEI can be implemented at the pan-European scale, it is necessary to further validate the index using a range of candidate distributions to determine sensitivity to distribution selection, identify recommended distributions, and highlight those instances where a given distribution may not be valid. This study rigorously compares a suite of candidate probability distributions using WATCH Forcing Data, a global, historical (1958-2001) climate dataset based on ERA40 reanalysis with 0.5 x 0.5 degree resolution and bias-correction based on CRU-TS2.1 observations. Using maximum likelihood estimation, alternative candidate distributions are fit for the SPI and SPEI across the range of European climate zones. When evaluated at this scale, the gamma distribution for the SPI results in negatively skewed values, exaggerating the index severity of extreme dry conditions, while decreasing the index severity of extreme high precipitation. This bias is

  18. 3D spectral synthesis and rotational line broadening

    OpenAIRE

    Ludwig, Hans-G.

    2007-01-01

    Spectral synthesis calculations based on three-dimensional stellar atmosphere models are limited by the affordable angular resolution of the radiation field. This hampers an accurate treatment of rotational line broadening. We aim to find a treatment of rotational broadening of a spherical star when the radiation field is only available at a modest number of limb-angles. We apply a combination of analytical considerations of the line-broadening process and numerical tests. We obtain a method ...

  19. Spherical Harmonic Analysis of Particle Velocity Distribution Function: Comparison of Moments and Anisotropies using Cluster Data

    Science.gov (United States)

    Gurgiolo, Chris; Vinas, Adolfo F.

    2009-01-01

    This paper presents a spherical harmonic analysis of the plasma velocity distribution function using high-angular, energy, and time resolution Cluster data obtained from the PEACE spectrometer instrument to demonstrate how this analysis models the particle distribution function and its moments and anisotropies. The results show that spherical harmonic analysis produced a robust physical representation model of the velocity distribution function, resolving the main features of the measured distributions. From the spherical harmonic analysis, a minimum set of nine spectral coefficients was obtained from which the moment (up to the heat flux), anisotropy, and asymmetry calculations of the velocity distribution function were obtained. The spherical harmonic method provides a potentially effective "compression" technique that can be easily carried out onboard a spacecraft to determine the moments and anisotropies of the particle velocity distribution function for any species. These calculations were implemented using three different approaches, namely, the standard traditional integration, the spherical harmonic (SPH) spectral coefficients integration, and the singular value decomposition (SVD) on the spherical harmonic methods. A comparison among the various methods shows that both SPH and SVD approaches provide remarkable agreement with the standard moment integration method.

  20. Doppler radar spectral width broadening due to beamwidth and wind shear

    Directory of Open Access Journals (Sweden)

    G. D. Nastrom

    1997-06-01

    Full Text Available The spectral width observed by Doppler radars can be due to several effects including the atmospheric turbulence within the radar sample volume plus effects associated with the background flow and the radar geometry and configuration. This study re-examines simple models for the effects due to finite beamwidth and vertical shear of the horizontal wind. Analytic solutions of 1- and 2-dimensional models are presented. Comparisons of the simple 2-dimensional model with numerical integrations of a 3-dimensional model with a symmetrical Gaussian beam show that the 2-dimensional model is usually adequate. The solution of the 2-dimensional model gives a formula that can be applied easily to large data sets. Analysis of the analytic solutions of the 2-dimensional model for off-vertical beams reveals a term that has not been included in mathematical formulas for spectral broadening in the past. This term arises from the simultaneous effects of the changing geometry due to curvature within a finite beamwidth and the vertical wind shear. The magnitude of this effect can be comparable to that of the well-known effects of beam-broadening and wind shear, and since it can have either algebraic sign, it can significantly reduce (or increase the expected spectral broadening, although under typical conditions it is smaller than the beam-broadening effect. The predictions of this simple model are found to be consistent with observations from the VHF radar at White Sands Missile Range, NM.

  1. Doppler radar spectral width broadening due to beamwidth and wind shear

    Directory of Open Access Journals (Sweden)

    G. D. Nastrom

    Full Text Available The spectral width observed by Doppler radars can be due to several effects including the atmospheric turbulence within the radar sample volume plus effects associated with the background flow and the radar geometry and configuration. This study re-examines simple models for the effects due to finite beamwidth and vertical shear of the horizontal wind. Analytic solutions of 1- and 2-dimensional models are presented. Comparisons of the simple 2-dimensional model with numerical integrations of a 3-dimensional model with a symmetrical Gaussian beam show that the 2-dimensional model is usually adequate. The solution of the 2-dimensional model gives a formula that can be applied easily to large data sets. Analysis of the analytic solutions of the 2-dimensional model for off-vertical beams reveals a term that has not been included in mathematical formulas for spectral broadening in the past. This term arises from the simultaneous effects of the changing geometry due to curvature within a finite beamwidth and the vertical wind shear. The magnitude of this effect can be comparable to that of the well-known effects of beam-broadening and wind shear, and since it can have either algebraic sign, it can significantly reduce (or increase the expected spectral broadening, although under typical conditions it is smaller than the beam-broadening effect. The predictions of this simple model are found to be consistent with observations from the VHF radar at White Sands Missile Range, NM.

  2. Superfluorescence in the presence of inhomogeneous broadening and relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Balko, B.; Kay, I.W.; Silk, J.D.; Vuduc, R.; Neuberger, J.W

    1997-05-15

    In this paper we show how inhomogeneous broadening produces dephasing, inhibits cooperative emission and thus reduces the intensity of the SF pulse. We also show how electronic relaxation or time-dependent hyperfine interactions can mollify the effect of inhomogeneous broadening so that SF can be recovered.

  3. Stark Broadening Parameters for Neutral Oxygen Spectral Lines

    Indian Academy of Sciences (India)

    Abstract. Stark broadening parameters for nine neutral oxygen (O I) lines have been determined within the impact approximation and the semiclassical perturbation method. The atomic data have been taken from the TOPbase and NIST atomic databases. The electron and proton Stark widths and shifts and ion broadening ...

  4. Stark Broadening in Compact Stars: Xe VI Lines

    Indian Academy of Sciences (India)

    Introduction. Compact stars like white dwarfs, pre-white dwarfs and neutron stars are particularly interesting for the applications of Stark broadening research, since in their atmo- spheres this broadening ...... 2015 Scientific Meeting of the. Labex Plas@par, which is a part of the programme “Investissements d'avenir” under.

  5. Inhomogeneous broadening in non-interacting nonlocal plasmonic ensembles

    DEFF Research Database (Denmark)

    Tserkezis, Christos; Maack, Johan Rosenkrantz; Liu, Z.

    2016-01-01

    The importance of inhomogeneous broadening due to the size dependence of plasmon resonances in few-nm metallic particle ensembles is investigated through different models describing the nonlocal optical response of plasmonic nanospheres. Modal shifts and plasmon line broadening are shown to becom...

  6. Line broadening in the PXRD patterns of layered hydroxides: The ...

    Indian Academy of Sciences (India)

    Unknown

    reflections and turbostratic disorder broadens the 0k´ reflections. The line broadening caused by struc- tural disorder has to be discounted before estimates of particle size are made by applying the Scherrer formula. Keywords. Layered double hydroxides; pyroaurite; structural disorder; stacking faults; turbostraticity;.

  7. Effects Comparison of Different Resilience Enhancing Strategies for Municipal Water Distribution Network: A Multidimensional Approach

    Directory of Open Access Journals (Sweden)

    Xudong Zhao

    2015-01-01

    Full Text Available Water distribution network (WDN is critical to the city service, economic rehabilitation, public health, and safety. Reconstructing the WDN to improve its resilience in seismic disaster is an important and ongoing issue. Although a considerable body of research has examined the effects of different reconstruction strategies on seismic resistance, it is still hard for decision-makers to choose optimal resilience enhancing strategy. Taking the pipeline ductile retrofitting and network meshed expansion as demonstration, we proposed a feasible framework to contrast the resilience enhancing effects of two reconstruction strategies—units retrofitting strategy and network optimization strategy—in technical and organizational dimension. We also developed a new performance response function (PRF which is based on network equilibrium theory to conduct the effects comparison in integrated technical and organizational dimension. Through the case study of municipal WDN in Lianyungang, China, the comparison results were thoroughly shown and the holistic decision-making support was provided.

  8. Comparison of sea-ice freeboard and thickness distributions from aircraft data and cryosat-2

    DEFF Research Database (Denmark)

    accurate range measurements. During the CryoSat Validation Experiment (CryoVEx) 2011 in the Lincoln Sea, Cryosat-2 underpasses were accomplished with two aircraft, which carried an airborne laser-scanner, a radar altimeter and an electromagnetic induction device for direct sea-ice thickness retrieval. Both...... aircraft flew in close formation at the same time of a CryoSat-2 overpass. This is a study about the comparison of the sea-ice freeboard and thickness distribution of airborne validation and CryoSat-2 measurements within the multi-year sea-ice region of the Lincoln Sea in spring, with respect...

  9. Comparison of sea-ice freeboard distributions from aircraft data and cryosat-2

    DEFF Research Database (Denmark)

    Ricker, Robert; Hendricks, Stefan; Helm, Veit

    2012-01-01

    highly accurate range measurements. During the CryoSat Validation Experiment (CryoVEx) 2011 in the Lincoln Sea Cryosat-2 underpasses were accomplished with two aircraft which carried an airborne laser scanner, a radar altimeter and an electromagnetic induction device for direct sea ice thickness...... retrieval. Both aircraft flew in close formation at the same time of a CryoSat-2 overpass. This is a study about the comparison of the sea-ice freeboard distribution of laser scanner and radar altimeter measurements with the CryoSat-2 product within the multi-year sea ice region of the Lincoln Sea in spring...

  10. Origins of spectral broadening of incoherent waves: Catastrophic process of coherence degradation

    Science.gov (United States)

    Xu, G.; Garnier, J.; Rumpf, B.; Fusaro, A.; Suret, P.; Randoux, S.; Kudlinski, A.; Millot, G.; Picozzi, A.

    2017-08-01

    We revisit the mechanisms underlying the process of spectral broadening of incoherent optical waves propagating in nonlinear media on the basis of nonequilibrium thermodynamic considerations. A simple analysis reveals that a prerequisite for the existence of a significant spectral broadening of the waves is that the linear part of the energy (Hamiltonian) has different contributions of opposite signs. It turns out that, at variance with the expected soliton turbulence scenario, an increase of the amount of disorder (incoherence) in the system does not require the generation of a coherent soliton structure. We illustrate the idea by considering the propagation of two wave components in an optical fiber with opposite dispersion coefficients. A wave turbulence approach to the problem reveals that the increase of kinetic energy in one component is offset by the negative reduction in the other component, so that the waves exhibit, as a general rule, virtually unlimited spectral broadening. More precisely, a self-similar solution of the kinetic equations reveals that the spectra of the incoherent waves tend to relax toward a homogeneous distribution in the wake of a front that propagates in frequency space with a decelerating velocity. We discuss this catastrophic process of spectral broadening in the light of different important phenomena, in particular supercontinuum generation, soliton turbulence, wave condensation, and the runaway motion of mechanical systems composed of positive and negative masses.

  11. Broadening the Participation of Native Americans in Earth Science

    Science.gov (United States)

    Bueno Watts, Nievita

    Climate change is not a thing of the future. Indigenous people are being affected by climate changes now. Native American Earth scientists could help Native communities deal with both climate change and environmental pollution issues, but are noticeably lacking in Earth Science degree programs. The Earth Sciences produce the lowest percentage of minority scientists when compared with other science and engineering fields. Twenty semi-structured interviews were gathered from American Indian/ Alaska Native Earth Scientists and program directors who work directly with Native students to broaden participation in the field. Data was analyzed using qualitative methods and constant comparison analysis. Barriers Native students faced in this field are discussed, as well as supports which go the furthest in assisting achievement of higher education goals. Program directors give insight into building pathways and programs to encourage Native student participation and success in Earth Science degree programs. Factors which impede obtaining a college degree include financial barriers, pressures from familial obligations, and health issues. Factors which impede the decision to study Earth Science include unfamiliarity with geoscience as a field of study and career choice, the uninviting nature of Earth Science as a profession, and curriculum that is irrelevant to the practical needs of Native communities or courses which are inaccessible geographically. Factors which impede progress that are embedded in Earth Science programs include educational preparation, academic information and counseling and the prevalence of a Western scientific perspective to the exclusion of all other perspectives. Intradepartmental relationships also pose barriers to the success of some students, particularly those who are non-traditional students (53%) or women (80%). Factors which support degree completion include financial assistance, mentors and mentoring, and research experiences. Earth scientists

  12. Eliciting hyperparameters of prior distributions for the parameters of paired comparison models

    Directory of Open Access Journals (Sweden)

    Nasir Abbas

    2013-02-01

    Full Text Available Normal 0 false false false EN-US X-NONE AR-SA In the study of paired comparisons (PC, items may be ranked or issues may be prioritized through subjective assessment of certain judges. PC models are developed and then used to serve the purpose of ranking. The PC models may be studied through classical or Bayesian approach. Bayesian inference is a modern statistical technique used to draw conclusions about the population parameters. Its beauty lies in incorporating prior information about the parameters into the analysis in addition to current information (i.e. data. The prior and current information are formally combined to yield a posterior distribution about the population parameters, which is the work bench of the Bayesian statisticians. However, the problems the Bayesians face correspond to the selection and formal utilization of prior distribution. Once the type of prior distribution is decided to be used, the problem of estimating the parameters of the prior distribution (i.e. elicitation still persists. Different methods are devised to serve the purpose. In this study an attempt is made to use Minimum Chi-square (hence forth MCS for the elicitation purpose. Though it is a classical estimation technique, but is used here for the election purpose. The entire elicitation procedure is illustrated through a numerical data set.

  13. A Comparison of Alternative Distributed Dynamic Cluster Formation Techniques for Industrial Wireless Sensor Networks.

    Science.gov (United States)

    Gholami, Mohammad; Brennan, Robert W

    2016-01-06

    In this paper, we investigate alternative distributed clustering techniques for wireless sensor node tracking in an industrial environment. The research builds on extant work on wireless sensor node clustering by reporting on: (1) the development of a novel distributed management approach for tracking mobile nodes in an industrial wireless sensor network; and (2) an objective comparison of alternative cluster management approaches for wireless sensor networks. To perform this comparison, we focus on two main clustering approaches proposed in the literature: pre-defined clusters and ad hoc clusters. These approaches are compared in the context of their reconfigurability: more specifically, we investigate the trade-off between the cost and the effectiveness of competing strategies aimed at adapting to changes in the sensing environment. To support this work, we introduce three new metrics: a cost/efficiency measure, a performance measure, and a resource consumption measure. The results of our experiments show that ad hoc clusters adapt more readily to changes in the sensing environment, but this higher level of adaptability is at the cost of overall efficiency.

  14. Self broadening in the nu-1 band of NH3

    Science.gov (United States)

    Markov, V. N.; Pine, A. S.; Buffa, G.; Tarrini, O.

    1993-01-01

    Self-broadening coefficients, pressure shifts, and integrated intensities have been measured for Q- and R-branch transitions in the nu-1 fundamental band of ammonia using a difference-frequency laser spectrometer. A strong, systematic J and K dependence of the broadening coefficients, reminiscent of the ground-state inversion transitions, is observed and compared with semiclassical line broadening calculations. Dicke narrowing is evident at intermediate pressures for the sharpest lines, primarily the R(J, 0) transitions. Incipient line mixing is apparent in the Q branch at pressures above about 0.1 bar.

  15. Pressure broadening of acetylene rotational Raman lines by argon

    NARCIS (Netherlands)

    Ceruti, M.; Frenkel, D.; McTaque, J.P.

    1980-01-01

    The anisotropic interaction between acetylene and argon has been studied by observing the density dependence of the acetylene pure rotational Raman line broadening. The observed cross sections are approximately twice that predicted from the known polarizabilities and acetylene molecular quadrupole

  16. Stark broadening parameter tables for neutral calcium spectral lines, II

    Directory of Open Access Journals (Sweden)

    Dimitrijević M.S.

    2000-01-01

    Full Text Available Electron-, proton-, and ionized helium-impact broadening parameter tables for neutral calcium spectral lines, have been presented as a function of the temperature and the perturber density. Calculations have been performed within the semiclassical perturbation approach.

  17. Recovery of superfluorescence in inhomogeneously broadened systems through rapid relaxation

    Science.gov (United States)

    Balko, B.; Kay, I. W.; Vuduc, R.; Neuberger, J. W.

    1997-05-01

    This paper shows that time-dependent hyperfine interactions of the nucleus with electrons can enhance the superfluorescence (SF) intensity by countering the destructive effect of inhomogeneous broadening on SF.

  18. Probing transverse momentum broadening in heavy ion collisions

    Directory of Open Access Journals (Sweden)

    A.H. Mueller

    2016-12-01

    Full Text Available We study the dijet azimuthal de-correlation in relativistic heavy ion collisions as an important probe of the transverse momentum broadening effects of a high energy jet traversing the quark–gluon plasma. We take into account both the soft gluon radiation in vacuum associated with the Sudakov logarithms and the jet PT-broadening effects in the QCD medium. We find that the Sudakov effects are dominant at the LHC, while the medium effects can play an important role at RHIC energies. This explains why the LHC experiments have not yet observed sizable PT-broadening effects in the measurement of dijet azimuthal correlations in heavy ion collisions. Future investigations at RHIC will provide a unique opportunity to study the PT-broadening effects and help to pin down the underlying mechanism for jet energy loss in a hot and dense medium.

  19. Tissue distribution comparison between healthy and fatty liver rats after oral administration of hawthorn leaf extract.

    Science.gov (United States)

    Yin, Jingjing; Qu, Jianguo; Zhang, Wenjie; Lu, Dongrui; Gao, Yucong; Ying, Xixiang; Kang, Tingguo

    2014-05-01

    Hawthorn leaves, a well-known traditional Chinese medicine, have been widely used for treating cardiovascular and fatty liver diseases. The present study aimed to investigate the therapeutic basis treating fatty liver disease by comparing the tissue distribution of six compounds of hawthorn leaf extract (HLE) in fatty liver rats and healthy rats after oral administration at first day, half month and one month, separately. Therefore, a sensitive and specific HPLC method with internal standard was developed and validated to determine chlorogenic acid, vitexin-4''-O-glucoside, vitexin-2''-O-rhamnoside, vitexin, rutin and hyperoside in the tissues including heart, liver, spleen, kidney, stomach and intestine. The results indicated that the six compounds in HLE presented some bioactivity in treating rat fatty liver as the concentrations of the six compounds varied significantly in inter- and intragroup comparisons (healthy and/or fatty liver group). Copyright © 2013 John Wiley & Sons, Ltd.

  20. Comparison of airborne and surface particulate size distributions in specific Hanford Nuclear Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Ottley, D.B.

    1995-05-01

    Settled dust from nuclear operations may be contaminated with radionuclides and become resuspended and subsequently breathed. This is the predominate radionuclide inhalation hazard scenario in nuclear facilities that have been deactivated and no longer have liquid in their process systems that may become directly airborne in accident situations. Comparisons were made between indoor ambient airborne particulate size distribution and that of resuspended dust that could become contaminated and subsequently airborne during decommissioning operations at selected nuclear facilities on the Hanford Site. Results indicate that only 5% of the particles, by count, above the breathing zone are greater than ten (10) {mu}m in size and that the particulates that could be resuspended into the breathing zone had a mean aerodynamic equivalent diameter of four (4) {mu}m or less.

  1. Comparison of impedance based fault location methods for power distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Mora-Florez, J. [Electrical Engineering School, Technological University of Pereira (UTP), La Julita, Pereira (Colombia); Melendez, J. [Electronics, Computer Engineering and Automatics Department, University of Girona (UdG), EPS, Campus Montilivi, 17071 Girona (Spain); Carrillo-Caicedo, G. [Electrical Engineering School, Industrial University of Santander (UIS), Cra 27-Cll 9, Bucaramanga (Colombia)

    2008-04-15

    Performance of 10 fault location methods for power distribution systems has been compared. The analyzed methods use only measurements of voltage and current at the substation. Fundamental component during pre-fault and fault are used in these methods to estimate the apparent impedance viewed from the measurement point. Deviation between pre-fault and fault impedance together with the system parameters are used to estimate the distance to the fault point. Fundamental aspects of each method have been considered in the analysis. Power system topology, line and load models and the necessity of additional information are relevant aspects that differentiate one method from another. The 10 selected methods have been implemented, tested and compared in a simulated network. The paper reports the results for several scenarios defined by significant values of the fault location and impedance. The estimated error has been used as a performance index in the comparison. (author)

  2. Low arousing positive affect broadens visual attention and alters the thought-action repertoire while broadened visual attention does not

    Directory of Open Access Journals (Sweden)

    Daniel Thomas Jäger

    2016-10-01

    Full Text Available The Broaden-and-Build Theory states that positive emotions broaden cognition and therefore build personal resources. However, missing theoretical precision regarding the interaction of the cognitive processes involved offers a variety of possible explanations for the mechanisms of broadening and building. In Experiment 1 we tested the causality assumption which states that positive emotions first broaden visual attention which in turn leads to broadened cognition. We examined the effects of a broadened, narrowed or neutral attentional scope of 72 subjects (30 men on their momentary thought-action repertoire. Results showed that there were no significant differences between groups regarding the breadth or the content of the thought-action repertoire. In Experiment 2 we studied the non-causality hypothesis which assumes a non-causal relationship between cognitive processes. We did so by investigating the effects of negative, neutral, and positive affect on the visual attentional scope of 85 subjects (41 men in Experiment 2a, as well as on the thought-action repertoire of 85 participants (42 men in Experiment 2b. Results revealed an attentional broadening effect in Experiment 2a but no differences between groups concerning the breadth of the thought-action repertoire in Experiment 2b. However, a theory driven content analysis showed that positive affect promoted social actions whereas negative affect endorsed resource protecting actions. Thus, our results favor the non-causality assumption. Moreover, results indicate that positive emotions do not target personal resources in general but rather resources associated with social behavior. In conclusion, we argue that the Broaden-and-Build Theory should be refined.

  3. Quantification of Optical Doppler broadening and optical path lengths of multiply scattered light with phase modulated low coherence interferometry

    NARCIS (Netherlands)

    Varghese, Babu; Rajan, Vinayakrishnan; van Leeuwen, Ton; Steenbergen, Wiendelt

    2007-01-01

    We show experimental validation of a novel technique to measure optical path length distributions and path length resolved Doppler broadening in turbid media for different reduced scattering coefficients and anisotropies. The technique involves a phase modulated low coherence Mach-Zehnder

  4. Hot Water Distribution System Program Documentation and Comparison to Experimental Data

    Energy Technology Data Exchange (ETDEWEB)

    Baskin, Evelyn [GE Infrastructure Energy; Craddick, William G [ORNL; Lenarduzzi, Roberto [ORNL; Wendt, Robert L [ORNL; Woodbury, Professor Keith A. [University of Alabama, Tuscaloosa

    2007-09-01

    In 2003, the California Energy Commission s (CEC s) Public Interest Energy Research (PIER) program funded Oak Ridge National Laboratory (ORNL) to create a computer program to analyze hot water distribution systems for single family residences, and to perform such analyses for a selection of houses. This effort and its results were documented in a report provided to CEC in March, 2004 [1]. The principal objective of effort was to compare the water and energy wasted between various possible hot water distribution systems for various different house designs. It was presumed that water being provided to a user would be considered suitably warm when it reached 105 F. Therefore, what was needed was a tool which could compute the time it takes for water reaching the draw point to reach 105 F, and the energy wasted during this wait. The computer program used to perform the analyses was a combination of a calculational core, produced by Dr. Keith A. Woodbury, Professor of Mechanical Engineering and Director, Alabama Industrial Assessment Center, University of Alabama, and a user interface based on LabVIEW, created by Dr. Roberto Lenarduzzi of ORNL. At that time, the computer program was in a relatively rough and undocumented form adequate to perform the contracted work but not in a condition where it could be readily used by those not involved in its generation. Subsequently, the CEC provided funding through Lawrence Berkeley National Laboratory (LBNL) to improve the program s documentation and user interface to facilitate use by others, and to compare the program s results to experimental data generated by Dr. Carl Hiller. This report describes the program and provides user guidance. It also summarizes the comparisons made to experimental data, along with options built into the program specifically to allow these comparisons. These options were necessitated by the fact that some of the experimental data required options and features not originally included in the program

  5. Satellite observed salinity distributions at high latitudes in the Northern Hemisphere: A comparison of four products

    Science.gov (United States)

    Garcia-Eidell, Cynthia; Comiso, Josefino C.; Dinnat, Emmanuel; Brucker, Ludovic

    2017-09-01

    Global surface ocean salinity measurements have been available since the launch of SMOS in 2009 and coverage was further enhanced with the launch of Aquarius in 2011. In the polar regions where spatial and temporal changes in sea surface salinity (SSS) are deemed important, the data have not been as robustly validated because of the paucity of in situ measurements. This study presents a comparison of four SSS products in the ice-free Arctic region, three using Aquarius data and one using SMOS data. The accuracy of each product is assessed through comparative analysis with ship and other in situ measurements. Results indicate RMS errors ranging between 0.33 and 0.89 psu. Overall, the four products show generally good consistency in spatial distribution with the Atlantic side being more saline than the Pacific side. A good agreement between the ship and satellite measurements was also observed in the low salinity regions in the Arctic Ocean, where SSS in situ measurements are usually sparse, at the end of summer melt seasons. Some discrepancies including biases of about 1 psu between the products in spatial and temporal distribution are observed. These are due in part to differences in retrieval techniques, geophysical filtering, and sea ice and land masks. The monthly SSS retrievals in the Arctic from 2011 to 2015 showed variations (within ˜1 psu) consistent with effects of sea ice seasonal cycles. This study indicates that spaceborne observations capture the seasonality and interannual variability of SSS in the Arctic with reasonably good accuracy.

  6. Point defects in MnSi and YBCO studied by Doppler Broadening Spectroscopy using a positron beam

    Energy Technology Data Exchange (ETDEWEB)

    Reiner, Markus

    2015-10-28

    The positron beam NEPOMUC was used in order to investigate MnSi and YBa{sub 2}Cu{sub 3}O{sub 7-δ} (YBCO) single crystals. The Doppler broadening of the annihilation radiation of electron-positron pairs was analyzed. Thus, the concentration of Mn vacancies in MnSi crystals was determined. In thin YBCO films, the Doppler broadening is correlated with the oxygen deficiency δ. Its spatial distribution and its high-temperature behavior were studied using positrons.

  7. Comparison of two spatial optimization techniques: a framework to solve multiobjective land use distribution problems.

    Science.gov (United States)

    Meyer, Burghard Christian; Lescot, Jean-Marie; Laplana, Ramon

    2009-02-01

    Two spatial optimization approaches, developed from the opposing perspectives of ecological economics and landscape planning and aimed at the definition of new distributions of farming systems and of land use elements, are compared and integrated into a general framework. The first approach, applied to a small river catchment in southwestern France, uses SWAT (Soil and Water Assessment Tool) and a weighted goal programming model in combination with a geographical information system (GIS) for the determination of optimal farming system patterns, based on selected objective functions to minimize deviations from the goals of reducing nitrogen and maintaining income. The second approach, demonstrated in a suburban landscape near Leipzig, Germany, defines a GIS-based predictive habitat model for the search of unfragmented regions suitable for hare populations (Lepus europaeus), followed by compromise optimization with the aim of planning a new habitat structure distribution for the hare. The multifunctional problem is solved by the integration of the three landscape functions ("production of cereals," "resistance to soil erosion by water," and "landscape water retention"). Through the comparison, we propose a framework for the definition of optimal land use patterns based on optimization techniques. The framework includes the main aspects to solve land use distribution problems with the aim of finding the optimal or best land use decisions. It integrates indicators, goals of spatial developments and stakeholders, including weighting, and model tools for the prediction of objective functions and risk assessments. Methodological limits of the uncertainty of data and model outcomes are stressed. The framework clarifies the use of optimization techniques in spatial planning.

  8. Broadening effects on opacity calculation of CH plasmas

    Science.gov (United States)

    Ghorashi, Seyed Alaeddin; Mahdavi, Mohammad

    2017-02-01

    Opacity is a function of the temperature and electron density of plasma. The plasma density can be determined by measurements of Stark-broadened K-shell spectral lines. The purpose of this work is to obtain a more detailed structure of opacity with regard to broadening effects. For this aim, the opacity frequency dependency and mean opacity of mixed plasmas are calculated under local thermodynamic equilibrium (LTE) conditions. The LTE state in inertial confinement fusion occurs when the collisional deexcitation rate from the upper level to the lower level greatly exceeds the spontaneous decay rate. Since the thermal radiation can be absorbed by the CH-ablator, by studying the behavior of the CH Polystyrene opacity, one can obtain the temperature and density of the plasma in investigations of matter found in stellar interiors, inertial fusion implosions, and Z pinches as a diagnostic technique. The main aspect of diagnostic application is spectrum broadening. The final results show that the Stark-broadened line shape is dependent on the density. Also, it is shown that the resonance peak and spectrum broadening of the opacity spectrum of a mixed plasma such as the CH-plasma is larger than a single atom plasma such as Carbon.

  9. Quantification of optical Doppler broadening and optical path lengths of multiply scattered light by phase modulated low coherence interferometry.

    Science.gov (United States)

    Varghese, B; Rajan, V; van Leeuwen, T G; Steenbergen, W

    2007-07-23

    We show experimental validation of a novel technique to measure optical path length distributions and path length resolved Doppler broadening in turbid media for different reduced scattering coefficients and anisotropies. The technique involves a phase modulated low coherence Mach-Zehnder interferometer, with separate fibers for illumination and detection. Water suspensions of Polystyrene microspheres with high scattering and low absorption levels are used as calibrated scattering phantoms. The path length dependent diffusion broadening or Doppler broadening of scattered light is shown to agree with Diffusive Wave Spectroscopy within 5%. The optical path lengths are determined experimentally from the zero order moment of the phase modulation peak around the modulation frequency in the power spectrum and the results are validated with Monte Carlo simulations.

  10. Quantification of optical Doppler broadening and optical path lengths of multiply scattered light by phase modulated low coherence interferometry

    Science.gov (United States)

    Varghese, B.; Rajan, V.; van Leeuwen, T. G.; Steenbergen, W.

    2007-07-01

    We show experimental validation of a novel technique to measure optical path length distributions and path length resolved Doppler broadening in turbid media for different reduced scattering coefficients and anisotropies. The technique involves a phase modulated low coherence Mach-Zehnder interferometer, with separate fibers for illumination and detection. Water suspensions of Polystyrene microspheres with high scattering and low absorption levels are used as calibrated scattering phantoms. The path length dependent diffusion broadening or Doppler broadening of scattered light is shown to agree with Diffusive Wave Spectroscopy within 5%. The optical path lengths are determined experimentally from the zero order moment of the phase modulation peak around the modulation frequency in the power spectrum and the results are validated with Monte Carlo simulations.

  11. Inhomogeneous and homogeneous broadening effects on nuclear resonance experiments

    Energy Technology Data Exchange (ETDEWEB)

    Balko, B.; Kay, I.W.; Nicoll, J.; Silk, J.D.; Herling, G

    1997-05-15

    Inhomogeneous broadening of resonance lines causes a reduction of absorption in nuclear resonance experiments. This is particularly devastating to the observation of the Moessbauer effect in isomers like {sup 107}Ag with a half-life of 44s. It has been suggested in the literature that homogeneous broadening can provide overlap of resonance lines and thus the Moessbauer effect can be recovered. The analysis presented in this paper shows that this is not the case for Moessbauer experiments, unless the radiative width {gamma}{sub {gamma}} also increases. Although overlap occurs when the lines are homogeneously broadened to a total width {gamma}{sub H} which exceeds the natural width {gamma}, and the inhomogeneous width {delta}, the Moessbauer absorption remains low because it is proportional to the factor of {gamma}{sub {gamma}}/{gamma}{sub H}.

  12. Inhomogeneous and homogeneous broadening effects onnuclear resonance experiments

    Science.gov (United States)

    Balko, B.; Kay, I. W.; Nicoll, J.; Silk, J. D.; Herling, G.

    1997-05-01

    Inhomogeneous broadening of resonance lines causes a reduction of absorption in nuclear resonance experiments. This is particularly devastating to the observation of the Mössbauer effect in isomers like 107Ag with a half-life of 44s.It has been suggested in the literature that homogeneous broadening can provide overlap of resonance lines and thus theMössbauer effect can be recovered. The analysis presented in this paper shows that this is not the case for Mössbauer experiments, unless the radiative width ΓΓ also increases. Although overlap occurs when the lines are homogeneously broadened to a total width Γ_H which exceeds the natural width Γ, and the inhomogeneous width Δ, the Mössbauer absorption remains low because it is proportional to the factor of Γγ/Γ H.

  13. Broadening of the thermal component of the prompt GRB emission due to rapid temperature evolution

    Science.gov (United States)

    Bharali, Priya; Sahayanathan, Sunder; Misra, Ranjeev; Boruah, Kalyanee

    2017-08-01

    The observations of the prompt emission of gamma ray bursts (GRB) by GLAST Burst Monitor (GBM), on board Fermi Gamma-ray Space Telescope, suggest the presence of a significant thermal spectral component, whose origin is not well understood. Recently, it has been shown that for long duration GRBs, the spectral width as defined as the logarithm of the ratio of the energies at which the spectrum falls to half its peak value, lie in the range of 0.84-1.3 with a median value of 1.07. Thus, while most of the GRB spectra are found to be too narrow to be explained by synchrotron emission from an electron distribution, they are also significantly broader than a blackbody spectrum whose width should be 0.54. Here, we consider the possibility that an intrinsic thermal spectrum from a fire-ball like model, may be observed to be broadened if the system undergoes a rapid temperature evolution. We construct a toy-model to show that for bursts with durations in the range 5-70 s, the widths of their 1 second time-averaged spectra can be at the most ≲ 0.557. Thus, while rapid temperature variation can broaden the detected spectral shape, the observed median value of ˜ 1.07 requires that there must be significant sub-photospheric emission and/or an anisotropic explosion to explain the broadening for most GRB spectra.

  14. Multigroup Free-atom Doppler-broadening Approximation. Theory

    Energy Technology Data Exchange (ETDEWEB)

    Gray, Mark Girard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-06

    Multigroup cross sections at a one target temperature can be Doppler-broadened to multigroup cross sections at a higher target temperature by matrix multiplication if the group structure suf- ficiently resolves the original temperature continuous energy cross section. Matrix elements are the higher temperature group weighted averages of the integral over the lower temperature group boundaries of the free-atom Doppler-broadening kernel. The results match theory for constant and 1/v multigroup cross sections at 618 lanl group structure resolution.

  15. Comparison of Wind Energy Generation Using the Maximum Entropy Principle and the Weibull Distribution Function

    Directory of Open Access Journals (Sweden)

    Muhammad Shoaib

    2016-10-01

    Full Text Available Proper knowledge of the wind characteristics of a site is of fundamental importance in estimating wind energy output from a selected wind turbine. The present paper focuses on assessing the suitability and accuracy of the fitted distribution function to the measured wind speed data for Baburband site in Sindh Pakistan. Comparison is made between the wind power densities obtained using the fitted functions based on Maximum Entropy Principle (MEP and Weibull distribution. In case of MEP-based function a system of (N+1 non-linear equations containing (N+1 Lagrange multipliers is defined as probability density function. The maximum entropy probability density functions is calculated for 3–9 low order moments obtained from measured wind speed data. The annual actual wind power density (PA is found to be 309.25 W/m2 while the Weibull based wind power density (PW is 297.25 W/m2. The MEP-based density for orders 5, 7, 8 and 9 (PE is 309.21 W/m2, whereas for order 6 it is 309.43 W/m2. To validate the MEP-based function, the results are compared with the Weibull function and the measured data. Kolmogorov–Smirnov test is performed between the cdf of the measured wind data and the fitted distribution function (Q95 = 0.01457 > Q = 10−4. The test confirms the suitability of MEP-based function for modeling measured wind speed data and for the estimation of wind energy output from a wind turbine. R2 test is also performed giving analogous behavior of the fitted MEP-based pdf to the actual wind speed data (R2 ~ 0.9. The annual energy extracted using the chosen wind turbine based on Weibull function is PW = 2.54 GWh and that obtained using MEP-based function is PE = 2.57–2.67 GWh depending on the order of moments.

  16. On the use of broadened admission criteria in higher education

    NARCIS (Netherlands)

    Niessen, A. Susan M.; Meijer, Rob R.

    There is an increasing interest in the use of broadened criteria for admission to higher education, often assessed through noncognitive instruments. We argue that there are several reasons why, despite some significant progress, the use of noncognitive predictors to select students is problematic in

  17. Broadening the Legal Academy, the Study of Customary Law: The ...

    African Journals Online (AJOL)

    MJM Venter

    Scotland. Email Anne.Griffiths@ed.ac.uk. Date published. 26 October 2017. Editor Prof P du Plessis. How to cite this article. Griffiths A "Broadening the Legal. Academy ... established legal curriculum that had to be up and running within a very ... and apply them to the creation of courses that in the case of family law would.

  18. Stark broadening parameter tables for in II: Part II

    Directory of Open Access Journals (Sweden)

    Dimitrijević M.S.

    2001-01-01

    Full Text Available Electron-, proton-, and ionized helium-impact broadening parameter tables for 101 In II multiplets, are presented as a function of temperature for the perturber density of 1016cm-3. Calculations have been performed within the semiclassical perturbation approach.

  19. Impact of optical gain broadening on characteristics of response ...

    Indian Academy of Sciences (India)

    Computationally, we have solved the rate equation for two-state InAs QD semiconductor lasers and the effect of inhomogeneous broadening on response function and output power due to variation of QD parameters have been investigated in the presence and absence of tunnelling. Also, we have studied these effects on ...

  20. The STARS Alliance: Viable Strategies for Broadening Participation in Computing

    Science.gov (United States)

    Dahlberg, Teresa; Barnes, Tiffany; Buch, Kim; Rorrer, Audrey

    2011-01-01

    The Students and Technology in Academia, Research, and Service (STARS) Alliance is a nationally-connected system of regional partnerships among higher education, K-12 schools, industry and the community with a mission to broaden the participation of women, under-represented minorities and persons with disabilities in computing (BPC). Each regional…

  1. Optical coherent control in semiconductors: Fringe contrast and inhomogeneous broadening

    DEFF Research Database (Denmark)

    Østergaard, John Erland; Vadim, Lyssenko; Hvam, Jørn Märcher

    2001-01-01

    in the interplay between the homogeneous and inhomogeneous broadenings are measured. Based on these experiments, a coherent control model describing the optical fringe contrast using different detection schemes, such as photoluminescence or four-wave mixing, is established. Significant spectral modulation...

  2. Impact of optical gain broadening on characteristics of response ...

    Indian Academy of Sciences (India)

    YASIN YEKTA KIA

    2017-09-11

    Sep 11, 2017 ... graphene and carbon-based materials. So, considering exciton dephasing time is a subtle issue to improve the performance of semiconductor QD lasers. In recent years, the study of homogeneous broadening has been an essential case in the literature to understand the lasing process. Exciton–phonon ...

  3. Coherent excitonic nonlinearity versus inhomogeneous broadening in single quantum wells

    DEFF Research Database (Denmark)

    Langbein, Wolfgang Werner; Borri, Paola; Hvam, Jørn Märcher

    1998-01-01

    The coherent response of excitons in semiconductor nanostructures, as measured in four wave mixing (FWM) experiments, depends strongly on the inhomogeneous broadening of the exciton transition. We investigate GaAs-AlGaAs single quantum wells (SQW) of 4 nm to 25 nm well width. Two main mechanisms ...

  4. Stark broadening tables for He I 4922 A

    Science.gov (United States)

    Barnard, A. J.; Cooper, J.; Smith, E. W.

    1975-01-01

    The Stark broadening of the He I 4922-A line and its forbidden components by both ions and electrons is calculated using a theory that includes ion dynamic effects. Tables are presented for temperatures from 5000 K to 40,000 K covering the density range 10 trillion to 10 quadrillion per cu cm for both helium and hydrogen ionic perturbers.-

  5. Broadening the concept of international entrepreneurship: 'Consumers as international entrepreneurs'

    NARCIS (Netherlands)

    Chandra, Y.; Coviello, N.

    2010-01-01

    We integrate theories from international business, entrepreneurship, innovation, marketing and network economics to develop a four-part typology of ‘consumers as international entrepreneurs’. This broadens the concept of international entrepreneurship and complements the firm-level focus customary

  6. GOLD: Building capacity for broadening participation in the Geosciences

    Science.gov (United States)

    Adams, Amanda; Patino, Lina; Jones, Michael B.; Rom, Elizabeth

    2017-04-01

    The geosciences continue to lag other science, technology, engineering, and mathematics (STEM) disciplines in the engagement, recruitment and retention of traditionally underrepresented and underserved minorities, requiring more focused and strategic efforts to address this problem. Prior investments made by the National Science Foundation (NSF) related to broadening participation in STEM have identified many effective strategies and model programs for engaging, recruiting, and retaining underrepresented students in the geosciences. These investments also have documented clearly the importance of committed, knowledgeable, and persistent leadership for making local progress in broadening participation in STEM and the geosciences. Achieving diversity at larger and systemic scales requires a network of diversity "champions" who can catalyze widespread adoption of these evidence-based best practices and resources. Although many members of the geoscience community are committed to the ideals of broadening participation, the skills and competencies that empower people who wish to have an impact, and make them effective as leaders in that capacity for sustained periods of time, must be cultivated through professional development. The NSF GEO Opportunities for Leadership in Diversity (GOLD) program was implemented in 2016, as a funding opportunity utilizing the Ideas Lab mechanism. Ideas Labs are intensive workshops focused on finding innovative solutions to grand challenge problems. The ultimate aim of this Ideas Lab, organized by the NSF Directorate for Geosciences (GEO), was to facilitate the design, pilot implementation, and evaluation of innovative professional development curricula that can unleash the potential of geoscientists with interests in broadening participation to become impactful leaders within the community. The expectation is that mixing geoscientists with experts in broadening participation research, behavioral change, social psychology, institutional

  7. Hydrogen Balmer Line Broadening in Solar and Stellar Flares

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, Adam F. [Department of Astrophysical and Planetary Sciences, University of Colorado Boulder, 2000 Colorado Avenue, Boulder, CO 80305 (United States); Allred, Joel C. [NASA/Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States); Uitenbroek, Han [National Solar Observatory, University of Colorado Boulder, 3665 Discovery Drive, Boulder, CO 80303 (United States); Tremblay, Pier-Emmanuel [Department of Physics, University of Warwick, Coventry CV47AL (United Kingdom); Brown, Stephen [School of Physics and Astronomy, Kelvin Building, University of Glasgow, G12 8QQ (United Kingdom); Carlsson, Mats [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway); Osten, Rachel A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Wisniewski, John P. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks Street, Norman, OK 73019 (United States); Hawley, Suzanne L., E-mail: Adam.Kowalski@lasp.colorado.edu [University of Washington Department of Astronomy, 3910 15th Avenue NE, Seattle, WA 98195 (United States)

    2017-03-10

    The broadening of the hydrogen lines during flares is thought to result from increased charge (electron, proton) density in the flare chromosphere. However, disagreements between theory and modeling prescriptions have precluded an accurate diagnostic of the degree of ionization and compression resulting from flare heating in the chromosphere. To resolve this issue, we have incorporated the unified theory of electric pressure broadening of the hydrogen lines into the non-LTE radiative-transfer code RH. This broadening prescription produces a much more realistic spectrum of the quiescent, A0 star Vega compared to the analytic approximations used as a damping parameter in the Voigt profiles. We test recent radiative-hydrodynamic (RHD) simulations of the atmospheric response to high nonthermal electron beam fluxes with the new broadening prescription and find that the Balmer lines are overbroadened at the densest times in the simulations. Adding many simultaneously heated and cooling model loops as a “multithread” model improves the agreement with the observations. We revisit the three-component phenomenological flare model of the YZ CMi Megaflare using recent and new RHD models. The evolution of the broadening, line flux ratios, and continuum flux ratios are well-reproduced by a multithread model with high-flux nonthermal electron beam heating, an extended decay phase model, and a “hot spot” atmosphere heated by an ultrarelativistic electron beam with reasonable filling factors: ∼0.1%, 1%, and 0.1% of the visible stellar hemisphere, respectively. The new modeling motivates future work to understand the origin of the extended gradual phase emission.

  8. The dangers of resource myopia in work and organisational psychology: a plea for broadening and integration broadening

    NARCIS (Netherlands)

    Drenth, P.J.D.; Heller, F.A.

    2004-01-01

    In this essay the limitations of the traditional quantitative approach in work and organisational psychology are put forward. It is argued that an extension of the methods, a broadening of the type of problems to be addressed, and a stronger integration with associated disciplines as well as with

  9. Peak broadening in paper chromatography and related techniques : III. Peak broadening in thin-layer chromatography on cellulose powder

    NARCIS (Netherlands)

    Ligny, C.L. de; Remijnse, A.G.

    1968-01-01

    The mechanism of peak broadening in thin-layer chromatography on cellulose powder was investigated by comparing the peak widths obtained in chromatography with those caused only by diffusion in the cellulose powder, for a set of amino acids of widely differing RF values and six kinds of cellulose

  10. Comparison between performances of three types of manual wheelchairs often distributed in low-resource settings.

    Science.gov (United States)

    Rispin, Karen; Wee, Joy

    2015-07-01

    This study was conducted to compare the performance of three types of chairs in a low-resource setting. The larger goal was to provide information which will enable more effective use of limited funds by wheelchair manufacturers and suppliers in low-resource settings. The Motivation Rough Terrain and Whirlwind Rough Rider were compared in six skills tests which participants completed in one wheelchair type and then a day later in the other. A hospital-style folding transport wheelchair was also included in one test. For all skills, participants rated the ease or difficulty on a visual analogue scale. For all tracks, distance traveled and the physiological cost index were recorded. Data were analyzed using repeated measures analysis of variance. The Motivation wheelchair outperformed Whirlwind wheelchair on rough and smooth tracks, and in some metrics on the tight spaces track. Motivation and Whirlwind wheelchairs significantly outperformed the hospital transport wheelchair in all metrics on the rough track skills test. This comparative study provides data that are valuable for manufacturers and for those who provide wheelchairs to users. The comparison with the hospital-style transport chair confirms the cost to users of inappropriate wheelchair provision. Implications for Rehabilitation For those with compromised lower limb function, wheelchairs are essential to enable full participation and improved quality of life. Therefore, provision of wheelchairs which effectively enable mobility in the cultures and environments in which people with disabilities live is crucial. This includes low-resource settings where the need for appropriate seating is especially urgent. A repeated measures study to measure wheelchair performances in everyday skills in the setting where wheelchairs are used gives information on the quality of mobility provided by those wheelchairs. This study highlights differences in the performance of three types of wheelchairs often distributed in low

  11. Results of APL rain gauge network measurements in mid-Atlantic coast region and comparisons of distributions with CCIR models

    Science.gov (United States)

    Goldhirsh, Julius; Gebo, Norman; Rowland, John

    1988-01-01

    In this effort are described cumulative rain rate distributions for a network of nine tipping bucket rain gauge systems located in the mid-Atlantic coast region in the vicinity of the NASA Wallops Flight Facility, Wallops Island, Virginia. The rain gauges are situated within a gridded region of dimensions of 47 km east-west by 70 km north-south. Distributions are presented for the individual site measurements and the network average for the year period June 1, 1986 through May 31, 1987. A previous six year average distribution derived from measurements at one of the site locations is also presented. Comparisons are given of the network average, the CCIR (International Radio Consultative Committee) climatic zone, and the CCIR functional model distributions, the latter of which approximates a log normal at the lower rain rate and a gamma function at the higher rates.

  12. Comparison of Surti goat milk with cow and buffalo milk for gross composition, nitrogen distribution, and selected minerals content

    OpenAIRE

    Kapadiya, Dhartiben B.; Darshna B. Prajapati; Amit Kumar Jain; Mehta, Bhavbhuti M.; Darji, Vijaykumar B.; Kishorkumar D. Aparnathi

    2016-01-01

    Aim: The study was undertaken to find out the gross composition, nitrogen distribution, and selected mineral content in Surti goat milk, and its comparison was made between cow and buffalo milk. Materials and Methods: Goat milk samples of Surti breed and buffalo milk samples were collected during the period from July to January 2014 at Reproductive Biology Research Unit, Anand Agricultural University (AAU), Anand. Cow milk samples of Kankrej breed were collected from Livestock Research Statio...

  13. Biological processes in the North Sea: comparison of Calanus helgolandicus and Calanus finmarchicus vertical distribution and production

    DEFF Research Database (Denmark)

    Jonasdottir, Sigrun; Koski, Marja

    2011-01-01

    Comparison of abundance, vertical distribution and reproduction of the cousin species, the boreal Calanus finmarchicus and temperate Calanus helgolandicus was carried out on four cruises in July and August north of the Dogger Bank, North Sea. During this period, the water column was highly strati...... ecosystem longer than previously thought, and with warmer surface temperatures retreat to cooler, deeper waters utilizing the deep chlorophyll maximum. This implies that C. finmarchicus cannot be reliably sampled with the Continuous Plankton Recorder during summer....

  14. Non-global and rapidity logarithms in narrow jet broadening

    Science.gov (United States)

    Becher, Thomas; Rahn, Rudi; Shao, Ding Yu

    2017-10-01

    We derive an all-order factorization theorem for the narrow jet broadening event shape, a measure of the transverse momentum in jet events. This is a non-global observable which receives logarithmically enhanced contributions associated with the large rapidity difference between soft and collinear radiation and which is also sensitive to soft recoil effects. Our work is the first factorization analysis of an observable of this type and we show that with regard to the non-global nature, the rapidity logarithms do not constitute an essential complication since they can be tied to the jet function, which is the same as for global observables. As a consequence, the leading non-global logarithms in narrow jet broadening are encoded in the same overall factor relevant for the hemisphere soft function and light jet mass.

  15. Positive emotions and the social broadening effects of Barack Obama.

    Science.gov (United States)

    Ong, Anthony D; Burrow, Anthony L; Fuller-Rowell, Thomas E

    2012-10-01

    Past experiments have demonstrated that the cognitive broadening produced by positive emotions may extend to social contexts. Building on this evidence, we hypothesized that positive emotions triggered by thinking about Barack Obama may broaden and expand people's sense of self to include others. Results from an expressive-writing study demonstrated that African American college students prompted to write about Obama immediately prior to and after the 2008 presidential election used more plural self-references, fewer other-references, and more social references. Mediation analyses revealed that writing about Obama increased positive emotions, which in turn increased the likelihood that people thought in terms of more-inclusive superordinate categories (we and us rather than they and them). Implications of these findings for the role of positive emotions in perspective-taking and intergroup relations are considered.

  16. On the Use of Broadened Admission Criteria in Higher Education.

    Science.gov (United States)

    Niessen, A Susan M; Meijer, Rob R

    2017-05-01

    There is an increasing interest in the use of broadened criteria for admission to higher education, often assessed through noncognitive instruments. We argue that there are several reasons why, despite some significant progress, the use of noncognitive predictors to select students is problematic in high-stakes educational selection and why the incremental validity will often be modest, even when studied in low-stakes contexts. Furthermore, we comment on the use of broadened admission criteria in relation to reducing adverse impact of testing on some groups, and we extend the literature by discussing an approach based on behavioral sampling, which showed promising results in Europe. Finally, we provide some suggestions for future research.

  17. Fundamental edge broadening effects during focused electron beam induced nanosynthesis

    Directory of Open Access Journals (Sweden)

    Roland Schmied

    2015-02-01

    Full Text Available The present study explores lateral broadening effects of 3D structures fabricated through focused electron beam induced deposition using MeCpPt(IVMe3 precursor. In particular, the scaling behavior of proximity effects as a function of the primary electron energy and the deposit height is investigated through experiments and validated through simulations. Correlated Kelvin force microscopy and conductive atomic force microscopy measurements identified conductive and non-conductive proximity regions. It was determined that the highest primary electron energies enable the highest edge sharpness while lower energies contain a complex convolution of broadening effects. Moreover, it is demonstrated that intermediate energies lead to even more complex proximity effects that significantly reduce lateral edge sharpness and thus should be avoided if desiring high lateral resolution.

  18. A comparison of two mass distributions applicable to globular clusters and dwarf galaxies

    Directory of Open Access Journals (Sweden)

    Ninković Slobodan D.

    2004-01-01

    Full Text Available A particular case of mass distribution in stellar systems, already described in the literature, is compared to the King model of mass distribution. For the cases which would correspond to the description of real stellar systems such as the globular clusters and dwarf galaxies, one finds a satisfactory agreement between these two mass distributions.

  19. Common-Mode Spectral Broadening for Coherent Beam Combination (PREPRINT)

    Science.gov (United States)

    2015-04-03

    Common-Mode Spectral Broadening for Coherent Beam Combination Jason E. Langseth,∗ Andrew J. Benedick, Steven J. Augst, Michael S. Riley, and T.Y. Fan...which effectively suppresses SBS in the amplifier yet allows for efficient CBC. The fringe contrast at low and high power was greater than 96%. OCIS...large inten- sity fluctuation caused by the misaligned PRBS phase modulation disappears and clear interference fringes are observed. The SPGD phase

  20. A method to enhance the resolution of broadened spectra

    Energy Technology Data Exchange (ETDEWEB)

    Cabral P, A.; Jimenez D, H.; Torres V, M.; Azorin N, J.; Gutierrez C, A.; Gonzalez M, P.R.; Lopez E, J. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Fuentes Z, G.A.; Cordoba, A. [UAM-I, 09340 Mexico D.F. (Mexico)

    1992-02-15

    A deconvolution method to analyze line overlapping broadened spectra is presented. Two approximation expressions from which the user can remove, either a Lorentzian or a Gaussian line from observed spectra are utilized. Moessbauer spectra, EPR and Thermoluminescence spectroscopies are analyzed. It is shown that in each case, the de convolved spectrum may provide valuable data to get a much closer characterization of a substance. (Author)

  1. Hydrogen Stark broadening by different kinds of model microfields

    Science.gov (United States)

    Seidel, J.

    1980-07-01

    A new model microfield is defined (the theta process) which in conjunction with the kangaroo process, is used to demonstrate the effects of different model microfields on hydrogen line profiles. The differences in the statistical features of the models give an estimate of the uncertainties associated with the method of model microfields. Stark broadening of hydrogen Lyman lines by either electrons or ions is investigated specifically.

  2. Line broadening in the neutral and ionized mercury spectra

    Science.gov (United States)

    Gavrilov, M.; Skočić, M.; Burger, M.; Bukvić, S.; Djeniže, S.

    2012-10-01

    The neutral, singly, doubly and triply ionized mercury (Hg I-IV, respectively) spectral line shapes and line center positions have been investigated in the laboratory helium plasma at electron densities ranging between 9.3 × 1022 m-3 and 1.93 × 1023 m-3 and electron temperatures around 19,500 K, both interesting for astrophysics. The mercury (natural isotope composition) atoms were sputtered from the cylindrical amalgamated gold plates located in the homogenous part of the pulsed helium discharge operating at a pressure of 665 Pa in a flowing regime. The mercury spectral line profiles were recorded using the McPherson model 209 spectrograph and the Andor ICCD camera as the detection system. This research presents Stark broadening parameters, the width (W) and the shift (d), of one Hg I, 19 Hg II, 6 Hg III and 4 Hg IV lines, not investigated so far. Our experimental W values were compared with the data calculated applying various approaches. The shape and intensity of astrophysically important 398.4 nm Hg II spectral line was discussed taking into account the isotope shift, hyperfine structure and Penning effects. At the mentioned plasma parameters the Stark broadening is found to be a main line broadening mechanism of the lines (λ > 200 nm) in the Hg I-IV spectra.

  3. Broadening of Cortical Inhibition Mediates Developmental Sharpening of Orientation Selectivity

    Science.gov (United States)

    Li, Ya-tang; Ma, Wen-pei; Pan, Chen-jie; Zhang, Li I.; Tao, Huizhong W.

    2012-01-01

    Orientation selectivity (OS) of visual cortical neurons is progressively sharpened during development. However, synaptic circuit mechanisms underlying the OS sharpening remain unclear. In the current study, in vivo whole-cell voltage-clamp recordings from layer 4 excitatory neurons in the developing mouse primary visual cortex revealed changes of orientation tuning profiles of their excitatory and inhibitory inputs during a post eye-opening period when OS of their spiking responses becomes sharpened. Besides a parallel strengthening of excitation and inhibition during this developmental period, the orientation tuning of excitatory inputs keeps relatively constant, whereas the tuning of inhibitory inputs is broadened, and becomes significantly broader than that of excitatory inputs. Neuron modelling and dynamic-clamp recording demonstrated that this developmental broadening of the inhibitory tuning is sufficient for sharpening OS. Depriving visual experience by dark rearing impedes the normal developmental strengthening of excitation, but a similar broadening of inhibitory tuning, likely caused by a non-selective strengthening of inhibitory connections, results in the apparently normal OS sharpening in excitatory neurons. Our results thus provide the first demonstration that an inhibitory synaptic mechanism can primarily mediate the functional refinement of cortical neurons. PMID:22442065

  4. A comparison of six statistical distributions for analysis of chromosome aberration data for radiation biodosimetry.

    Science.gov (United States)

    Ainsbury, Elizabeth A; Vinnikov, Volodymyr A; Maznyk, Nataliya A; Lloyd, David C; Rothkamm, Kai

    2013-07-01

    The Poisson distribution is the most widely recognised and commonly used distribution for cytogenetic radiation biodosimetry. However, it is recognised that, due to the complexity of radiation exposure cases, other distributions may be more properly applied. Here, the Poisson, gamma, negative binomial, beta, Neyman type-A and Hermite distributions are compared in terms of their applicability to 'real-life' radiation exposure situations. The identification of the most appropriate statistical model in each particular exposure situation more correctly characterises data. The results show that for acute, homogeneous (whole-body) exposures, the Poisson distribution can still give a good fit to the data. For localised partial-body exposures, the Neyman type-A model was found to be the most robust. Overall, no single distribution was found to be universally appropriate. A distribution-specific method of analysis of cytogenetic data is therefore recommended. Such an approach may lead potentially to more accurate biological dose estimates.

  5. Instrumental broadening of spectral line profiles due to discrete representation of a continuous physical quantity

    Energy Technology Data Exchange (ETDEWEB)

    Dulov, E.N. [Department of Physics, Kazan State University, 420008, Kremlevskaya st. 18, Kazan (Russian Federation)], E-mail: fe57@rambler.ru; Khripunov, D.M. [Department of Physics, Kazan State University, 420008, Kremlevskaya st. 18, Kazan (Russian Federation)

    2008-07-15

    It is the usual situation in spectroscopy that a continuous physical quantity, which plays the role of a spectral function argument (i.e. the abscissa of a spectrum), is sampled electronically as discrete point clouds or channels. Each channel corresponds to the midpoint of a small interval of the continuous argument. The experimentally registered value of intensity in the channel describes the averaged spectral intensity in this interval. However, an approximation of spectra by a continuous theoretical model function often assumes that the interval is small enough, and tabulation of the theoretical model function may be used without appreciable disadvantages for the fitting results. At this point, a new type of approximation error appears, such as the error of midpoint approximation to a definite integral in the rectangle method of numeric integration. This paper aims at quantitative estimation of this error in the cases of a pure Lorentz lineshape and a generalized Voigt contour. It is shown that discrete representation of continuous spectral data leads to some non-physical broadening in comparison with the tabulated model function. As a first approximation it is normal broadening. We show that even in the case of a Lorentz true lineshape we must use the tabulated Voigt function measured in channels fixed Gauss linewidth rather than a tabulated Lorentzian. Application of the results of this paper is demonstrated on Moessbauer spectra.

  6. On the Application of Stark Broadening Data Determined with a Semiclassical Perturbation Approach

    Directory of Open Access Journals (Sweden)

    Milan S. Dimitrijević

    2014-08-01

    Full Text Available The significance of Stark broadening data for problems in astrophysics, physics, as well as for technological plasmas is discussed and applications of Stark broadening parameters calculated using a semiclassical perturbation method are analyzed.

  7. Cost comparison of competing local distribution systems for communication satellite traffic

    Science.gov (United States)

    Dopfel, F. E.

    1979-01-01

    The boundaries of market areas which favor various means for distributing communications satellite traffic are considered. The distribution methods considered are: control Earth station with cable access, rooftop Earth stations, Earth station with radio access, and various combinations of these methods. The least cost system for a hypothetical region described by number of users and the average cable access mileage is discussed. The region is characterized by a function which expresses the distribution of users. The results indicate that the least cost distribution is central Earth station with cable access for medium to high density areas of a region combined with rooftop Earth stations or (for higher volumes) radio access for remote users.

  8. A comparison of Poisson-one-inflated power series distributions for ...

    African Journals Online (AJOL)

    A class of Poisson-one-inflated power series distributions (the binomial, the Poisson, the negative binomial, the geometric, the log-series and the misrecorded Poisson) are proposed for modeling rural out-migration at the household level. The probability mass functions of the mixture distributions are derived and fitted to the ...

  9. Poisson adjacency distributions in genome comparison: multichromosomal, circular, signed and unsigned cases.

    Science.gov (United States)

    Xu, Wei; Alain, Benoît; Sankoff, David

    2008-08-15

    The number of common adjacencies of genetic markers, as a measure of the similarity of two genomes, has been widely used as indicator of evolutionary relatedness and as the basis for inferring phylogenetic relationships. Its probability distribution enables statistical tests in detecting whether significant evolutionary signal remains in the marker order. In this article, we derive the probability distributions of the number of adjacencies for a number of types of genome--signed or unsigned, circular or linear, single-chromosome or multichromosomal. Generating functions are found for singlechromosome cases, from which exact counts can be calculated. Probability approaches are adopted for multichromosomal cases, where we.nd the exact values for expectations and variances. In both cases, the limiting distributions are derived in term of numbers of adjacencies. For all unsigned cases, the limiting distribution is Poisson with parameter 2; for all signed cases, the limiting distribution is Poisson with parameter (1/2).

  10. Comparison of the effectiveness of two protocols of antirabies bait distribution for foxes (Vulpes vulpes).

    Science.gov (United States)

    Vuillaume, P; Bruyere, V; Aubert, M

    1998-01-01

    In a plateau and hill region of France (the Doubs), two protocols of rabies vaccine bait distribution targeted at foxes were compared: helicopter distribution of vaccine baits alone (control zone) and a combined aerial distribution by helicopter with an additional deposit of vaccine baits at fox den entrances by foot (test zone). In the test zone covering an area of 436 km2, baits were distributed by helicopter at a rate of 13.4 baits/km2. Additionally, an average of 11.4 vaccine baits at the entrances of 871 fox dens were terrestrially distributed by 110 persons (9,964 baits). In this test zone, 90% of the young foxes were marked with tetracycline which permitted estimation of the bait consumption; however, only 38% had significant titre of rabies antibodies and less than one fox cub per 2.4 of those having consumed at least one bait were immunized. In the control zone, these percentages were significantly lower: respectively, 35 and 17% and one fox cub per 4.2. The relative lack of benefit between bait uptake and rate of immunological response may be due to maternal immunity which could have interfered with fox cub active immunization. A booster effect following a second distribution of baits by foot may be suggested in both adult foxes and their offspring. That these baits needed to be terrestrially distributed in order to obtain a booster effect is uncertain. Terrestrial distribution at fox den entrances is difficult to do and entails additional expenses not incurred in aerial distribution. The cost of terrestrial vaccination is 3.5 times higher than classical aerial vaccination and takes 63.5 times longer. A cost effective analysis of this type of supplementary terrestrial intervention determined that bait deposit at den entrances can be recommended for restricted areas, where residual focii exist, as a complement to the aerial distribution of baits.

  11. Spectroscopic Study of Air-Broadened Nitrous Oxide in the ν_3 Band

    Science.gov (United States)

    Hashemi, Robab; Naseri, Hossein; Predoi-Cross, Adriana; Smith, Mary Ann H.; Devi, V. Malathy

    2017-06-01

    We present results of a recent analysis of laboratory spectra to determine line positions, intensities, air-broadened half-widths and pressure-induced shifts and their temperature dependences in the ν_3 fundamental band of N_2O. The spectra used in this study were recorded using the 1-m McMath-Pierce Fourier transform spectrometer while it was located at the National Solar Observatory on Kitt Peak, AZ. Multispectrum analysis software was used to retrieve the line parameters using the Voigt and speed-dependent Voigt line profiles. The line mixing coefficients were calculated using the Exponential Power Gap scaling law. Comparisons with similar published results will be presented. D. C. Benner, C. P. Rinsland, V. Malathy Devi, M. A. H. Smith, D. Atkins, JQSRT 53 (1995) 705-721.

  12. BORED PILES WITH THE BROADENING IN THE CONTEXT OF A LARGE DEPTH OF FREEZING

    Directory of Open Access Journals (Sweden)

    Олег Михайлович Преснов

    2017-08-01

    Full Text Available In the climatic conditions of Siberia pile foundations are working under the influence of forces of frost heave. Therefore, the length of piles accepted to take into account anchoring. However, in the construction of light buildings, bearing capacity of foundations used for no more than 30 to 40 % and most of the funds being spent inefficiently. In this work we consider the design of piles, resulting in lower costs for construction in these conditions is bored piles with the widening. From calculations it is seen that a variant of the bored piles with the broadening in comparison with the conventional reduces the volume of concrete production piles (and therefore cost 44% (almost 2 times.

  13. Broadening Participation in the Society for Integrative and Comparative Biology.

    Science.gov (United States)

    Wilga, Cheryl A D; Nishiguchi, Michele; Tsukimura, Brian

    2017-07-01

    The goal of the Society for Integrative and Comparative Biology's Broadening Participation Committee (SICB BPC) is to increase the number of underrepresented group (URG) members within the society and to expand their capabilities as future researchers and leaders within SICB. Our short-term 10-year goal was to increase the recruitment and retention of URG members in the society by 10%. Our long-term 25-year goal is to increase the membership of URG in the society through recruitment and retention until the membership demographic mirrors that of the US Census. Our plans to accomplish this included establishment of a formal standing committee, establishment of a moderate budget to support BPC activities, hosting professional development workshops, hosting diversity and mentor socials, and obtaining grant funds to supplement our budget. This paper documents broadening participation activities in the society, discusses the effectiveness of these activities, and evaluates BPC goals after 5 years of targeted funded activities. Over the past 5 years, the number of URG members rose by 5.2% to a total of 16.2%, members who report ethnicity and gender increased by 25.2% and 18%, respectively, and the number of members attending BPC activities has increased to 33% by 2016. SICB has made significant advances in broadening participation, not only through increased expenditures, but also with a commitment by its members and leadership to increase diversity. Most members realize that increasing diversity will both improve the Society's ability to develop different approaches to tackling problems within integrative biology, and help solve larger global issues that are evident throughout science and technology fields. In addition, having URG members as part of the executive committee would provide other URG members role models within the society, as well as have a voice in the leadership that represents diversity and inclusion for all scientists. © The Author 2017. Published by

  14. Distribution of body weight and height: comparison of estimates based on self-reported and observed measures.

    Science.gov (United States)

    Millar, W J

    1986-01-01

    The distribution of weight in the adult population aged 20-69 years was examined by comparison of estimates obtained from the 1985 Health Promotion Survey and the 1981 Canada Fitness Survey. The Health Promotion Survey obtained information on self-reported weight and height, and the Canada Fitness Survey utilised measured weight and height. The classification of respondents into weight categories followed the recommendations of the 1973 Fogarty Conference on Obesity. Values of the Quetelet index defined as W/H2, where W = kilograms and H = metres, were used to define four weight categories: underweight, acceptable weight, overweight, and obese. The comparisons of prevalence estimates of the various weight categories indicate that self-reported weight and height leads to a systematic weight misclassification bias. The implications of this bias for epidemiological studies are discussed and suggestions are offered to handle the bias. PMID:3655624

  15. Stabilizing effect of line broadening in Raman fiber lasers

    Science.gov (United States)

    Krause, Michael; Cierullies, Sven; Renner, Hagen

    2003-11-01

    We show phenomenologically that power-dependent Stokes line broadening can stabilize Raman fiber lasers (RFLs) against pump power changes. To this aim we assume, according to experimental observations in the literature, that an increase of the Stokes power in any cavity increases the corresponding spectral linewidth. This reduces the effective reflectivity of the fiber Bragg gratings of the cavity and thus increases the total cavity loss. The latter counteracts the power increase and thus stabilizes the RFL. While single-wavelength RFLs are only slightly affected, the stabilizing effect for multi-wavelength RFLs can be particularly strong.

  16. Ab Initio Computation of Dynamical Properties: Pressure Broadening

    Science.gov (United States)

    Wiesenfeld, Laurent; Drouin, Brian

    2014-06-01

    Rotational spectroscopy of polar molecules is the main observational tool in many areas of astrophysics, for gases of low densities (n ˜ 102 - 108 cm-3). Spectral line shapes in astrophysical media are largely dominated by turbulence-induced Doppler effects and natural line broadening are negligible. However line broadening remains an important tool for denser gases, like planetary high atmospheres. Understanding the excitation schemes of polar molecules requires the knowledge of excitation transfer rate due to collisional excitation, between the polar molecule and the ambient gas, usually H2. Transport properties in ionized media also require a precise knowledge of momentum transfer rates by elastic collisions. In order to assess the theoretically computed cross section and energy/momentum transfer rates, direct absolute experiments are scarce. The best way is to measure not individual scattering events but rather the global effect of the buffer gas, thanks to the pressure broadening cross sections, whose magnitude can be measured without any scaling parameters. At low temperatures, both elastic and inelastic scattering amplitudes are tested. At higher temperature, depending on the interaction strength, only inelastic scattering cross section are shown to play a significant role 1 ,2. Thanks to the advances of computer capabilities, it has become practical to compute spectral line parameters fromab initio quantum chemistry. In particular, the theory of rotational line broadening is readily incorporated into scattering quantum dynamical theory, like close-coupling schemes. The only approximations used in the computation are the isolated collision/isolated line approximations. We compute the non-binding interaction potential with high precision quantum chemistry and fit the resulting ab initio points onto a suitable functional. We have recently computed several such systems, for molecules in H2 buffer gas: H2O,3 H2CO,4 HCO+ .5 Detailed computations taking into

  17. Numerical computation of doppler-broadening in the resonance domain

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, R. [Commissariat a l' Energie Atomique et aux Energies Alternatives, Service d' Etudes de Reacteurs et de Mathematiques Appliquees, CEA DEN DM2S/SERMA, 91191 Gif-sur-Yvette cedex (France); Hewko, C. [Commissariat a l' Energie Atomique et aux Energies Alternatives, Service d' Etudes de Reacteurs et de Mathematiques Appliquees, CEA DEN DM2S/SERMA, 91191 Gif-sur-Yvette cedex (France); AREVA NP/PEPDD-F, Tour Areva, Place J. Millier, 92084 La Defense (France); Santandrea, S. [Commissariat a l' Energie Atomique et aux Energies Alternatives, Service d' Etudes de Reacteurs et de Mathematiques Appliquees, CEA DEN DM2S/SERMA, 91191 Gif-sur-Yvette cedex (France)

    2013-07-01

    We have implemented an accurate and fast calculation of the Doppler-broadened kernel PT(E {yields} E') for neutron elastic scattering based on a gas model. An exponential cutoff which accounts for the asymptotic behavior of the error function helps limit the range of integration while eliminating difference effects. This allows for calculating a kernel library for {sup 238}U over a very fine energy grid covering the resonance range in only a few hours in a laptop. We give an example showing the impact of {sup 238}U elastic up-scattering on the values of self shielded cross sections. (authors)

  18. From forensic epigenetics to forensic epigenomics: broadening DNA investigative intelligence.

    Science.gov (United States)

    Vidaki, Athina; Kayser, Manfred

    2017-12-21

    Human genetic variation is a major resource in forensics, but does not allow all forensically relevant questions to be answered. Some questions may instead be addressable via epigenomics, as the epigenome acts as an interphase between the fixed genome and the dynamic environment. We envision future forensic applications of DNA methylation analysis that will broaden DNA-based forensic intelligence. Together with genetic prediction of appearance and biogeographic ancestry, epigenomic lifestyle prediction is expected to increase the ability of police to find unknown perpetrators of crime who are not identifiable using current forensic DNA profiling.

  19. Effect of Pressure Broadening on Emission and Transmission Spectra of H2O Modeled for sub-Neptune/super-Earth exoplanets: An Application to JWST

    Science.gov (United States)

    Gharib Nezhad, Ehsan; Line, Michael R.; Lyons, James R.

    2017-10-01

    Water is the most readily detected molecule over a diverse range of exoplanet properties (solar composition hot-Jupiters to high metallicity super-earths/neptunes). It is also one of the most important sources of opacity that govern radiative energy balance. It is well known that pressure/collisional broadening significantly influences the opacity of a given molecule. Laboratory spectroscopic studies have shown that the line-broadening (i.e. Doppler, Lorentzian) is influence by several factors including temperature, pressure, dipole moment of the broadeners (or bath gases), and the rotational quantum numbers. Since absorption cross-sections (or opacities) are central to both atmospheric modeling and observational research, there is a critical need to investigate the effect of pressure line-broadening on the absorption cross-sections and subsequent influence on observed transmission and emission spectra of transiting exoplanets. Typical data-model comparisons (either forward modeling or retrieval's) generally rely upon pre-computed grids of absorption cross-sections that assume trace molecules are broadened by a solar composition mixture (e.g., mainly H2 and He as a bath gas). However, as the metallicity of a planetary atmosphere increases, as anticipated for smaller planets in the sub-Neptune-Super Earth range, broadening due to other gases (e.g., N2, CO2, H2O, CH4, CO) can become significant and the H2-He broadening is no longer appropriate. In this work, we assess the influence of different background broadeners on the absorption cross-section of water, and subsequent influence on observed transmission/emission spectra. Initial results suggest that the choice of foreign broadener can result in up to a factor of ~5 increase in pressure broadened wings of the absorption cross sections, resulting in a factor of 1.6x reduction in the atmospheric spectral modulation. Such a difference will be detectible in the hi-resolution/SNR spectra anticipated with JWST, and will

  20. Comparison of Communication Architectures and Network Topologies for Distributed Propulsion Controls (Preprint)

    Science.gov (United States)

    2013-05-01

    application being considered in this paper; however, the methods and analyses used to compare the topologies as well as the results are, to some extent...Course Technology Ptr, 2005. [22] Hermann Kopetz. A comparison of ttp/c and flexray. Institut für Technische Informatik, Technische Universität

  1. Comparison of 3-dimensional proton-photon dose distribution and evaluation of side effects after radiotherapy

    CERN Document Server

    Poljanc, K

    2000-01-01

    The use of high precision radiation with particles (protons and ions) allows the radiation of tumors near risk organs and immedicable tumors. The aim of this work is the comparison between normal tissue complication probability for craniocerebral tumors of children and youth during simulation of photontherapy and proton therapy. The multivariate analysis gives the possibility to determine the tolerance dose for certain organs.

  2. Nanoparticles and metrology: a comparison of methods for the determination of particle size distributions

    Science.gov (United States)

    Coleman, Victoria A.; Jämting, Åsa K.; Catchpoole, Heather J.; Roy, Maitreyee; Herrmann, Jan

    2011-10-01

    Nanoparticles and products incorporating nanoparticles are a growing branch of nanotechnology industry. They have found a broad market, including the cosmetic, health care and energy sectors. Accurate and representative determination of particle size distributions in such products is critical at all stages of the product lifecycle, extending from quality control at point of manufacture to environmental fate at the point of disposal. Determination of particle size distributions is non-trivial, and is complicated by the fact that different techniques measure different quantities, leading to differences in the measured size distributions. In this study we use both mono- and multi-modal dispersions of nanoparticle reference materials to compare and contrast traditional and novel methods for particle size distribution determination. The methods investigated include ensemble techniques such as dynamic light scattering (DLS) and differential centrifugal sedimentation (DCS), as well as single particle techniques such as transmission electron microscopy (TEM) and microchannel resonator (ultra high-resolution mass sensor).

  3. Performance Comparison of Cooperative and Distributed Spectrum Sensing in Cognitive Radio

    OpenAIRE

    Sun, Zheng; Xu, Wenjun; He, Zhiqiang; Niu, Kai

    2008-01-01

    In this paper, we compare the performances of cooperative and distributed spectrum sensing in wireless sensor networks. After introducing the basic problem, we describe two strategies: 1) a cooperative sensing strategy, which takes advantage of cooperation diversity gain to increase probability of detection and 2) a distributed sensing strategy, which by passing the results in an inter-node manner increases energy efficiency and fairness among nodes. Then, we compare the performances of the s...

  4. Encoder power consumption comparison of Distributed Video Codec and H.264/AVC in low-complexity mode

    DEFF Research Database (Denmark)

    Ukhanova, Ann; Belyaev, Evgeny; Forchhammer, Søren

    2010-01-01

    This paper presents a power consumption comparison of a novel approach to video compression based on distributed video coding (DVC) and widely used video compression based on H.264/AVC standard. We have used a low-complexity configuration for H.264/AVC codec. It is well-known that motion estimation...... (ME) and CABAC entropy coder consume much power so we eliminate ME from the codec and use CAVLC instead of CABAC. Some investigations show that low-complexity DVC outperforms other algorithms in terms of encoder side energy consumption . However, estimations of power consumption for H.264/AVC and DVC...

  5. A Performance Comparison of Tree and Ring Topologies in Distributed System

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Min [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    A distributed system is a collection of computers that are connected via a communication network. Distributed systems have become commonplace due to the wide availability of low-cost, high performance computers and network devices. However, the management infrastructure often does not scale well when distributed systems get very large. Some of the considerations in building a distributed system are the choice of the network topology and the method used to construct the distributed system so as to optimize the scalability and reliability of the system, lower the cost of linking nodes together and minimize the message delay in transmission, and simplify system resource management. We have developed a new distributed management system that is able to handle the dynamic increase of system size, detect and recover the unexpected failure of system services, and manage system resources. The topologies used in the system are the tree-structured network and the ring-structured network. This thesis presents the research background, system components, design, implementation, experiment results and the conclusions of our work. The thesis is organized as follows: the research background is presented in chapter 1. Chapter 2 describes the system components, including the different node types and different connection types used in the system. In chapter 3, we describe the message types and message formats in the system. We discuss the system design and implementation in chapter 4. In chapter 5, we present the test environment and results, Finally, we conclude with a summary and describe our future work in chapter 6.

  6. The Color-Magnitude Distribution of Hilda Asteroids: Comparison with Jupiter Trojans

    Science.gov (United States)

    Wong, Ian; Brown, Michael E.

    2017-02-01

    Current models of solar system evolution posit that the asteroid populations in resonance with Jupiter are comprised of objects scattered inward from the outer solar system during a period of dynamical instability. In this paper, we present a new analysis of the absolute magnitude and optical color distribution of Hilda asteroids, which lie in 3:2 mean-motion resonance with Jupiter, with the goal of comparing the bulk properties with previously published results from an analogous study of Jupiter Trojans. We report an updated power-law fit of the Hilda magnitude distribution through H = 14. Using photometric data listed in the Sloan Moving Object Catalog, we confirm the previously reported strong bimodality in visible spectral slope distribution, indicative of two subpopulations with differing surface compositions. When considering collisional families separately, we find that collisional fragments follow a unimodal color distribution with spectral slope values consistent with the bluer of the two subpopulations. The color distributions of Hildas and Trojans are comparable and consistent with a scenario in which the color bimodality in both populations developed prior to emplacement into their present-day locations. We propose that the shallower magnitude distribution of the Hildas is a result of an initially much larger Hilda population, which was subsequently depleted as smaller bodies were preferentially ejected from the narrow 3:2 resonance via collisions. Altogether, these observations provide a strong case supporting a common origin for Hildas and Trojans as predicted by current dynamical instability theories of solar system evolution.

  7. Magnetic transition broadening and local lattice distortion in the negative thermal expansion antiperovskite Cu1-xSnxNMn3

    Science.gov (United States)

    Tong, P.; Louca, Despina; King, Graham; Llobet, Anna; Lin, J. C.; Sun, Y. P.

    2013-01-01

    The local distortion indicated by the split of the Cu/Sn-Mn bonds for the negative thermal expansion (NTE) materials Cu1-xSnxNMn3 (x = 0.1 and 0.5) was observed using neutron pair distribution function. The distribution of Cu/Sn-Mn bonds upon Sn doping is suggested to be attributable to the fluctuation in the hybridization of Mn d with Sn p orbitals. Accordingly, the antiferromagnetic (AFM) coupling mediated by the p-d hybridization fluctuates in strength. Consequently, the AFM transition closely coupled with the volume change is broadened, leading to the NTE.

  8. Measuring coral size-frequency distribution using stereo video technology, a comparison with in situ measurements.

    Science.gov (United States)

    Turner, Joseph A; Polunin, Nicholas V C; Field, Stuart N; Wilson, Shaun K

    2015-05-01

    Coral colony size-frequency distribution data offer valuable information about the ecological status of coral reefs. Such data are usually collected by divers in situ, but stereo video is being increasingly used for monitoring benthic marine communities and may be used to collect size information for coral colonies. This study compared the size-frequency distributions of coral colonies obtained by divers measuring colonies 'in situ' with digital video imagery collected using stereo video and later processed using computer software. The size-frequency distributions of the two methods were similar for corymbose colonies, although distributions were different for massive, branching and all colonies combined. The differences are mainly driven by greater abundance of colonies >50 cm and fewer colonies 5 cm and was able to record measurements on 87% of the colonies detected. However, stereo video only detected 57% of marked colonies coral recruits. Estimates of colony size made with the stereo video were smaller than the in situ technique for all growth forms, particularly for massive morphologies. Despite differences in size distributions, community assessments, which incorporated genera, growth forms and size, were similar between the two techniques. Stereo video is suitable for monitoring coral community demographics and provided data similar to in situ measure for corymbose corals, but the ability to accurately measure massive and branching coral morphologies appeared to decline with increasing colony size.

  9. Statistical correlation of spectral broadening in VLF transmitter signal and low-frequency ionospheric turbulence from observation on DEMETER satellite

    Directory of Open Access Journals (Sweden)

    A. Rozhnoi

    2008-10-01

    Full Text Available In our earlier papers we have found the effect of VLF transmitter signal depression over epicenters of the large earthquakes from observation on the French DEMETER satellite that can be considered as new method of global diagnostics of seismic influence on the ionosphere. At present paper we investigate a possibility VLF signal-ionospheric turbulence interaction using additional characteristic of VLF signal-spectrum broadening. This characteristic is important for estimation of the interaction type: linear or nonlinear scattering. Our main results are the following:
    – There are two zones of increased spectrum broadening, which are centered near magnetic latitudes Φ=±10° and Φ=±40°. Basing on the previous case study research and ground ionosonde registrations, probably it is evidence of nonlinear (active scattering of VLF signal on the ionospheric turbulence. However occurrence rate of spectrum broadening in the middle-latitude area is higher than in the near-equatorial zone (~15–20% in comparison with ~100% in former area that is probably coincides with the rate of ionospheric turbulence.
    – From two years statistics of observation in the selected 3 low-latitude regions and 1 middle-latitude region inside reception area of VLF signal from NWC transmitter we find a correlation of spectrum broadening neither with ion-cyclotron noise (f=150–500 Hz, which possibly means poor representation of the turbulence by the noise due to its mixture with natural ELF emission (which correlates with whistler, nor with magnetic storm activity.
    – We find rather evident correlation of ion-cyclotron frequency noise, VLF signal depression and weak correlation of spectrum broadening with seismicity in the middle-latitude region over Japan. But in the low-latitude regions we do not find such a correlation. Statistical decrease of VLF signal supports our previous case study results. However rather weak spectrum broadening

  10. A comparison study of steady-state vibrations with single fractional-order and distributed-order derivatives

    Directory of Open Access Journals (Sweden)

    Duan Jun-Sheng

    2017-12-01

    Full Text Available We conduct a detailed study and comparison for the one-degree-of-freedom steady-state vibrations under harmonic driving with a single fractional-order derivative and a distributed-order derivative. For each of the two vibration systems, we consider the stiffness contribution factor and damping contribution factor of the term of fractional derivatives, the amplitude and the phase difference for the response. The effects of driving frequency on these response quantities are discussed. Also the influences of the order α of the fractional derivative and the parameter γ parameterizing the weight function in the distributed-order derivative are analyzed. Two cases display similar response behaviors, but the stiffness contribution factor and damping contribution factor of the distributed-order derivative are almost monotonic change with the parameter γ, not exactly like the case of single fractional-order derivative for the order α. The case of the distributed-order derivative provides us more options for the weight function and parameters.

  11. Performance Comparison of Time-Frequency Distributions for Estimation of Instantaneous Frequency of Heart Rate Variability Signals

    Directory of Open Access Journals (Sweden)

    Nabeel Ali Khan

    2017-02-01

    Full Text Available The instantaneous frequency (IF of a non-stationary signal is usually estimated from a time-frequency distribution (TFD. The IF of heart rate variability (HRV is an important parameter because the power in a frequency band around the IF can be used for the interpretation and analysis of the respiratory rate but also for a more accurate analysis of heart rate (HR signals. In this study, we compare the performance of five states of the art kernel-based time-frequency distributions (TFDs in terms of their ability to accurately estimate the IF of HR signals. The selected TFDs include three widely used fixed kernel methods: the modified B distribution, the S-method and the spectrogram; and two adaptive kernel methods: the adaptive optimal kernel TFD and the recently developed adaptive directional TFD. The IF of the respiratory signal, which is usually easier to estimate as the respiratory signal is a mono-component with small amplitude variations with time, is used as a reference to examine the accuracy of the HRV IF estimates. Experimental results indicate that the most reliable estimates are obtained using the adaptive directional TFD in comparison to other commonly used methods such as the adaptive optimal kernel TFD and the modified B distribution.

  12. Comparison of four modeling tools for the prediction of potential distribution for non-indigenous weeds in the United States

    Science.gov (United States)

    Magarey, Roger; Newton, Leslie; Hong, Seung C.; Takeuchi, Yu; Christie, Dave; Jarnevich, Catherine S.; Kohl, Lisa; Damus, Martin; Higgins, Steven I.; Miller, Leah; Castro, Karen; West, Amanda; Hastings, John; Cook, Gericke; Kartesz, John; Koop, Anthony

    2017-01-01

    This study compares four models for predicting the potential distribution of non-indigenous weed species in the conterminous U.S. The comparison focused on evaluating modeling tools and protocols as currently used for weed risk assessment or for predicting the potential distribution of invasive weeds. We used six weed species (three highly invasive and three less invasive non-indigenous species) that have been established in the U.S. for more than 75 years. The experiment involved providing non-U. S. location data to users familiar with one of the four evaluated techniques, who then developed predictive models that were applied to the United States without knowing the identity of the species or its U.S. distribution. We compared a simple GIS climate matching technique known as Proto3, a simple climate matching tool CLIMEX Match Climates, the correlative model MaxEnt, and a process model known as the Thornley Transport Resistance (TTR) model. Two experienced users ran each modeling tool except TTR, which had one user. Models were trained with global species distribution data excluding any U.S. data, and then were evaluated using the current known U.S. distribution. The influence of weed species identity and modeling tool on prevalence and sensitivity effects was compared using a generalized linear mixed model. Each modeling tool itself had a low statistical significance, while weed species alone accounted for 69.1 and 48.5% of the variance for prevalence and sensitivity, respectively. These results suggest that simple modeling tools might perform as well as complex ones in the case of predicting potential distribution for a weed not yet present in the United States. Considerations of model accuracy should also be balanced with those of reproducibility and ease of use. More important than the choice of modeling tool is the construction of robust protocols and testing both new and experienced users under blind test conditions that approximate operational conditions.

  13. Comparison Of Mercury Distribution Between The Types Of Spent Fluorescent Lamp

    Directory of Open Access Journals (Sweden)

    Rhee S.W.

    2015-06-01

    Full Text Available Spent fluorescent lamps(SFLs such as linear type lamp, compact type lamp and U-type lamp are used to estimate mercury distribution in the components of lamps. Determination of mercury concentration in the components of spent fluorescent lamp is performed by the DMA method. Mercury concentration in the components of spent fluorescent lamp can be varied with the manufactures of lamp. Mercury portion in phosphor powder and glass from any types of spent fluorescent lamp is estimated to be higher than 99% by the analysis of mercury distribution. Through mercury distribution in the components for SFLs, the mercury concentration in phosphor powder is much higher than that in other components regardless of the type of lamp. Hence, it is desirable that phosphor powder of spent fluorescent lamps should be controlled separately and safely.

  14. Comparisons of select ATLAS $t\\bar{t}$ differential distributions with various NLO predictions

    CERN Document Server

    The ATLAS collaboration

    2013-01-01

    Differential $t\\bar{t}$ cross-section results have been published by the ATLAS experiment at the LHC for a variety of kinematic distributions using an integrated luminosity of 2 ${\\rm fb}^{-1}$ proton-proton collision data collected at a center-of-mass energy of $\\sqrt{s} = 7$ TeV. Some of these distributions can potentially be used to improve the precision of the parton distribution functions. In this document we compare select differential spectra with predictions determined at NLO QCD using the MCFM program and accounting for a wide variety of theoretical systematic uncertainties. The data are compared with each of the following PDF models with NLO accuracy: CT10, MSTW 2008, NNPDF 2.3, HERAPDF1.5, and ABM11.

  15. The distribution of stars around the Milky Way's central black hole. III. Comparison with simulations

    Science.gov (United States)

    Baumgardt, H.; Amaro-Seoane, P.; Schödel, R.

    2018-01-01

    Context. The distribution of stars around a massive black hole (MBH) has been addressed in stellar dynamics for the last four decades by a number of authors. Because of its proximity, the centre of the Milky Way is the only observational test case where the stellar distribution can be accurately tested. Past observational work indicated that the brightest giants in the Galactic centre (GC) may show a density deficit around the central black hole, not a cusp-like distribution, while we theoretically expect the presence of a stellar cusp. Aims: We here present a solution to this long-standing problem. Methods: We performed direct-summation N-body simulations of star clusters around massive black holes and compared the results of our simulations with new observational data of the GC's nuclear cluster. Results: We find that after a Hubble time, the distribution of bright stars as well as the diffuse light follow power-law distributions in projection with slopes of Γ ≈ 0.3 in our simulations. This is in excellent agreement with what is seen in star counts and in the distribution of the diffuse stellar light extracted from adaptive-optics (AO) assisted near-infrared observations of the GC. Conclusions: Our simulations also confirm that there exists a missing giant star population within a projected radius of a few arcsec around Sgr A*. Such a depletion of giant stars in the innermost 0.1 pc could be explained by a previously present gaseous disc and collisions, which means that a stellar cusp would also be present at the innermost radii, but in the form of degenerate compact cores.

  16. A uniform measurement expression for cross method comparison of nanoparticle aggregate size distributions

    DEFF Research Database (Denmark)

    Dudkiewicz, Agnieszka; Wagner, Stephan; Lehner, Angela

    2015-01-01

    plasma mass spectrometry detection (AF4-ICP-MS). Transformed size distributions are then compared between the methods and conclusions drawn on methods’ measurement accuracy, limits of detection and quantification related to the synthetic amorphous silca’s size. Two out of the six tested methods (GEMMA...... and AF4-ICP-MS) cross validate the MED distributions between each other, providing a true measurement. The measurement accuracy of other four techniques is shown to be compromised either by the high limit of detection and quantification (CLS, NTA, Wet-SEM) or the sample preparation that is biased...

  17. Empirical comparison of heuristic load distribution in point-to-point multicomputer networks

    Science.gov (United States)

    Grunwald, Dirk C.; Nazief, Bobby A. A.; Reed, Daniel A.

    1990-01-01

    The study compared several load placement algorithms using instrumented programs and synthetic program models. Salient characteristics of these program traces (total computation time, total number of messages sent, and average message time) span two orders of magnitude. Load distribution algorithms determine the initial placement for processes, a precursor to the more general problem of load redistribution. It is found that desirable workload distribution strategies will place new processes globally, rather than locally, to spread processes rapidly, but that local information should be used to refine global placement.

  18. Comparison of the Frontier Distributed Database Caching System with NoSQL Databases

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    Non-relational "NoSQL" databases such as Cassandra and CouchDB are best known for their ability to scale to large numbers of clients spread over a wide area. The Frontier distributed database caching system, used in production by the Large Hadron Collider CMS and ATLAS detector projects, is based on traditional SQL databases but also has the same high scalability and wide-area distributability for an important subset of applications. This paper compares the architectures, behavior, performance, and maintainability of the two different approaches and identifies the criteria for choosing which approach to prefer over the other.

  19. Binding-energy distribution and dephasing of localized biexcitons

    DEFF Research Database (Denmark)

    Langbein, Wolfgang Werner; Hvam, Jørn Märcher; Umlauff, M.

    1997-01-01

    We report on the binding energy and dephasing of localized biexciton states in narrow ZnSe multiple quantum wells. The measured binding-energy distribution of the localized biexcitons shows a width of 2.2 meV centered at 8.5 meV, and is fairly independent of the exciton localization energy. In four......-wave mixing, the biexciton photon echo decays fast and nonexponentially. This behavior results from the inhomogeneous broadening of the biexciton binding energy, as we show by a comparison with an analytical model calculation. The fast decay is thus not related to a fast microscopic biexciton dephasing....

  20. Comparison of Environment Impact between Conventional and Cold Chain Management System in Paprika Distribution Process

    Directory of Open Access Journals (Sweden)

    Eidelweijs A Putri

    2012-09-01

    Full Text Available Pasir Langu village in Cisarua, West Java, is the largest central production area of paprika in Indonesia. On average, for every 200 kilograms of paprika produced, there is rejection amounting to 3 kilograms. This resulted in money loss for wholesalers and wastes. In one year, this amount can be approximately 11.7 million Indonesian rupiahs. Recently, paprika wholesalers in Pasir Langu village recently are developing cold chain management system to maintain quality of paprika so that number of rejection can be reduced. The objective of this study is to compare environmental impacts between conventional and cold chain management system in paprika distribution process using Life Cycle Assessment (LCA methodology and propose Photovoltaic (PV system in paprika distribution process. The result implies that the cold chain system produces more CO2 emission compared to conventional system. However, due to the promotion of PV system, the emission would be reduced. For future research, it is necessary to reduce CO2 emission from transportation process since this process is biggest contributor of CO2 emission at whole distribution process. Keywords: LCA, environmentally friendly distribution, paprika,cold chain, PV system

  1. A survey and experimental comparison of distributed SPARQL engines for very large RDF data

    KAUST Repository

    Abdelaziz, Ibrahim

    2017-10-19

    Distributed SPARQL engines promise to support very large RDF datasets by utilizing shared-nothing computer clusters. Some are based on distributed frameworks such as MapReduce; others implement proprietary distributed processing; and some rely on expensive preprocessing for data partitioning. These systems exhibit a variety of trade-offs that are not well-understood, due to the lack of any comprehensive quantitative and qualitative evaluation. In this paper, we present a survey of 22 state-of-the-art systems that cover the entire spectrum of distributed RDF data processing and categorize them by several characteristics. Then, we select 12 representative systems and perform extensive experimental evaluation with respect to preprocessing cost, query performance, scalability and workload adaptability, using a variety of synthetic and real large datasets with up to 4.3 billion triples. Our results provide valuable insights for practitioners to understand the trade-offs for their usage scenarios. Finally, we publish online our evaluation framework, including all datasets and workloads, for researchers to compare their novel systems against the existing ones.

  2. Inter-regional output distribution: a comparison of Russian and Chinese experience

    NARCIS (Netherlands)

    Herzfeld, T.

    2008-01-01

    Several studies report increasing inter-regional inequality in transition countries over the course of economic reforms, but most of them fail to look at the underlying dynamics. Using the cases of Russia and China, this article analyses the evolution of inter-regional output distribution during

  3. Comparison of "E-Rater"[R] Automated Essay Scoring Model Calibration Methods Based on Distributional Targets

    Science.gov (United States)

    Zhang, Mo; Williamson, David M.; Breyer, F. Jay; Trapani, Catherine

    2012-01-01

    This article describes two separate, related studies that provide insight into the effectiveness of "e-rater" score calibration methods based on different distributional targets. In the first study, we developed and evaluated a new type of "e-rater" scoring model that was cost-effective and applicable under conditions of absent human rating and…

  4. Intraperitoneal photodynamic therapy: comparison of red and green light distribution and toxicity

    NARCIS (Netherlands)

    Veenhuizen, R. B.; Ruevekamp, M. C.; Oppelaar, H.; Ransdorp, B.; van de Vijver, M.; Helmerhorst, T. J.; Kenemans, P.; Stewart, F. A.

    1997-01-01

    The aim of this study was to compare red (652 nm) and green (514 nm) light for photodynamic therapy (PDT) of the peritoneal cavity with emphasis on light distribution and toxicity. Red-light PDT was limited by intestinal toxicity and it was hypothesized that less penetrating green light would allow

  5. Distributional effects of flood risk management - a cross-country comparison of preflood compensation

    NARCIS (Netherlands)

    van Doorn - Hoekveld, Willemijn|info:eu-repo/dai/nl/344848752; Goytia, Susana; Suykens, C.B.R.|info:eu-repo/dai/nl/343709848; Homewood, Stephen; Thuillier, Thomas; Manson, Corinne; Chmielewski, Piotr; Matczak, Piotr; van Rijswick, H.F.M.W.|info:eu-repo/dai/nl/099909189

    2016-01-01

    We seek to examine the manner in which either the EU member states of France, the Netherlands, Poland, and Sweden or parts of them, such as the country of England in the UK or the Flemish Region in Belgium, deal with the distributional effects of the flood risk management strategies prevention,

  6. Comparison of equilibrium and non-equilibrium distribution coefficients for the human drug carbamazepine

    Science.gov (United States)

    The distribution coefficient (KD) for the human drug carbamazepine was measured using a non-equilibrium technique. Repacked soil columns were prepared using an Airport silt loam (Typic Natrustalf) with an average organic matter content of 2.45%. Carbamazepine solutions were then leached through th...

  7. Comparison of Water Distribution Characteristics for Two Kinds of Sprinklers Used for Center Pivot Irrigation Systems

    Directory of Open Access Journals (Sweden)

    Jian Jiao

    2017-04-01

    Full Text Available Sprinkler selection influences the water distribution uniformity of center pivot irrigation systems. The sprinkling uniformity of the center pivot is crucial for the yield and quality of crops on a large scale. Rotating and fixed spray plate sprinklers (RSPSs and FSPSs are the two most popular types. However, sprinkler selection is mainly based on price, not on differences in performance between them. Under low-wind field conditions, the water distributions of individual RSPSs and FSPSs with different nozzles (2.78, 4.76, and 6.75 mm in diameter were measured using a catch can method. Cubic spline interpolation was used for data conversion for FSPS measurements; the nozzle configuration model was used to simulate the water distribution of the same-nozzle-sprinkler pipe section and full circular irrigated areas in a simulated center pivot under three sprinkler intervals of 1.5, 3.0, and 4.5 m respectively. Results showed that (1 individual RSPSs distributed the most water around the sprinkler, whereas individual FSPSs distributed the most water over a ring-shaped region at the periphery of the sprinkler, and the wetted radii for RSPSs and FSPSs ranged from 4.88 to 7.05 m and from 5.02 to 6.85 m, respectively; (2 same-nozzle-sprinkler pipe sections of RSPSs distributed the most water around the central axes of the pipe sections, and their sprinkling uniformities were 44.7%–51.0%, whereas FSPSs distributed the most water over both sides of the axes symmetrically, and less water around the axes, with sprinkling uniformities of 40.3%–58.0%; and (3 the sprinkling uniformities of the full circular irrigated areas were 85.8%–91.7% and 85.8%–86.2% when using RSPSs and FSPSs, respectively, under different sprinkler intervals, and the uniformities were 3.1% and 6.2% higher using RSPSs than FSPSs with sprinkler intervals of 3.0 and 4.5 m, respectively. RSPS accommodated larger sprinkler intervals (>3.0 m and maintained superior sprinkling

  8. Comparison of plantar pressure distribution in CAD-CAM and prefabricated foot orthoses in patients with flexible flatfeet.

    Science.gov (United States)

    Khodaei, Banafsheh; Saeedi, Hassan; Jalali, Maryam; Farzadi, Maede; Norouzi, Ehsan

    2017-12-01

    The effect of foot orthoses on plantar pressure distribution has been proven by researchers but there are some controversies about advantages of custom-made foot orthoses to less expensive prefabricated foot orthoses. Nineteen flatfeet adults between 18 and 45 participated in this study. CAD-CAM foot orthoses were made for these patients according to their foot scan. Prefabricated foot orthoses were prepared according to their foot size. Plantar pressure, force and contact area were measured using pedar ® -x in-shoe system wearing shoe alone, wearing CAD-CAM foot orthoses and wearing prefabricated foot orthoses. Repeated measures ANOVA model with post-hoc, Bonferroni comparison were used to test differences. CAD-CAM and prefabricated foot orthoses both decreased pressure and force under 2nd, 3-5 metatarsal and heel regions comparing to shoe alone condition. CAD-CAM foot orthosis increased pressure under lateral toe region in comparison to shoe alone and prefabricated foot orthosis. Both foot orthoses increased pressure and contact area in medial midfoot region comparing to shoe alone condition. Increased forces were seen at hallux and lateral toes by prefabricated foot orthoses in comparison with CAD-CAM foot orthoses and control condition, respectively. According to the results, both foot orthoses could decrease the pressure under heel and metatarsal area. It seems that the special design of CAD-CAM foot orthoses could not make great differences in plantar pressure distribution in this sample. Further research is required to determine whether these results are associated with different scan systems or design software. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Comparison of Two Methods Used to Model Shape Parameters of Pareto Distributions

    Science.gov (United States)

    Liu, C.; Charpentier, R.R.; Su, J.

    2011-01-01

    Two methods are compared for estimating the shape parameters of Pareto field-size (or pool-size) distributions for petroleum resource assessment. Both methods assume mature exploration in which most of the larger fields have been discovered. Both methods use the sizes of larger discovered fields to estimate the numbers and sizes of smaller fields: (1) the tail-truncated method uses a plot of field size versus size rank, and (2) the log-geometric method uses data binned in field-size classes and the ratios of adjacent bin counts. Simulation experiments were conducted using discovered oil and gas pool-size distributions from four petroleum systems in Alberta, Canada and using Pareto distributions generated by Monte Carlo simulation. The estimates of the shape parameters of the Pareto distributions, calculated by both the tail-truncated and log-geometric methods, generally stabilize where discovered pool numbers are greater than 100. However, with fewer than 100 discoveries, these estimates can vary greatly with each new discovery. The estimated shape parameters of the tail-truncated method are more stable and larger than those of the log-geometric method where the number of discovered pools is more than 100. Both methods, however, tend to underestimate the shape parameter. Monte Carlo simulation was also used to create sequences of discovered pool sizes by sampling from a Pareto distribution with a discovery process model using a defined exploration efficiency (in order to show how biased the sampling was in favor of larger fields being discovered first). A higher (more biased) exploration efficiency gives better estimates of the Pareto shape parameters. ?? 2011 International Association for Mathematical Geosciences.

  10. Workshops Without Walls: broadening access to science around the world.

    Science.gov (United States)

    Arslan, Betül K; Boyd, Eric S; Dolci, Wendy W; Dodson, K Estelle; Boldt, Marco S; Pilcher, Carl B

    2011-08-01

    The National Aeronautics and Space Administration (NASA) Astrobiology Institute (NAI) conducted two "Workshops Without Walls" during 2010 that enabled global scientific exchange--with no travel required. The second of these was on the topic "Molecular Paleontology and Resurrection: Rewinding the Tape of Life." Scientists from diverse disciplines and locations around the world were joined through an integrated suite of collaborative technologies to exchange information on the latest developments in this area of origin of life research. Through social media outlets and popular science blogs, participation in the workshop was broadened to include educators, science writers, and members of the general public. In total, over 560 people from 31 US states and 30 other nations were registered. Among the scientific disciplines represented were geochemistry, biochemistry, molecular biology and evolution, and microbial ecology. We present this workshop as a case study in how interdisciplinary collaborative research may be fostered, with substantial public engagement, without sustaining the deleterious environmental and economic impacts of travel.

  11. Doppler broadening thermometry based on cavity ring-down spectroscopy

    CERN Document Server

    Cheng, C -F; Sun, Y R; Tan, Y; Kang, P; Hu, S -M

    2015-01-01

    A Doppler broadening thermometry (DBT) instrument is built based on cavity ring-down spectroscopy (CRDS) for precise determination of the Boltzmann constant. Compared with conventional direct absorption methods, the high-sensitivity of CRDS allows to reach a satisfied precision at lower sample pressures, which also reduces the influence due to collisions. By recording the spectrum of C$_2$H$_2$ at 787 nm, we demonstrate a statistical uncertainty of 6 ppm (part per million) in the determined linewidth values by several hours' measurement at a sample pressure of 1.5 Pa. The influence on the spectroscopy-determined temperatures has been investigated, including the "hidden" weak lines overlapped with the selected transition for DBT measurements. The reproducibility has also been examined to be better than 10 ppm, and it indicates that the instrument is feasible for DBT measurement toward a precision at the ppm level.

  12. Brillouin resonance broadening due to structural variations in nanoscale waveguides

    CERN Document Server

    Wolff, Christian; Steel, Michael J; Eggleton, Benjamin J; Poulton, Christopher G

    2015-01-01

    We study the impact of structural variations (that is slowly varying geometry aberrations and internal strain fields) on the resonance width and shape of stimulated Brillouin scattering (SBS) in nanoscale waveguides. We find that they lead to an inhomogeneous resonance broadening through two distinct mechanisms: firstly, the acoustic frequency is directly influenced via mechanical nonlinearities; secondly, the optical wave numbers are influenced via the opto-mechanical nonlinearity leading to an additional acoustic frequency shift via the phase-matching condition. We find that this second mechanism is proportional to the opto-mechanical coupling and, hence, related to the SBS-gain itself. It is absent in intra-mode forward SBS, while it plays a significant role in backward scattering. In backward SBS increasing the opto-acoustic overlap beyond a threshold defined by the fabrication tolerances will therefore no longer yield the expected quadratic increase in overall Stokes amplification. Our results can be tra...

  13. E-cigarettes: a need to broaden the debate.

    Science.gov (United States)

    Latif, E; Nair, M

    2016-11-01

    The unregulated market for e-cigarettes continues to grow, with debates on their efficacy and impact on global public health. E-cigarettes, or electronic nicotine delivery systems (ENDs), are marketed as a 'safe' alternative to tobacco products and a tool for 'harm reduction'. Some public health experts are calling it a 'game changer' and favour the 'harm reduction' strategy, while others dispute this claim. In our opinion, the debate needs to be broadened to encompass other related concerns and effects on non-users and affected stakeholders. As with tobacco control, a holistic approach is needed to build a raft of policies that effectively address the issue from all angles and look beyond the direct health implications of e-cigarette use to explore the social, economic, political and environmental aspects of this debate, putting 'harm reduction' in context.

  14. Comparison of hydrological simulations of climate change using perturbation of observations and distribution-based scaling

    DEFF Research Database (Denmark)

    Van Roosmalen, Lieke Petronella G; Sonnenborg, Torben; Jensen, Karsten Høgh

    2011-01-01

    Projected climate change eff ects on groundwater and stream discharges were investigated through simulations with a distributed, physically based, surface water–groundwater model. Input to the hydrological model includes precipitation, reference evapotranspiration, and temperature data...... output, while the other consisted of distribution-based scaling (DBS) of the RCM output. Distributionbased scaling resulted in RCM control period data closely approaching the observed climate data and thereby considerably improved the simulation of recharge and stream discharges. When comparing...... the simulations using both methods, only small differences between the projected changes in hydrological variables for the scenario period were found. Mean annual recharge increased by 15% for the DBS method and 12% for POD, and drain flow increased by 24 and 19%, respectively, while the increases in base flow...

  15. Comparison of frequency distributions of doubled haploid and single seed descent lines in barley.

    Science.gov (United States)

    Choo, T M; Reinbergs, E; Park, S J

    1982-09-01

    Both doubled haploid (DH) and single seed descent (SSD) methods were used to derive homozygous lines from two crosses of barley. The frequency distributions of grain yield, heading date, and plant height of the DH and SSD lines were compared by the Mann-Whitney U test, Kolmogorov-Smirnov twosample test and Wald-Wolfowitz runs test. It was found that the DH lines distributed in the same manner as the SSD lines with respect to the three characters. The results indicated that although the SSD method had more opportunity for recombination than the DH method, it did not produce a sample of recombinants which differed significantly from the DH sample; thus both methods were equally efficient for use in deriving homozygous lines from F1 hybrids in a relatively short time.

  16. Recycling oriented comparison of mercury distribution in new and spent fluorescent lamps and their potential risk.

    Science.gov (United States)

    Hobohm, Julia; Krüger, Oliver; Basu, Srotoswini; Kuchta, Kerstin; van Wasen, Sebastian; Adam, Christian

    2017-02-01

    This study compares the mercury distribution in the vapor phase, the phosphor powder and the glass matrix of new and spent fluorescent lamps. The spent fluorescent lamps were obtained at the collection yards of a public waste management company in Hamburg, Germany. An innovative systematic sampling method is utilized to collect six spent and eight corresponding new, off-the-shelf fluorescent lamp samples. The efficiency of several acid digestion methods for the determination of the elemental composition was studied and elemental mass fractions of K, Na, Y, Ca, Ba, Eu, Al, Pb, Mg, Hg, and P were measured. The study also finds aqua regia to be the best reagent for acid digestion. However, no significant difference in mercury distribution was found in the different phases of the new and spent fluorescent lamps. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Comparison of the Frontier Distributed Database Caching System to NoSQL Databases

    Science.gov (United States)

    Dykstra, Dave

    2012-12-01

    One of the main attractions of non-relational “NoSQL” databases is their ability to scale to large numbers of readers, including readers spread over a wide area. The Frontier distributed database caching system, used in production by the Large Hadron Collider CMS and ATLAS detector projects for Conditions data, is based on traditional SQL databases but also adds high scalability and the ability to be distributed over a wide-area for an important subset of applications. This paper compares the major characteristics of the two different approaches and identifies the criteria for choosing which approach to prefer over the other. It also compares in some detail the NoSQL databases used by CMS and ATLAS: MongoDB, CouchDB, HBase, and Cassandra.

  18. Comparison of the Frontier Distributed Database Caching System with NoSQL Databases

    CERN Document Server

    Dykstra, David

    2012-01-01

    One of the main attractions of non-relational "NoSQL" databases is their ability to scale to large numbers of readers, including readers spread over a wide area. The Frontier distributed database caching system, used in production by the Large Hadron Collider CMS and ATLAS detector projects for Conditions data, is based on traditional SQL databases but also has high scalability and wide-area distributability for an important subset of applications. This paper compares the major characteristics of the two different approaches and identifies the criteria for choosing which approach to prefer over the other. It also compares in some detail the NoSQL databases used by CMS and ATLAS: MongoDB, CouchDB, HBase, and Cassandra.

  19. Extreme rainfall distribution mapping: Comparison of two approaches in West Africa

    Science.gov (United States)

    Panthou, G.; Vischel, T.; Lebel, T.; Blanchet, J.; Quantin, G.; Ali, A.

    2012-12-01

    In a world where populations are increasingly exposed to natural hazards, extreme rainfall mapping remains an important subject of research. Extreme rainfall maps are required for both flood risk management and civil engineering structure design, the challenge being to take into account the local information provided by point rainfall series as well as the necessity of some regional coherency. Such a coherency is not guaranteed when extreme value distributions are fitted separately to individual maximum rainfall series. Two approaches based on the extreme value theory (Block Maxima Analysis) are compared here, with an application to extreme rainfall mapping in West Africa. Annual daily rainfall maxima are extracted from rain-gauges series and modeled over the study region by GEV (Generalized Extreme Value) distributions. These two approaches are the following: (i) The Local Fit and Interpolation (LFI) approach which consists of a spatial interpolation of the GEV distribution parameters estimated independently at each raingauge serie. (ii) The Spatial Maximum Likelihood Estimation (SMLE) which directly estimates the GEV distribution over the entire region by a single maximum likelihood fit using jointly all measurements combined with spatial covariates. Five LFI and three SMLE methods are considered, using the information provided by 126 daily rainfall series covering the period 1950-1990. The methods are first evaluated in calibration. Then the predictive skills and the robustness are assessed through a cross validation and an independent network validation process. The SMLE approach, especially when using the mean annual rainfall as covariate, appears to perform better for most of the scores computed. Using a reference series of 104 years of daily data recorded at Niamey (Niger), it is also shown that the SMLE approach has the capacity to deal more efficiently with the effect of local outliers by using the spatial information provided by nearby stations.

  20. Comparison Of Mercury Distribution Between The Types Of Spent Fluorescent Lamp

    OpenAIRE

    Rhee S.W.; Park H.-S.; Choi H.H.

    2015-01-01

    Spent fluorescent lamps(SFLs) such as linear type lamp, compact type lamp and U-type lamp are used to estimate mercury distribution in the components of lamps. Determination of mercury concentration in the components of spent fluorescent lamp is performed by the DMA method. Mercury concentration in the components of spent fluorescent lamp can be varied with the manufactures of lamp. Mercury portion in phosphor powder and glass from any types of spent fluorescent lamp is estimated to be higher...

  1. State-Level Comparison of Processes and Timelines for Distributed Photovoltaic Interconnection in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Ardani, K. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Davidson, C. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Margolis, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Nobler, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-01-01

    This report presents results from an analysis of distributed photovoltaic (PV) interconnection and deployment processes in the United States. Using data from more than 30,000 residential (up to 10 kilowatts) and small commercial (10-50 kilowatts) PV systems, installed from 2012 to 2014, we assess the range in project completion timelines nationally (across 87 utilities in 16 states) and in five states with active solar markets (Arizona, California, New Jersey, New York, and Colorado).

  2. Claudin-1, -2, -4, and -5: comparison of expression levels and distribution in equine tissues

    OpenAIRE

    Lee, Bonn; Kang, Hee Young; Lee, Dong Oh; Ahn, Changhwan; Jeung, Eui-Bae

    2016-01-01

    Claudins, which are known as transmembrane proteins play an essential role in tight junctions (TJs) to form physical barriers and regulate paracellular transportation. To understand equine diseases, it is helpful to measure the tissue-specific expression of TJs in horses. Major equine diseases such as colic and West Nile cause damage to TJs. In this study, the expression level and distribution of claudin-1, -2, -4, and -5 in eight tissues were assessed by Western blotting and immunohistochemi...

  3. The histology of ovarian cancer: worldwide distribution and implications for international survival comparisons (CONCORD-2).

    Science.gov (United States)

    Matz, Melissa; Coleman, Michel P; Sant, Milena; Chirlaque, Maria Dolores; Visser, Otto; Gore, Martin; Allemani, Claudia

    2017-02-01

    Ovarian cancers comprise several histologically distinct tumour groups with widely different prognosis. We aimed to describe the worldwide distribution of ovarian cancer histology and to understand what role this may play in international variation in survival. The CONCORD programme is the largest population-based study of global trends in cancer survival. Data on 681,759 women diagnosed during 1995-2009 with cancer of the ovary, fallopian tube, peritoneum and retroperitonum in 51 countries were included. We categorised ovarian tumours into six histological groups, and explored the worldwide distribution of histology. During 2005-2009, type II epithelial tumours were the most common. The proportion was much higher in Oceania (73.1%), North America (73.0%) and Europe (72.6%) than in Central and South America (65.7%) and Asia (56.1%). By contrast, type I epithelial tumours were more common in Asia (32.5%), compared with only 19.4% in North America. From 1995 to 2009, the proportion of type II epithelial tumours increased from 68.6% to 71.1%, while the proportion of type I epithelial tumours fell from 23.8% to 21.2%. The proportions of germ cell tumours, sex cord-stromal tumours, other specific non-epithelial tumours and tumours of non-specific morphology all remained stable over time. The distribution of ovarian cancer histology varies widely worldwide. Type I epithelial, germ cell and sex cord-stromal tumours are generally associated with higher survival than type II tumours, so the proportion of these tumours may influence survival estimates for all ovarian cancers combined. The distribution of histological groups should be considered when comparing survival between countries and regions. Copyright © 2016. Published by Elsevier Inc.

  4. Comparison of retention and stability of implant-retained overdentures based upon implant number and distribution.

    Science.gov (United States)

    Scherer, Michael D; McGlumphy, Edwin A; Seghi, Robert R; Campagni, Wayne V

    2013-01-01

    The purpose of this investigation was to evaluate the effects of number and distribution of implants upon in vitro dislodging forces to a simulated implant-supported overdenture and to examine differences between several different attachment systems. An experiment was undertaken utilizing a model simulating a mandibular edentulous ridge with dental implants in positions on the model approximating tooth positions in the natural dentition. A cobalt-chromium-cast testing framework was used to measure the peak load required to disconnect an attachment. Four different types of commercially available attachments were used in various positions on the model in sequence to evaluate the effects of retention and stability of overdentures based on implant number and distribution: (1) ERA, (2) O-Ring, (3) Locator, and (4) Ball. For each group, 10 measurements were made of peak dislodging forces. Means were calculated and differences among the systems, directions, and groups were identified using a repeated measured analysis of variance (α = .05). The interactions between the attachment system, direction of force, and implant number and distribution were statistically significant. Vertical dislodging forces of the simulated overdenture prosthesis increased with additional widely spaced implants. Oblique dislodging forces of the simulated prosthesis increased with additional widely spaced implants except in the two-implant model with all attachments, and in the four-implant groups with Locator attachments. Anteroposterior dislodging forces of a simulated overdenture prosthesis increased with additional widely spaced implants except in the four-implant groups with Ball and Locator attachments. Ball attachments reported the highest levels of retention and stability followed by Locator, O-Ring, and ERA. Within the limitations of this study, retention and stability of an implant overdenture prosthesis are significantly affected by implant number, implant distribution, and abutment

  5. Comparison of High-Fidelity Computational Tools for Wing Design of a Distributed Electric Propulsion Aircraft

    Science.gov (United States)

    Deere, Karen A.; Viken, Sally A.; Carter, Melissa B.; Viken, Jeffrey K.; Derlaga, Joseph M.; Stoll, Alex M.

    2017-01-01

    A variety of tools, from fundamental to high order, have been used to better understand applications of distributed electric propulsion to aid the wing and propulsion system design of the Leading Edge Asynchronous Propulsion Technology (LEAPTech) project and the X-57 Maxwell airplane. Three high-fidelity, Navier-Stokes computational fluid dynamics codes used during the project with results presented here are FUN3D, STAR-CCM+, and OVERFLOW. These codes employ various turbulence models to predict fully turbulent and transitional flow. Results from these codes are compared for two distributed electric propulsion configurations: the wing tested at NASA Armstrong on the Hybrid-Electric Integrated Systems Testbed truck, and the wing designed for the X-57 Maxwell airplane. Results from these computational tools for the high-lift wing tested on the Hybrid-Electric Integrated Systems Testbed truck and the X-57 high-lift wing presented compare reasonably well. The goal of the X-57 wing and distributed electric propulsion system design achieving or exceeding the required ?? (sub L) = 3.95 for stall speed was confirmed with all of the computational codes.

  6. A comparison of the grip force distribution in natural hands and in prosthetic hands.

    Science.gov (United States)

    Kargov, Artem; Pylatiuk, Christian; Martin, Jan; Schulz, Stefan; Döderlein, Leonhard

    2004-06-17

    The aim of this study is to analyse the grip force distribution for different prosthetic hand designs and the human hand fulfilling a functional task. A cylindrical object is held with a power grasp and the contact forces are measured at 20 defined positions. The distributions of contact forces in standard electric prostheses, in a experimental prosthesis with an adaptive grasp, and in human hands as a reference are analysed and compared. Additionally, the joint torques are calculated and compared. Contact forces of up to 24.7 N are applied by the middle and distal phalanges of the index finger, middle finger, and thumb of standard prosthetic hands, whereas forces of up to 3.8 N are measured for human hands. The maximum contact forces measured in a prosthetic hand with an adaptive grasp are 4.7 N. The joint torques of human hands and the adaptive prosthesis are comparable. The analysis of grip force distribution is proposed as an additional parameter to rate the performance of different prosthetic hand designs.

  7. A comparison of conventional and radio frequency tempering of beef meats: Effects on product temperature distribution.

    Science.gov (United States)

    Farag, K W; Lyng, J G; Morgan, D J; Cronin, D A

    2008-10-01

    This study aimed to develop radio frequency (RF) pilot-scale protocols for tempering beef meat blends (4kg blocks) to achieve average temperatures between -2 and -5°C. Post-tempering temperature distribution in these blocks was compared to products tempered by conventional methods. The optimum RF power-time combination for tempering lean and 50:50 lean:fat mixtures to the target range was 500W for 11min which produced respective means of -3.6°C (s.d. 1.1) and -3.4°C (s.d. 1.5). In contrast, 400W for 11min was optimum for fat (mean -4.9°C, s.d. 2.1). This study shows the principal advantages of RF over conventional tempering as an approximate 30 fold tempering time reduction and a greater uniformity of end point temperature distribution under the conditions employed. Furthermore, power consumption was reduced approximately ninefold with RF compared to conventional tempering. More uniform temperature distribution was achieved in samples that were comminuted to a greater extent.

  8. Comparison of biofilm cell quantification methods for drinking water distribution systems.

    Science.gov (United States)

    Waller, Sharon A; Packman, Aaron I; Hausner, Martina

    2018-01-01

    Drinking water quality typically degrades after treatment during conveyance through the distribution system. Potential causes include biofilm growth in distribution pipes which may result in pathogen retention, inhibited disinfectant diffusion, and proliferation of bad tastes and odors. However, there is no standard method for direct measurement of biofilms or quantification of biofilm cells in drinking water distribution systems. Three methods are compared here for quantification of biofilm cells grown in pipe loops samplers: biofilm heterotrophic plate count (HPC), biofilm biovolume by confocal laser scanning microscopy (CLSM) and biofilm total cell count by flow cytometry (FCM) paired with Syto 9. Both biofilm biovolume by CLSM and biofilm total cell count by FCM were evaluated for quantification of the whole biofilms (including non-viable cells and viable but not culturable cells). Signal-to-background ratios and overall performance of biofilm biovolume by CLSM and biofilm total cell count by FCM were found to vary with the pipe material. Biofilm total cell count by FCM had a low signal-to-background ratio on all materials, indicating that further development is recommended before application in drinking water environments. Biofilm biovolume by CLSM showed the highest signal-to-background ratio for cement and cast iron, which suggests promise for wider application in full-scale systems. Biofilm biovolume by CLSM and Syto 9 staining allowed in-situ biofilm cell quantification thus elimination variable associated with cell detachment for quantification but had limitations associated with non-specific staining of cement and, to a lesser degree, auto-fluorescence of both cement and polyvinyl chloride materials. Due to variability in results obtained from each method, multiple methods are recommended to assess biofilm growth in drinking water distribution systems. Of the methods investigated here, HPC and CLSM and recommended for further development towards

  9. Optimizing intrapulmonary perfluorocarbon distribution: fluoroscopic comparison of mode of ventilation and body position.

    Science.gov (United States)

    Bateman, S T; Doctor, A; Price, B; Murphy, M A; Thompson, J E; Zurakowski, D; Taylor, G A; Arnold, J H

    2001-03-01

    Partial liquid ventilation with the perfluorochemical, perflubron, has been shown to improve lung mechanics and enhance gas exchange in the treatment of severe acute lung injury. However, the most effective strategy to provide optimal intrapulmonary distribution of perflubron has not been fully accessed. The objective of this study was to examine the effect of body position (supine vs. rotational) and mode of ventilation (conventional mechanical ventilation [CMV] vs. high-frequency oscillatory ventilation [HFOV]) on perflubron distribution and oxygenation improvement. Prospective, randomized, animal trial. Research laboratory at a university medical center. Twenty healthy piglets (4.5-6.6 kg). Subjects underwent repetitive saline lavage to achieve a uniform degree of lung injury and then were randomized to either CMV or were converted to HFOV. Within each ventilator group, animals were randomized to supine positioning (S) or rotational positioning with alternation between supine and prone position (R) during incremental dosing of three 5-mL/kg doses of perflubron. Arterial blood gas tensions, hemodynamic variables, and the oxygenation index were recorded after each dose of 5 mL/kg. Lateral cinefluoroscopic images after each dose were digitized for computer analysis of density. A density index was calculated for a 2-cm2 window in three dorsal and three ventral lung regions. Uniformity of distribution was calculated by comparing the mean density among the six regions. Oxygenation improvements were compared between groups. There were no significant differences in hemodynamic variables or gas exchange after lung injury in the four groups. Rotational positioning produced significantly more uniform perflubron distribution during both CMV and HFOV. This effect was independent of the mode of ventilation. The mean ventral density index was affected by rotating position and HFOV mode of ventilation after 10 mL/kg of perflubron, and rotating position was affected only after

  10. Genome-wide comparison of ferritin family from Archaea, Bacteria, Eukarya, and Viruses: its distribution, characteristic motif, and phylogenetic relationship

    Science.gov (United States)

    Bai, Lina; Xie, Ting; Hu, Qingqing; Deng, Changyan; Zheng, Rong; Chen, Wanping

    2015-10-01

    Ferritins are highly conserved proteins that are widely distributed in various species from archaea to humans. The ubiquitous characteristic of these proteins reflects the pivotal contribution of ferritins to the safe storage and timely delivery of iron to achieve iron homeostasis. This study investigated the ferritin genes in 248 genomes from various species, including viruses, archaea, bacteria, and eukarya. The distribution comparison suggests that mammals and eudicots possess abundant ferritin genes, whereas fungi contain very few ferritin genes. Archaea and bacteria show considerable numbers of ferritin genes. Generally, prokaryotes possess three types of ferritin (the typical ferritin, bacterioferritin, and DNA-binding protein from starved cell), whereas eukaryotes have various subunit types of ferritin, thereby indicating the individuation of the ferritin family during evolution. The characteristic motif analysis of ferritins suggested that all key residues specifying the unique structural motifs of ferritin are highly conserved across three domains of life. Meanwhile, the characteristic motifs were also distinguishable between ferritin groups, especially phytoferritins, which show a plant-specific motif. The phylogenetic analyses show that ferritins within the same subfamily or subunits are generally clustered together. The phylogenetic relationships among ferritin members suggest that both gene duplication and horizontal transfer contribute to the wide variety of ferritins, and their possible evolutionary scenario was also proposed. The results contribute to a better understanding of the distribution, characteristic motif, and evolutionary relationship of the ferritin family.

  11. Comparison of simulated and experimental results of temperature distribution in a closed two-phase thermosyphon cooling system

    Science.gov (United States)

    Shaanika, E.; Yamaguchi, K.; Miki, M.; Ida, T.; Izumi, M.; Murase, Y.; Oryu, T.; Yanamoto, T.

    2017-12-01

    Superconducting generators offer numerous advantages over conventional generators of the same rating. They are lighter, smaller and more efficient. Amongst a host of methods for cooling HTS machinery, thermosyphon-based cooling systems have been employed due to their high heat transfer rate and near-isothermal operating characteristics associated with them. To use them optimally, it is essential to study thermal characteristics of these cryogenic thermosyphons. To this end, a stand-alone neon thermosyphon cooling system with a topology resembling an HTS rotating machine was studied. Heat load tests were conducted on the neon thermosyphon cooling system by applying a series of heat loads to the evaporator at different filling ratios. The temperature at selected points of evaporator, adiabatic tube and condenser as well as total heat leak were measured. A further study involving a computer thermal model was conducted to gain further insight into the estimated temperature distribution of thermosyphon components and heat leak of the cooling system. The model employed boundary conditions from data of heat load tests. This work presents a comparison between estimated (by model) and experimental (measured) temperature distribution in a two-phase cryogenic thermosyphon cooling system. The simulation results of temperature distribution and heat leak compared generally well with experimental data.

  12. Conversion of Chord Length Data into Bubble Size Distribution: Generation of Chord Length Data and the Methodology Comparison

    Energy Technology Data Exchange (ETDEWEB)

    Hien, Hoang Nhan; Euh, D. J.; Song, C. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Yun, B. J. [Pusan National University, Busan (Korea, Republic of)

    2012-05-15

    Bubble size and its distribution play an important role in thermal hydrodynamic processes in multiphase flow systems. By using the conductivity or optical probe techniques, the size and distribution of bubbles can only be inferred indirectly from a measured chord length data (CLD). Some methods are proposed to convert a CLD into the bubble size distribution (BSD), and they can be classified into parametric, semi-parametric and non-parametric. Most of methods are derived from the following relation of the conditional probability functions that are established under the geometric constraints: P(y) = {infinity}{integral}0 P(R) P(y|R) dR where P(R) is PDF of bubbles of all sizes R pierced by a probe, and P(y|R) is PDF of chord length y corresponding to bubbles of a specified size R. These methods are limited to flows of bubbles having symmetric shapes, i.e. spherical, ellipsoidal, or capspherical. Although the methods were developed from a common relation, there are no physical bases as well as the lack of experimental data to validate them. In this work, the CLD is generated for comparing different conversion methods. The range of bubble size is determined by the Hinze's theory. The CLDs are applied to numerical backward transforms (NBT), analytical backward transform (ABT), and analytical semi-parametric method using Parzen window estimator (ParzenES) to obtain the BSD. A comparison for the obtained results is performed

  13. Inter-comparison of Dose Distributions Calculated by FLUKA, GEANT4, MCNP, and PHITS for Proton Therapy

    Science.gov (United States)

    Yang, Zi-Yi; Tsai, Pi-En; Lee, Shao-Chun; Liu, Yen-Chiang; Chen, Chin-Cheng; Sato, Tatsuhiko; Sheu, Rong-Jiun

    2017-09-01

    The dose distributions from proton pencil beam scanning were calculated by FLUKA, GEANT4, MCNP, and PHITS, in order to investigate their applicability in proton radiotherapy. The first studied case was the integrated depth dose curves (IDDCs), respectively from a 100 and a 226-MeV proton pencil beam impinging a water phantom. The calculated IDDCs agree with each other as long as each code employs 75 eV for the ionization potential of water. The second case considered a similar condition of the first case but with proton energies in a Gaussian distribution. The comparison to the measurement indicates the inter-code differences might not only due to different stopping power but also the nuclear physics models. How the physics parameter setting affect the computation time was also discussed. In the third case, the applicability of each code for pencil beam scanning was confirmed by delivering a uniform volumetric dose distribution based on the treatment plan, and the results showed general agreement between each codes, the treatment plan, and the measurement, except that some deviations were found in the penumbra region. This study has demonstrated that the selected codes are all capable of performing dose calculations for therapeutic scanning proton beams with proper physics settings.

  14. Inter-comparison of Dose Distributions Calculated by FLUKA, GEANT4, MCNP, and PHITS for Proton Therapy

    Directory of Open Access Journals (Sweden)

    Yang Zi-Yi

    2017-01-01

    Full Text Available The dose distributions from proton pencil beam scanning were calculated by FLUKA, GEANT4, MCNP, and PHITS, in order to investigate their applicability in proton radiotherapy. The first studied case was the integrated depth dose curves (IDDCs, respectively from a 100 and a 226-MeV proton pencil beam impinging a water phantom. The calculated IDDCs agree with each other as long as each code employs 75 eV for the ionization potential of water. The second case considered a similar condition of the first case but with proton energies in a Gaussian distribution. The comparison to the measurement indicates the inter-code differences might not only due to different stopping power but also the nuclear physics models. How the physics parameter setting affect the computation time was also discussed. In the third case, the applicability of each code for pencil beam scanning was confirmed by delivering a uniform volumetric dose distribution based on the treatment plan, and the results showed general agreement between each codes, the treatment plan, and the measurement, except that some deviations were found in the penumbra region. This study has demonstrated that the selected codes are all capable of performing dose calculations for therapeutic scanning proton beams with proper physics settings.

  15. Genome-wide comparison of ferritin family from Archaea, Bacteria, Eukarya, and Viruses: its distribution, characteristic motif, and phylogenetic relationship.

    Science.gov (United States)

    Bai, Lina; Xie, Ting; Hu, Qingqing; Deng, Changyan; Zheng, Rong; Chen, Wanping

    2015-10-01

    Ferritins are highly conserved proteins that are widely distributed in various species from archaea to humans. The ubiquitous characteristic of these proteins reflects the pivotal contribution of ferritins to the safe storage and timely delivery of iron to achieve iron homeostasis. This study investigated the ferritin genes in 248 genomes from various species, including viruses, archaea, bacteria, and eukarya. The distribution comparison suggests that mammals and eudicots possess abundant ferritin genes, whereas fungi contain very few ferritin genes. Archaea and bacteria show considerable numbers of ferritin genes. Generally, prokaryotes possess three types of ferritin (the typical ferritin, bacterioferritin, and DNA-binding protein from starved cell), whereas eukaryotes have various subunit types of ferritin, thereby indicating the individuation of the ferritin family during evolution. The characteristic motif analysis of ferritins suggested that all key residues specifying the unique structural motifs of ferritin are highly conserved across three domains of life. Meanwhile, the characteristic motifs were also distinguishable between ferritin groups, especially phytoferritins, which show a plant-specific motif. The phylogenetic analyses show that ferritins within the same subfamily or subunits are generally clustered together. The phylogenetic relationships among ferritin members suggest that both gene duplication and horizontal transfer contribute to the wide variety of ferritins, and their possible evolutionary scenario was also proposed. The results contribute to a better understanding of the distribution, characteristic motif, and evolutionary relationship of the ferritin family.

  16. Pressure-induced shift and broadening of acetylene lines in the region 6580-6600 cm-1.

    Science.gov (United States)

    Nadezhdinskii, A I; Ponurovskii, Ya Ya

    2007-04-01

    Highly accurate measurements of pressure shift and broadening parameters of acetylene absorption lines in the region 6580-6600 cm-1 have been performed by tunable diode laser spectroscopy (TDLS). For these purposes the three channel spectrometer with distributed-feedback diode laser, operated at 1.53 microm was used. The laser is generating pulses of 4-10 ms duration at a repetition frequency of 40 Hz. A temperature-stabilization system, using a thermoelectric cooling unit affords a temperature stability of the order of 10(-4)K in the temperature range from -15 to +50 degrees C. A three channels acquisition system ensured simultaneous real time recording of the sample gas absorption spectrum and of two spectral calibration signals (Fabry-Perot fringes and low-pressure reference lines). We have measured the pressure-induced self-shift and broadening coefficients for six lines of the R-branch in the nu1+nu3 rotation-vibration band of acetylene 12C2H2. The self-shift coefficients have been determined for these lines in the wide pressure region. A non-linear behavior of the pressure dependence of the shift was observed. The temperature exponent n of pressure-induced broadening and shift are reported.

  17. Comparison of measured and simulated fast ion velocity distributions in the TEXTOR tokamak

    DEFF Research Database (Denmark)

    Moseev, Dmitry; Meo, Fernando; Korsholm, Søren Bang

    2011-01-01

    Here we demonstrate a comprehensive comparison of collective Thomson scattering (CTS) measurements with steady-state Monte Carlo simulations performed with the ASCOT and VENUS codes. The measurements were taken at a location on the magnetic axis as well as at an off-axis location, using two...... projection directions at each location. The simulations agree with the measurements on-axis, but for the off-axis geometries discrepancies are observed for both projection directions. For the near perpendicular projection direction with respect to the magnetic field, the discrepancies between measurement...... and simulations can be explained by uncertainty in plasma parameters. However, the discrepancies between measurement and simulations for the more parallel projection direction cannot be explained solely by uncertainties in plasma parameters. Here anomalous fast ion transport is a possible explanation...

  18. Comparison of monthly rain rates derived from GPI and SSM/I using probability distribution functions

    Science.gov (United States)

    Chiu, Long S.; Chang, Alfred T. C.; Janowiak, John

    1993-01-01

    Three years of monthly rain rates over 5 deg x 5 deg latitude-longitude boxes have been calculated for oceanic regions 50 deg N-50 deg S from measurements taken by the Special Sensor Microwave/Imager on board the Defense Meteorological Satellite Program satellites using the technique developed by Wilheit et al. (1987, 1991). The annual and seasonal zonal-mean rain rates are larger than Jaeger's (1983) climatological estimates but are smaller than those estimated from the GOES precipitation index (GPI) for the same period. Regional comparison with the GPI showed that these rain rates are smaller in the north Indian Ocean and in the southern extratropics where the GPI is known to overestimate. The differences are also dominated by a jump at 170 deg W in the GPI rain rates across the mid-Pacific Ocean. This jump is attributed to the fusion of different satellite measurements in producing the GPI.

  19. Species distribution models: A comparison of statistical approaches for livestock and disease epidemics.

    Science.gov (United States)

    Hollings, Tracey; Robinson, Andrew; van Andel, Mary; Jewell, Chris; Burgman, Mark

    2017-01-01

    In livestock industries, reliable up-to-date spatial distribution and abundance records for animals and farms are critical for governments to manage and respond to risks. Yet few, if any, countries can afford to maintain comprehensive, up-to-date agricultural census data. Statistical modelling can be used as a proxy for such data but comparative modelling studies have rarely been undertaken for livestock populations. Widespread species, including livestock, can be difficult to model effectively due to complex spatial distributions that do not respond predictably to environmental gradients. We assessed three machine learning species distribution models (SDM) for their capacity to estimate national-level farm animal population numbers within property boundaries: boosted regression trees (BRT), random forests (RF) and K-nearest neighbour (K-NN). The models were built from a commercial livestock database and environmental and socio-economic predictor data for New Zealand. We used two spatial data stratifications to test (i) support for decision making in an emergency response situation, and (ii) the ability for the models to predict to new geographic regions. The performance of the three model types varied substantially, but the best performing models showed very high accuracy. BRTs had the best performance overall, but RF performed equally well or better in many simulations; RFs were superior at predicting livestock numbers for all but very large commercial farms. K-NN performed poorly relative to both RF and BRT in all simulations. The predictions of both multi species and single species models for farms and within hypothetical quarantine zones were very close to observed data. These models are generally applicable for livestock estimation with broad applications in disease risk modelling, biosecurity, policy and planning.

  20. Thermal stress comparison in modular power converter topologies for smart transformers in the electrical distribution system

    DEFF Research Database (Denmark)

    Andresen, Markus; Ma, Ke; Liserre, Marco

    2015-01-01

    A Smart Transformer (ST) can cover an important managing role in the future electrical distribution grid. For the moment, the reliability and cost are not competitive with traditional transformers and create a barrier for its application. This work conduct detail designs and analysis...... for a promising modular ST solution, which is composed of Modular Multi-level converter, Quad Active Bridge DC-DC converters, and two-level voltage source converters. The focus is put on the loading conditions and thermal stress of power semiconductor devices in order to discover critical parts of the whole...

  1. Comparison of residential window distributions and effects of mass and insulation

    Science.gov (United States)

    Hannifan, M.; Christensen, C.; Perkins, R.

    1981-07-01

    The energy requirements and comfort implications of various window distributions and window areas (representing conventional, sun-tempered, and passive solar designs) are investigated for single-family residences in Albuquerque, NM, Denver, CO, and Madison, WI. Three distinct mass levels ranging from lightweight to heavyweight interiors and three distinct insulations levels, including energy-conserving, night-insulated, and superinsulated cases, are analyzed. Energy requirements are reported for residences with electric resistance heating and mechanical air conditioning. Comfort conditions reported are based on interior average air temperatures and mean-squared errors.

  2. KURTOSIS CORRECTION METHOD FOR VARIABLE CONTROL CHARTS - A COMPARISON IN LAPLACE DISTRIBUTION

    Directory of Open Access Journals (Sweden)

    Metlapalli Chaitanya Priya

    2010-12-01

    Full Text Available A variable quality characteristic is assumed to follow the well known Laplace Distribution. Control chart constants for the process mean, process dispersion based on a number of sub group statistics including sub group mean and range are evaluated from the first principles. Limits obtained through kurtosis correction method are borrowed from Tadikamalla and Popescu (2003. The performance of these sets of control limits is compared through a simulation study and the relative preferences are arrived at. The methods are illustrated by an example.

  3. Intermethod comparison of the particle size distributions of colloidal silica nanoparticles.

    Science.gov (United States)

    Tuoriniemi, Jani; Johnsson, Ann-Cathrin J H; Holmberg, Jenny Perez; Gustafsson, Stefan; Gallego-Urrea, Julián A; Olsson, Eva; Pettersson, Jan B C; Hassellöv, Martin

    2014-06-01

    There can be a large variation in the measured diameter of nanoparticles depending on which method is used. In this work, we have strived to accurately determine the mean particle diameter of 30-40 nm colloidal silica particles by using six different techniques. A quantitative agreement between the particle size distributions was obtained by scanning electron microscopy (SEM), and electrospray-scanning mobility particle sizer (ES-SMPS). However, transmission electron microscopy gave a distribution shifted to smaller sizes. After confirming that the magnification calibration was consistent, this was attributed to sample preparation artifacts. The hydrodynamic diameter, d h , was determined by dynamic light scattering (DLS) both in batch mode, and hyphenated with sedimentation field flow fractionation. Surprisingly the d h were smaller than the SEM, and ES-SMPS diameters. A plausible explanation for the smaller sizes found with DLS is that a permeable gel layer forms on the particle surface. Results from nanoparticle tracking analysis were strongly biased towards larger diameters, most likely because the silica particles provide low refractive index contrast. Calculations confirmed that the sensitivity is, depending on the shape of the laser beam, strongly size dependent for particles with diameters close to the visualization limit.

  4. Spatial distribution of the daily rainfall concentration index in Argentina: comparison with other countries

    Science.gov (United States)

    Llano, María Paula

    2017-08-01

    The precipitation is a meteorological variable studied in Argentina mainly in annual, seasonal and monthly scales. Its variability is a significant climate element and also a critical socioeconomic factor. This study aims to contribute to the knowledge of daily rainfall in Argentina. Daily records of precipitation for 66 stations provided by the Servicio Meteorológico Nacional are used (period 1991-2014). The spatial distribution of the annual precipitation presents an east-west gradient in the north of the country. In monthly scale, there are different precipitation distributions such as a double maximum in the centre-east zone or a single maximum in the northwest in summer time and in the southern Andes range during the winter. To carry out the study, the concentration index (CI) of daily precipitation with a resolution of 1 mm is used. Precipitation in Argentina, given its vast territory, presents a great variability with a wide range of rainfall regimes; CI values are found between 0.54 and 0.68. These values are categorized as high (greater than 0.61) and low (less than 0.58). The north of the country and the Atlantic coast show the highest CI values. The lower values are present in the Andes range and in the south of the country. The results are compared with other studies in the world.

  5. Gamma-ray Burst Formation Environment: Comparison of Redshift Distributions of GRB Afterglows

    Directory of Open Access Journals (Sweden)

    Sung-Eun Kim

    2005-12-01

    Full Text Available Since gamma-ray bursts(GRBs have been first known to science societites in 1973, many scientists are involved in their studies. Observations of GRB afterglows provide us with much information on the environment in which the observed GRBs are born. Study of GRB afterglows deals with longer timescale emissions in lower energy bands (e.g., months or even up to years than prompt emissions in gamma-rays. Not all the bursts accompany afterglows in whole ranges of wavelengths. It has been suggested as a reason for that, for instance, that radio and/or X-ray afterglows are not recorded mainly due to lower sensitivity of detectors, and optical afterglows due to extinctions in intergalactic media or self-extinctions within a host galaxy itself. Based on the idea that these facts may also provide information on the GRB environment, we analyze statistical properties of GRB afterglows. We first select samples of the redshift-known GRBs according to the wavelength of afterglow they accompanied. We then compare their distributions as a function of redshift, using statistical methods. As a results, we find that the distribution of the GRBs with X-ray afterglows is consistent with that of the GRBs with optical afterglows. We, therefore, conclude that the lower detection rate of optical afterglows is not due to extinctions in intergalactic media.

  6. Distributional effects of flood risk management - a cross-country comparison of preflood compensation

    Directory of Open Access Journals (Sweden)

    Willemijn J. van Doorn-Hoekveld

    2016-12-01

    Full Text Available We seek to examine the manner in which either the EU member states of France, the Netherlands, Poland, and Sweden or parts of them, such as the country of England in the UK or the Flemish Region in Belgium, deal with the distributional effects of the flood risk management strategies prevention, defense, and mitigation. Measures carried out in each of these strategies can cause preflood harm, as in the devaluation of property or loss of income. However, different member states and authorities address this harm in different ways. A descriptive overview of the different compensation regimes in the field of flood risk management is followed by an analysis of these differences and an explanation of what may cause them, such as the geographical differences that lead to differences in the way that they interfere with private rights and the dominant legal principles that underlie compensation regimes. An elaborated compensation regime could lead to more equitable and legitimate flood risk management because the burdens are fairly spread and all interests - including those of injured parties - are considered in the decision-making process. Our aim is to stimulate the hardly existent discussion on the financial harm that is caused by measures to prevent floods (preflood, in addition to the already existing discussion on the ex post flood distributional effects.

  7. Cost comparison of unit dose and traditional drug distribution in a long-term-care facility.

    Science.gov (United States)

    Lepinski, P W; Thielke, T S; Collins, D M; Hanson, A

    1986-11-01

    Unit dose and traditional drug distribution systems were compared in a 352-bed long-term-care facility by analyzing nursing time, medication-error rate, medication costs, and waste. Time spent by nurses in preparing, administering, charting, and other tasks associated with medications was measured with a stop-watch on four different nursing units during six-week periods before and after the nursing home began using unit dose drug distribution. Medication-error rate before and after implementation of the unit dose system was determined by patient profile audits and medication inventories. Medication costs consisted of patient billing costs (acquisition cost plus fee) and cost of medications destroyed. The unit dose system required a projected 1507.2 hours less nursing time per year. Mean medication-error rates were 8.53% and 0.97% for the traditional and unit dose systems, respectively. Potential annual savings because of decreased medication waste with the unit dose system were $2238.72. The net increase in cost for the unit dose system was estimated at $615.05 per year, or approximately $1.75 per patient. The unit dose system appears safer and more time-efficient than the traditional system, although its costs are higher.

  8. Comparison of cancer stage distribution in the immigrant and host populations of Norway, 1990-2014.

    Science.gov (United States)

    Thøgersen, Håvard; Møller, Bjørn; Robsahm, Trude Eid; Aaserud, Stein; Babigumira, Ronnie; Larsen, Inger Kristin

    2017-07-01

    Cancer stage at diagnosis is the most important prognostic factor for survival. We conducted a nationwide, population-based cohort study to investigate cancer stage distribution in immigrants compared to the host population of Norway. All patients recorded in the Cancer Registry of Norway in 1990-2014 were included (17,709 immigrants and 431,936 Norwegians). Individual level sociodemographic data was obtained from Statistics Norway. Ordered logistic regression was used to estimate if immigrants were diagnosed with cancer at a more advanced stage than Norwegians. Seven cancer sites were analyzed (breast, cervix, colorectal, liver, lung and trachea, prostate and stomach). With exception of breast cancer, we did not observe a clear pattern of more advanced cancer stage distribution in immigrants compared to Norwegians. Odds ratios and corresponding 95% confidence intervals for being diagnosed with a more advanced stage of breast cancer for non-Western immigrant groups compared to Norwegians were: Eastern Europe: 1.41 (1.20-1.65), Middle East: 1.58 (1.19-2.10), sub-Saharan Africa: 1.44 (0.99-2.08), South Asia: 1.40 (1.07-1.83) and East Asia: 0.90 (0.72-1.13). Sub-analyses showed that late detection of breast cancer in young non-Western immigrants might be of particular concern. Young (cancer compared to young Norwegians. © 2017 UICC.

  9. Comparison of velocity distribution function errors introduced by particle reweighting schemes in PIC-DSMC simulations

    Science.gov (United States)

    Moore, Christopher; Boerner, Jeremy; Moore, Stan; Cartwright, Keith; Pointon, Timothy

    2014-10-01

    Many PIC simulations span many orders of magnitude in the plasma density and therefore a constant particle weight results in too few particles in regions (or time periods) of low density or too many particles when the density is high. The standard solution is to employ a reweighting scheme in which low-weight particles are merged in order to keep the number of particles per cell roughly constant while conserving mass and momentum. Unfortunately merger schemes distort a general velocity distribution function (VDF) of particles (one can conserve arbitrarily higher moments such as energy flux by merging N to M particles for N > M > 1) and often merge routines act like artificial collisions that thermalize the distribution and lead to simulation error. We will compare the accuracy of the unique reweighting scheme used in our PIC-DSMC code and common reweighting schemes (e.g. redrawing from a constructed VDF or rouletting) through two benchmarks. The first compares the time varying VDF from various merge routines to an analytic solution for relaxation of a bimodal VDF to a Maxwellian through elastic collisions. The second benchmark compares error introduced in the VDF due to merging electrons during a breakdown simulation. Sandia National Laboratories is a multiprogram laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under Contract DE-AC04-94AL85000.

  10. A Microstructural Study of Load Distribution in Cartilage: A Comparison of Stress Relaxation versus Creep Loading

    Directory of Open Access Journals (Sweden)

    Ashvin Thambyah

    2015-01-01

    Full Text Available The compressive response of articular cartilage has been extensively investigated and most studies have focussed largely on the directly loaded matrix. However, especially in relation to the tissue microstructure, less is known about load distribution mechanisms operating outside the directly loaded region. We have addressed this issue by using channel indentation and DIC microscopy techniques that provide visualisation of the matrix microstructural response across the regions of both direct and nondirect loading. We hypothesise that, by comparing the microstructural response following stress relaxation and creep compression, new insights can be revealed concerning the complex mechanisms of load bearing. Our results indicate that, with stress relaxation, the initial mode of stress decay appears to primarily involve relaxation of the surface layer. In the creep loading protocol, the main mode of stress release is a lateral distribution of load via the mid matrix. While these two modes of stress redistribution have a complex relationship with the zonally differentiated tissue microstructure and the depth of strain, four mechanostructural mechanisms are proposed to describe succinctly the load responses observed.

  11. Venus upper atmosphere winds traced by temperature and night ariglow distributions: VTGCM comparisons with PVO and VEX data

    Science.gov (United States)

    Bougher, Stephen; Brecht, Amanda; Parkinson, Chris; Rafkin, Scot; Foster, Ben

    New Venus upper atmosphere measurements from Venus Express (VEX), when examined in the light of previous Pioneer Venus Orbiter (PVO) and ground-based measurements, suggest that the dynamics of the Venus middle and upper atmospheres ( 80-200 km) is highly variable [e.g. Bertaux et al., 2007; Bougher et al., 1997; 2006; Gerard et al., 2008; Lellouch et al., 1997; Schubert et al., 2007]. A superposition of variable retrograde superrotating zonal (RSZ) winds and more stable subsolar-to-antisolar (SS-AS) winds is known to dominate the global dynamics of this region. Presently, key night airglow distributions (NO ultraviolet and O2 near-IR) and lower thermosphere temperature distributions are being used as excellent tracers of these changing global wind patterns. The National Center for Atmospheric Research (NCAR) thermospheric general circulation model for Venus (VTGCM) has been upgraded to better simulate these night airglow and temperature distributions. The objectives of this modeling effort are to: (1) reproduce the observed mean structure of these features, thereby unfolding the average wind patterns, and (2) identify and quantify the importance of the processes that drive daily variations in the global circulation (i.e. planetary scale waves and tidal modes). The VTGCM is a three dimensional model that calculates temperatures, 3-component neutral winds, and the concentration of specific neutral and ion species. This model can also compute the O2 and NO night airglow intensity (horizontal) and volume emission rate (vertical) distributions for comparison to available PVO and VEX datasets. The most important change is the VTGCM bottom boundary, which has been lowered to 70 km near cloud tops. This upgrade insures that all possible dynamical influences that contribute to maintaining these airglow layers, and their variations, can be captured within the VTGCM domain. Model simulations for both VEX and PVO observing periods will be presented, illustrating the new VTGCM

  12. Aerosol vertical distribution over east China from RIEMS-Chem simulation in comparison with CALIPSO measurements

    Science.gov (United States)

    Li, Jiawei; Han, Zhiwei

    2016-10-01

    The horizontal and vertical distributions of aerosol extinction coefficient (AEC) and mass concentration over east China in October 2010 were investigated by using an online-coupled regional climate model and CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) data. Model performance was evaluated comprehensively against ground observations of meteorological variables and PM10 concentrations and CALIPSO retrieved AEC profiles, which demonstrated a good ability of the model in simulating spatial distribution and evolution of aerosol concentration and optical properties. Severe pollution episodes were found over wide areas of east China during the study period, with the maximum mean PM10 concentration exceeding 200 μg m-3 in the Chongqing district and a part of the lower reaches of the Yellow River on 8-10 October. Both CALIPSO retrievals and model simulations revealed high AEC values (≥1 km-1) often occurred within 2 km above ground over most areas of east China. AEC vertical profile in or in the vicinity of China major cities along CALIPSO orbit track exhibited two typical features: one was AEC reached its maximum (∼4 km-1) near the surface (<200 m) and decreased rapidly to < 0.1 km-1 at altitudes above 1 km, another one was AEC peaked at higher altitudes of about 0.5-1 km with a maximum up to 3 km-1. AEC vertical profile was strongly dependent on vertical distribution of both aerosol concentration, composition and relative humidity. The vertical cross sections over typical regions of east China exhibited a decreasing AEC in magnitude from the continent to the China seas. Over the continent, AEC was either maximum near the surface or peaked at higher altitudes (0.5-1.0 km) due to increases of relative humidity or aerosol concentration in those regions, whereas over the seas of China, AEC profile was characterized by peak values at an altitude around 1 km, mainly due to an elevated relative humidity there, which favored rapid aerosol

  13. Distribution and retention in bone of /sup 226/Ra and comparison with the ICRP 20 model

    Energy Technology Data Exchange (ETDEWEB)

    Holtzman, R.B.; Rundo, J.; Sha, J.Y.; Spaletto, M.I.

    1981-01-01

    Analyses are presented of the ratios of /sup 226/Ra to calcium in over 650 samples of compact and cancellous bone from 66 female and 26 male subjects who had died from less than one to 60 years after first exposure to radium. The /sup 226/Ra/Ca ratios were normalized to the terminal /sup 226/Ra skeletal content. The /sup 226/Ra/Ca ratios for vertebrae were essentialy identical to those for other cancellous bone for a given subject. Comparisons of the data with predictions of the ICRP model of alkaline earth metabolism show that for female cancellous bone the normalized /sup 226/Ra/Ca ratios tended to be greater than predicted, while those for female cortical bone (femoral and tibial shaft) tended to be less. The data for males were fitted better by the model. A modification of the model to reduce the amount of radium deposited in soft tissue fitted the data better in some respects. A straight line linear least squares fit to the data appeared to fit as well as, or better than, the models. A radiation effect was suggested in that the normalized /sup 226/Ra/Ca ratio for vertebrae relative to the ratio expected increased with skeletal absorbed dose for vertebra. However, no such effect was apparent for compact bone or for the cancellous bone as a whole.

  14. On the Stark broadening of Cr VI spectral lines in astrophysical plasma

    Science.gov (United States)

    Dimitrijević, M. S.; Simić, Z.; Sahal-Bréchot, S.

    2017-02-01

    Stark broadening parameters for Cr VI lines have been calculated using semiclassical perturbation method for conditions of interest for stellar plasma. Here are presented, as an example of obtained results, Stark broadening parameters for electron- and proton-impact broadening for Cr VI 4s 2S-4p 2P° λ = 1430 Å and Cr VI 4p 2P°-5s 2S λ = 611.8 Å multiplets. The obtained results are used to demonstrate the importance of Stark broadening of Cr VI in DO white dwarf atmospheres. Also the obtained results will enter in STARK-B database which is included in Virtual Atomic and Molecula Data Center - VAMDC.

  15. Broader spectrum of β-thalassemia mutations in Oman: regional distribution and comparison with neighboring countries.

    Science.gov (United States)

    Hassan, Suha M; Harteveld, Cornelis L; Bakker, Egbert; Giordano, Piero C

    2015-01-01

    The objective of this study was to expand and study the molecular spectrum of β-thalassemia (β-thal) mutations in Oman by examining cases from seven different regions and comparing the prevalence with neighboring countries. A total of 446 cases of β hemoglobinopathies was obtained and analyzed to determine the frequency and distribution of the different β alleles. The molecular spectrum of β-thal in Oman revealed the presence of 32 mutations from different origins and 11 alleles are reported for the first time in the Omani population. The wide heterogeneous spectrum of β-thal mutations found can be associated with the history of trade and migration as well as the past domination from other countries. The presented data will facilitate the development of a comprehensive prevention strategy in Oman.

  16. A comparison of LMC and SDL complexity measures on binomial distributions

    Science.gov (United States)

    Piqueira, José Roberto C.

    2016-02-01

    The concept of complexity has been widely discussed in the last forty years, with a lot of thinking contributions coming from all areas of the human knowledge, including Philosophy, Linguistics, History, Biology, Physics, Chemistry and many others, with mathematicians trying to give a rigorous view of it. In this sense, thermodynamics meets information theory and, by using the entropy definition, López-Ruiz, Mancini and Calbet proposed a definition for complexity that is referred as LMC measure. Shiner, Davison and Landsberg, by slightly changing the LMC definition, proposed the SDL measure and the both, LMC and SDL, are satisfactory to measure complexity for a lot of problems. Here, SDL and LMC measures are applied to the case of a binomial probability distribution, trying to clarify how the length of the data set implies complexity and how the success probability of the repeated trials determines how complex the whole set is.

  17. BrO vertical distributions from SCIAMACHY limb measurements: comparison of algorithms and retrieval results

    Directory of Open Access Journals (Sweden)

    A. Rozanov

    2011-07-01

    Full Text Available This study presents two scientific and one operational retrieval algorithms used to obtain vertical distributions of bromine monoxide (BrO from observations of the scattered solar light performed by the SCIAMACHY instrument in limb viewing geometry. The study begins with a discussion of the theoretical basis of all algorithms followed by an investigation of the retrieval sensitivity. Simulations with three different radiative transfer models allow us to analyze influence of the forward model implementation upon the retrieval results. By means of synthetic retrievals we analyze major sources of uncertainties in the resulting BrO profiles such as different BrO cross sections, their temperature dependence, and stratospheric aerosols. Finally, the reliability of SCIAMACHY BrO profile retrievals is demonstrated comparing results from different algorithms to each other and to balloon-borne observations.

  18. Comparison of subcellular distribution and chemical forms of cadmium among four soybean cultivars at young seedlings.

    Science.gov (United States)

    Wang, Peng; Deng, Xiaojuan; Huang, Yian; Fang, Xiaolong; Zhang, Jie; Wan, Haibo; Yang, Cunyi

    2015-12-01

    The hydroponic experiment was carried out to investigate the Cd subcellular distribution and chemical forms in roots and shoots among four soybean seedling cultivars with two Cd treatments. HX3 and GC8, two tolerant and low-grain-Cd-accumulating cultivars, had the lowest Cd concentration in roots and high Cd concentration in shoots, while BX10 and ZH24, two sensitive and high-grain-Cd-accumulating cultivars, had the highest Cd concentration in roots and the lowest Cd concentration in shoots at young seedling stage. Furthermore, the sequence of Cd subcellular distribution in roots at two Cd levels was cell wall (53.4-75.5 %) > soluble fraction (15.8-40.4 %) > organelle fraction (2.0-14.7 %), but in shoots, was soluble fraction (39.3-74.8 %) > cell wall (16.0-52.0 %) > organelle (4.8-19.5 %). BX10 and ZH24 had higher Cd concentration in all subcellular fractions in roots, but HX3 and GC8 had higher Cd concentration of soluble fraction in shoots. The sequence of Cd chemical forms in roots was FNacl (64.1-79.5 %) > FHAC (3.4-21.5 %) > Fd-H2O (3.6-13.0 %) > Fethanol (1.4-21.8) > FHCl (0.3-1.6 %) > Fother (0.2-1.4 %) at two Cd levels but, in shoots, was FNacl (19.7-51.4 %) ≥ FHAC (10.2-31.4 %) ≥ Fd-H2O (8.8-28.2 %) ≥ Fethanol (8.9-38.6 %) > FHCl (0.2-9.6 %) > Fother (2.5-11.2 %). BX10 and ZH24 had higher Cd concentrations in each extracted solutions from roots, but from shoots for GC8 and HX3. Taken together, the results uncover that root cell walls and leaf vacuoles might play important roles in Cd detoxification and limiting the symplastic movement of Cd.

  19. Broadening Participation of Women and Underrepresented Minorities in STEM through a Hybrid Online Transfer Program.

    Science.gov (United States)

    Drew, Jennifer C; Galindo-Gonzalez, Sebastian; Ardissone, Alexandria N; Triplett, Eric W

    2016-01-01

    The Microbiology and Cell Science (MCS) Department at the University of Florida (UF) developed a new model of a 2 + 2 program that uses a hybrid online approach to bring its science, technology, engineering, and mathematics (STEM) curriculum to students. In this paradigm, 2-year graduates transfer as online students into the Distance Education in MCS (DE MCS) bachelor of science program. The program has broadened access to STEM with a steadily increasing enrollment that does not draw students away from existing on-campus programs. Notably, half of the DE MCS students are from underrepresented minority (URM) backgrounds and two-thirds are women, which represents a greater level of diversity than the corresponding on-campus cohort and the entire university. Additionally, the DE MCS cohort has comparable retention and academic performance compared with the on-campus transfer cohort. Of those who have earned a BS through the DE MCS program, 71% are women and 61% are URM. Overall, these data demonstrate that the hybrid online approach is successful in increasing diversity and provides another viable route in the myriad of STEM pathways. As the first of its kind in a STEM field, the DE MCS program serves as a model for programs seeking to broaden their reach. © 2016 J. C. Drew et al. CBE—Life Sciences Education © 2016 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  20. Plasma motions and non-thermal line broadening in flaring twisted coronal loops

    Science.gov (United States)

    Gordovskyy, M.; Kontar, E. P.; Browning, P. K.

    2016-05-01

    Context. Observation of coronal extreme ultra-violet (EUV) spectral lines sensitive to different temperatures offers an opportunity to evaluate the thermal structure and flows in flaring atmospheres. This, in turn, can be used to estimate the partitioning between the thermal and kinetic energies released in flares. Aims: Our aim is to forward-model large-scale (50-10 000 km) velocity distributions to interpret non-thermal broadening of different spectral EUV lines observed in flares. The developed models allow us to understand the origin of the observed spectral line shifts and broadening, and link these features to particular physical phenomena in flaring atmospheres. Methods: We use ideal magnetohydrodynamics (MHD) to derive unstable twisted magnetic fluxtube configurations in a gravitationally stratified atmosphere. The evolution of these twisted fluxtubes is followed using resistive MHD with anomalous resistivity depending on the local density and temperature. The model also takes thermal conduction and radiative losses in the continuum into account. The model allows us to evaluate average velocities and velocity dispersions, which would be interpreted as non-thermal velocities in observations, at different temperatures for different parts of the models. Results: Our models show qualitative and quantitative agreement with observations. Thus, the line-of-sight (LOS) velocity dispersions demonstrate substantial correlation with the temperature, increasing from about 20-30 km s-1 around 1 MK to about 200-400 km s-1 near 10-20 MK. The average LOS velocities also correlate with velocity dispersions, although they demonstrate a very strong scattering compared to the observations. We also note that near footpoints the velocity dispersions across the magnetic field are systematically lower than those along the field. We conclude that the correlation between the flow velocities, velocity dispersions, and temperatures are likely to indicate that the same heating

  1. Comparison of modern pollen distribution between the northern and southern parts of the South China Sea.

    Science.gov (United States)

    Luo, Chuanxiu; Chen, Muhong; Xiang, Rong; Liu, Jianguo; Zhang, Lanlan; Lu, Jun

    2015-04-01

    The authors conducted a palynological analysis based on different number of air pollen samples for the northern and southern parts of the South China Sea, respectively, in order to give a reference to reconstruct the paleoclimate of the area. (1) Fifteen air pollen samples were collected from the northern part of the South China Sea from August to September 2011, and 13 air pollen samples were collected from the southern part of the South China Sea in December 2011. The pollen types were more abundant in the north than in the south. The total pollen number and concentration in the north was 10 times more than that in the south, which may be because of the sampling season. Airborne pollen types and concentrations have a close relationship with wind direction and distance from the sampling point to the continent. (2) Seventy-four samples were collected from surface sediments in the northern part of the South China Sea in the autumn. Thirty-three samples were collected from surface sediments in the southern part of the South China Sea in the winter. Pollen concentrations in the north were nearly 10 times higher than that in the south. This is because trilete spores are transported by rivers from Hainan Island to the sea and also by the summer monsoon-forced marine current. (3) Ten air pollen samples and 10 surface sediments samples were selected for comparison. The pollen and spores in the air were mainly herbaceous and woody pollen, excluding fern spores, having seasonal pollen characteristics. Pollen in the surface sediments were mainly trilete, Pinus, and herbaceous, and may also show a combination of annual pollen characteristics.

  2. Comparison of SNP Variation and Distribution in Indigenous Ethiopian and Korean Cattle (Hanwoo Populations

    Directory of Open Access Journals (Sweden)

    Zewdu Edea

    2012-09-01

    Full Text Available Although a large number of single nucleotide polymorphisms (SNPs have been identified from the bovine genome-sequencing project, few of these have been validated at large in Bos indicus breeds. We have genotyped 192 animals, representing 5 cattle populations of Ethiopia, with the Illumina Bovine 8K SNP BeadChip. These include 1 Sanga (Danakil, 3 zebu (Borana, Arsi and Ambo, and 1 zebu × Sanga intermediate (Horro breeds. The Hanwoo (Bos taurus was included for comparison purposes. Analysis of 7,045 SNP markers revealed that the mean minor allele frequency (MAF was 0.23, 0.22, 0.21, 0.21, 0.23, and 0.29 for Ambo, Arsi, Borana, Danakil, Horro, and Hanwoo, respectively. Significant differences of MAF were observed between the indigenous Ethiopian cattle populations and Hanwoo breed (p < 0.001. Across the Ethiopian cattle populations, a common variant MAF (≥0.10 and ≤0.5 accounted for an overall estimated 73.79% of the 7,045 SNPs. The Hanwoo displayed a higher proportion of common variant SNPs (90%. Investigation within Ethiopian cattle populations showed that on average, 16.64% of the markers were monomorphic, but in the Hanwoo breed, only 6% of the markers were monomorphic. Across the sampled Ethiopian cattle populations, the mean observed and expected heterozygosities were 0.314 and 0.313, respectively. The level of SNP variation identified in this particular study highlights that these markers can be potentially used for genetic studies in African cattle breeds.

  3. Uncertainty in the spatial distribution of tropical forest biomass: a comparison of pan-tropical maps.

    Science.gov (United States)

    Mitchard, Edward Ta; Saatchi, Sassan S; Baccini, Alessandro; Asner, Gregory P; Goetz, Scott J; Harris, Nancy L; Brown, Sandra

    2013-10-26

    Mapping the aboveground biomass of tropical forests is essential both for implementing conservation policy and reducing uncertainties in the global carbon cycle. Two medium resolution (500 m - 1000 m) pantropical maps of vegetation biomass have been recently published, and have been widely used by sub-national and national-level activities in relation to Reducing Emissions from Deforestation and forest Degradation (REDD+). Both maps use similar input data layers, and are driven by the same spaceborne LiDAR dataset providing systematic forest height and canopy structure estimates, but use different ground datasets for calibration and different spatial modelling methodologies. Here, we compare these two maps to each other, to the FAO's Forest Resource Assessment (FRA) 2010 country-level data, and to a high resolution (100 m) biomass map generated for a portion of the Colombian Amazon. We find substantial differences between the two maps, in particular in central Amazonia, the Congo basin, the south of Papua New Guinea, the Miombo woodlands of Africa, and the dry forests and savannas of South America. There is little consistency in the direction of the difference. However, when the maps are aggregated to the country or biome scale there is greater agreement, with differences cancelling out to a certain extent. When comparing country level biomass stocks, the two maps agree with each other to a much greater extent than to the FRA 2010 estimates. In the Colombian Amazon, both pantropical maps estimate higher biomass than the independent high resolution map, but show a similar spatial distribution of this biomass. Biomass mapping has progressed enormously over the past decade, to the stage where we can produce globally consistent maps of aboveground biomass. We show that there are still large uncertainties in these maps, in particular in areas with little field data. However, when used at a regional scale, different maps appear to converge, suggesting we can provide

  4. Determining Arsenic Distribution in Urban Soils: A Comparison with Nonurban Soils

    Directory of Open Access Journals (Sweden)

    Tait Chirenje

    2002-01-01

    Full Text Available There are many challenges in the determination of arsenic background concentrations in soils. However, these challenges are magnified when those determinations are carried out on urban soils. Irrespective of this, it is important to correctly identify and understand the extent of pollution in order to provide efficient preventative, remedial actions and cost-effective management of contaminated areas. This review paper discusses the factors that make the determination of arsenic background concentrations in urban areas different from similar determinations in nonurban areas. It also proposes solutions, where applicable, that are based on experience in determining arsenic background concentrations in both urban and nonurban areas in Florida, and from other studies in the literature. Urban soils are considerably different from nonurban areas because they have significant human disturbance, making them more difficult to study. They are characterized by high spatial and temporal variability, compaction, and modified chemical and physical characteristics. These differences have to be addressed during site selection, sample collection, and statistical analyses when determining arsenic distribution.

  5. A comparison of cancer burden and research spending reveals discrepancies in the distribution of research funding

    Directory of Open Access Journals (Sweden)

    Carter Ashley JR

    2012-07-01

    Full Text Available Abstract Background Ideally, the distribution of research funding for different types of cancer should be equitable with respect to the societal burden each type of cancer imposes. These burdens can be estimated in a variety of ways; “Years of Life Lost” (YLL measures the severity of death in regard to the age it occurs, "Disability-Adjusted Life-Years" (DALY estimates the effects of non-lethal disabilities incurred by disease and economic metrics focus on the losses to tax revenue, productivity or direct medical expenses. We compared research funding from the National Cancer Institute (NCI to a variety of burden metrics for the most common types of cancer to identify mismatches between spending and societal burden. Methods Research funding levels were obtained from the NCI website and information for societal health and economic burdens were collected from government databases and published reports. We calculated the funding levels per unit burden for a wide range of different cancers and burden metrics and compared these values to identify discrepancies. Results Our analysis reveals a considerable mismatch between funding levels and burden. Some cancers are funded at levels far higher than their relative burden suggests (breast cancer, prostate cancer, and leukemia while other cancers appear underfunded (bladder, esophageal, liver, oral, pancreatic, stomach, and uterine cancers. Conclusions These discrepancies indicate that an improved method of health care research funding allocation should be investigated to better match funding levels to societal burden.

  6. Claudin-1, -2, -4, and -5: comparison of expression levels and distribution in equine tissues.

    Science.gov (United States)

    Lee, Bonn; Kang, Hee Young; Lee, Dong Oh; Ahn, Changhwan; Jeung, Eui-Bae

    2016-12-30

    Claudins, which are known as transmembrane proteins play an essential role in tight junctions (TJs) to form physical barriers and regulate paracellular transportation. To understand equine diseases, it is helpful to measure the tissue-specific expression of TJs in horses. Major equine diseases such as colic and West Nile cause damage to TJs. In this study, the expression level and distribution of claudin-1, -2, -4, and -5 in eight tissues were assessed by Western blotting and immunohistochemistry methods. Claudin-1 was primarily identified in the lung, duodenum, and uterus, claudin-2 was evenly observed in equine tissues, claudin-4 was abundantly detected in the liver, kidney and uterus, and claudin-5 was strongly expressed in the lung, duodenum, ovary, and uterus, as determined by Western blotting method. The localization of equine claudins was observed by immunohistochemistry methods. These findings provide knowledge regarding the expression patterns and localization of equine claudins, as well as valuable information to understand tight junction-related diseases according to tissue specificity and function of claudins in horses.

  7. A New Stellar Atmosphere Grid and Comparisons with HST /STIS CALSPEC Flux Distributions

    Energy Technology Data Exchange (ETDEWEB)

    Bohlin, Ralph C.; Fleming, Scott W.; Gordon, Karl D.; Koekemoer, Anton M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Mészáros, Szabolcs; Kovács, József [ELTE Gothard Astrophysical Observatory, H-9700 Szombathely, Szent Imre Herceg St. 112 (Hungary)

    2017-05-01

    The Space Telescope Imaging Spectrograph has measured the spectral energy distributions for several stars of types O, B, A, F, and G. These absolute fluxes from the CALSPEC database are fit with a new spectral grid computed from the ATLAS-APOGEE ATLAS9 model atmosphere database using a chi-square minimization technique in four parameters. The quality of the fits are compared for complete LTE grids by Castelli and Kurucz (CK04) and our new comprehensive LTE grid (BOSZ). For the cooler stars, the fits with the MARCS LTE grid are also evaluated, while the hottest stars are also fit with the NLTE Lanz and Hubeny OB star grids. Unfortunately, these NLTE models do not transition smoothly in the infrared to agree with our new BOSZ LTE grid at the NLTE lower limit of T {sub eff} = 15,000 K. The new BOSZ grid is available via the Space Telescope Institute MAST archive and has a much finer sampled IR wavelength scale than CK04, which will facilitate the modeling of stars observed by the James Webb Space Telescope . Our result for the angular diameter of Sirius agrees with the ground-based interferometric value.

  8. Comparison of biofilm ecology supporting growth of individual Naegleria species in a drinking water distribution system.

    Science.gov (United States)

    Puzon, Geoffrey J; Wylie, Jason T; Walsh, Tom; Braun, Kalan; Morgan, Matthew J

    2017-04-01

    Free-living amoebae (FLA) are common components of microbial communities in drinking water distribution systems (DWDS). FLA are of clinical importance both as pathogens and as reservoirs for bacterial pathogens, so identifying the conditions promoting amoebae colonisation of DWDSs is an important public health concern for water utilities. We used high-throughput amplicon sequencing to compare eukaryotic and bacterial communities associated with DWDS biofilms supporting distinct FLA species (Naegleria fowleri, N. lovaniensis or Vermamoeba sp.) at sites with similar physical/chemical conditions. Eukaryote and bacterial communities were characteristics of different FLA species presence, and biofilms supporting Naegleria growth had higher bacterial richness and higher abundance of Proteobacteria, Bacteroidetes (bacteria), Nematoda and Rotifera (eukaryota). The eukaryotic community in the biofilms had the greatest difference in relation to the presence of N. fowleri, while the bacterial community identified individual bacterial families associated with the presence of different Naegleria species. Our results demonstrate that ecogenomics data provide a powerful tool for studying the microbial and meiobiotal content of biofilms, and, in these samples can effectively discriminate biofilm communities supporting pathogenic N. fowleri. The identification of microbial species associated with N. fowleri could further be used in the management and control of N. fowleri in DWDS. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Comparison of Traditional and Open-Access Appointment Scheduling for Exponentially Distributed Service Time

    Directory of Open Access Journals (Sweden)

    Chongjun Yan

    2015-01-01

    Full Text Available This paper compares the performance measures of traditional appointment scheduling (AS with those of an open-access appointment scheduling (OA-AS system with exponentially distributed service time. A queueing model is formulated for the traditional AS system with no-show probability. The OA-AS models assume that all patients who call before the session begins will show up for the appointment on time. Two types of OA-AS systems are considered: with a same-session policy and with a same-or-next-session policy. Numerical results indicate that the superiority of OA-AS systems is not as obvious as those under deterministic scenarios. The same-session system has a threshold of relative waiting cost, after which the traditional system always has higher total costs, and the same-or-next-session system is always preferable, except when the no-show probability or the weight of patients’ waiting is low. It is concluded that open-access policies can be viewed as alternative approaches to mitigate the negative effects of no-show patients.

  10. Determination of plasma sheath current distributions by comparison of Zeeman spectroscopy with B-dot measurements in laser ablation Z-pinch experiments

    Science.gov (United States)

    Dutra, Eric; Presura, Radu; Angermeier, William; Mancini, Roberto; Covington, Aaron

    2017-10-01

    In plasma pinch experiments, measurements of current distributions and losses across the anode-cathode (A-K) gap are needed to ensure uniform and repeatable implosions. Traditional B-dots measure current a considerable distance away from the plasma source and provide little detailed information on the current distribution across the plasma sheath near the pinch. In the experiments presented here, visible spectroscopic techniques were used to measure magnetically induced Zeeman splitting. Ionic plasma species were chosen such that the Zeeman splitting of different fine structure doublets split non-uniformly with increasing magnetic field strength in the plasma. This differential splitting enables measurements of non-directional B-field strengths in the plasma across a wide range of conditions. More specifically, the optical emission of Al III, C IV, and O VI doublets, 2P3/2 to 2S1/2 and 2P1/2 to 2S1/2 transitions were measured and used to determine the Zeeman broadening. We have applied this technique to diagnose time- and space-resolved B-field strengths in laser ablation Z-pinch experiments (LAZE). Experiments were conducted at the Nevada Terawatt Facility (NTF) using the TW-class Leopard laser and the 1 MA Zebra Z-pinch. The currents inferred from Zeeman spectroscopy measurements were compared to those determined from the B-dot diagnostics. DOE/NV/25946 ''3272.

  11. Mass transfer kinetics, band broadening and column efficiency.

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2012-01-20

    Important progress was recently made in our understanding of the physico-chemical aspects of mass transfer kinetics in chromatographic columns, in methods used for accurate determination of the different contributions to the height equivalent to a theoretical plate (HETP), and in the application of these advances to the elucidation of mass transfer mechanisms in columns packed with recent chromatographic supports (sub-2 μm fully porous particles, sub-3 μm core-shell particles, and monoliths). The independent contributions to the HETP are longitudinal diffusion, eddy dispersion, liquid-solid mass transfer (including trans-particle or trans-skeleton mass transfer and external film mass transfer), and the contributions caused by the thermal heterogeneity of the column. The origin and importance of these contributions are investigated in depth. This work underlines the areas in which improvements are needed, an understanding of the contribution of the external film mass transfer term, a better design of HPLC instruments providing a decrease of the extra-column band broadening contributions to the apparent HETP, the development of better packing procedures giving more radially homogeneous column beds, and new packing materials having a higher thermal conductivity to eliminate the nefarious impact of heat effects in very high pressure liquid chromatography (vHPLC) and supercritical fluid chromatography (SFC). Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Cavity-ring-down Doppler-broadening primary thermometry

    Science.gov (United States)

    Gotti, Riccardo; Moretti, Luigi; Gatti, Davide; Castrillo, Antonio; Galzerano, Gianluca; Laporta, Paolo; Gianfrani, Livio; Marangoni, Marco

    2018-01-01

    A step forward in Doppler-broadening thermometry is demonstrated using a comb-assisted cavity-ring-down spectroscopic approach applied to an isolated near-infrared line of carbon dioxide at thermodynamic equilibrium. Specifically, the line-shape of the Pe(12 ) line of the (30012 )←(00001 ) band of C O2 at 1.578 µm is accurately measured and its Doppler width extracted from a refined multispectrum fitting procedure accounting for the speed dependence of the relaxation rates, which were found to play a role even at the very low pressures explored, from 1 to 7 Pa. The thermodynamic gas temperature is retrieved with relative uncertainties of 8 ×10-6 (type A) and 11 ×10-6 (type B), which ranks the system at the first place among optical methods. Thanks to a measurement time of only ≈5 h , the technique represents a promising pathway toward the optical determination of the thermodynamic temperature with a global uncertainty at the 10-6 level.

  13. Workshops Without Walls: broadening access to science around the world.

    Directory of Open Access Journals (Sweden)

    Betül K Arslan

    2011-08-01

    Full Text Available The National Aeronautics and Space Administration (NASA Astrobiology Institute (NAI conducted two "Workshops Without Walls" during 2010 that enabled global scientific exchange--with no travel required. The second of these was on the topic "Molecular Paleontology and Resurrection: Rewinding the Tape of Life." Scientists from diverse disciplines and locations around the world were joined through an integrated suite of collaborative technologies to exchange information on the latest developments in this area of origin of life research. Through social media outlets and popular science blogs, participation in the workshop was broadened to include educators, science writers, and members of the general public. In total, over 560 people from 31 US states and 30 other nations were registered. Among the scientific disciplines represented were geochemistry, biochemistry, molecular biology and evolution, and microbial ecology. We present this workshop as a case study in how interdisciplinary collaborative research may be fostered, with substantial public engagement, without sustaining the deleterious environmental and economic impacts of travel.

  14. Egyptian government broadens ban on female genital mutilation.

    Science.gov (United States)

    1996-01-01

    An estimated 70-90% of girls in Egypt are subjected to female genital mutilation (FGM) before reaching puberty. Many Egyptians believe the practice to be ordained by Islam. Whether this is true, however, remains an issue of debate among Muslim scholars. Some Egyptian Christians also secure FGM for their girls. Egyptian law prohibits anyone without medical training from performing FGM, and any physician or health worker who causes permanent damage to a girl may face 3-10 years of hard labor. However, the law is frequently ignored, especially in rural areas, where village barbers and midwives perform the operations. In October 1995, Egyptian state hospitals were banned from performing FGM. Egypt has since broadened its ban to bar all health care workers in both state-run hospitals and private clinics from performing the procedure. No health care worker affiliated with the Ministry of Health is therefore allowed to perform FGM. Almost all Egyptian doctors are affiliated with the Ministry. While this recent move by the Health Minister is laudable, it remains to be seen whether he can enforce it. The secretary-general of the Egyptian Organization for Human Rights has urged parliament to enact legislation criminalizing FGM.

  15. Accumulation of plutonium in mammalian wildlife tissues: comparison of recent data with the ICRP distribution models

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, M.; Child, D.; Davis, E.; Hotchkis, M.; Payne, T. [Australian Nuclear Science and Technology Org. (Australia); Ikeda-Ohno, A. [University of New South Wales (Australia); Twining, J. [Austral Radioecology (Australia)

    2014-07-01

    We examined the distribution of plutonium (Pu) in the tissues of mammalian wildlife to address the paucity of such data under environmental exposure conditions. Pu activity concentrations were measured in Macropus rufus (red kangaroo), Oryctolagus cuniculus (European rabbit), and Pseudomys hermannsburgensis (sandy inland mouse)inhabiting the relatively undisturbed, semi-arid conditions at the former Taranaki weapons test site at Maralinga, Australia. Of the absorbed Pu (distributed via circulatory and lymph systems) accumulation was foremost in bone (83% ±10% SD), followed by muscle (9% ±10%), liver (7% ±7%), kidneys (0.5% ±0.3%), and heart (0.4% ±0.4%). The bone values are higher than those reported in ICRP 19 and 48 (45-50% bone), while the liver values are lower than ICRP values (30-45% liver). The ICRP values were based on data dominated by relatively soluble forms of Pu, including prepared solutions and single-atom ions produced by decay following the volatilisation of uranium during nuclear detonation (fallout Pu, ICRP 1986). In contrast, the Maralinga data relates to low-soluble forms of Pu used in tests designed to simulate accidental release and dispersal. We measured Pu in lung, GI-tract and the skin and fur as distinct from the absorbed Pu in bone, liver, muscle, and kidneys. Compared with the mean absorbed activity concentrations, the results for lung tissues were higher by up to one order of magnitude, and those in the GI tract contents and the washed skin/fur were higher by more than two orders of magnitude. These elevated levels are consistent with the presence of low-soluble Pu, including particulate forms, which pass through, or adhere upon, certain organs, but are not readily absorbed into the bloodstream. This more transitory Pu can provide dose to the lung and GI tract organs, as well as provide potential transfer of contamination when consumed in predator-prey food chains, or during human foodstuff consumption. For example, activity

  16. Plume Aerosol Size Distribution Modeling and Comparisons to PrAIRie2005 Field Study Data

    Science.gov (United States)

    Cho, S.; Liggio, J.; Makar, P.; Li, S.; Racinthe, J.

    2006-12-01

    As part of the analysis phase of the PrAIRie2005 field study, the effects of different Edmonton-area emission sources on local air-quality are being examined. Four large coal-fired power-plants are located to the West of the city. Here, the effects of these power-plants on urban and regional air-quality will be examined, using both plume and regional air-quality models. During the last few decades, coal-fired power plants have been found to be as a major source of pollution, affecting public-health. According to NACEC (North American Commission for Environmental Corporation, 2001)'s report, 46 of the top 50 air polluters in North America were power plants. The importance of such sources has resulted in several attempts to improve understanding of the basic formation mechanisms of plume particulate matter. Sulphur dioxide contributes to acidifying emissions and to the production of secondary acidic aerosols that have been linked to a number of serious human health problems, acid rain and visibility (Seinfeld and Pandis, 1998; Hidy, 1984; Wilson and McMurray, 1981). Primary particulate matter originating directly from coal-fired power plants may also increase secondary particulate mass by providing a surface for sulphuric acid absorption . Environment Canada's PrAIRie2005 field study between August 12th and September 7th, 2005 included overflights and downwind measurements near the Edmonton powerplants (Wabamun, Sundance, Keephills and Genesee). The data collected consisted of particle size distributions, ozone, NOX, total mass and the chemical composition of fine particles. In order to investigate and improve our understanding of the formation mechanisms and physical properties of power-plant-generated aerosols in the Edmonton area, the Plume Aerosol Microphysical (PAM) model has been employed. This model accounts for gas-phase chemistry, aerosol microphysical processes (i.e. homogeneous/heterogeneous nucleation, condensation/evaporation and coagulation) and

  17. Interplay of charge distribution and conformation in peptides: comparison of theory and experiment.

    Science.gov (United States)

    Makowska, Joanna; Bagińska, Katarzyna; Kasprzykowski, F; Vila, Jorge A; Jagielska, Anna; Liwo, Adam; Chmurzyński, Lech; Scheraga, Harold A

    2005-01-01

    We assessed the correlation between charge distribution and conformation of flexible peptides by comparing the theoretically calculated potentiometric-titration curves of two model peptides, Ac-Lys5-NHMe (a model of poly-L-lysine) and Ac-Lys-Ala11-Lys-Gly2-Tyr-NH2 (P1) in water and methanol, with the experimental curves. The calculation procedure consisted of three steps: (i) global conformational search of the peptide under study using the electrostatically driven Monte Carlo (EDMC) method with the empirical conformational energy program for peptides (ECEPP)/3 force field plus the surface-hydration (SRFOPT) or the generalized Born surface area (GBSA) solvation model as well as a molecular dynamics method with the assisted model building and energy refinement (AMBER)99/GBSA force field; (ii) reevaluation of the energy in the pH range considered by using the modified Poisson-Boltzmann approach and taking into account all possible protonation microstates of each conformation, and (iii) calculation of the average degree of protonation of the peptide at a given pH value by Boltzmann averaging over conformations. For Ac-Lys5-NHMe, the computed titration curve agrees qualitatively with the experimental curve of poly-L-lysine in 95% methanol. The experimental titration curves of peptide P1 in water and methanol indicate a remarkable downshift of the first pK(a) value compared to the values for reference compounds (n-butylamine and phenol, respectively), suggesting the presence of a hydrogen bond between the tyrosine hydroxyl oxygen and the H(epsilon) proton of a protonated lysine side chain. The theoretical titration curves agree well with the experimental curves, if conformations with such hydrogen bonds constitute a significant part of the ensemble; otherwise, the theory predicts too small a downward pH shift. Copyright 2005 Wiley Periodicals, Inc

  18. Distribution of Propranolol in Periocular Tissues: A Comparison of Topical and Systemic Administration

    Science.gov (United States)

    Yang, Michael B.; Liu, Hongzhuo; Li, S. Kevin

    2011-01-01

    Abstract Purpose Oral propranolol has become a promising treatment of capillary hemangiomas (CHs) despite concerns of side effects associated with systemic beta-blockers. The objective of this study was to investigate the distribution of propranolol in periocular tissues and in plasma after topical application of propranolol as compared with intravenous and oral administration of propranolol. Methods Each rabbit received propranolol as ophthalmic solution (1%) in one eye (1.5 mg dose), intravenous injection (1.5 mg dose), or commercially available propranolol oral solution (5 mg dose). The periocular tissues (e.g., eyelids and extraocular muscles) and blood were collected and assayed for propranolol. Results After topical instillation of 1.5 mg propranolol, high amounts of propranolol were rapidly delivered to the eyelids and extraocular muscles (4−32 μg/g at 1 h after dosing). The drug in these tissues was slowly cleared, and significant amounts of the drug (>0.4 μg/g) were still present at 24 h after the topical application. After oral administration of a clinically relevant dose of 5 mg propranolol, the drug concentrations in the periocular tissues were relatively low (propranolol, the drug concentrations in the eyelids and extraocular muscles were in the range of 0.2−1 μg/g at 1 h after dosing. The plasma concentration of the drug after the intravenous injection was significantly higher than that after topical application of the same dose. The higher drug concentrations in the periocular tissues of the treated eyes as compared with untreated eyes suggest direct penetration of the drug into the periocular tissues from the administration site after topical application. Conclusions Topical administration can provide increased concentrations of propranolol in the periocular tissues and, thus, is superior to systemic administration for the treatment of periocular CH. PMID:21810027

  19. Comparison of plantar pressure distribution between three different shoes and three common movements in futsal.

    Science.gov (United States)

    Teymouri, Meghdad; Halabchi, Farzin; Mirshahi, Maryam; Mansournia, Mohammad Ali; Mousavi Ahranjani, Ali; Sadeghi, Amir

    2017-01-01

    Analysis of in-shoe pressure distribution during sport-specific movements may provide a clue to improve shoe design and prevent injuries. This study compared the mean and the peak pressures over the whole foot and ten separate areas of the foot, wearing different shoes during specific movements. Nine male adult recreational futsal players performed three trials of three sport-specific movements (shuffle, sprint and penalty kick), while they were wearing three brands of futsal shoes (Adidas, Lotto and Tiger). Plantar pressures on dominant feet were collected using the F-SCAN system. Peak and mean pressures for whole foot and each separate area were extracted. For statistical analysis, the mean differences in outcome variables between different shoes and movements were estimated using random-effects regression model using STATA ver.10. In the average calculation of the three movements, the peak pressure on the whole foot in Adidas shoe was less than Lotto [8.8% (CI95%: 4.1-13.6%)] and Tiger shoes [11.8% (CI95%:7-16.7%)], (P<0.001). Also, the recorded peak pressure on the whole foot in penalty kick was 61.1% (CI95%: 56.3-65.9%) and 57.6% (CI95%: 52.8-62.3%) less than Shuffle and Sprint tests, respectively (P<0.001). Areas with the highest peak pressure during all 3 movements were not different between all shoes. This area was medial forefoot in cases of shuffle and sprint movements and medial heel in case of penalty kick.

  20. Comparison of plantar pressure distribution between three different shoes and three common movements in futsal.

    Directory of Open Access Journals (Sweden)

    Meghdad Teymouri

    Full Text Available Analysis of in-shoe pressure distribution during sport-specific movements may provide a clue to improve shoe design and prevent injuries. This study compared the mean and the peak pressures over the whole foot and ten separate areas of the foot, wearing different shoes during specific movements.Nine male adult recreational futsal players performed three trials of three sport-specific movements (shuffle, sprint and penalty kick, while they were wearing three brands of futsal shoes (Adidas, Lotto and Tiger. Plantar pressures on dominant feet were collected using the F-SCAN system. Peak and mean pressures for whole foot and each separate area were extracted. For statistical analysis, the mean differences in outcome variables between different shoes and movements were estimated using random-effects regression model using STATA ver.10.In the average calculation of the three movements, the peak pressure on the whole foot in Adidas shoe was less than Lotto [8.8% (CI95%: 4.1-13.6%] and Tiger shoes [11.8% (CI95%:7-16.7%], (P<0.001. Also, the recorded peak pressure on the whole foot in penalty kick was 61.1% (CI95%: 56.3-65.9% and 57.6% (CI95%: 52.8-62.3% less than Shuffle and Sprint tests, respectively (P<0.001.Areas with the highest peak pressure during all 3 movements were not different between all shoes. This area was medial forefoot in cases of shuffle and sprint movements and medial heel in case of penalty kick.

  1. A geospatial comparison of distributed solar heat and power in Europe and the US.

    Science.gov (United States)

    Norwood, Zack; Nyholm, Emil; Otanicar, Todd; Johnsson, Filip

    2014-01-01

    The global trends for the rapid growth of distributed solar heat and power in the last decade will likely continue as the levelized cost of production for these technologies continues to decline. To be able to compare the economic potential of solar technologies one must first quantify the types and amount of solar resource that each technology can utilize; second, estimate the technological performance potential based on that resource; and third, compare the costs of each technology across regions. In this analysis, we have performed the first two steps in this process. We use physical and empirically validated models of a total of 8 representative solar system types: non-tracking photovoltaics, 2d-tracking photovoltaics, high concentration photovoltaics, flat-plate thermal, evacuated tube thermal, concentrating trough thermal, concentrating solar combined heat and power, and hybrid concentrating photovoltaic/thermal. These models are integrated into a simulation that uses typical meteorological year weather data to create a yearly time series of heat and electricity production for each system over 12,846 locations in Europe and 1,020 locations in the United States. Through this simulation, systems composed of various permutations of collector-types and technologies can be compared geospatially and temporally in terms of their typical production in each location. For example, we see that silicon solar cells show a significant advantage in yearly electricity production over thin-film cells in the colder climatic regions, but that advantage is lessened in regions that have high average irradiance. In general, the results lead to the conclusion that comparing solar technologies across technology classes simply on cost per peak watt, as is usually done, misses these often significant regional differences in annual performance. These results have implications for both solar power development and energy systems modeling of future pathways of the electricity system.

  2. A geospatial comparison of distributed solar heat and power in Europe and the US.

    Directory of Open Access Journals (Sweden)

    Zack Norwood

    Full Text Available The global trends for the rapid growth of distributed solar heat and power in the last decade will likely continue as the levelized cost of production for these technologies continues to decline. To be able to compare the economic potential of solar technologies one must first quantify the types and amount of solar resource that each technology can utilize; second, estimate the technological performance potential based on that resource; and third, compare the costs of each technology across regions. In this analysis, we have performed the first two steps in this process. We use physical and empirically validated models of a total of 8 representative solar system types: non-tracking photovoltaics, 2d-tracking photovoltaics, high concentration photovoltaics, flat-plate thermal, evacuated tube thermal, concentrating trough thermal, concentrating solar combined heat and power, and hybrid concentrating photovoltaic/thermal. These models are integrated into a simulation that uses typical meteorological year weather data to create a yearly time series of heat and electricity production for each system over 12,846 locations in Europe and 1,020 locations in the United States. Through this simulation, systems composed of various permutations of collector-types and technologies can be compared geospatially and temporally in terms of their typical production in each location. For example, we see that silicon solar cells show a significant advantage in yearly electricity production over thin-film cells in the colder climatic regions, but that advantage is lessened in regions that have high average irradiance. In general, the results lead to the conclusion that comparing solar technologies across technology classes simply on cost per peak watt, as is usually done, misses these often significant regional differences in annual performance. These results have implications for both solar power development and energy systems modeling of future pathways of the

  3. A Geospatial Comparison of Distributed Solar Heat and Power in Europe and the US

    Science.gov (United States)

    Norwood, Zack; Nyholm, Emil; Otanicar, Todd; Johnsson, Filip

    2014-01-01

    The global trends for the rapid growth of distributed solar heat and power in the last decade will likely continue as the levelized cost of production for these technologies continues to decline. To be able to compare the economic potential of solar technologies one must first quantify the types and amount of solar resource that each technology can utilize; second, estimate the technological performance potential based on that resource; and third, compare the costs of each technology across regions. In this analysis, we have performed the first two steps in this process. We use physical and empirically validated models of a total of 8 representative solar system types: non-tracking photovoltaics, 2d-tracking photovoltaics, high concentration photovoltaics, flat-plate thermal, evacuated tube thermal, concentrating trough thermal, concentrating solar combined heat and power, and hybrid concentrating photovoltaic/thermal. These models are integrated into a simulation that uses typical meteorological year weather data to create a yearly time series of heat and electricity production for each system over 12,846 locations in Europe and 1,020 locations in the United States. Through this simulation, systems composed of various permutations of collector-types and technologies can be compared geospatially and temporally in terms of their typical production in each location. For example, we see that silicon solar cells show a significant advantage in yearly electricity production over thin-film cells in the colder climatic regions, but that advantage is lessened in regions that have high average irradiance. In general, the results lead to the conclusion that comparing solar technologies across technology classes simply on cost per peak watt, as is usually done, misses these often significant regional differences in annual performance. These results have implications for both solar power development and energy systems modeling of future pathways of the electricity system. PMID

  4. Comparison of modern pollen distribution between northern and southern South China Sea

    Science.gov (United States)

    Luo, C.; Chen, M.; Xiang, R.; Liu, J.; Zhang, L.; Lu, J.

    2013-12-01

    southern of SCS are mainly 21-117 grains/g. Pollen concentration of the northern is nearly 10 times more than in the southern SCS. This is because most pollen types is transported from the north by the Pearl River and rivers in Taiwan, only Trilete-spore is not transported by the above rivers, it may be transported by rivers from Hainan Island and summer monsoon forced marine current. 3. Pollen from surface water of the South China Sea 5 samples were collected from surface water of the South China Sea. It was found that the 1st sample has most abundant of Algae, because it is located in the entrance of Hanjiang River. Pollen grains in the sample number 4 are rare; this is probably because that it is located on the boundary current of the northern part of the South China Sea. 4. Comparison of pollen from air, ocean surface water, surface sediments Pollen and spore in air contain mainly herbaceous and woody pollen, excluding fern spores. Ocean surface water contain mainly the Dicranopteris dichotoma , Polypodiales and other Trilete-spores, with pollen of aquatic plants Alismataceae occurring, excluding Pinus pollen. Pollen in the surface sediments are mainly Trilete-spores, Pinus and herbaceous, and may be a combination of annual pollen characteristics. Acknowledgments This work was funded by the National Natural Science Foundation of China (grants NSFC 41176049).

  5. Temperature dependences of self- and N2-broadened line-shape parameters in the ν3 and ν5 bands of 12CH3D: Measurements and calculations

    Science.gov (United States)

    Predoi-Cross, A.; Malathy Devi, V.; Sutradhar, P.; Sinyakova, T.; Buldyreva, J.; Sung, K.; Smith, M. A. H.; Mantz, A. W.

    2016-07-01

    This paper presents the results of a spectroscopic line shape study of self- and nitrogen-broadened 12CH3D transitions in the ν3 and ν5 bands in the Triad region. We combined five pure gas spectra with eighteen spectra of lean mixtures of 12CH3D and nitrogen, all recorded with a Bruker IFS-125 HR Fourier transform spectrometer. The spectra have been analyzed simultaneously using a multispectrum nonlinear least squares fitting technique. N2-broadened line parameters for 184 transitions in the ν3 band and 205 transitions in the ν5 band were measured. In addition, line positions and line intensities were measured for 168 transitions in the ν3 band and 214 transitions in the ν5 band. We have observed 10 instances of weak line mixing corresponding to K″=3 A1 or A2 transitions. Comparisons were made for the N2-broadening coefficients and associated temperature exponents with corresponding values calculated using a semi-classical Robert Bonamy type formalism that involved an inter-molecular potential with terms corresponding to short- and long-range interactions, and exact classical molecular trajectories. The theoretical N2-broadened coefficients are overestimated for high J values, but are in good agreement with the experimental values for small and middle range J values.

  6. Power broadening effects on Electromagnetically Induced Transparency in $^{20}$Ne vapor

    CERN Document Server

    Lubotzky, Boaz; Kong, Tao; Katz, Nadav; Ron, Guy

    2014-01-01

    We report here the first observation of electromagnetically induced transparency (EIT) in $^{20}$Ne. The power broadening of the EIT linewidth is measured as a function of neon pressure and RF excitation power. Doppler effects on the EIT broadening are found even at low pressures and low intensities, where the linewidth should be governed only by homogeneous effects.

  7. Compensation of loss-induced beam broadening in HMMs by a μ-negative HMM

    DEFF Research Database (Denmark)

    Repan, T.; Novitsky, Andrey; Willatzen, Morten

    2017-01-01

    Losses play a crucial role when realistic hyperbolic metamaterials are considered. Importantly, losses lead to a broadening of beams propagating through a hyperbolic medium. Here we show that a part of the loss-induced broadening can be attributed to phase accumulation of plane-wave components...

  8. Compensation of loss-induced beam broadening in HMMs by a 휇-negative HMM

    DEFF Research Database (Denmark)

    Repän, Taavi; Novitsky, Andrey; Willatzen, Morten

    2017-01-01

    Losses play a crucial role when realistic hyperbolic metamaterials are considered. Importantly, losses lead to a broadening of beams propagating through a hyperbolic medium. Here we show that a part of the loss-induced broadening can be attributed to phase accumulation of plane-wave components...

  9. Doppler broadening as a probe of the chemical environment following oxygen-14 decay

    NARCIS (Netherlands)

    Nickles, RJ; Jensen, M; Paans, AMJ; Holm, S; Schueller, MJ; Vaalburg, W

    2000-01-01

    A search for the Doppler broadening following the beta decay of oxygen-14 was conducted with high resolution gamma spectroscopy on the 2313 keV gamma ray. Such a broadening should signal the mass of the labeled molecule and the nature of the stopping medium. Oxygen-14 labeled H2O, O-2 and CO2

  10. Correction of Doppler-broadened Rayleigh backscattering effects in H2O dial measurements

    Science.gov (United States)

    Ansmann, A.; Bosenberg, J.

    1986-01-01

    A general method of solutions for treating effects of Doppler-broadened Rayleigh backscattering in H2O Differential Absorption Lidar (DIAL) measurements are described and discussed. Errors in vertical DIAL measuremtns caused by this laser line broadening effect can be very large and, therfore, this effect has to be accounted for accurately. To analyze and correct effects of Doppler-broadened Rayleigh backscattering in DIAL experiments, a generalized DIAL approximation was derived starting from a lidar equation, which includes Doppler broadening. To evaluate the accuracy of H2O DIAL measurements, computer simulations were performed. It was concluded that correction of Doppler broadened Rayleigh backscattering is possible with good accuracy in most cases of tropospheric H2O DIAL measurements, but great care has to be taken when layers with steep gradients of Mie backscattering like clouds or inversion layers are present.

  11. Abundance, distribution and diversity of gelatinous predators along the northern Mid-Atlantic Ridge: A comparison of different sampling methodologies.

    Science.gov (United States)

    Hosia, Aino; Falkenhaug, Tone; Baxter, Emily J; Pagès, Francesc

    2017-01-01

    The diversity and distribution of gelatinous zooplankton were investigated along the northern Mid-Atlantic Ridge (MAR) from June to August 2004.Here, we present results from macrozooplankton trawl sampling, as well as comparisons made between five different methodologies that were employed during the MAR-ECO survey. In total, 16 species of hydromedusae, 31 species of siphonophores and four species of scyphozoans were identified to species level from macrozooplankton trawl samples. Additional taxa were identified to higher taxonomic levels and a single ctenophore genus was observed. Samples were collected at 17 stations along the MAR between the Azores and Iceland. A divergence in the species assemblages was observed at the southern limit of the Subpolar Frontal Zone. The catch composition of gelatinous zooplankton is compared between different sampling methodologies including: a macrozooplankton trawl; a Multinet; a ringnet attached to bottom trawl; and optical platforms (Underwater Video Profiler (UVP) & Remotely Operated Vehicle (ROV)). Different sampling methodologies are shown to exhibit selectivity towards different groups of gelatinous zooplankton. Only ~21% of taxa caught during the survey were caught by both the macrozooplankton trawl and the Multinet when deployed at the same station. The estimates of gelatinous zooplankton abundance calculated using these two gear types also varied widely (1.4 ± 0.9 individuals 1000 m-3 estimated by the macrozooplankton trawl vs. 468.3 ± 315.4 individuals 1000 m-3 estimated by the Multinet (mean ± s.d.) when used at the same stations (n = 6). While it appears that traditional net sampling can generate useful data on pelagic cnidarians, comparisons with results from the optical platforms suggest that ctenophore diversity and abundance are consistently underestimated, particularly when net sampling is conducted in combination with formalin fixation. The results emphasise the importance of considering sampling methodology

  12. Comparison of Plantar Pressure Distribution in Dominant & Non-dominant leg of female Kata and Kumite National Team

    Directory of Open Access Journals (Sweden)

    Elnaz Dizaji

    2016-09-01

    Full Text Available Objective: The aim of this study was to compare the plantar pressure distribution of dominant and non-dominant legs of females who were participated in the kata and kumite national team. Methods: Twelve kumite and 8 kata female athletes of the Karate national team participated in this study. Plantar pressure was measured using emed platform during barefoot walking. After dividing the foot into 10 masks, peak pressure, pressure-time integral, maximum force and force-time integral were calculated. Wilcoxon and U-Mann-Witney tests were used to analyze parameters at a significance level of p ≤ 0.05. Results: In comparison of kata and kumite teams it was found that, kata plantar pressure parameters in Metatarsal-2 (p=0.05 and Metatarsals-3, 4, 5 (p=0.04 were significantly less than those in kumite. Also, in comparison of dominant and non-dominant leg, plantar pressure parameters of dominant leg were less in Metatarsal-2 (p=0.04 and more in Bigtoe (p=0.04 and Toes-3, 4, 5 (p=0.03 than those in the non-dominant leg. Conclusion: Results may be indicative different of natures of the two athletic fields in that Kumite has a higher impact on plantar pressure due to higher mechanical loads. Furthermore, the unequal use of the legs may affect plantar pressure because of leg dominance. Thus, further and more comprehensive studies are necessary to prevent exercise-induced adaptations in professional levels and their treatments.

  13. Abundance, distribution and diversity of gelatinous predators along the northern Mid-Atlantic Ridge: A comparison of different sampling methodologies.

    Directory of Open Access Journals (Sweden)

    Aino Hosia

    Full Text Available The diversity and distribution of gelatinous zooplankton were investigated along the northern Mid-Atlantic Ridge (MAR from June to August 2004.Here, we present results from macrozooplankton trawl sampling, as well as comparisons made between five different methodologies that were employed during the MAR-ECO survey. In total, 16 species of hydromedusae, 31 species of siphonophores and four species of scyphozoans were identified to species level from macrozooplankton trawl samples. Additional taxa were identified to higher taxonomic levels and a single ctenophore genus was observed. Samples were collected at 17 stations along the MAR between the Azores and Iceland. A divergence in the species assemblages was observed at the southern limit of the Subpolar Frontal Zone. The catch composition of gelatinous zooplankton is compared between different sampling methodologies including: a macrozooplankton trawl; a Multinet; a ringnet attached to bottom trawl; and optical platforms (Underwater Video Profiler (UVP & Remotely Operated Vehicle (ROV. Different sampling methodologies are shown to exhibit selectivity towards different groups of gelatinous zooplankton. Only ~21% of taxa caught during the survey were caught by both the macrozooplankton trawl and the Multinet when deployed at the same station. The estimates of gelatinous zooplankton abundance calculated using these two gear types also varied widely (1.4 ± 0.9 individuals 1000 m-3 estimated by the macrozooplankton trawl vs. 468.3 ± 315.4 individuals 1000 m-3 estimated by the Multinet (mean ± s.d. when used at the same stations (n = 6. While it appears that traditional net sampling can generate useful data on pelagic cnidarians, comparisons with results from the optical platforms suggest that ctenophore diversity and abundance are consistently underestimated, particularly when net sampling is conducted in combination with formalin fixation. The results emphasise the importance of considering

  14. Some Strategies From SOARS for Broadening Participation in the Geosciences

    Science.gov (United States)

    Haacker-Santos, R.; Pandya, R.; Calhoun, A.

    2006-12-01

    The mission of SOARS® is to broaden participation in the geosciences by increasing the number of Black or African-American, American Indian or Alaska Native, Hispanic or Latino, female, and first-generation college students who enroll and succeed in graduate school in the atmospheric and related sciences. This mission contributes to national goals of developing a diverse, internationally competitive, and globally engaged workforce of scientists and engineers. SOARS is a multiyear undergraduate-to-graduate bridge program that uses three strategies: a strong learning community, a multidimensional mentoring program, and experience in research. Our presentation will describe SOARS' strategies in more detail, with an eye toward how such strategies might be adapted for other programs. To do this, we will draw upon recent research that documents how these strategies can be successfully implemented, including: - A survey of over 124 higher-education based STEM programs - A workshop report from the American Chemical Society emphasizing cooperation between industry and academia - An independent ethnographic study of the Significant Opportunities in Atmospheric and Related Science (SOARS®) program, administered by the University Corporation for Atmospheric Research (UCAR) In the 11 years since SOARS' founding, 104 students have participated in the program. Of those participants, 16 are still enrolled as undergraduates, and 60 have gone on to purse graduate school in STEM. Overall, this represents a success rate 91%. Of the 35 SOARS participants who have entered the workforce, 26 are in STEM related disciplines. Four SOARS participants have already earned their PhD, and additional 17 are in PhD programs. Seventeen protégés have earned Master's and entered the workforce, and 17 more protégés are enrolled in Master's programs.

  15. Doppler Broadening Thermometry Based on Cavity Ring-Down Spectroscopy

    Science.gov (United States)

    Hu, Shui-Ming; Cheng, Cunfeng; Wang, Jin; Tan, Yan; Sun, Yu Robert; Liu, An-Wen; Zhang, Jin-Tao

    2014-06-01

    A Doppler broadening thermometry is implemented using a laser-locked cavity ring-down spectrometer [1,2] combined with a temperature-stabilized sample cell. The temperature fluctuation of the gas sample cell is kept below 1 mK for hours. The probing laser is frequency locked at a longitudinal mode of a Fabry-Pérot interferometer made of ultra-low-expansion glass, and the spectral scan is implemented by scanning the sideband produced by an electro-optic modulator. As a result, a kHz precision has been maintained during the measurement of the spectrum of 10 GHz wide. A ro-vibrational line of C_2H_2 is measured at sample pressures of a few Pa. Using a pair of mirrors with a reflectivity of 0.99997 at 787 nm, we are able to detect absorption line profiles with a signal-to-noise ratio of 10^5. Fitting of the recorded spectra allows us to determine the Doppler width with a statistical uncertainty of 10 ppm. Further improvements on the experimental reproducibility and investigations on the collision effects will probably lead to an optical determination of the Boltzmann constant with an uncertainty of a few ppm. H. Pan, C.-F. Cheng, Y. R. Sun, B. Gao, A.-W. Liu, S.-M. Hu, ``Laser-locked, continuously tunable high resolution cavity ring-down spectrometer," Rev. Sci. Instrum. 82, 103110 (2011) Y. R. Sun, H. Pan, C.-F. Cheng, A.-W. Liu, J.-T. Zhang, S.-M. Hu, ``Application of cavity ring-down spectroscopy to the Boltzmann constant determination," Opt. Express, 19, 19993 (2011)

  16. Cardiovascular RNA interference therapy: the broadening tool and target spectrum.

    Science.gov (United States)

    Poller, Wolfgang; Tank, Juliane; Skurk, Carsten; Gast, Martina

    2013-08-16

    Understanding of the roles of noncoding RNAs (ncRNAs) within complex organisms has fundamentally changed. It is increasingly possible to use ncRNAs as diagnostic and therapeutic tools in medicine. Regarding disease pathogenesis, it has become evident that confinement to the analysis of protein-coding regions of the human genome is insufficient because ncRNA variants have been associated with important human diseases. Thus, inclusion of noncoding genomic elements in pathogenetic studies and their consideration as therapeutic targets is warranted. We consider aspects of the evolutionary and discovery history of ncRNAs, as far as they are relevant for the identification and selection of ncRNAs with likely therapeutic potential. Novel therapeutic strategies are based on ncRNAs, and we discuss here RNA interference as a highly versatile tool for gene silencing. RNA interference-mediating RNAs are small, but only parts of a far larger spectrum encompassing ncRNAs up to many kilobasepairs in size. We discuss therapeutic options in cardiovascular medicine offered by ncRNAs and key issues to be solved before clinical translation. Convergence of multiple technical advances is highlighted as a prerequisite for the translational progress achieved in recent years. Regarding safety, we review properties of RNA therapeutics, which may immunologically distinguish them from their endogenous counterparts, all of which underwent sophisticated evolutionary adaptation to specific biological contexts. Although our understanding of the noncoding human genome is only fragmentary to date, it is already feasible to develop RNA interference against a rapidly broadening spectrum of therapeutic targets and to translate this to the clinical setting under certain restrictions.

  17. Doppler Broadening Thermometry Based on Cavity Ring-Down Spectroscopy

    Science.gov (United States)

    Wang, Jin; Sun, Yu Robert; Cheng, Cunfeng; Tao, Lei-Gang; Tan, Yan; Kang, Peng; Liu, An-Wen; Hu, Shui-Ming

    2016-06-01

    A Doppler broadening thermometry (DBT) instrument is implemented based on a laser-locked cavity ring-down spectrometer. [1,2] It can be used to determine the Boltzmann constant by measuring the Doppler width of a molecular ro-vibrational transition in the near infrared. Compared with conventional direct absorption methods, the high-sensitivity of CRDS allows to reach satisfied precision at lower sample pressures, which reduces the influence due to collisions. By measuring the ro-vibrational transition of C_2H_2 at 787 nm, we demonstrate a statistical uncertainty of 6 ppm (part per million) in the determined linewidth by several hours' measurement at a sample pressure of 1.5 Pa. [3] However, the complicity in the spectrum of a polyatomic molecule induces potential systematic influence on the line profile due to nearby ``hidden'' lines from weak bands or minor isotopologues. Recently, the instrument has been upgraded in both sensitivity and frequency accuracy. A narrow-band fiber laser frequency-locked to a frequency comb is applied, and overtone transitions at 1.56 μm of the 12C16O molecule are used in the CRDS-DBT measurements. The simplicity of the spectrum of the diatomic CO molecule eliminates the potential influence from ``hidden'' lines. Our preliminary measurements and analysis show that it is feasible to pursue a DBT measurement toward the 1 ppm precision. H. Pan, et al., Rev. Sci. Instrum. 82, 103110 (2011) Y. R. Sun, et al., Opt. Expr., 19, 19993 (2011) C.-F. Cheng, et al., Metrologia, 52, S385 (2015)

  18. Comparison of Lumped and Distributed Hydrologic Models Used for Planning and Water Resources Management at the Combeima River Basin, Colombia.

    Science.gov (United States)

    Salgado, F., II; Vélez, J.

    2014-12-01

    The catchment area is considered as the planning unit of natural resources where multiple factors as biotic, abiotic and human interact in a web of relationships making this unit a complex system. It is also considered by several authors as the most suitable unit for studying the water movement in nature and a tool for the understanding of natural processes. This research implements several hydrological models commonly used in water resources management and planning. It is the case of Témez, abcd, T, P, ARMA (1,1), and the lumped conceptual model TETIS. This latest model has been implemented in its distributed version for comparison purposes and it has been the basis for obtaining information, either through the reconstruction of natural flow series, filling missing data, forecasting or simulation. Hydrological models make use of lumped data of precipitation and potential evapotranspiration, as well as the following parameters for each one of the models which are related to soil properties as capillary storage capacity; the hydraulic saturated conductivity of the upper and lower layers of the soil, and residence times in the flow surface, subsurface layers and base flow. The calibration and the validation process of the models were performed making adjustments to the parameters listed above, taking into account the consistency in the efficiency indexes and the adjustment between the observed and simulated flows using the flow duration curve. The Nash index gave good results for the TETIS model and acceptable values were obtained to the other models. The calibration of the distributed model was complex and its results were similar to those obtained with the aggregated model. This comparison allows planners to use the hydrological multimodel techniques to reduce the uncertainty associated with planning processes in developing countries. Moreover, taking into account the information limitations required to implement a hydrological models, this application can be a

  19. More on the narrowing of impact broadened radio recombination lines at high principal quantum number

    Science.gov (United States)

    Bell, M. B.

    2012-07-01

    Recently Alexander and Gulyaev have suggested that the apparent decrease in impact broadening of radio recombination lines seen at high principal quantum number n may be a product of the data reduction process, possibly resulting from the presence of noise on the telescope spectra that is not present on the calculated comparison spectra. This is an interesting proposal. However, there are serious problems with their analysis that need to be pointed out. Perhaps the most important of these is the fact that for principal quantum numbers below n=200, where the widths are not in question, their processed generated profile widths do not fit the widths of the processed lines obtained at the telescope. After processing, the halfwidths of the generated and telescope profiles must agree below n=200 if we are to believe that the processed generated linewidths above n=200 are meaningful. Theirs do not. Furthermore, we find that after applying the linewidth reduction factors found by Alexander and Gulyaev for their noise added profiles to our generated profiles to simulate their noise adding effect, the processed widths we obtain still do not come close to explaining the narrowing seen in the telescope lines for n values in the range 200technique instead of simply a further manipulation of the frequency-switched data.

  20. Elemental distribution and sample integrity comparison of freeze-dried and frozen-hydrated biological tissue samples with nuclear microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Vavpetič, P., E-mail: primoz.vavpetic@ijs.si [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Vogel-Mikuš, K. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Jeromel, L. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Ogrinc Potočnik, N. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); FOM-Institute AMOLF, Science Park 104, 1098 XG Amsterdam (Netherlands); Pongrac, P. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Department of Plant Physiology, University of Bayreuth, Universitätstr. 30, 95447 Bayreuth (Germany); Drobne, D.; Pipan Tkalec, Ž.; Novak, S.; Kos, M.; Koren, Š.; Regvar, M. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Pelicon, P. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2015-04-01

    The analysis of biological samples in frozen-hydrated state with micro-PIXE technique at Jožef Stefan Institute (JSI) nuclear microprobe has matured to a point that enables us to measure and examine frozen tissue samples routinely as a standard research method. Cryotome-cut slice of frozen-hydrated biological sample is mounted between two thin foils and positioned on the sample holder. The temperature of the cold stage in the measuring chamber is kept below 130 K throughout the insertion of the samples and the proton beam exposure. Matrix composition of frozen-hydrated tissue is consisted mostly of ice. Sample deterioration during proton beam exposure is monitored during the experiment, as both Elastic Backscattering Spectrometry (EBS) and Scanning Transmission Ion Microscopy (STIM) in on–off axis geometry are recorded together with the events in two PIXE detectors and backscattered ions from the chopper in a single list-mode file. The aim of this experiment was to determine differences and similarities between two kinds of biological sample preparation techniques for micro-PIXE analysis, namely freeze-drying and frozen-hydrated sample preparation in order to evaluate the improvements in the elemental localisation of the latter technique if any. In the presented work, a standard micro-PIXE configuration for tissue mapping at JSI was used with five detection systems operating in parallel, with proton beam cross section of 1.0 × 1.0 μm{sup 2} and a beam current of 100 pA. The comparison of the resulting elemental distributions measured at the biological tissue prepared in the frozen-hydrated and in the freeze-dried state revealed differences in elemental distribution of particular elements at the cellular level due to the morphology alteration in particular tissue compartments induced either by water removal in the lyophilisation process or by unsatisfactory preparation of samples for cutting and mounting during the shock-freezing phase of sample preparation.

  1. Continuous tree distribution in China: A comparison of two estimates from Moderate-Resolution Imaging Spectroradiometer and Landsat data

    Science.gov (United States)

    Liu, Ronggao; Liang, Shunlin; Liu, Jiyuan; Zhuang, Dafang

    2006-04-01

    Forest change is a major contributor to changes in carbon stocks and trace gas fluxes between terrestrial and atmospheric layers. This study compares two satellite estimates of percent tree distribution data sets over China. One estimate is from the Chinese National Land Cover Data Set (NLCD) generated by a multiyear national land cover project in China through visual interpretation of Landsat thematic mapper (TM) and the Enhanced Thematic Mapper Plus (ETM+) images primarily acquired in the year 2000. The other estimate is the Moderate-Resolution Imaging Spectroradiometer (MODIS) standard product (MOD44B) from the same year. The two products reveal some common features, but significant discrepancies exist. Detailed analyses are carried out with different land cover types and over different regions. Comparison results show that the difference of the total tree canopy area for the whole country is 159,000 km2. The pixel counts in the NLCD data set for dense forest are ˜4 times those in the MODIS data set with the reverse holding for sparse forest. Generally, the percent tree canopy area of the NLCD data set is larger in eastern China and lower in the Tibetan plateau margin region. For different land cover types the percentage of tree canopy areas shows a good agreement for evergreen forests but a large discrepancy for deciduous forests. The largest variations are associated with grassland and nonvegetation classes. Regarding the spatial distributions of their differences, Inner Mongolia is the place where both data sets show a diverse result, but Guizhou and Fujian present the least divergence among those provinces with the tree canopy area being more than 20,000 km2.

  2. [Nerve distribution and density in the canine hip joint capsule. Comparison of healthy and dysplastic hip joints].

    Science.gov (United States)

    Giebels, Felix; Prescher, Andreas; Wagenpfeil, Stefan; Bücker, Arno; Kinzel, Sylvia

    2017-04-19

    The hip-joint capsule is exposed to increased tension forces during canine hip dysplasia, resulting in inflammation of the capsular tissue. It has been postulated that inflammation is associated with an increased nerve-distribution density. Therefore, it could be supposed that the nerve-distribution density in the hip-joint capsule is higher in dogs with dysplastic hip compared to healthy dogs. In 16 Labrador Retriever dogs that had been euthanised due to unrelated reasons, the hip joints were classified as normoplastic (group 1, n = 18) or dysplastic (group 2, n = 14) based on radiography. Following staining of the capsular nerve fibres by the Sihler method, histological specimens of the hip-joint capsules were scanned. By subdividing each specimen into 10 quadrants numbered from dorsomedial (Q01) to craniodorsolateral (Q10), the ratio of black to white pixels was calculated digitally for each specimen and each quadrant by using a semiautomatic image analysis. Statistical analysis was performed using an independent t-test. Comparison of the mean values of each quadrant showed a significantly higher (p hip-joint capsule in dogs with dysplastic hip could be the result of increased tension forces on this area following hip-joint dysplasia. The craniodorsal region of the hip-joint capsule is an important origin of pain and coxarthrosis in canine hip dysplasia. The results provide the pathophysiological basis for the efficacy of hip-joint denervation. Denervation of the cranial region of the acetabular rim is essential to reduce capsular inflammation and joint-related pain in canine hip dysplasia.

  3. Analytic 1D Approximation of the Divertor Broadening S in the Divertor Region for Conductive Heat Transport

    CERN Document Server

    Nille, Dirk; Eich, Thomas

    2016-01-01

    Topic is the divertor broadening $S$, being a result of perpendicular transport in the scrape-off layer and resulting in a better distribution of the power load onto the divertor target. Recent studies show a scaling of the divertor broadening with an inverse power law to the target temperature $T_t$, promising its reduction to be a way of distributing the power entering the divertor volume onto a large surface area. It is shown that for pure conductive transport in the divertor region the suggested inverse power law scaling to $T_t$ is only valid for high target electron temperatures. For decreasing target temperatures ($T_t < 20\\,$eV) the increase of $S$ stagnates and the conductive model results in a finite value of $S$ even for zero target temperature. It is concluded that the target temperature is no valid parameter for a power law scaling, as it is not representative for the entire divertor volume. This is shown in simulations solving the 2D heat diffusion equation, which is used as reference for an ...

  4. Comparison of Water-Load Distributions Obtained during Seaplane Landings with Bureau of Aeronautics Specifications. TED No. NACA 2413

    Science.gov (United States)

    Smiley, Robert F.; Haines, Gilbert A.

    1949-01-01

    Bureau of Aeronautics Design Specifications SS-IC-2 for water loads in sheltered water are compared with experimental water loads obtained during a full--scale landing investigation. This investigation was conducted with a JRS-1 flying boat which has a 20 degrees dead-rise V-bottom with a partial chine flare. The range of landing conditions included airspeeds between 88 and 126 feet per second, sinking speeds between 1.6 and 9.1 feet per second, flight angles less than 6 degrees, and trims between 2 degrees and 12 degrees. Landings were moderate and were made in calm water. Measurements were obtained of maximum over-all loads, maximum pitching moments, and pressure distributions. Maximum experimental loads include over-all load factors of 2g, moments of 128,000 pound-feet, and maximum local pressures greater than 40 pounds per square inch. Experimental over-all loads are approximately one-half the design values, while local pressures are of the same order as or larger than pressures calculated from specifications for plating, stringer, floor, and frame design. The value of this comparison is limited, to some extent, by the moderate conditions of the test and by the necessary simplifying assumptions used in comparing the specifications with the experimental loads.

  5. Comparison of Eimeria species distribution and salinomycin resistance in commercial broiler operations utilizing different coccidiosis control strategies.

    Science.gov (United States)

    Jenkins, M; Klopp, S; Ritter, D; Miska, K; Fetterer, R

    2010-09-01

    The purpose of the present study was to evaluate the species composition and salinomycin sensitivity of Eimeria oocysts isolated from commercial broiler farms that differed by means of coccidiosis control (anticoccidial drugs [ACD] vs. live oocyst vaccines [VAC]). A comparison of Eimeria species composition and salinomycin sensitivity was also made before and after a producer switched from salinomycin to live oocyst vaccines. In general, no significant difference was observed in the concentration of Eimeria spp. oocysts in litter from VAC-utilizing farms compared to litter from ACD-utilizing farms. Application of PCR-based methods to detect coccidia found that Eimeria species distribution in litter from VAC operations more closely resembled the species composition in the live oocyst vaccines. Drug sensitivity testing found that Eimeria oocysts from VAC operations displayed greater salinomycin sensitivity as measured by weight gain and feed conversion efficiency compared to oocysts from ACD farms. These findings provide additional evidence for the usefulness of live oocyst vaccines to restore ionophore sensitivity in poultry operations that contain an ionophore-resistant population of Eimeria spp. oocysts.

  6. COMPARISON OF BACTERIAL FORAGING OPTIMIZATION AND ARTIFICIAL BEE COLONY OPTIMIZATION TECHNIQUE FOR DISTRIBUTED GENERATION SIZING AND PLACEMENT IN AN ELECTRICAL DISTRIBUTION SYSTEM

    OpenAIRE

    J. A. Baskar*, Dr. R. Hariprakash (IITM), Dr. M. Vijayakumar

    2017-01-01

    Integration of Distributed Generation (DG) in an electrical distribution system has increased recently due to voltage improvement, line loss reduction, environmental advantages, and postponement of system upgrading, and increasing reliability. Improper location and capacity of DG may affect the voltage stability on the Distribution System (DS). Optimization techniques are tools used to predict size and locate the DG units in the system, so as to utilize these units optimally within certain li...

  7. The effect of broadened linewidth induced by dispersion on the performance of resonant optical gyroscope

    Science.gov (United States)

    Zhang, Hao; Li, Wenxiu; Han, Peng; Chang, Xiaoyang; Liu, Jiaming; Lin, Jian; Xue, Xia; Zhu, Fang; Yang, Yang; Liu, Xiaojing; Zhang, Xiaofu; Huang, Anping; Xiao, Zhisong; Fang, Jiancheng

    2018-01-01

    Anomalous dispersion enhancement physical mechanism for Sagnac effect is described by special relativity derivation, and three kinds of definitions of minimum detectable angular rate of resonance optical gyroscope (ROG) are compared and the relations among them are investigated. The effect of linewidth broadening induced by anomalous dispersion on the sensitivity of ROG is discussed in this paper. Material dispersion-broadened resonance linewidth deteriorates the performance of a passive ROG and dispersion enhancement effect, while the sensitivity of a structural dispersion ROG is enhanced by two orders of magnitude even considering the dispersion-broadened resonance linewidth.

  8. Determination of Van der Waals broadening at temperatures of astrophysical interest.

    Science.gov (United States)

    Evans, J. M., Jr.; Cooper, J.

    1972-01-01

    Discussion of the results of experiments analyzing the widths of shock-excited emission lines at temperatures of about 5000 K. The width of two neutral silicon lines (4102 and 5948 A) were measured as broadened by argon, and the shift of one of these lines (4102 A) was determined. Likewise, the width one of the lines of cesium (4593 A) was measured as broadened by argon and neon. These data are compared with other experimental data to determine the temperature dependence of the broadening. Significant disagreements with simple theory are found, the experimental values of the widths being larger than the theoretical values by factors of 1.5-2.

  9. Spectral broadening of acoustic tones generated by unmanned aerial vehicles in a turbulent atmosphere

    DEFF Research Database (Denmark)

    Ostashev, Vladimir E.; Wilson, D. K.; Finn, Anthony

    2016-01-01

    The acoustic spectrum emitted by unmanned aerial vehicles (UAVs) and other aircraft can be distorted by propagation through atmospheric turbulence. Since most UAVs are propeller-based, they generate a series of acoustic tones and harmonics. In this paper, spectral broadening of these tones due......, spectral broadening is calculated and analyzed for typical meteorological regimes of the atmospheric boundary layer and different flight trajectories of UAVs. Experimental results are presented and compared with theoretical predictions. Spectral broadening might also provide a means for remotely sensing...

  10. [Calculating the stark broadening of welding arc spectra by Fourier transform method].

    Science.gov (United States)

    Pan, Cheng-Gang; Hua, Xue-Ming; Zhang, Wang; Li, Fang; Xiao, Xiao

    2012-07-01

    It's the most effective and accurate method to calculate the electronic density of plasma by using the Stark width of the plasma spectrum. However, it's difficult to separate Stark width from the composite spectrum linear produced by several mechanisms. In the present paper, Fourier transform was used to separate the Lorentz linear from the spectrum observed, thus to get the accurate Stark width. And we calculated the distribution of the TIG welding arc plasma. This method does not need to measure arc temperature accurately, to measure the width of the plasma spectrum broadened by instrument, and has the function to reject the noise data. The results show that, on the axis, the electron density of TIG welding arc decreases with the distance from tungsten increasing, and changes from 1.21 X 10(17) cm(-3) to 1.58 x 10(17) cm(-3); in the radial, the electron density decreases with the distance from axis increasing, and near the tungsten zone the biggest electronic density is off axis.

  11. Stress distribution calculations through a snow slab of varying elastic modulus; comparison with stability evaluation in the field

    Science.gov (United States)

    Swinkels, Laura; Borstad, Chris

    2017-04-01

    Field observations are the main tools for assessing the snow stability concerning dry snow slab avalanche release. Often, theoretical studies cannot directly be translated into useful information for avalanche recreationists and forecasters in the field, and vice versa; field observations are not always objective and quantifiable for theoretical studies. Moreover, numerical models often simplify the snowpack and generally use an isotropic single layer slab which is not representative of the real-life situation. The aim of this study is to investigate the stress distribution in a snowpack with an elastic modulus that continuously varies with depth. The focus lies on the difference between a slab with a gradient in hardness and a slab with isotropic hardness and the effect on the calculated maximum stress and the stability evaluation in the field. Approximately 20 different snow pits were evaluated in the mountains around Tromsø, Norway and Longyearbyen, Svalbard. In addition to the standard snowpack observations, the hardness was measured using a thin-blade gauge. Extended column tests were executed for stability evaluation. Measurements from the field were used as input for stress calculations for each snow pit using a line load solution for a sloping half space with a non-homogeneous elastic modulus. The hardness measurements were used to calculate the elastic modulus and a power law relation was fit through the modulus in the slab. The calculated shear stress was compared to the estimated stability and character of the specific snowpack The results show that the approach used for this study improves the calculation of stress at a given depth, although many assumptions and simplifications were still needed. Comparison with the snow profiles indicate that calculated stresses correlate well with the observed snowpack properties and stability. The calculated shear stresses can be introduced in the standard stability index and give a better indication for the

  12. Effects of positive mood on attention broadening for self-related information.

    Science.gov (United States)

    Grol, Maud; Koster, Ernst H W; Bruyneel, Lynn; De Raedt, Rudi

    2014-07-01

    Studies on cognitive effects of positive emotions have associated positive emotions to broadened attention. Given the widely investigated relationship between self-focused attention and mood, it is important to investigate the effect of positive mood on visuospatial attention for self-related information. We used a performance-based measure to assess fluctuations in attentional broadening from self-related contrasted to not-self-related information. In Experiment 1, we checked that the self-related versus not-self-related stimuli did not evoke differential attention effects in general. In Experiment 2, we manipulated mood and found that an increase in positive mood was associated with a relative broadening of attention for self-related information. These results suggest that the meaning of the target of attention provides an interesting dimension for further investigation into the relation between positive emotions and attentional broadening.

  13. Analysis of compressive failure of layered materials by kink band broadening

    DEFF Research Database (Denmark)

    Jensen, Henrik Myhre

    1999-01-01

    Failure by steady state kink band broadening in uni-directional fibre composites or layered materials is analysed. An incremental scheme for calculation of kink band broadening stresses and lock-up conditions in the band for arbitrary material behaviour is presented. The method is illustrated by ...... by material data which are representative for polymer matrix composites for which experimental work exists. (C) 1999 Elsevier Science Ltd. All rights reserved....

  14. Superheating effects in line broadening of dense alkali vapors

    Science.gov (United States)

    Pichler, G.; Makdisi, Y.; Kokaj, J.; Mathew, J.; Rakić, M.; Beuc, R.

    2017-02-01

    We used the superheating of the dense alkali vapor in order to separate atomic from the molecular photoionization spectrum. Homonuclear and heteronuclear alkali molecules are essentially two electron systems and therefore simultaneous excitation of two atoms above the ionization limit will form autoionizing potential curves which will bring about new bands in the photoionization spectrum. We present a satisfactory comparison between experimental and theoretical emission coefficient function of diffuse bands (cesium dimer excimer) at temperatures up to 1000 °C, where the metal vapor was heavily superheated. New results for Rb2 photoionization process reveal similar structured photoionization continuum but with reduced number of photoionization bands.

  15. A comparison of methods to handle skew distributed cost variables in the analysis of the resource consumption in schizophrenia treatment.

    Science.gov (United States)

    Kilian, Reinhold; Matschinger, Herbert; Löeffler, Walter; Roick, Christiane; Angermeyer, Matthias C

    2002-03-01

    Transformation of the dependent cost variable is often used to solve the problems of heteroscedasticity and skewness in linear ordinary least square regression of health service cost data. However, transformation may cause difficulties in the interpretation of regression coefficients and the retransformation of predicted values. The study compares the advantages and disadvantages of different methods to estimate regression based cost functions using data on the annual costs of schizophrenia treatment. Annual costs of psychiatric service use and clinical and socio-demographic characteristics of the patients were assessed for a sample of 254 patients with a diagnosis of schizophrenia (ICD-10 F 20.0) living in Leipzig. The clinical characteristics of the participants were assessed by means of the BPRS 4.0, the GAF, and the CAN for service needs. Quality of life was measured by WHOQOL-BREF. A linear OLS regression model with non-parametric standard errors, a log-transformed OLS model and a generalized linear model with a log-link and a gamma distribution were used to estimate service costs. For the estimation of robust non-parametric standard errors, the variance estimator by White and a bootstrap estimator based on 2000 replications were employed. Models were evaluated by the comparison of the R2 and the root mean squared error (RMSE). RMSE of the log-transformed OLS model was computed with three different methods of bias-correction. The 95% confidence intervals for the differences between the RMSE were computed by means of bootstrapping. A split-sample-cross-validation procedure was used to forecast the costs for the one half of the sample on the basis of a regression equation computed for the other half of the sample. All three methods showed significant positive influences of psychiatric symptoms and met psychiatric service needs on service costs. Only the log- transformed OLS model showed a significant negative impact of age, and only the GLM shows a significant

  16. Curve fitting of the corporate recovery rates: the comparison of Beta distribution estimation and kernel density estimation.

    Directory of Open Access Journals (Sweden)

    Rongda Chen

    Full Text Available Recovery rate is essential to the estimation of the portfolio's loss and economic capital. Neglecting the randomness of the distribution of recovery rate may underestimate the risk. The study introduces two kinds of models of distribution, Beta distribution estimation and kernel density distribution estimation, to simulate the distribution of recovery rates of corporate loans and bonds. As is known, models based on Beta distribution are common in daily usage, such as CreditMetrics by J.P. Morgan, Portfolio Manager by KMV and Losscalc by Moody's. However, it has a fatal defect that it can't fit the bimodal or multimodal distributions such as recovery rates of corporate loans and bonds as Moody's new data show. In order to overcome this flaw, the kernel density estimation is introduced and we compare the simulation results by histogram, Beta distribution estimation and kernel density estimation to reach the conclusion that the Gaussian kernel density distribution really better imitates the distribution of the bimodal or multimodal data samples of corporate loans and bonds. Finally, a Chi-square test of the Gaussian kernel density estimation proves that it can fit the curve of recovery rates of loans and bonds. So using the kernel density distribution to precisely delineate the bimodal recovery rates of bonds is optimal in credit risk management.

  17. Influence of resonant collisions on the self-broadening of acetylene

    Science.gov (United States)

    Lehmann, Kevin K.

    2017-03-01

    Iwakuni et al. [Phys. Rev. Lett. 117, 143902 (2016)] have reported an ortho-para alternation of ˜10% in the self pressure broadening coefficients for ro-vibrational lines of the C2H2 transitions in the ν1+ν3 C-H (local mode) overtone band near 197 THz (1.52 μm). These authors attributed this effect to the contribution of resonant collisions, where the rotational energy change of one molecule is exactly compensated by the rotational energy change of its collision partner. Resonant collisions are known to be important in the case of self pressure broadening of highly polar molecules, such as HCN, but have not previously been invoked in the case of nonpolar molecules, such as acetylene, where the long range potential is dominated by the quadrupole-quadrupole electrostatic interaction. In the present work, the simple semiclassical Anderson-theory approach is used to estimate the rates of C2H2-C2H2 rotationally inelastic collisions and these used to predict pressure broadening rates, ignoring other contributions to the broadening, which should not have resonant enhancements. It is found that exactly resonant collisions do not make a major contribution to the broadening and these calculations predict an ortho-para alternation of the pressure broadening coefficients far below what was inferred by Iwakuni et al. The present results are consistent with a large body of published work that reported self-broadening coefficients of C2H2 ro-vibrational transitions that found negligible dependence on the vibrational transition and no even-odd alternation, even for Q and S branch transitions where any such effect is predicted to be much larger than for the P and R branch transitions studied by Iwakuni et al.

  18. Analytical inversions in remote sensing of particle size distributions. IV - Comparison of Fymat and Box-McKellar solutions in the anomalous diffraction approximation

    Science.gov (United States)

    Fymat, A. L.; Smith, C. B.

    1979-01-01

    It is shown that the inverse analytical solutions, provided separately by Fymat and Box-McKellar, for reconstructing particle size distributions from remote spectral transmission measurements under the anomalous diffraction approximation can be derived using a cosine and a sine transform, respectively. Sufficient conditions of validity of the two formulas are established. Their comparison shows that the former solution is preferable to the latter in that it requires less a priori information (knowledge of the particle number density is not needed) and has wider applicability. For gamma-type distributions, and either a real or a complex refractive index, explicit expressions are provided for retrieving the distribution parameters; such expressions are, interestingly, proportional to the geometric area of the polydispersion.

  19. Comparison of predicted and experimental real-gas pressure distributions on space shuttle orbiter nose for shuttle entry air data system

    Science.gov (United States)

    Shinn, J. L.

    1980-01-01

    An experimental investigation of inviscid real-gas effects on the pressure distribution along the Space Shuttle Orbiter nose center line up to an angle of attack of 32 deg was performed in support of the Shuttle Entry Air Data System (SEADS). Free-stream velocities from 4.8 to 6.6 kn/s were generated at hypersonic conditions with helium, air, and CO2, resulting in normal-shock density ratios from 3.7 to 18.4. The experimental results for pressure distribution agreed closely with numerical results. Modified Newtonian theory deviates from both experiment and the numerical results as angle of attack increases or shock density ratio decreases. An evaluation of the use of modified Newtonian theory for predicting SEADS pressure distributions in actual flight conditions was made through comparison with numerical predictions.

  20. Does the radial-tangential macroturbulence model adequately describe the spectral line broadening of solar-type stars?*

    Science.gov (United States)

    Takeda, Yoichi; UeNo, Satoru

    2017-06-01

    In incorporating the effect of atmospheric turbulence in the broadening of spectral lines, the so-called radial-tangential macroturbulence (RTM) model has been widely used in the field of solar-type stars, which was devised from intuitive appearance of the granular velocity field of the Sun. Since this model assumes that turbulent motions are restricted to only radial and tangential directions, it has a special broadening function with notably narrow width due to the projection effect, the validity of which has not yet been confirmed in practice. With the aim of checking whether this RTM model adequately represents the actual solar photospheric velocity field, we carried out an extensive study on the non-thermal velocity dispersion along the line of sight (Vlos) by analyzing spectral lines at various points of the solar disk based on locally averaged as well as high-spatial-resolution spectra, and found the following results. First, the center-to-limb run of Vlos derived from ground-based low-resolution spectra is simply monotonic with a slightly increasing tendency, which contradicts the specific trend (an appreciable peak at θ ≃ 45°) predicted from RTM. Second, the Vlos values derived from a large number of spectra based on high-resolution space observation were revealed to follow a nearly normal distribution, without any sign of the peculiar distribution expected for the RTM case. These two observational facts indicate that the actual solar velocity field is not simply dichotomous as assumed in RTM, but directionally more chaotic. We thus conclude that RTM is not an adequate model, at least for solar-type stars, as it would significantly overestimate the turbulent velocity dispersion by a factor of ˜2. The classical Gaussian macroturbulence model should be more reasonable in this respect.

  1. Comparison of Different Turbulence Models for Numerical Simulation of Pressure Distribution in V-Shaped Stepped Spillway

    Directory of Open Access Journals (Sweden)

    Zhaoliang Bai

    2017-01-01

    Full Text Available V-shaped stepped spillway is a new shaped stepped spillway, and the pressure distribution is quite different from that of the traditional stepped spillway. In this paper, five turbulence models were used to simulate the pressure distribution in the skimming flow regimes. Through comparing with the physical value, the realizable k-ε model had better precision in simulating the pressure distribution. Then, the flow pattern of V-shaped and traditional stepped spillways was given to illustrate the unique pressure distribution using realizable k-ε turbulence model.

  2. Differential effects of K(+) channel blockers on frequency-dependent action potential broadening in supraoptic neurons.

    Science.gov (United States)

    Hlubek, M D; Cobbett, P

    2000-09-15

    Recordings were made from magnocellular neuroendocrine cells dissociated from the supraoptic nucleus of the adult guinea pig to determine the role of voltage gated K(+) channels in controlling the duration of action potentials and in mediating frequency-dependent action potential broadening exhibited by these neurons. The K(+) channel blockers charybdotoxin (ChTx), tetraethylammonium (TEA), and 4-aminopyridine (4-AP) increased the duration of individual action potentials indicating that multiple types of K(+) channel are important in controlling action potential duration. The effect of these K(+) channel blockers was almost completely reversed by simultaneous blockade of voltage gated Ca(2+) channels with Cd(2+). Frequency-dependent action potential broadening was exhibited by these neurons during trains of action potentials elicited by membrane depolarizing current pulses presented at 10 Hz but not at 1 Hz. 4-AP but not ChTx or TEA inhibited frequency-dependent action potential broadening indicating that frequency-dependent action potential broadening is dependent on increasing steady-state inactivation of A-type K(+) channels (which are blocked by 4-AP). A model of differential contributions of voltage gated K(+) channels and voltage gated Ca(2+) channels to frequency-dependent action potential broadening, in which an increase of Ca(2+) current during each successive action potential is permitted as a result of the increasing steady-state inactivation of A-type K(+) channels, is presented.

  3. Happy heart, smiling eyes: A systematic review of positive mood effects on broadening of visuospatial attention.

    Science.gov (United States)

    Vanlessen, Naomi; De Raedt, Rudi; Koster, Ernst H W; Pourtois, Gilles

    2016-09-01

    Positive mood contributes to mental and physical wellbeing. The broaden-and-build theory (Fredrickson, 2001) proposed that the beneficial effects of positive mood on life quality result from attentional broadening. In this article, we systematically review (following PRISMA guidelines; Moher et al., 2009), a host of studies investigating the nature and extent of attentional changes triggered by the experience of positive mood, with a focus on vision. While several studies reported a broadening of attention, others found that positive mood led to a more diffuse information processing style. Positive mood appears to lessen attention selectivity in a way that is context-specific and bound to limitations. We propose a new framework in which we postulate that positive mood impacts the balance between internally and externally directed attention, through modulations of cognitive control processes, instead of broadening attention per se. This novel model is able to accommodate discrepant findings, seeks to translate the phenomenon of the so-called broadening of attention with positive mood into functional terms, and provides plausible neurobiological mechanisms underlying this effect, suggesting a crucial role of the anterior and posterior cingulate cortex in this interaction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Digital nonlinearity compensation in high-capacity optical communication systems considering signal spectral broadening effect.

    Science.gov (United States)

    Xu, Tianhua; Karanov, Boris; Shevchenko, Nikita A; Lavery, Domaniç; Liga, Gabriele; Killey, Robert I; Bayvel, Polina

    2017-10-11

    Nyquist-spaced transmission and digital signal processing have proved effective in maximising the spectral efficiency and reach of optical communication systems. In these systems, Kerr nonlinearity determines the performance limits, and leads to spectral broadening of the signals propagating in the fibre. Although digital nonlinearity compensation was validated to be promising for mitigating Kerr nonlinearities, the impact of spectral broadening on nonlinearity compensation has never been quantified. In this paper, the performance of multi-channel digital back-propagation (MC-DBP) for compensating fibre nonlinearities in Nyquist-spaced optical communication systems is investigated, when the effect of signal spectral broadening is considered. It is found that accounting for the spectral broadening effect is crucial for achieving the best performance of DBP in both single-channel and multi-channel communication systems, independent of modulation formats used. For multi-channel systems, the degradation of DBP performance due to neglecting the spectral broadening effect in the compensation is more significant for outer channels. Our work also quantified the minimum bandwidths of optical receivers and signal processing devices to ensure the optimal compensation of deterministic nonlinear distortions.

  5. Broadening our approaches to studying dispersal in raptors

    Science.gov (United States)

    Morrison, J.L.; Wood, P.B.

    2009-01-01

    Dispersal is a behavioral process having consequences for individual fitness and population dynamics. Recent advances in technology have spawned new theoretical examinations and empirical studies of the dispersal process in birds, providing opportunities for examining how this information may be applied to studies of the dispersal process in raptors. Many raptors are the focus of conservation efforts; thus, reliable data on all aspects of a species' population dynamics, including dispersal distances, movement rates, and mortality rates of dispersers, are required for population viability analyses that are increasingly used to inform management. Here, we address emerging issues and novel approaches used in the study of avian dispersal, and provide suggestions to consider when developing and implementing studies of dispersal in raptors. Clarifying study objectives is essential for selection of an appropriate methodology and sample size needed to obtain accurate estimates of movement distances and rates. Identifying an appropriate study-area size will allow investigators to avoid underestimating population connectivity and important population parameters. Because nomadic individuals of some species use temporary settling areas or home ranges before breeding, identification of these areas is critical for conservation efforts focusing on habitats other than breeding sites. Study designs for investigating raptor dispersal also should include analysis of environmental and social factors influencing dispersal, to improve our understanding of condition-dependent dispersal strategies. Finally, we propose a terminology for use in describing the variety of movements associated with dispersal behavior in raptors, and we suggest this terminology could be used consistently to facilitate comparisons among studies. ?? 2009 The Raptor Research Foundation, Inc.

  6. Implementation of On-the-Fly Doppler Broadening in MCNP5 for Multiphysics Simulation of Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    William Martin

    2012-11-16

    A new method to obtain Doppler broadened cross sections has been implemented into MCNP, removing the need to generate cross sections for isotopes at problem temperatures. Previous work had established the scientific feasibility of obtaining Doppler-broadened cross sections "on-the-fly" (OTF) during the random walk of the neutron. Thus, when a neutron of energy E enters a material region that is at some temperature T, the cross sections for that material at the exact temperature T are immediately obtained by interpolation using a high order functional expansion for the temperature dependence of the Doppler-broadened cross section for that isotope at the neutron energy E. A standalone Fortran code has been developed that generates the OTF library for any isotope that can be processed by NJOY. The OTF cross sections agree with the NJOY-based cross sections for all neutron energies and all temperatures in the range specified by the user, e.g., 250K - 3200K. The OTF methodology has been successfully implemented into the MCNP Monte Carlo code and has been tested on several test problems by comparing MCNP with conventional ACE cross sections versus MCNP with OTF cross sections. The test problems include the Doppler defect reactivity benchmark suite and two full-core VHTR configurations, including one with multiphysics coupling using RELAP5-3D/ATHENA for the thermal-hydraulic analysis. The comparison has been excellent, verifying that the OTF libraries can be used in place of the conventional ACE libraries generated at problem temperatures. In addition, it has been found that using OTF cross sections greatly reduces the complexity of the input for MCNP, especially for full-core temperature feedback calculations with many temperature regions. This results in an order of magnitude decrease in the number of input lines for full-core configurations, thus simplifying input preparation and reducing the potential for input errors. Finally, for full-core problems with multiphysics

  7. Broadening microwave absorption via a multi-domain structure

    Directory of Open Access Journals (Sweden)

    Zhengwang Liu

    2017-04-01

    Full Text Available Materials with a high saturation magnetization have gained increasing attention in the field of microwave absorption; therefore, the magnetization value depends on the magnetic configuration inside them. However, the broad-band absorption in the range of microwave frequency (2-18 GHz is a great challenge. Herein, the three-dimensional (3D Fe/C hollow microspheres are constructed by iron nanocrystals permeating inside carbon matrix with a saturation magnetization of 340 emu/g, which is 1.55 times as that of bulk Fe, unexpectedly. Electron tomography, electron holography, and Lorentz transmission electron microscopy imaging provide the powerful testimony about Fe/C interpenetration and multi-domain state constructed by vortex and stripe domains. Benefiting from the unique chemical and magnetic microstructures, the microwave minimum absorption is as strong as −55 dB and the bandwidth (<−10 dB spans 12.5 GHz ranging from 5.5 to 18 GHz. Morphology and distribution of magnetic nano-domains can be facilely regulated by a controllable reduction sintering under H2/Ar gas and an optimized temperature over 450–850 °C. The findings might shed new light on the synthesis strategies of the materials with the broad-band frequency and understanding the association between multi-domain coupling and microwave absorption performance.

  8. Broadening microwave absorption via a multi-domain structure

    Science.gov (United States)

    Liu, Zhengwang; Che, Renchao; Wei, Yong; Liu, Yupu; Elzatahry, Ahmed A.; Dahyan, Daifallah Al.; Zhao, Dongyuan

    2017-04-01

    Materials with a high saturation magnetization have gained increasing attention in the field of microwave absorption; therefore, the magnetization value depends on the magnetic configuration inside them. However, the broad-band absorption in the range of microwave frequency (2-18 GHz) is a great challenge. Herein, the three-dimensional (3D) Fe/C hollow microspheres are constructed by iron nanocrystals permeating inside carbon matrix with a saturation magnetization of 340 emu/g, which is 1.55 times as that of bulk Fe, unexpectedly. Electron tomography, electron holography, and Lorentz transmission electron microscopy imaging provide the powerful testimony about Fe/C interpenetration and multi-domain state constructed by vortex and stripe domains. Benefiting from the unique chemical and magnetic microstructures, the microwave minimum absorption is as strong as -55 dB and the bandwidth (spans 12.5 GHz ranging from 5.5 to 18 GHz. Morphology and distribution of magnetic nano-domains can be facilely regulated by a controllable reduction sintering under H2/Ar gas and an optimized temperature over 450-850 °C. The findings might shed new light on the synthesis strategies of the materials with the broad-band frequency and understanding the association between multi-domain coupling and microwave absorption performance.

  9. The flux distribution from a 1.25m2 target aligned heliostat: comparison of ray tracing and experimental results

    CSIR Research Space (South Africa)

    Maliage, M

    2012-05-01

    Full Text Available model with the experimental flux distribution measured using a calorimeter. Preliminary results show that the near-Gaussian shape and radial extent of the flux distribution in the focal spot of the 1.25m2 heliostat is well predicted by ray...

  10. Comparison of CO2 Lidar Backscatter with Particle Size Distribution and GOES-7 Data in Hurricane Juliette

    Science.gov (United States)

    Jarzembski, Maurice; Pueschel, R. F.; Srivastava, Vandana; McCaul, E. W., Jr.; Cutten, Dean R.; Jedlovec, Gary J.; Atkinson, R. J.

    1999-01-01

    Backscatter measurements using 9.1 and 10.6 micron continuous wave lidars were obtained along with particle size distributions in 1995 Hurricane Juliette at altitude approximately 11.7 km. Agreement between lidar backscatter and cloud particle size distribution was excellent. Measurements also correlated well with concurrent GOES-7 infrared images of cloud top height.

  11. Comparison of indoor air distribution and thermal environment for different combinations of radiant heating systems with mechanical ventilation systems

    DEFF Research Database (Denmark)

    Wu, Xiaozhou; Fang, Lei; Olesen, Bjarne W.

    2018-01-01

    air distribution and the thermal environment for all combinations of radiant heating systems with mechanical ventilation systems. Therefore, in this article, the indoor air distribution and the thermal environment were comparatively analyzed in a room with floor heating (FH) or ceiling heating (CH...

  12. Vibrational Dependence of Line Coupling and Line Mixing in Self-Broadened Parallel Bands of NH3

    Science.gov (United States)

    Ma, Q.; Boulet, C.; Tipping, R. H.

    2017-01-01

    Line coupling and line mixing effects have been calculated for several self-broadened NH3 lines in parallel bands involving an excited v2 mode. It is well known that once the v2 mode is excited, the inversion splitting quickly increases as this quantum number increases. In the present study, we have shown that the v2 dependence of the inversion splitting plays a dominant role in the calculated line-shape parameters. For the v2 band with a 36 cm-1 splitting, the intra-doublet couplings practically disappear and for the 2v2 and 2v2 - v2 bands with much higher splitting values, they are completely absent. With respect to the inter-doublet coupling, it becomes the most efficient coupling mechanism for the v2 band, but it is also completely absent for bands with higher v2 quantum numbers. Because line mixing is caused by line coupling, the above conclusions on line coupling are also applicable for line mixing. Concerning the check of our calculated line mixing effects, while the present formalism has well explained the line mixing signatures observed in the v1 band, there are large discrepancies between the measured Rosenkranz mixing parameters and our calculated results for the v2 and 2v2 bands. In order to clarify these discrepancies, we propose to make some new measurements. In addition, we have calculated self-broadened half-widths in the v2 and 2v2 bands and made comparisons with several measurements and with the values listed in HITRAN 2012. In general, the agreements with measurements are very good. In contrast, the agreement with HITRAN 2012 is poor, indicating that the empirical formula used to predict the HITRAN 2012 data has to be updated.

  13. Comparison of fin-and-tube interlaced and face split evaporators with flow mal-distribution and compensation

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Elmegaard, Brian; Larsen, L.F.S.

    2011-01-01

    Flow mal-distribution in fin-and tube evaporators for residential air-conditioning is investigated by numerical simulation. In particularly, the interlaced and the face split evaporator are compared in flow maldistribution conditions. The considered sources of mal-distribution are: Liquid....../vapor distribution and airflow distribution. Furthermore, compensation of flow mal-distribution by control of individual channel superheat is studied for each type of evaporator. It is shown that the interlaced evaporator is better at flow maldistribution than the face split evaporator. However, if individual...... channel superheats are controlled, the face split evaporator achieves the best performance, i.e. an increase of 7% in UA-value and 1.6% to 2.4% in COP compared to the interlaced evaporator without compensation....

  14. [Monitoring microbiological safety of small systems of water distribution. Comparison of two sampling programs in a town in central Italy].

    Science.gov (United States)

    Papini, Paolo; Faustini, Annunziata; Manganello, Rosa; Borzacchi, Giancarlo; Spera, Domenico; Perucci, Carlo A

    2005-01-01

    To determine the frequency of sampling in small water distribution systems (distribution. We carried out two sampling programs to monitor the water distribution system in a town in Central Italy between July and September 1992; the Poisson distribution assumption implied 4 water samples, the assumption of negative binomial distribution implied 21 samples. Coliform organisms were used as indicators of water safety. The network consisted of two pipe rings and two wells fed by the same water source. The number of summer customers varied considerably from 3,000 to 20,000. The mean density was 2.33 coliforms/100 ml (sd= 5.29) for 21 samples and 3 coliforms/100 ml (sd= 6) for four samples. However the hypothesis of homogeneity was rejected (p-value network, determining the samples' size according to heterogeneity hypothesis strengthens the statement that water is drinkable compared with homogeneity assumption.

  15. Curriculum of broaden education and theory of teaching activity in school Physical Education

    Directory of Open Access Journals (Sweden)

    Sirléia Silvano

    2016-05-01

    Full Text Available This paper focuses on the conception of curriculum with broaden character in Physical Education and Davidov and Leontiev’s learning theory as possibility of focusing on human education in the omnilateral perspective. We endorse the necessity that the curriculum dynamics – dealing with knowledge, school systematization and standardization of school practices – becomes effective in a curriculum of broaden character. We consider that dealing with knowledge involves the necessity to create conditions that promote the transmission and assimilation of school knowledge. We refer therefore to a scientific direction of the teaching process, in other words, that the teacher leads the student to enter into study activity; from abstract knowledge rising to concrete theoretical knowledge, which is brought about by curriculum organization from a broaden conception.

  16. Gamma-ray emission spectrum from thermonuclear fusion reactions without intrinsic broadening

    DEFF Research Database (Denmark)

    Nocente, M.; Källne, J.; Salewski, Mirko

    2015-01-01

    First principle calculations of the gamma-ray energy spectrum arising from thermonuclear reactions without intrinsic broadening in fusion plasmas are presented, extending the theoretical framework needed to interpret measurements up to the accuracy level enabled by modern high resolution instrume......First principle calculations of the gamma-ray energy spectrum arising from thermonuclear reactions without intrinsic broadening in fusion plasmas are presented, extending the theoretical framework needed to interpret measurements up to the accuracy level enabled by modern high resolution...... information that can be extracted from the gamma-ray emission spectrum of fusion reactions without intrinsic broadening and are of relevance for applications to high performance plasmas of present and next generation devices....

  17. The broadened-specification fuels combustion technology program at Pratt and Whitney Aircraft

    Science.gov (United States)

    Lohmann, R. P.

    1980-01-01

    The impact of the use of broadened specification fuels on combustor design was investigated. Particular emphasis was placed on establishing the viability of various combustor modifications to permit the use of broadened specification fuels while meeting exhaust emissions and performance specifications and maintaining acceptable combustor operational and durability characteristics. Three different combustor concepts will be evaluated. Various design modifications on the operating capability of each of the combustor concepts with experimental referee broadened specification Fuel. The modifications that were evaluated included perturbations of the combustor airflow schedules to alter local stoichiometry and residence time histories revisions to the fuel injectors, and variations in liner cooling including the use of thermal barrier coatings and/or advanced cooling concepts.

  18. The effect of Kerr nonlinearity and Doppler broadening on slow light propagation

    Science.gov (United States)

    Ali, Hazrat; Ziauddin; Ahmad, Iftikhar

    2014-02-01

    The influence of Kerr nonlinearity and Doppler broadening on the slow light propagation of a dispersive atomic medium is revisited using a four-level Λ-type (87Rb) atomic system under the condition of electromagnetically induced transparency (EIT). The medium exhibits an EIT process which is accompanied by normal dispersion, i.e., sub-luminal (slow light) pulse propagation. In the presence of Kerr nonlinearity and the Doppler broadening effect the dispersion property of the proposed atomic medium is modified, which leads to enhancement of the positive group index of the medium. The combined effect of Kerr nonlinearity and Doppler broadening on slow light propagation inside the medium is the major motivation for this work.

  19. Ghost features in Doppler-broadened spectra of rovibrational transitions in trapped HD$^+$ ions

    CERN Document Server

    Patra, Sayan

    2016-01-01

    Doppler broadening plays an important role in laser rovibrational spectroscopy of trapped deuterated molecular hydrogen ions (HD$^+$), even at the millikelvin temperatures achieved through sympathetic cooling by laser-cooled beryllium ions. Recently, Biesheuvel \\textit{et al.} \\cite{Biesheuvel2016} presented a theoretical lineshape model for such transitions which not only considers linestrengths and Doppler broadening, but also the finite sample size and population redistribution by blackbody radiation, which are important in view of the long storage and probe times achievable in ion traps. Here, we employ the rate equation model developed by Biesheuvel \\textit{et al.} to theoretically study the Doppler-broadened hyperfine structure of the $(v,L):(0,3)\\rightarrow(4,2)$ rovibrational transition in HD$^+$ at 1442~nm. We observe prominent yet hitherto unrecognized ghost features in the simulated spectrum, whose positions depend on the Doppler width, transition rates, and saturation levels of the hyperfine compo...

  20. Line-Broadening in Low-Temperature Solid-State NMR Spectra of Fibrils

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Thomas; Dotta, Claudio; Balacescu, Livia; Gath, Julia; Hunkeler, Andreas [ETH Zurich, Physical Chemistry (Switzerland); Böckmann, Anja, E-mail: a.bockmann@ibcp.fr [Université de Lyon 1, Institut de Biologie et Chimie des Protéines, UMR 5086 CNRS (France); Meier, Beat H., E-mail: beme@ethz.ch [ETH Zurich, Physical Chemistry (Switzerland)

    2017-01-15

    The temperature-dependent resonance-line broadening of HET-s(218–289) in its amyloid form is investigated in the range between 110 K and 280 K. Significant differences are observed between residues in the structured hydrophobic triangular core, which are broadened the least and can be detected down to 100 K, and in the solvent-exposed parts, which are broadened the most and often disappear from the observed spectrum around 200 K. Below the freezing of the bulk water, around 273 K, the protein fibrils are still surrounded by a layer of mobile water whose thickness decreases with temperature, leading to drying out of the fibrils.

  1. GEANT4 simulation of the effects of Doppler energy broadening in Compton imaging.

    Science.gov (United States)

    Uche, C Z; Cree, M J; Round, W H

    2011-09-01

    A Monte Carlo approach was used to study the effects of Doppler energy broadening on Compton camera performance. The GEANT4 simulation toolkit was used to model the radiation transport and interactions with matter in a simulated Compton camera. The low energy electromagnetic physics model of GEANT4 incorporating Doppler broadening developed by Longo et al. was used in the simulations. The camera had a 9 × 9 cm scatterer and a 10 × 10 cm absorber with a scatterer to-absorber separation of 5 cm. Modelling was done such that only the effects of Doppler broadening were taken into consideration and effects of scatterer and absorber thickness and pixelation were not taken into account, thus a 'perfect' Compton camera was assumed. Scatterer materials were either silicon or germanium and the absorber material was cadmium zinc telluride. Simulations were done for point sources 10 cm in front of the scatterer. The results of the simulations validated the use of the low energy model of GEANT4. As expected, Doppler broadening was found to degrade the Compton camera imaging resolution. For a 140.5 keV source the resulting full-width-at-half-maximum (FWHM) of the point source image without accounting for Doppler broadening and using a silicon scatterer was 0.58 mm. This degraded to 7.1 mm when Doppler broadening was introduced and degraded further to 12.3 mm when a germanium scatterer was used instead of silicon. But for a 511 keV source, the FWHM was better than for a 140 keV source. The FWHM improved to 2.4 mm for a silicon scatterer and 4.6 mm for a germanium scatterer. Our result for silicon at 140.5 keV is in very good agreement with that published by An et al.

  2. Comparison between the calculated and measured dose distributions for four beams of 6 MeV linac in a human-equivalent phantom

    Directory of Open Access Journals (Sweden)

    Reda Sonia M.

    2006-01-01

    Full Text Available Radiation dose distributions in various parts of the body are of importance in radiotherapy. Also, the percent depth dose at different body depths is an important parameter in radiation therapy applications. Monte Carlo simulation techniques are the most accurate methods for such purposes. Monte Carlo computer calculations of photon spectra and the dose ratios at surfaces and in some internal organs of a human equivalent phantom were performed. In the present paper, dose distributions in different organs during bladder radiotherapy by 6 MeV X-rays were measured using thermoluminescence dosimetry placed at different points in the human-phantom. The phantom was irradiated in exactly the same manner as in actual bladder radiotherapy. Four treatment fields were considered to maximize the dose at the center of the target and minimize it at non-target healthy organs. All experimental setup information was fed to the MCNP-4b code to calculate dose distributions at selected points inside the proposed phantom. Percent depth dose distribution was performed. Also, the absorbed dose as ratios relative to the original beam in the surrounding organs was calculated by MCNP-4b and measured by thermoluminescence dosimetry. Both measured and calculated data were compared. Results indicate good agreement between calculated and measured data inside the phantom. Comparison between MCNP-4b calculations and measurements of depth dose distribution indicated good agreement between both.

  3. The density broadening in a sodium F=2 condensate detected by a pulse train

    Directory of Open Access Journals (Sweden)

    Jianing Han

    2011-09-01

    Full Text Available The dipole-blockaded sodium clock transition has been detected by high resolution microwave spectroscopy, the multiple-pulse spectroscopy. This spectroscopic technique has been first used to detect the density broadening and shifting in a Sodium Bose Einstein Condensate (BEC by probing the sodium clock-transition. Moreover, by narrowing the pulse-width of the pulses, some of the broadening mechanisms can be partially reduced. The results reported here are essential steps toward the ground-state quantum computing, few-body spectroscopy, spin squeezing and quantum metrology.

  4. Acousto-optics bandwidth broadening in a Bragg cell based on arbitrary synthesized signal methods.

    Science.gov (United States)

    Peled, Itay; Kaminsky, Ron; Kotler, Zvi

    2015-06-01

    In this work, we present the advantages of driving a multichannel acousto-optical deflector (AOD) with a digitally synthesized multifrequency RF signal. We demonstrate a significant bandwidth broadening of ∼40% by providing well-tuned phase control of the array transducers. Moreover, using a multifrequency, complex signal, we manage to suppress the harmonic deflections and return most of the spurious energy to the main beam. This method allows us to operate the AOD with more than an octave of bandwidth with negligible spurious energy going to the harmonic beams and a total bandwidth broadening of over 70%.

  5. Single photon quantum non-demolition measurements in the presence of inhomogeneous broadening

    Energy Technology Data Exchange (ETDEWEB)

    Greentree, Andrew D; Hollenberg, L C L; Prawer, S [Centre for Quantum Computer Technology, School of Physics, University of Melbourne, Melbourne, VIC 3010 (Australia); Beausoleil, R G [Hewlett-Packard Laboratories, 1501 Page Mill Rd, Palo Alto, CA 94304-1123 (United States); Munro, W J; Spiller, T P [Hewlett-Packard Laboratories, Filton Road, Stoke Gifford, Bristol BS34 8QZ (United Kingdom); Nemoto, Kae [National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo 101-8430 (Japan)], E-mail: andrew.greentree@ph.unimelb.edu.au

    2009-09-15

    Electromagnetically induced transparency (EIT) has often been proposed for generating nonlinear optical effects at the single photon level; in particular, as a means to effect a quantum non-demolition measurement of a single-photon field. Previous treatments have usually considered homogeneously broadened samples, but realizations in any medium will have to contend with inhomogeneous broadening. Here we reappraise an earlier scheme (Munro et al 2005 Phys. Rev. A 71 033819) with respect to inhomogeneities and show an alternative mode of operation that is preferred in an inhomogeneous environment. We further show the implications of these results on a potential implementation in diamond-containing nitrogen-vacancy colour centres.

  6. Single photon quantum non-demolition measurements in the presence of inhomogeneous broadening

    Science.gov (United States)

    Greentree, Andrew D.; Beausoleil, R. G.; Hollenberg, L. C. L.; Munro, W. J.; Nemoto, Kae; Prawer, S.; Spiller, T. P.

    2009-09-01

    Electromagnetically induced transparency (EIT) has often been proposed for generating nonlinear optical effects at the single photon level; in particular, as a means to effect a quantum non-demolition measurement of a single-photon field. Previous treatments have usually considered homogeneously broadened samples, but realizations in any medium will have to contend with inhomogeneous broadening. Here we reappraise an earlier scheme (Munro et al 2005 Phys. Rev. A 71 033819) with respect to inhomogeneities and show an alternative mode of operation that is preferred in an inhomogeneous environment. We further show the implications of these results on a potential implementation in diamond-containing nitrogen-vacancy colour centres.

  7. Influence of peak-broadening and interdetector volume error on size-exclusive chromatographic analysis with dual viscometric-concentration detection using the universal calibration method.

    Science.gov (United States)

    Netopilík, M

    2001-04-27

    The effect of peak-broadening and error in interdetector volume on the local calibration curve and experimental molecular-mass averages obtained by size-exclusion chromatography (SEC) with dual concentration/viscosity detection, and determination of molecular mass using the universal calibration (UC) method, is theoretically examined using a polymer sample with a molecular-mass distribution (MMD) approximated by the log-normal function. Although peak-broadening is often neglected, its effect on the slope of the local calibration curve and, consequently, on the experimentally obtained values of the weight-to-number average ratio is large. To obtain the right values of these parameters, a numerical correction is usually recommended. While using the UC method, the relationships between the extent of peak broadening, calibration slopes and interdetector volume are complex and can contribute to the occurrence of undiscovered errors. For this reason, an understanding of this problem, using a model, is necessary. The results of the UC method are compared with those obtained using dual-detection with known Mark-Houwink-Kuhn-Sakurada parameters (MHKS method), light-scattering (LS)/concentration detection as well as with the results obtained using conventional calibration. Due to peak-broadening, the slope of a local calibration curve and the weight-to-number average ratio, (Mw/Mn)", obtained using the UC method, increase compared to the theoretical values, whereas they decrease using the MHKS or LS methods. The increase when using the UC method is even larger compared to evaluation using conventional calibration. The effect of the error in interdetector volume on the slopes of local calibrations and the weight-to-number average ratios is opposite in the UC method to that found using the MHKS and LS methods.

  8. Three-dimensional fuel pin model validation by prediction of hydrogen distribution in cladding and comparison with experiment

    Energy Technology Data Exchange (ETDEWEB)

    Aly, A. [North Carolina State Univ., Raleigh, NC (United States); Avramova, Maria [North Carolina State Univ., Raleigh, NC (United States); Ivanov, Kostadin [Pennsylvania State Univ., University Park, PA (United States); Motta, Arthur [Pennsylvania State Univ., University Park, PA (United States); Lacroix, E. [Pennsylvania State Univ., University Park, PA (United States); Manera, Annalisa [Univ. of Michigan, Ann Arbor, MI (United States); Walter, D. [Univ. of Michigan, Ann Arbor, MI (United States); Williamson, R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Gamble, K. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-10-29

    To correctly describe and predict this hydrogen distribution there is a need for multi-physics coupling to provide accurate three-dimensional azimuthal, radial, and axial temperature distributions in the cladding. Coupled high-fidelity reactor-physics codes with a sub-channel code as well as with a computational fluid dynamics (CFD) tool have been used to calculate detailed temperature distributions. These high-fidelity coupled neutronics/thermal-hydraulics code systems are coupled further with the fuel-performance BISON code with a kernel (module) for hydrogen. Both hydrogen migration and precipitation/dissolution are included in the model. Results from this multi-physics analysis is validated utilizing calculations of hydrogen distribution using models informed by data from hydrogen experiments and PIE data.

  9. Testing the efficacy of downscaling in species distribution modelling: a comparison between MaxEnt and Favourability Function models

    Energy Technology Data Exchange (ETDEWEB)

    Olivero, J.; Toxopeus, A.G.; Skidmore, A.K.; Real, R.

    2016-07-01

    Statistical downscaling is used to improve the knowledge of spatial distributions from broad–scale to fine–scale maps with higher potential for conservation planning. We assessed the effectiveness of downscaling in two commonly used species distribution models: Maximum Entropy (MaxEnt) and the Favourability Function (FF). We used atlas data (10 x 10 km) of the fire salamander Salamandra salamandra distribution in southern Spain to derive models at a 1 x 1 km resolution. Downscaled models were assessed using an independent dataset of the species’ distribution at 1 x 1 km. The Favourability model showed better downscaling performance than the MaxEnt model, and the models that were based on linear combinations of environmental variables performed better than models allowing higher flexibility. The Favourability model minimized model overfitting compared to the MaxEnt model. (Author)

  10. Comparison of Microbial Communities in a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification

    Science.gov (United States)

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system. After six months of continuous operation, coupons were incubated in CDC reactors receiving water from the simulated system to study biofilm development. The study was organized ...

  11. Testing the efficacy of downscaling in species distribution modelling: a comparison between MaxEnt and Favourability Function models

    Directory of Open Access Journals (Sweden)

    Olivero, J.

    2016-03-01

    Full Text Available Statistical downscaling is used to improve the knowledge of spatial distributions from broad–scale to fine–scale maps with higher potential for conservation planning. We assessed the effectiveness of downscaling in two commonly used species distribution models: Maximum Entropy (MaxEnt and the Favourability Function (FF. We used atlas data (10 x 10 km of the fire salamander Salamandra salamandra distribution in southern Spain to derive models at a 1 x 1 km resolution. Downscaled models were assessed using an independent dataset of the species’ distribution at 1 x 1 km. The Favourability model showed better downscaling performance than the MaxEnt model, and the models that were based on linear combinations of environmental variables performed better than models allowing higher flexibility. The Favourability model minimized model overfitting compared to the MaxEnt model.

  12. A Monte Carlo procedure for the construction of complementary cumulative distribution functions for comparison with the EPA release limits for radioactive waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Helton, J.C.; Shiver, A.W.

    1994-10-01

    A Monte Carlo procedure for the construction of complementary cumulative distribution functions (CCDFs) for comparison with the US Environmental Protection Agency (EPA) release limits for radioactive waste disposal (40 CFR 191, Subpart B) is described and illustrated with results from a recent performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP). The Monte Carlo procedure produces CCDF estimates similar to those obtained with stratified sampling in several recent PAs for the WIPP. The advantages of the Monte Carlo procedure over stratified sampling include increased resolution in the calculation of probabilities for complex scenarios involving drilling intrusions and better use of the necessarily limited number of mechanistic calculations that underlie CCDF construction.

  13. Asymptotic Comparison of the Solutions of Linear Time-Delay Systems with Point and Distributed Lags with Those of Their Limiting Equations

    Directory of Open Access Journals (Sweden)

    M. De la Sen

    2009-01-01

    Full Text Available This paper investigates the relations between the particular eigensolutions of a limiting functional differential equation of any order, which is the nominal (unperturbed linear autonomous differential equations, and the associate ones of the corresponding perturbed functional differential equation. Both differential equations involve point and distributed delayed dynamics including Volterra class dynamics. The proofs are based on a Perron-type theorem for functional equations so that the comparison is governed by the real part of a dominant zero of the characteristic equation of the nominal differential equation. The obtained results are also applied to investigate the global stability of the perturbed equation based on that of its corresponding limiting equation.

  14. Uncovering Tacit Knowledge: A Pilot Study to Broaden the Concept of Knowledge in Knowledge Translation

    Directory of Open Access Journals (Sweden)

    Edwards Nancy

    2011-08-01

    Full Text Available Abstract Background All sectors in health care are being asked to focus on the knowledge-to-practice gap, or knowledge translation, to increase service effectiveness. A social interaction approach to knowledge translation assumes that research evidence becomes integrated with previously held knowledge, and practitioners build on and co-create knowledge through mutual interactions. Knowledge translation strategies for public health have not provided anticipated positive changes in evidence-based practice, possibly due in part to a narrow conceptualization of knowledge. More work is needed to understand the role of tacit knowledge in decision-making and practice. This pilot study examined how health practitioners applied tacit knowledge in public health program planning and implementation. Methods This study used a narrative approach, where teams from two public health units in Ontario, Canada were conveniently selected. Respondents participated in individual interviews and focus groups at each site. Questions were designed to understand the role of tacit knowledge as it related to the program planning process. Data were analyzed through a combination of content analysis and thematic comparison. Results The findings highlighted two major aspects of knowledge that arose: the use of tacit knowledge and the integration of tacit and explicit knowledge. Tacit knowledge included: past experiences, organization-specific knowledge, community contextual knowledge, and the recognition of the tacit knowledge of others. Explicit knowledge included: research literature, the Internet, popular magazines, formal assessments (surveys and interviews, legislation and regulations. Participants sometimes deliberately combined tacit and explicit knowledge sources in planning. Conclusions This pilot demonstrated that front-line public health workers draw upon both tacit knowledge and explicit knowledge in their everyday lived reality. Further, tacit knowledge plays an

  15. GIS based spatial noise impact analysis (SNIA of the broadening of national highway in Sikkim Himalayas: a case study

    Directory of Open Access Journals (Sweden)

    Polash Banerjee

    2016-11-01

    Full Text Available Mountainous areas create a complex and challenging environment to conduct noise impact analysis of development projects. This paper presents a noise impact analysis methodology using Geographic Information Systems (GIS and Traffic Noise Model (FHWA TNM 2.5 to portray spatial distribution of noise due to the broadening of the national highway in the mountainous terrain of East Sikkim. Two noise level indices viz., Hourly Equivalent Sound Level (Leq(H and Day and Night Average Sound Level (Ldn were calculated for the year 2004 as pre-project scenario, 2014 as project implementation scenario and 2039 as post-project scenario. The overall trend shows that the proportion of area under adverse noise level decreases from pre-project scenario to project implementation scenario. Over the time the adverse noise impact in the post-project scenario reaches very close to pre-project scenario in case of both the noise indices. Overlay analysis of noise based landuse maps over actual landuse map show that non-compliance of noise based landuse will show similar trend. This trend is mainly attributed to traffic composition and highway broadening induced-traffic volume. The study shows that TNM and spatial interpolation of noise data using Empirical Bayesian Kriging (EBK are reliable tools to perform noise impact analysis in mountainous areas. Multiple regression analysis show that, radial distance and elevation difference of noise receivers from the nearest point in the highway are significant predictors of Leq(H and Ldn at lower percentage of heavy trucks in traffic composition.

  16. Evolutionary dynamics of microsatellite distribution in plants: insight from the comparison of sequenced brassica, Arabidopsis and other angiosperm species.

    Science.gov (United States)

    Shi, Jiaqin; Huang, Shunmou; Fu, Donghui; Yu, Jinyin; Wang, Xinfa; Hua, Wei; Liu, Shengyi; Liu, Guihua; Wang, Hanzhong

    2013-01-01

    Despite their ubiquity and functional importance, microsatellites have been largely ignored in comparative genomics, mostly due to the lack of genomic information. In the current study, microsatellite distribution was characterized and compared in the whole genomes and both the coding and non-coding DNA sequences of the sequenced Brassica, Arabidopsis and other angiosperm species to investigate their evolutionary dynamics in plants. The variation in the microsatellite frequencies of these angiosperm species was much smaller than those for their microsatellite numbers and genome sizes, suggesting that microsatellite frequency may be relatively stable in plants. The microsatellite frequencies of these angiosperm species were significantly negatively correlated with both their genome sizes and transposable elements contents. The pattern of microsatellite distribution may differ according to the different genomic regions (such as coding and non-coding sequences). The observed differences in many important microsatellite characteristics (especially the distribution with respect to motif length, type and repeat number) of these angiosperm species were generally accordant with their phylogenetic distance, which suggested that the evolutionary dynamics of microsatellite distribution may be generally consistent with plant divergence/evolution. Importantly, by comparing these microsatellite characteristics (especially the distribution with respect to motif type) the angiosperm species (aside from a few species) all clustered into two obviously different groups that were largely represented by monocots and dicots, suggesting a complex and generally dichotomous evolutionary pattern of microsatellite distribution in angiosperms. Polyploidy may lead to a slight increase in microsatellite frequency in the coding sequences and a significant decrease in microsatellite frequency in the whole genome/non-coding sequences, but have little effect on the microsatellite distribution with

  17. Evolutionary dynamics of microsatellite distribution in plants: insight from the comparison of sequenced brassica, Arabidopsis and other angiosperm species.

    Directory of Open Access Journals (Sweden)

    Jiaqin Shi

    Full Text Available Despite their ubiquity and functional importance, microsatellites have been largely ignored in comparative genomics, mostly due to the lack of genomic information. In the current study, microsatellite distribution was characterized and compared in the whole genomes and both the coding and non-coding DNA sequences of the sequenced Brassica, Arabidopsis and other angiosperm species to investigate their evolutionary dynamics in plants. The variation in the microsatellite frequencies of these angiosperm species was much smaller than those for their microsatellite numbers and genome sizes, suggesting that microsatellite frequency may be relatively stable in plants. The microsatellite frequencies of these angiosperm species were significantly negatively correlated with both their genome sizes and transposable elements contents. The pattern of microsatellite distribution may differ according to the different genomic regions (such as coding and non-coding sequences. The observed differences in many important microsatellite characteristics (especially the distribution with respect to motif length, type and repeat number of these angiosperm species were generally accordant with their phylogenetic distance, which suggested that the evolutionary dynamics of microsatellite distribution may be generally consistent with plant divergence/evolution. Importantly, by comparing these microsatellite characteristics (especially the distribution with respect to motif type the angiosperm species (aside from a few species all clustered into two obviously different groups that were largely represented by monocots and dicots, suggesting a complex and generally dichotomous evolutionary pattern of microsatellite distribution in angiosperms. Polyploidy may lead to a slight increase in microsatellite frequency in the coding sequences and a significant decrease in microsatellite frequency in the whole genome/non-coding sequences, but have little effect on the microsatellite

  18. Evolutionary Dynamics of Microsatellite Distribution in Plants: Insight from the Comparison of Sequenced Brassica, Arabidopsis and Other Angiosperm Species

    Science.gov (United States)

    Shi, Jiaqin; Huang, Shunmou; Fu, Donghui; Yu, Jinyin; Wang, Xinfa; Hua, Wei; Liu, Shengyi; Liu, Guihua; Wang, Hanzhong

    2013-01-01

    Despite their ubiquity and functional importance, microsatellites have been largely ignored in comparative genomics, mostly due to the lack of genomic information. In the current study, microsatellite distribution was characterized and compared in the whole genomes and both the coding and non-coding DNA sequences of the sequenced Brassica, Arabidopsis and other angiosperm species to investigate their evolutionary dynamics in plants. The variation in the microsatellite frequencies of these angiosperm species was much smaller than those for their microsatellite numbers and genome sizes, suggesting that microsatellite frequency may be relatively stable in plants. The microsatellite frequencies of these angiosperm species were significantly negatively correlated with both their genome sizes and transposable elements contents. The pattern of microsatellite distribution may differ according to the different genomic regions (such as coding and non-coding sequences). The observed differences in many important microsatellite characteristics (especially the distribution with respect to motif length, type and repeat number) of these angiosperm species were generally accordant with their phylogenetic distance, which suggested that the evolutionary dynamics of microsatellite distribution may be generally consistent with plant divergence/evolution. Importantly, by comparing these microsatellite characteristics (especially the distribution with respect to motif type) the angiosperm species (aside from a few species) all clustered into two obviously different groups that were largely represented by monocots and dicots, suggesting a complex and generally dichotomous evolutionary pattern of microsatellite distribution in angiosperms. Polyploidy may lead to a slight increase in microsatellite frequency in the coding sequences and a significant decrease in microsatellite frequency in the whole genome/non-coding sequences, but have little effect on the microsatellite distribution with

  19. Comparison of minute distribution frequency for anesthesia start and end times from an anesthesia information management system and paper records.

    Science.gov (United States)

    Phelps, Michael; Latif, Asad; Thomsen, Robert; Slodzinski, Martin; Raghavan, Rahul; Paul, Sharon Leigh; Stonemetz, Jerry

    2017-08-01

    Use of an anesthesia information management system (AIMS) has been reported to improve accuracy of recorded information. We tested the hypothesis that analyzing the distribution of times charted on paper and computerized records could reveal possible rounding errors, and that this effect could be modulated by differences in the user interface for documenting certain event times with an AIMS. We compared the frequency distribution of start and end times for anesthesia cases completed with paper records and an AIMS. Paper anesthesia records had significantly more times ending with "0" and "5" compared to those from the AIMS (p < 0.001). For case start times, AIMS still exhibited end-digit preference, with times whose last digits had significantly higher frequencies of "0" and "5" than other integers. This effect, however, was attenuated compared to that for paper anesthesia records. For case end times, the distribution of minutes recorded with AIMS was almost evenly distributed, unlike those from paper records that still showed significant end-digit preference. The accuracy of anesthesia case start times and case end times, as inferred by statistical analysis of the distribution of the times, is enhanced with the use of an AIMS. Furthermore, the differences in AIMS user interface for documenting case start and case end times likely affects the degree of end-digit preference, and likely accuracy, of those times.

  20. Second harmonic generation of spectrally broadened femtosecond ytterbium laser radiation in a gas-filled capillary

    Energy Technology Data Exchange (ETDEWEB)

    Didenko, N V; Konyashchenko, Aleksandr V; Kostryukov, P V; Losev, Leonid L; Tenyakov, S Yu

    2011-09-30

    A 300-fs radiation pulse of an ytterbium laser with a wavelength of 1030 nm and energy of 150 {mu}J were converted to a 15-fs pulse with a wavelength of 515 nm by broadening the emission spectrum in a capillary filled with xenon and by generating the second harmonic in a KDP crystal. The energy efficiency of the conversion was 30 %.

  1. Broaden Engineering Technology students' knowledge through hands-on with motion robotics

    Science.gov (United States)

    The skills and knowledge that employers value most are not always well-aligned with undergraduate engineering technology programs. With the support of a federal grant, we identify and propose to broaden the undergraduate student experience to include training in transferable skills with agricultura...

  2. Calculation of the density shift and broadening of the transition lines in pionic helium: Computational problems

    Energy Technology Data Exchange (ETDEWEB)

    Bakalov, Dimitar, E-mail: dbakalov@inrne.bas.bg [Bulgarian Academy of Sciences, INRNE (Bulgaria)

    2015-08-15

    The potential energy surface and the computational codes, developed for the evaluation of the density shift and broadening of the spectral lines of laser-induced transitions from metastable states of antiprotonic helium, fail to produce convergent results in the case of pionic helium. We briefly analyze the encountered computational problems and outline possible solutions of the problems.

  3. On quantum-mechanical unified theories of collisional spectral line broadening

    NARCIS (Netherlands)

    Schuller, F.; Nienhuis, G.

    1982-01-01

    We compare the Baranger-type unified theory of line broadening with a quantum version of the binary-collision approach. For the simple model system of a two-state atom, where both treatments are well-defined, the binary-collision theory results only from the exact formalism after an inversion of an

  4. On magnetic field stochasticity and nonthermal line broadening in solar flares

    Science.gov (United States)

    Antonucci, E.; Rosner, R.; Tsinganos, K.

    1986-01-01

    Observations of nonthermal line broadening seen in solar flares by the Solar Maximum Mission satellite are discussed in light of recent results on the generation of magnetic field stochasticity. It is shown that a consistent model for the data can be constructed by assuming that the observations signal the destruction of an ambient magnetohydrodynamic equilibrium.

  5. Reframing the land grab debate: The need to broaden and deepen the agenda

    NARCIS (Netherlands)

    Zoomers, A.; van Westen, A.C.M.

    2013-01-01

    This article does not present new evidence about the land rush, but reveals the urgent need of broadening the debate by including a few key issues that are so far neglected. Transnational land acquisitions are a logical outcome of globalisation and neoliberal policies resulting in processes of

  6. Broadening Educational Outcomes: Social Relations, Skills Development, and Employability for Youth

    Science.gov (United States)

    Dejaeghere, Joan; Wiger, Nancy Pellowski; Willemsen, Laura Wangsness

    2016-01-01

    This article argues that, if a global development aim is to address educational inequalities, the post-2015 agenda needs to conceptually and practically broaden the focus of learning to include social relations as important processes and outcomes for achieving educational equity. We draw on Sen's capability approach and Bourdieu's forms of capital…

  7. Homogeneous broadening effect on temperature dependence of green upconversion luminescence in erbium doped fibers

    Energy Technology Data Exchange (ETDEWEB)

    Egatz-Gómez, A. [Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Arcos de Jalón 118, Madrid 28037 (Spain); Department of Biomedical Engineering, Texas A and M University, College Station, TX 77843 (United States); Calderón, Oscar G., E-mail: oscargc@fis.ucm.es [Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Arcos de Jalón 118, Madrid 28037 (Spain); Melle, Sonia; Carreño, F.; Antón, M.A. [Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Arcos de Jalón 118, Madrid 28037 (Spain); Gort, Elske M. [Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Arcos de Jalón 118, Madrid 28037 (Spain); Department of Biomedical Engineering, University of Groningen, 9700 RB Groningen (Netherlands)

    2013-07-15

    We study the green upconversion luminescence of Er{sup 3+} ions in an aluminosilicate optical fiber upon near infrared excitation at 787 nm. The dependence of the upconversion luminescence on temperature has been determined. As temperature drops from room to cryogenic temperatures, the upconversion green emission reaches a maximum around 40 K, and then decreases. A nearly quadratic dependence of the upconversion luminescence with excitation power is found, which is consistent with a sequential stepwise two-photon absorption process. These results have been explained with a semiclassical model that considers the inhomogeneous broadening of the optical transitions due to glass imperfections, and the dependence of the homogeneous linewidth broadening on temperature. -- Highlights: ► We study green upconversion luminescence of Er{sup 3+} ions in a fiber excited at 787 nm. ► Upconversion luminescence variation from room to cryogenic temperature is analyzed. ► Upconversion emission consists in a sequential two-photon absorption process. ► A semiclassical model considering inhomogeneous broadening explains the results. ► Homogeneous broadening is responsible for the upconversion temperature dependence.

  8. Broadening the definition of resilience and "reappraising" the use of appetitive motivation.

    Science.gov (United States)

    Soenke, Melissa; O'Connor, Mary-Frances; Greenberg, Jeff

    2015-01-01

    Kalisch et al.'s PASTOR model synthesizes current knowledge of resilience, focusing on mechanisms as a common pathway to outcomes and highlighting neuroscience as a method for exploring this. We propose the model broaden its definition of resiliency to include positive indices of recovery, include positive affect as a mechanism, and approach motivation as distinct from overcoming aversive motivation.

  9. Saturation broadening effect in an InP photonic-crystal nanocavity switch

    DEFF Research Database (Denmark)

    Yu, Yi; Palushani, Evarist; Heuck, Mikkel

    2014-01-01

    Pump-probe measurements on InP photonic-crystal nanocavities show large-contrast fast switching at low pulse energy. For large pulse energies, large resonance shifts passing across the probe lead to switching contrast saturation and switching time-window broadening. © 2014 OSA....

  10. Effects of Level Broadening on the Magnetothermal Oscillations in Two-Dimensional Electron Systems.

    Science.gov (United States)

    1985-03-25

    On the other hand, Gerhardts (1976) arrived at a Gaussin form for level broadening. A In what follows in the present article, we remark on the case...Soc. (London) A 211 517 V A %l Gerhardts R R 1976 Surf. Sei. 58 227 fvi Isihara A and Kojima D Y 1979 Phys. Rev. B 19 846 and Shiva Y 1983

  11. Broadening of Plasmonic Resonance Due to Electron Collisions with Nanoparticle Boundary: а Quantum Mechanical Consideration

    DEFF Research Database (Denmark)

    Uskov, Alexander; Protsenko, Igor E.; Mortensen, N. Asger

    2014-01-01

    We present a quantum mechanical approach to calculate broadening of plasmonic resonances in metallic nanostructures due to collisions of electrons with the surface of the structure. The approach is applicable if the characteristic size of the structure is much larger than the de Broglie electron...

  12. Effects of wall condition on flow distributions in arterial modeling: comparison of rigid, dynamic, and compliant walls

    Energy Technology Data Exchange (ETDEWEB)

    He, Fan [Beijing University of Civil Engineering and Architecture, Beijing (China); Hua, Lu; Gao, Li jian [Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China)

    2016-03-15

    Blood flow distributions were evaluated using various computational strategies. Three commonly used wall conditions in arterial modeling were employed, namely rigid, dynamic and compliant walls. The results show that the velocity distributions are similar under rigid and dynamic walls, developing into the Poiseuille flow, but they are blunt under compliant walls. The peak pressure under rigid walls is highest, but the model of dynamic walls has a good approximation of pressure against the model of compliant walls. The results indicate that a model of compliant walls appears to be a computationally and reasonably accurate approximation of blood velocity distributions compared with the analysis under rigid or dynamic walls. Introducing fluid-structure interaction into arterial modeling is necessary to ensure reliable results and information. However, a model of dynamic walls seems to be a computationally inexpensive yet reasonably accurate approximation for pressure.

  13. Comparison of the distribution of magnesium in plasma determined by size exclusion chromatography and 31P NMR spectroscopy.

    Science.gov (United States)

    Batista, A; Corbett, R; Tidor, S; Castleman, E; Laptook, A; Sherry, A D

    2000-03-01

    The distribution of magnesium in plasma, bound to proteins (pMg), complexed to low molecular weight anions (cMg) and ionized (iMg), was compared by size exclusion chromatography and an approach using a combination of atomic absorption spectroscopy, ion selective electrodes and 31P nuclear magnetic resonance spectroscopy. The distribution of pMg:cMg:iMg was 28:13:59 as determined by chromatography and 26:14:60 as determined by the latter methodology. These results are consistent with the hypothesis that plasma proteins and weak complexing anions correspond to high and low affinity magnesium binding ligands in plasma, respectively.

  14. In vivo imaging of the spectral line broadening of the human lung in a single breathhold.

    Science.gov (United States)

    Carinci, Flavio; Meyer, Cord; Breuer, Felix A; Jakob, Peter M

    2016-09-01

    To present a technique, which allows for the in vivo quantification of the spectral line broadening of the human lung in a single breathhold. The line broadening is an interesting parameter of the lung because it can provide information about important lung properties, namely: inflation and oxygen uptake. The proposed technique integrates the asymmetric spin-echo (ASE) approach, which is commonly used to quantify the line broadening, with a single shot turbo spin-echo pulse sequence with half-Fourier acquisition (HASTE), to reduce the acquisition times. Imaging experiments were performed at 1.5 Tesla on 14 healthy volunteers, using a ASE-prepared HASTE sequence. The line broadening was quantified using a two-points method. Data were acquired at different breathing states: functional residual capacity (FRC) and total lung capacity (TLC), and with different breathing gases: room-air and pure-oxygen. Image acquisition was accomplished within a single breathhold of approximately 15 s duration. The violation of the Carr-Purcell-Meiboom-Gill conditions, deriving from inhomogeneities of the static magnetic field, was overcome by means of radiofrequency-phase cycling and generalized autocalibrating partially parallel acquisitions (GRAPPA) reconstruction. Significant increase of the line broadening was observed with both lung inflation and oxygen concentration (P lung parenchyma at different breathing states (1.48 ± 0.29 ppm at FRC and 1.95 ± 0.43 ppm at TLC) are in agreement with previous reports and show excellent reproducibility, with a coefficient of variation lung in vivo. Image acquisition can be accomplished in a single breathhold, which could be suitable for clinical applications on patients with lung diseases. J. Magn. Reson. Imaging 2016;44:745-757. © 2016 International Society for Magnetic Resonance in Medicine.

  15. Comparison of general obesity and measures of body fat distribution in older adults in relation to cancer risk

    NARCIS (Netherlands)

    Freisling, Heinz; Arnold, Melina; Soerjomataram, Isabelle; O'Doherty, Mark George; Ordóñez-Mena, José Manuel; Bamia, Christina; Kampman, Ellen; Leitzmann, Michael; Romieu, Isabelle; Kee, Frank

    2017-01-01

    Background:We evaluated the associations of anthropometric indicators of general obesity (body mass index, BMI), an established risk factor of various cancer, and body fat distribution (waist circumference, WC; hip circumference, HC; and waist-to-hip ratio, WHR), which may better reflect

  16. Comparison of particle-size distributions determined by optical scanning and by sieving in the assessment of masticatory performance.

    Science.gov (United States)

    Eberhard, L; Schindler, H J; Hellmann, D; Schmitter, M; Rammelsberg, P; Giannakopoulos, N N

    2012-05-01

    Aim of this study was to introduce a feasible and valid technique for the assessment of masticatory performance that is comparable to the standard sieving method. Twenty-one chewing samples (Optosil) comminuted by healthy dentate adults were analysed with a sieving and scanning method. Scanning was performed using a conventional flatbed scanner (1200dpi). All scanned images underwent image analysis (ImageJ), which yielded descriptive parameters such as area, best-fitting ellipse for each particle. Of the 2D-image, a volume was estimated for each particle, which was converted into a weight. To receive a discrete distribution of particle sizes comparable to sieving, five chewing samples were used to calculate a size-dependent area-volume-conversion factor. The sieving procedure was carried out with a stack of 10 sieves, and the retained particles per sieve were weighed. The cumulated weights yielded by either method were curve-fitted with the Rosin-Rammler distribution to determine the median particle size x(50) . The Rosin-Rammler distributions for sieving and scanning resemble each other. The distributions show a high correlation (0·919-1·0, n= 21, Psieving. On average, scanning overestimates the x(50) values by 2·4%. A modified Bland-Altman plot reveals that 95% of the x(50) values fall within 10% of the average x(50) . The scanning method is a valid, simple and feasible method to determine masticatory performance. © 2012 Blackwell Publishing Ltd.

  17. Comparison of Particle-Associated Bacteria from a Drinking Water Treatment Plant and Distribution Reservoirs with Different Water Sources

    NARCIS (Netherlands)

    Liu, G.; Ling, F.Q.; Van der Mark, E.J.; Zhang, X.D.; Knezev, A.; Verberk, J.Q.J.C.; Van der Meer, W.G.J.; Medema, G.J.; Liu, W.T.; Van Dijk, J.C.

    2016-01-01

    This study assessed the characteristics of and changes in the suspended particles and the associated bacteria in an unchlorinated drinking water distribution system and its reservoirs with different water sources. The results show that particle-associated bacteria (PAB) were present at a level of

  18. Comparison of techniques for reconstruction of a distribution from moments in the context of a pharmaceutical drying process

    DEFF Research Database (Denmark)

    Mortier, Séverine Thérèse F.C.; De Beer, Thomas; Gernaey, Krist V.

    2014-01-01

    The use of moment-based methods to solve a Population Balance Model (PBM) induces the need to reconstruct a distribution from the moments for system analysis. Several reconstruction methods are investigated (i.e. parameter fitting methods and the method of splines), compared with each other as well...

  19. Comparison of Particle-Associated Bacteria from a Drinking Water Treatment Plant and Distribution Reservoirs with Different Water Sources

    Science.gov (United States)

    Liu, G.; Ling, F. Q.; van der Mark, E. J.; Zhang, X. D.; Knezev, A.; Verberk, J. Q. J. C.; van der Meer, W. G. J.; Medema, G. J.; Liu, W. T.; van Dijk, J. C.

    2016-01-01

    This study assessed the characteristics of and changes in the suspended particles and the associated bacteria in an unchlorinated drinking water distribution system and its reservoirs with different water sources. The results show that particle-associated bacteria (PAB) were present at a level of 0.8–4.5 × 103 cells ml−1 with a biological activity of 0.01–0.04 ng l−1 ATP. Different PAB communities in the waters produced from different sources were revealed by a 16S rRNA-based pyrosequencing analysis. The quantified biomass underestimation due to the multiple cells attached per particle was ≥ 85%. The distribution of the biologically stable water increased the number of cells per particle (from 48 to 90) but had minor effects on the PAB community. Significant changes were observed at the mixing reservoir. Our results show the characteristics of and changes in suspended PAB during distribution, and highlight the significance of suspended PAB in the distribution system, because suspended PAB can lead to a considerable underestimation of biomass, and because they exist as biofilm, which has a greater mobility than pipe-wall biofilm and therefore presents a greater risk, given the higher probability that it will reach the customers’ taps and be ingested. PMID:26832989

  20. Comparison of Microbial Communities in a Simulated Chloraminated Drinking Water Distribution System Subjected to Episodes of Nitrification (poster)

    Science.gov (United States)

    Bacterial populations were examined in a simulated chloraminated drinking water distribution system (i.e. PVC pipe loop). After six months of continuous operation, coupons were incubated in CDC reactors receiving water from the simulated system to study biofilm development. The s...

  1. Paleodemographic age-at-death distributions of two Mexican skeletal collections: a comparison of transition analysis and traditional aging methods.

    Science.gov (United States)

    Bullock, Meggan; Márquez, Lourdes; Hernández, Patricia; Ruíz, Fernando

    2013-09-01

    Traditional methods of aging adult skeletons suffer from the problem of age mimicry of the reference collection, as described by Bocquet-Appel and Masset (1982). Transition analysis (Boldsen et al., 2002) is a method of aging adult skeletons that addresses the problem of age mimicry of the reference collection by allowing users to select an appropriate prior probability. In order to evaluate whether transition analysis results in significantly different age estimates for adults, the method was applied to skeletal collections from Postclassic Cholula and Contact-Period Xochimilco. The resulting age-at-death distributions were then compared with age-at-death distributions for the two populations constructed using traditional aging methods. Although the traditional aging methods result in age-at-death distributions with high young adult mortality and few individuals living past the age of 50, the age-at-death distributions constructed using transition analysis indicate that most individuals who lived into adulthood lived past the age of 50. Copyright © 2013 Wiley Periodicals, Inc.

  2. The Impact of School Finance Litigation on Resource Distribution: A Comparison of Court-Mandated Equity and Adequacy Reforms

    Science.gov (United States)

    Springer, Matthew G.; Liu, Keke; Guthrie, James W.

    2008-01-01

    While there is a wealth of research on school finance equity and adequacy, and school finance theory clearly documents differences between the two concepts, no study has examined whether the reforms engendered by each approach actually differ in terms of resource distribution. This study examines the issues using district level data on expenditure…

  3. Comparison of Particle-Associated Bacteria from a Drinking Water Treatment Plant and Distribution Reservoirs with Different Water Sources.

    Science.gov (United States)

    Liu, G; Ling, F Q; van der Mark, E J; Zhang, X D; Knezev, A; Verberk, J Q J C; van der Meer, W G J; Medema, G J; Liu, W T; van Dijk, J C

    2016-02-02

    This study assessed the characteristics of and changes in the suspended particles and the associated bacteria in an unchlorinated drinking water distribution system and its reservoirs with different water sources. The results show that particle-associated bacteria (PAB) were present at a level of 0.8-4.5 × 10(3) cells ml(-1) with a biological activity of 0.01-0.04 ng l(-1) ATP. Different PAB communities in the waters produced from different sources were revealed by a 16S rRNA-based pyrosequencing analysis. The quantified biomass underestimation due to the multiple cells attached per particle was ≥ 85%. The distribution of the biologically stable water increased the number of cells per particle (from 48 to 90) but had minor effects on the PAB community. Significant changes were observed at the mixing reservoir. Our results show the characteristics of and changes in suspended PAB during distribution, and highlight the significance of suspended PAB in the distribution system, because suspended PAB can lead to a considerable underestimation of biomass, and because they exist as biofilm, which has a greater mobility than pipe-wall biofilm and therefore presents a greater risk, given the higher probability that it will reach the customers' taps and be ingested.

  4. Satellite observations of tropospheric ammonia and carbon monoxide: Global distributions, regional correlations and comparisons to model simulations

    Science.gov (United States)

    Ammonia (NH3) and carbon monoxide (CO) are primary pollutants emitted to the Earth's atmosphere from common as well as distinct sources associated with anthropogenic and natural activities. The seasonal and global distributions and correlations of NH3 and CO from the Tropospheric...

  5. Conductance-based refractory density approach: comparison with experimental data and generalization to lognormal distribution of input current.

    Science.gov (United States)

    Chizhov, Anton V

    2017-12-01

    The conductance-based refractory density (CBRD) approach is an efficient tool for modeling interacting neuronal populations. The model describes the firing activity of a statistical ensemble of uncoupled Hodgkin-Huxley-like neurons, each receiving individual Gaussian noise and a common time-varying deterministic input. However, the approach requires experimental validation and extension to cases of distributed input signals (or input weights) among different neurons of such an ensemble. Here the CBRD model is verified by comparing with experimental data and then generalized for a lognormal (LN) distribution of the input weights. The model with equal weights is shown to reproduce efficiently the post-spike time histograms and the membrane voltage of experimental multiple trial response of single neurons to a step-wise current injection. The responses reveal a more rapid reaction of the firing-rate than voltage. Slow adaptive potassium channels strongly affected the shape of the responses. Next, a computationally efficient CBRD model is derived for a population with the LN input weight distribution and is compared with the original model with equal input weights. The analysis shows that the LN distribution: (1) provides a faster response, (2) eliminates oscillations, (3) leads to higher sensitivity to weak stimuli, and (4) increases the coefficient of variation of interspike intervals. In addition, a simplified firing-rate type model is tested, showing improved precision in the case of a LN distribution of weights. The CBRD approach is recommended for complex, biophysically detailed simulations of interacting neuronal populations, while the modified firing-rate type model is recommended for computationally reduced simulations.

  6. Inhomogeneous broadening of phosphorus donor lines in the far-infrared spectra of single-crystalline SiGe

    NARCIS (Netherlands)

    Lynch, S. A.; Matmon, G.; Pavlov, S. G.; Litvinenko, K. L.; Redlich, B.; van der Meer, A. F. G.; Abrosimov, N. V.; Hubers, H. W.

    2010-01-01

    The origins of line broadening in the far-infrared spectrum of phosphorus donors in SiGe are investigated. Using a combination of Fourier transform infrared (FT-IR) spectroscopy and time-resolved pump-probe measurements, we show that the line shapes are dominated by inhomogenous broadening.

  7. Pairwise comparison of soil organic particle-size distributions in native savannas and Eucalyptus plantations in Congo

    OpenAIRE

    D'Annunzio, R.; Conche, Sofian; Landais, D; Saint André, L.; Joffre, R.; Barthès, Bernard

    2008-01-01

    Conversion of native vegetation into fast-growing tree plantations is known to affect soil organic matter (SOM): soil carbon (C) and nitrogen (N) content and their distribution in particle-size fractions can be modified in various ways depending on numerous factors, such as soil properties, SOM levels prior to conversion, climatic conditions, silvicultural practices and fire occurrence. Since 1978, 43,000 ha of clonal eucalyptus plantations have been established on sandy coastal plains under ...

  8. Comparison of Three Supply Distribution Systems for Medical and Surgical Supplies in the Veterans Administration Sierra Pacific Network

    Science.gov (United States)

    2011-12-01

    medicine, surgery, psychiatry, 21 rehabilitation, neurology, oncology , dentistry, geriatrics , and extended care. With nearly 900 beds, including...facility sizes, patient base, and complexity of services provided, “one fit” for all three facilities may not exist. 14. SUBJECT TERMS Distribution...the difference in facility sizes, patient base, and complexity of services provided, “one fit” for all three facilities may not exist. vi THIS

  9. Evaluation of heterogeneity dose distributions for Stereotactic Radiotherapy (SRT: comparison of commercially available Monte Carlo dose calculation with other algorithms

    Directory of Open Access Journals (Sweden)

    Takahashi Wataru

    2012-02-01

    Full Text Available Abstract Background The purpose of this study was to compare dose distributions from three different algorithms with the x-ray Voxel Monte Carlo (XVMC calculations, in actual computed tomography (CT scans for use in stereotactic radiotherapy (SRT of small lung cancers. Methods Slow CT scan of 20 patients was performed and the internal target volume (ITV was delineated on Pinnacle3. All plans were first calculated with a scatter homogeneous mode (SHM which is compatible with Clarkson algorithm using Pinnacle3 treatment planning system (TPS. The planned dose was 48 Gy in 4 fractions. In a second step, the CT images, structures and beam data were exported to other treatment planning systems (TPSs. Collapsed cone convolution (CCC from Pinnacle3, superposition (SP from XiO, and XVMC from Monaco were used for recalculating. The dose distributions and the Dose Volume Histograms (DVHs were compared with each other. Results The phantom test revealed that all algorithms could reproduce the measured data within 1% except for the SHM with inhomogeneous phantom. For the patient study, the SHM greatly overestimated the isocenter (IC doses and the minimal dose received by 95% of the PTV (PTV95 compared to XVMC. The differences in mean doses were 2.96 Gy (6.17% for IC and 5.02 Gy (11.18% for PTV95. The DVH's and dose distributions with CCC and SP were in agreement with those obtained by XVMC. The average differences in IC doses between CCC and XVMC, and SP and XVMC were -1.14% (p = 0.17, and -2.67% (p = 0.0036, respectively. Conclusions Our work clearly confirms that the actual practice of relying solely on a Clarkson algorithm may be inappropriate for SRT planning. Meanwhile, CCC and SP were close to XVMC simulations and actual dose distributions obtained in lung SRT.

  10. Comparison of the stress distribution in the metallic layers of flexible pipes using two alternative Bflex formulations

    OpenAIRE

    Shi, Yunzhu

    2014-01-01

    Axisymmetric load is the most common load acting on flexible pipe. Modelling axisymmetric load correctly is very important to estimate the strength of a flexible pipe. The purpose of the thesis is to compare the stress distribution in metallic layers under three load case, i.e. tension, internal pressure and external pressure. Literature study and discussion to mechanical properties of flexible pipe and finite element modelling method are included in the thesis. The modelling program is BFLEX...

  11. Comparison and correlation of menstrual dysfunctions and regional fat distribution in female student athletes and non-athletes

    Directory of Open Access Journals (Sweden)

    Azam Zarneshan

    2014-03-01

    Full Text Available Background: In spite of the presence of menstrual dysfunctions in female student athletes, few studies have been conducted to analyse the reasons and athletic factors affecting them. Regional distribution of fat is one of the important factors that plays a role in causing menstrual disorders, and since menstrual cycle disorders can lead to many problems, the present study was aimed to compare and analyse the menstrual dysfunctions and regional patterns of fat distribution in female student athletes and non-athletes. Methods: The present study was descriptive analytical which was carried out on 206 female student athletes and non-athletes studying in Shahid Madani University of Azarbaijan selected through convenience sampling in 2013. Subcutaneous fat was measured using calipers and a questionnaire was given to subjects in order to collect their personal and their menstrual cycles’ information. The collected data were analysed by SPSS (version 16 statistical software. Results: The findings of the study revealed a significant difference between athletes and non-athletes in terms of the incidence of menstrual dysfunctions of amenorrhea, oligomenorrhea, menorrhagia, hypomenorhea and hypermenorrhea (p<0.05. Moreover, there was a negative relationship between thigh fat and amenorrhea (p=0.024, suprailiac and menorrhagia (p=0.015, chest and hypomenorhea (p=0.033, and waist circumference and hypermenorhea (p=0.011 in athletes. Conclusion: Overall, the findings of this study showed that prevalence of menstrual disorders was higher in athletes than non-athletes and low distribution of fat in the lower region of athletes’ body may be disturbed during menstrual periods (amenorrhea and low distribution of fat in the abdominal and upper parts of body may lead to irregular uterine bleeding (menorrhagia, hypomenorhea and hypermenorhea.

  12. Heuristic Techniques for Simultaneous Scheduling of Production and Distribution in Multi-Echelon Structures: Theory and Empirical Comparisons

    OpenAIRE

    Jack F. Williams

    1981-01-01

    Seven heuristic algorithms are discussed. Each can be used for production scheduling in an assembly network (a network where each work station has at most one immediate successor work station, but may have any number of immediate predecessor work stations), distribution scheduling in an arborescence network (a network where each warehouse or stocking point is supplied by at most one immediate predecessor stocking point, but may itself supply any number of immediate successor stocking points),...

  13. Modelling of the Bubble Size Distribution in an Aerated Stirred Tank: Theoretical and Numerical Comparison of Different Breakup Models

    Directory of Open Access Journals (Sweden)

    Kálal Zbyněk

    2014-09-01

    Full Text Available The main topic of this study is the mathematical modelling of bubble size distributions in an aerated stirred tank using the population balance method. The air-water system consisted of a fully baffled vessel with a diameter of 0.29 m, which was equipped with a six-bladed Rushton turbine. The secondary phase was introduced through a ring sparger situated under the impeller. Calculations were performed with the CFD software CFX 14.5. The turbulent quantities were predicted using the standard k-ε turbulence model. Coalescence and breakup of bubbles were modelled using the MUSIG method with 24 bubble size groups. For the bubble size distribution modelling, the breakup model by Luo and Svendsen (1996 typically has been used in the past. However, this breakup model was thoroughly reviewed and its practical applicability was questioned. Therefore, three different breakup models by Martínez-Bazán et al. (1999a, b, Lehr et al. (2002 and Alopaeus et al. (2002 were implemented in the CFD solver and applied to the system. The resulting Sauter mean diameters and local bubble size distributions were compared with experimental data.

  14. Nerve endoneurial microstructure facilitates uniform distribution of regenerative fibers: a post hoc comparison of midgraft nerve fiber densities.

    Science.gov (United States)

    Johnson, Philip J; Newton, Piyaraj; Hunter, Daniel A; Mackinnon, Susan E

    2011-02-01

    Despite their inferiority to nerve autograft, clinical alternatives are commonly used for reconstruction of peripheral nerve injuries because of their convenient off-the-shelf availability. Previously, our group compared isografts with NeuraGen(®) (Integra, Plainsboro, NJ) nerve guides, which are a commercially available type I collagen conduit and processed rat allografts comparable to Avance(®) (AxoGen, Alachua, FL) human decellularized allograft product. From this study, qualitative observations were made of distinct differences in the pattern of regenerating fibers within conduits, acellular allografts, and isografts. In the current post hoc analysis, these observations were quantified. Using nerve density, we statistically compared the differential pattern of regenerating axon fibers within grafts and conduit. The conduits exhibited a consistent decrease in midgraft density when compared with the isograft and acellularized allografts at two gap lengths (14 mm and 28 mm) and time points (12 and 22 weeks). The decrease in density was accompanied by clustered distribution of nerve fibers in conduits, which contrasted the evenly distributed regeneration seen in processed allografts and isografts. We hypothesize that the lack of endoneurial microstructure of conduits results in the clustering regenerating fibers, and that the presence of microstructure in the acellularized allograft and isografts facilitates even distribution of regenerating fibers. © Thieme Medical Publishers.

  15. Regional Analysis of Building Distributed Energy Costs and CO2 Abatement: A U.S. - China Comparison

    Energy Technology Data Exchange (ETDEWEB)

    Mendes, Goncalo; Feng, Wei; Stadler, Michael; Steinbach, Jan; Lai, Judy; Zhou, Nan; Marnay, Chris; Ding, Yan; Zhao, Jing; Tian, Zhe; Zhu, Neng

    2014-04-09

    The following paper conducts a regional analysis of the U.S. and Chinese buildings? potential for adopting Distributed Energy Resources (DER). The expected economics of DER in 2020-2025 is modeled for a commercial and a multi-family residential building in different climate zones. The optimal building energy economic performance is calculated using the Distributed Energy Resources Customer Adoption Model (DER CAM) which minimizes building energy costs for a typical reference year of operation. Several DER such as combined heat and power (CHP) units, photovoltaics, and battery storage are considered. The results indicate DER have economic and environmental competitiveness potential, especially for commercial buildings in hot and cold climates of both countries. In the U.S., the average expected energy cost savings in commercial buildings from DER CAM?s suggested investments is 17percent, while in Chinese buildings is 12percent. The electricity tariffs structure and prices along with the cost of natural gas, represent important factors in determining adoption of DER, more so than climate. High energy pricing spark spreads lead to increased economic attractiveness of DER. The average emissions reduction in commercial buildings is 19percent in the U.S. as a result of significant investments in PV, whereas in China, it is 20percent and driven by investments in CHP. Keywords: Building Modeling and Simulation, Distributed Energy Resources (DER), Energy Efficiency, Combined Heat and Power (CHP), CO2 emissions 1. Introduction The transition from a centralized and fossil-based energy paradigm towards the decentralization of energy supply and distribution has been a major subject of research over the past two decades. Various concerns have brought the traditional model into question; namely its environmental footprint, its structural inflexibility and inefficiency, and more recently, its inability to maintain acceptable reliability of supply. Under such a troubled setting

  16. Comparison of cadmium absorption, translocation, subcellular distribution and chemical forms between two radish cultivars (Raphanus sativus L.).

    Science.gov (United States)

    Xin, Juan; Zhao, Xiaohu; Tan, Qiling; Sun, Xuecheng; Hu, Chengxiao

    2017-11-01

    Cadmium (Cd) absorption and accumulation vary greatly not only among plant species but also among cultivars within the same species. In order to better understand the mechanisms of Cd absorption, transportation and distribution, we examined the differences of Cd absorption, translocation, subcellular distribution and chemical forms between L19, a Cd-tolerant genotype, and H4, a Cd-sensitive genotype, using kinetic analysis and soil culture experiment. Kinetic assays showed that the different Cd concentrations between the two cultivars might be ascribed to root absorption and translocation from root to shoot. The investigations of subcellular distribution and chemical forms verified that Cd concentrations of all subcellular fractions in H4 were all higher than in L19. Meanwhile, most of the Cd was associated with cell walls in the root of H4, but the Cd in the root of L19 and leaf of the two cultivars was mainly stored in soluble fraction, which could be one possible mechanism of tolerance to Cd toxicity. In addition, Cd fractions extracted by 1M NaCl and 2% HAC were predominant in root and leaf of both cultivars and the concentrations and proportions extracted by water and 80% ethanol in root and 1M NaCl in leaf were all higher in H4 than in L19. These results indicate that the Cd in H4 is more active than L19, which could be responsible for the sensitivity of H4 to Cd damage. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. A comparison of acoustic and observed sediment classifications as predictor variables for modelling biotope distributions in Galway Bay, Ireland

    Science.gov (United States)

    O'Carroll, Jack P. J.; Kennedy, Robert; Ren, Lei; Nash, Stephen; Hartnett, Michael; Brown, Colin

    2017-10-01

    The INFOMAR (Integrated Mapping For the Sustainable Development of Ireland's Marine Resource) initiative has acoustically mapped and classified a significant proportion of Ireland's Exclusive Economic Zone (EEZ), and is likely to be an important tool in Ireland's efforts to meet the criteria of the MSFD. In this study, open source and relic data were used in combination with new grab survey data to model EUNIS level 4 biotope distributions in Galway Bay, Ireland. The correct prediction rates of two artificial neural networks (ANNs) were compared to assess the effectiveness of acoustic sediment classifications versus sediments that were visually classified by an expert in the field as predictor variables. To test for autocorrelation between predictor variables the RELATE routine with Spearman rank correlation method was used. Optimal models were derived by iteratively removing predictor variables and comparing the correct prediction rates of each model. The models with the highest correct prediction rates were chosen as optimal. The optimal models each used a combination of salinity (binary; 0 = polyhaline and 1 = euhaline), proximity to reef (binary; 0 = within 50 m and 1 = outside 50 m), depth (continuous; metres) and a sediment descriptor (acoustic or observed) as predictor variables. As the status of benthic habitats is required to be assessed under the MSFD the Ecological Status (ES) of the subtidal sediments of Galway Bay was also assessed using the Infaunal Quality Index. The ANN that used observed sediment classes as predictor variables could correctly predict the distribution of biotopes 67% of the time, compared to 63% for the ANN using acoustic sediment classes. Acoustic sediment ANN predictions were affected by local sediment heterogeneity, and the lack of a mixed sediment class. The all-round poor performance of ANNs is likely to be a result of the temporally variable and sparsely distributed data within the study area.

  18. Comparison of sediment and nutrient export and runoff characteristics from watersheds with centralized versus distributed stormwater management

    Science.gov (United States)

    Hopkins, Kristina G.; Loperfido, J.V.; Craig, Laura S.; Noe, Gregory; Hogan, Dianna

    2017-01-01

    Stormwater control measures (SCMs) are used to retain stormwater and pollutants. SCMs have traditionally been installed in a centralized manner using detention to mitigate peak flows. Recently, distributed SCM networks that treat runoff near the source have been increasingly utilized. The aim of this study was to evaluate differences among watersheds that vary in SCM arrangement by assessing differences in baseflow nutrient (NOx-N and PO4−) concentrations and fluxes, stormflow export of suspended sediments and particulate phosphorus (PP), and runoff characteristics. A paired watershed approach was used to compare export between 2004 and 2016 from one forested watershed (For-MD), one suburban watershed with centralized SCMs (Cent-MD), and one suburban watershed with distributed SCMs (Dist-MD). Results indicated baseflow nitrate (NOx-N) concentrations typically exceeded 1 mg-N/L in all watersheds and were highest in Dist-MD. Over the last 10 years in Dist-MD, nitrate concentrations in both stream baseflow and in a groundwater well declined as land use shifted from agriculture to suburban. Baseflow nitrate export temporarily increased during the construction phase of SCM development in Dist-MD. This temporary pulse of nitrate may be attributed to the conversion of sediment control facilities to SCMs and increased subsurface flushing as infiltration SCMs came on line. During storm flow, Dist-MD tended to have less runoff and lower maximum specific discharge than Cent-MD for small events (1.3 cm). Mass export estimated during paired storm events indicated Dist-MD exported 30% less sediment and 31% more PP than Cent-MD. For large precipitation events, export of sediment and PP was similar among all three watersheds. Results suggest that distributed SCMs can reduce runoff and sediment loads during small rain events compared to centralized SCMs, but these differences become less evident for large events when peak discharge likely leads to substantial bank erosion.

  19. [An assessment of abdominal fatty tissue distribution in obese children. A comparison between echography and computed tomography].

    Science.gov (United States)

    Ferrozzi, F; Zuccoli, G; Tognini, G; Castriota-Scanderbeg, A; Bacchini, E; Bernasconi, S; Campani, R

    1999-12-01

    Computed tomography (CT) and, more recently, ultrasound (US), have proved excellent tools for quantifying adipose tissue distribution. Body fat distribution is an important factor in the treatment of obesity and its complications. We investigated the correlation between CT and US measurements in pediatric obesity. Forty obese children and adolescents aged 4.1-14.8 years were submitted to CT and US. Intra-abdominal, subcutaneous and total body fat were calculated (in cm2), with the CT image analysis software. The rectus muscle-spine and rectus muscle-aorta distances, as indicative of visceral fat thickness, were measured on US images with(out) compression. The distance between skin-fat and fat-rectus muscle interfaces was measured as subcutaneous fat thickness. We also compared US-CT findings with other morphometric variables--i.e., patient's (ideal) body weight and skin fold measures. At US, the rectus muscle-aorta and rectus muscle-spine distances ranged 2.4-7.5 cm (mean: 4.47 cm) and 3.6-8.9 cm (mean: 5.79 cm), respectively. The skin-rectus muscle distance ranged 1.2-7.5 cm (mean: 3.14 cm). A statistically significant correlation was found between the CT measurement of visceral fat and the aorta-rectus muscle and rectus muscle-spine distances (r = 0.80 and 0.74, respectively). The US measurements of subcutaneous fat were correlated with CT subcutaneous fat area (r = 0.82). No correlation was found between overweight, as calculated by body mass index, and CT or US fat. Our findings indicate that US is as useful as CT in evaluating body fat distribution in pediatric obesity.

  20. Exploring trophic strategies of exotic caprellids (Crustacea: Amphipoda): Comparison between habitat types and native vs introduced distribution ranges

    Science.gov (United States)

    Ros, Macarena; Tierno de Figueroa, José Manuel; Guerra-García, José Manuel; Navarro-Barranco, Carlos; Lacerda, Mariana Baptista; Vázquez-Luis, Maite; Masunari, Setuko

    2014-02-01

    The trophic ecology of non-native species is a key aspect to understand their invasion success and the community effects. Despite the important role of caprellid amphipods as trophic intermediates between primary producers and higher levels of marine food webs, there is very little information on their feeding habits. This is the first comprehensive study on the trophic strategies of two co-occurring introduced caprellids in the Spanish coasts: Caprella scaura and Paracaprella pusilla. The diet of 446 specimens of C. scaura and 230 of P. pusilla was analyzed to investigate whether there were differences in the feeding habits in relation to habitat characteristics (natural vs artificial hard substrata), type of host substrata (bryozoans and hydroids) and native vs introduced distribution ranges (Brazil vs Spain). Results revealed differences in diet preferences of the two species that have important implications for their trophic behaviour and showed a limited food overlap, which may favour their coexistence in introduced areas. In general terms, P. pusilla is a predator species, showing preference by crustacean prey in all of its life stages, while C. scaura feeds mainly on detritus. Although no sex-related diet shifts were observed in either of the species, evidence of ontogenetic variation in diet of C. scaura was found, with juveniles feeding on more amount of prey than adults. No diet differences were found between native and introduced populations within the same habitat type. However, P. pusilla exhibited a shift in its diet when different habitats were compared in the same distribution area, and C. scaura showed a flexible feeding behaviour between different host substrata in the same habitat type. This study shows that habitat characteristics at different scales can have greater influence on the feeding ecology of exotic species than different distribution ranges, and support the hypothesis that a switch between feeding strategies depending on habitat

  1. Chromosomal distribution of rDNA in Pan paniscus, Gorilla gorilla beringei, and Symphalangus syndactylus: comparison to related primates

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, A.S.; Atwood, K.C.; Warburton, D.

    1976-01-01

    Hybridization in situ was used to identify rDNA in chromosomes of the pygmy chimpanzee, mountain gorilla, and siamang gibbon. In contrast to other Pongids, and man, the gorilla has only two pairs of rDNA-containing chromosomes. The single pair in the siamang bears no resemblance to the nucleolar chromosome of the closely related lar gibbon. Pan paniscus and P. troglodytes have the same rDNA distribution, and similar karyotypes except in the structure of chromosome 23p. Grain counts over unbanded preparations show that the human, orangutan, and both chimpanzees have about the same total rDNA multiplicity.

  2. Collisional electron broadening of Stark sublevels of an atom of hydrogen in a plasma

    Energy Technology Data Exchange (ETDEWEB)

    Sholin, G.V.; Demura, A.V.; Lisitsa, V.S.

    1972-12-31

    A theoretical examination was made of the contours of the hydrogen lines in plasma, excited as a result of the static interaction of ions and collisional electrons with consideration of the special characteristics connected with the presence of supplementary degeneration in the Coulomb field. General expressions were obtained for the half-width of the Stark component of every line of the hydrogen spectrum in parabolic coordinates. A subsequent analysis was carried out of the transition from the overlapping of the Stark component to the isolated lines. It was found that such a transition is accompanied by annulment of the nondiagornl matrix elements of the operator of the collisional electron broadening. The form of the interference member in the operator of the collisional electron broadening is corrected with consideration of the perturbation of the upper and lower levels. The calculations carried out made it possible to improve the agreement between theory and experiment for lines with strong central components. (tr-auth)

  3. Spectral broadening in anatase titanium dioxide waveguides at telecommunication and near-visible wavelengths.

    Science.gov (United States)

    Evans, Christopher C; Shtyrkova, Katia; Bradley, Jonathan D B; Reshef, Orad; Ippen, Erich; Mazur, Eric

    2013-07-29

    We observe spectral broadening of femtosecond pulses in single-mode anatase-titanium dioxide (TiO(2)) waveguides at telecommunication and near-visible wavelengths (1565 and 794 nm). By fitting our data to nonlinear pulse propagation simulations, we quantify nonlinear optical parameters around 1565 nm. Our fitting yields a nonlinear refractive index of 0.16 × 10(-18) m(2)/W, no two-photon absorption, and stimulated Raman scattering from the 144 cm(-1) Raman line of anatase with a gain coefficient of 6.6 × 10(-12) m/W. Additionally, we report on asymmetric spectral broadening around 794 nm. The wide wavelength applicability and negligible two-photon absorption of TiO(2) make it a promising material for integrated photonics.

  4. Broadening participation in Natural Sciences and Mathematics at the University of Maryland Baltimore County

    Science.gov (United States)

    Rous, Philip

    2013-03-01

    Over the past two decades, UMBC has undertaken a series of efforts to broaden participation in the natural sciences and mathematics, beginning with the establishment of the Meyerhoff program. Using as examples the multiple initiatives that followed, and with a focus on the challenge of increasing access and success of all students who enter as both freshmen and transfer students, I will describe a model of culture change that we have employed repeatedly to understand and guide our efforts in broadening participation. Particular attention will be paid to the concept of cultural capital, the role of innovators and the challenge of scaling small-scale innovations towards institutional change. Supported by the National Science Foundation and the Bill and Melinda Gates Foundation.

  5. Controllability of Electromagnetically Induced Transparency in a Doppler Broadened Four-Level Atomic System

    Science.gov (United States)

    Abd-Elnabi, Somia; Osman, K. I.

    2013-04-01

    The influence of Doppler broadening on a four-level N-type atomic system has been investigated in the presence of spontaneous generating coherence. The atomic system interacting with three electromagnetic fields and includes the nonradiative decay, the effect of co- and counter-propagation of the fields is considered. The probe susceptibility behaviors can be modified by Doppler broadening via nonperturbative treatments of the density matrix elements solution in the absence and presence of the spontaneous generating coherence. Some interesting features are enhanced for the spectral behaviors and controllability of electromagnetically induced transparency, which were found to be in good agreement to some experimental results without including Zeeman sublevels to the system.

  6. Seeing the world through target-tinted glasses: Positive mood broadens perceptual tuning.

    Science.gov (United States)

    Uddenberg, Stefan; Shim, Won Mok

    2015-06-01

    Research shows that positive mood can serve to broaden the scope of attention at both the perceptual and conceptual level (e.g., increasing the size of spatial attentional focus and semantic access to remote associates). We investigated whether this relaxation of attentional filters by positive affect reduces their selectivity for basic visual features. We induced positive, neutral, or negative affect and asked observers to identify a target motion direction in a series of rapid random moving dot displays. Using a reverse correlation method, we examined the differential effects of emotion on observers' perceptual tuning curves for motion direction. Here we find that positive affect reduces selectivity for motion direction by broadening observers' perceptual tuning relative to both neutral and negative affect conditions. These findings provide the first behavioral evidence that positive emotion influences selectivity for basic visual features through modulation of tuning properties. (c) 2015 APA, all rights reserved).

  7. From discrete to continuous the broadening of number concepts in early modern England

    CERN Document Server

    Neal, Katherine

    2002-01-01

    In the early modern period, a crucial transformation occurred in the classical conception of number and magnitude. Traditionally, numbers were merely collections of discrete units that measured some multiple. Magnitude, on the other hand, was usually described as being continuous, or being divisible into parts that are infinitely divisible. This traditional idea of discrete number versus continuous magnitude was challenged in the early modern period in several ways. This detailed study explores how the development of algebraic symbolism, logarithms, and the growing practical demands for an expanded number concept all contributed to a broadening of the number concept in early modern England. An interest in solving practical problems was not, in itself, enough to cause a generalisation of the number concept. It was the combined impact of novel practical applications together with the concomitant development of such mathematical advances as algebraic notation and logarithms that produced a broadened number conce...

  8. In-medium jet evolution: interplay between broadening and decoherence effects

    CERN Document Server

    Apolinário, Liliana; Milhano, Guilherme; Salgado, Carlos A.

    2016-01-01

    The description of the modifications of the coherence pattern in a parton shower, in the presence of a QGP, has been actively addressed in recent studies. Among the several achievements, finite energy corrections, transverse momentum broadening due to medium interactions and interference effects between successive emissions have been extensively improved as they seem to be essential features for a correct description of the results obtained in heavy-ion collisions. In this work, based on the insights of our previous work [1], we explore the physical interplay between broadening and decoherence, by generalising previous studies of medium-modifications of the antenna spectrum [2, 3, 4] - so far restricted to the case where transverse motion is neglected. The result allow us to identify two quantities controlling the decoherence of a medium modified shower that can be used as building blocks for a successful future generation of jet quenching Monte Carlo simulators: a generalisation of the $\\Delta_{med}$ paramet...

  9. Distribution of the brown recluse spider (Araneae: Sicariidae) in Georgia with comparison to poison center reports of envenomations.

    Science.gov (United States)

    Vetter, Richard S; Hinkle, Nancy C; Ames, Lisa M

    2009-01-01

    Georgia is on the southeastern margin of the native range of the brown recluse spider, Loxosceles reclusa Gertsch and Mulaik. The brown recluse is not a common Georgia spider and has limited distribution in the state. Using recent submissions, previously published records, and examination of museum specimens, we document the spider's presence in 31 (19.5%) of Georgia's 159 counties, with almost all being found in the northern portion. The spider was collected almost exclusively north of the Fall Line (a transition zone separating the Piedmont and the Coastal Plain geological provinces). Only two locations in the southern Coastal Plain province produced L. reclusa specimens; these southern finds are considered spiders that were transported outside their range. There were six finds of the non-native world tramp species, L. rufescens (Dufour), three south of the Fall Line. In conspicuous contrast, over a 5-yr period, a Georgia poison center database recorded 963 reports of brown recluse spider bites from 103 counties. These figures greatly outnumber the historic verifications of brown recluses in the state for both specimen quantity and county occurrence, indicating improbable spider involvement and the overdiagnosis of bites. In the southern half of the state, medical diagnoses of brown recluse spider bites have virtually zero probability of being correct. Bite diagnoses should be made with caution in north Georgia given the spider's spotty distribution with low frequency of occurrence.

  10. Variation of Soil Aggregation along the Weathering Gradient: Comparison of Grain Size Distribution under Different Disruptive Forces.

    Science.gov (United States)

    Wei, Yujie; Wu, Xinliang; Xia, Jinwen; Shen, Xue; Cai, Chongfa

    2016-01-01

    The formation and stabilization of soil aggregates play a key role in soil functions. To date, few studies have been performed on the variation of soil aggregation with increasing soil weathering degree. Here, soil aggregation and its influencing factors along the weathering gradient were investigated. Six typical zonal soils (derived from similar parent materials) were sampled from temperate to tropical regions. Grain size distribution (GSD) in aggregate fragmentation with increasing disruptive forces (air-dried, water dispersion and chemical dispersion) was determined by laser diffraction particle size analyzer. Different forms of sesquioxides were determined by selective chemical extraction and their contributions to soil aggregation were identified by multiple stepwise regression analysis. The high variability of sesquioxides in different forms appeared with increasing free oxide content (Fed and Ald) from the temperate to tropical soils. The transformation of GSD peak to small size varied with increasing disruptive forces (psoils showed a similar fragmentation process. Aggregate water stability generally increased with increasing soil weathering (pstability in eluvium (A) horizon than in illuvium (B) horizon (pstability against slaking (R2 = 55%, paggregates (R2 = 93%, paggregates (including stability, size distribution and specific surface area) were closely related with pH, organic matter, cation exchange capacity (CEC), bulk density (BD), and free oxides (including various forms) (psoil aggregation conforms to aggregate hierarchy theory to some extent along the weathering gradient and different forms of sesquioxides perform their specific roles in the formation and stabilization of different size aggregates.

  11. A Critical Comparison of Alternative Distribution Configurations in Omni-Channel Retailing in Terms of Cost and Greenhouse Gas Emissions

    Directory of Open Access Journals (Sweden)

    Marco Melacini

    2018-01-01

    Full Text Available New opportunities and challenges forced by the ever-increasing importance of the online channel have arisen for retailers. The retailing industry is moving to a new phase, in which the distinctions between traditional and online channels disappear, namely omni-channel (OC retailing. At the same time, the awareness of environmentally sustainable processes has been enhanced around the world and the environmental impact that results from the online order fulfilment process is becoming a key issue for logistics managers. The new challenge is to understand how multiple channels can be synergistically managed to provide a seamless customer experience, taking an economic and environmental perspective simultaneously. Retailers need to define the distribution configuration for serving the online demand, making decisions on the integration level between online and traditional channels. In this paper, we developed an assessment model of the operational costs and greenhouse gas emissions for three distribution configurations in OC retailing. The model was also applied to a real case operating in the consumer electronics industry. Results highlighted that the search for synergies between online and traditional flows in both warehouse and transport activities is a key factor for the economic and environmental sustainability of OC systems.

  12. Systemic Distribution and Tumor Localization of Adoptively Transferred Lymphocytes in Mice: Comparison with Physiologically Based Pharmacokinetic Model

    Directory of Open Access Journals (Sweden)

    Robert J. Melder

    2002-01-01

    Full Text Available The mechanisms by which tumors are able to evade cellular immune responses are still largely unknown. It is likely, however, that the initial recruitment of lymphocytes to tumor vessels is limited by cell retention in normal tissue, which results in a low flux of these cells into the tumor vasculature. We grew MCaIV. (20mouse mammary carcinoma tumors in the leg of SCID mice and injected 111In-oxine-labeled, primed T lymphocytes directed against the tumor intravenously. The systemic distribution of cells in normal organs was similar between mice injected with primed and control lymphocyte populations, except for a delayed clearance of primed lymphocytes from the lungs. Kinetics of lymphocyte localization to the tumor were identical between the primed and control lymphocyte populations. Splenectomy before the injection of primed lymphocytes increased delivery of cells to the lungs and liver after 1 hour with no significant improvement in tumor localization. Within 24 to 168 hours after injection, localization of cells in the liver of splenectomized mice was higher than in the control group. However, no significant difference in tumor localization was observed between groups. A physiologically based compartmental model of lymphocyte distribution predicted the compartmental sequestration and identified model parameters critical for experimental planning and therapeutic optimization.

  13. Ab initio computation of the broadening of water rotational lines by molecular hydrogen

    OpenAIRE

    Wiesenfeld, Laurent; Faure, Alexandre

    2010-01-01

    Theoretical cross sections for the pressure broadening by hydrogen of rotational transitions of water are compared to the latest available measurements in the temperature range 65-220 K. A high accuracy interaction potential is employed in a full close coupling calculation. A good agreement with experiment is observed above ~80 K while the sharp drop observed experimentally at lower temperatures is not predicted by our calculations. Possible explanations for this discrepancy include the failu...

  14. Spectrally resolved four-wave mixing in semiconductors: Influence of inhomogeneous broadening

    DEFF Research Database (Denmark)

    Erland, J.; Pantke, K.-H.; Mizeikis, V.

    1994-01-01

    We study the influence of inhomogeneous broadening on results obtained from spectrally resolved transient four-wave mixing. In particular, we study the case where more resonances are coherently excited, leading to polarization interference or quantum beats, depending on the microscopic nature of ...... of the resonances. To demonstrate the ideas, we present experimental results from bulk CdSe and from GaAs multiple quantum wells....

  15. Doppler broadening effect on collision cross section functions - Deconvolution of the thermal averaging

    Science.gov (United States)

    Bernstein, R. B.

    1973-01-01

    The surprising feature of the Doppler problem in threshold determination is the 'amplification effect' of the target's thermal energy spread. The small thermal energy spread of the target molecules results in a large dispersion in relative kinetic energy. The Doppler broadening effect in connection with thermal energy beam experiments is discussed, and a procedure is recommended for the deconvolution of molecular scattering cross-section functions whose dominant dependence upon relative velocity is approximately that of the standard low-energy form.

  16. Music-induced positive mood broadens the scope of auditory attention

    OpenAIRE

    Putkinen, Vesa; Makkonen, Tommi; Eerola, Tuomas

    2017-01-01

    Abstract Previous studies indicate that positive mood broadens the scope of visual attention, which can manifest as heightened distractibility. We used event-related potentials (ERP) to investigate whether music-induced positive mood has comparable effects on selective attention in the auditory domain. Subjects listened to experimenter-selected happy, neutral or sad instrumental music and afterwards participated in a dichotic listening task. Distractor sounds in the unattended channel elicite...

  17. Comparison of dose distribution for proton beams and electrons: advantages and disadvantages; Comparacao de distribuicao de dose para feixes de protons e eletrons: vantagens e desvantagens

    Energy Technology Data Exchange (ETDEWEB)

    Neto, Joao T.M.; Ferreira, Maira B.; Braga, Victor B. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2016-07-01

    This study consists of a simulation of cancer therapy using a beam of protons and electrons. By comparing dose distribution curves for both beams we have showed the advantages and disadvantages of both therapies. The study was performed with Monte Carlo simulations using Geant4 code for a brain tumor, and it was found that the presence of the Bragg peak in proton beam allows a higher dose deposition in tumor and protection of adjacent tissues, while the electron beam has an entry dose in the tissue higher than the proton, yielding to the tissue neighbors of the tumor, unnecessary radiation. Moreover, it was also found significant production of neutrons from the proton beam, showing its main disadvantage. The continuation of this work will add the comparison with clinical beams of photons. (author)

  18. Comparison of Threshold Detection Methods for the Generalized Pareto Distribution (GPD): Application to the NOAA-NCDC Daily Rainfall Dataset

    Science.gov (United States)

    Deidda, Roberto; Mamalakis, Antonis; Langousis, Andreas

    2015-04-01

    One of the most crucial issues in statistical hydrology is the estimation of extreme rainfall from data. To that extent, based on asymptotic arguments from Extreme Excess (EE) theory, several studies have focused on developing new, or improving existing methods to fit a Generalized Pareto Distribution (GPD) model to rainfall excesses above a properly selected threshold u. The latter is generally determined using various approaches that can be grouped into three basic classes: a) non-parametric methods that locate the changing point between extreme and non-extreme regions of the data, b) graphical methods where one studies the dependence of the GPD parameters (or related metrics) to the threshold level u, and c) Goodness of Fit (GoF) metrics that, for a certain level of significance, locate the lowest threshold u that a GPD model is applicable. In this work, we review representative methods for GPD threshold detection, discuss fundamental differences in their theoretical bases, and apply them to daily rainfall records from the NOAA-NCDC open-access database (http://www.ncdc.noaa.gov/oa/climate/ghcn-daily/). We find that non-parametric methods that locate the changing point between extreme and non-extreme regions of the data are generally not reliable, while graphical methods and GoF metrics that rely on limiting arguments for the upper distribution tail lead to unrealistically high thresholds u. The latter is expected, since one checks the validity of the limiting arguments rather than the applicability of a GPD distribution model. Better performance is demonstrated by graphical methods and GoF metrics that rely on GPD properties. Finally, we discuss the effects of data quantization (common in hydrologic applications) on the estimated thresholds. Acknowledgments: The research project is implemented within the framework of the Action «Supporting Postdoctoral Researchers» of the Operational Program "Education and Lifelong Learning" (Action's Beneficiary: General

  19. Toward a broadband astro-comb: effects of nonlinear spectral broadening in optical fibers.

    Science.gov (United States)

    Chang, Guoqing; Li, Chih-Hao; Phillips, David F; Walsworth, Ronald L; Kärtner, Franz X

    2010-06-07

    We propose and analyze a new approach to generate a broadband astro-comb by spectral broadening of a narrowband astro-comb inside a highly nonlinear optical fiber. Numerical modeling shows that cascaded four-wave-mixing dramatically degrades the input comb's side-mode suppression and causes side-mode amplitude asymmetry. These two detrimental effects can systematically shift the center-of-gravity of astro-comb spectral lines as measured by an astrophysical spectrograph with resolution approximately 100,000; and thus lead to wavelength calibration inaccuracy and instability. Our simulations indicate that this performance penalty, as a result of nonlinear spectral broadening, can be compensated by using a filtering cavity configured for double-pass. As an explicit example, we present a design based on an Yb-fiber source comb (with 1 GHz repetition rate) that is filtered by double-passing through a low finesse cavity (finesse = 208), and subsequent spectrally broadened in a 2-cm, SF6-glass photonic crystal fiber. Spanning more than 300 nm with 16 GHz line spacing, the resulting astro-comb is predicted to provide 1 cm/s (approximately 10 kHz) radial velocity calibration accuracy for an astrophysical spectrograph. Such extreme performance will be necessary for the search for and characterization of Earth-like extra-solar planets, and in direct measurements of the change of the rate of cosmological expansion.

  20. Comparison fo CO2 Lidar Backscatter with Particle Size Distribution and GOES-7 Data in Hurricane Juliette

    Science.gov (United States)

    Jarzembski, Maurice A.; Srivastava, Vandana; McCaul, Eugene W., Jr.; Jedlovec, Gary J.; Atkinson, Robert J.; Pueschel, Rudy F.; Cutten, Dean R.

    1999-01-01

    Two NASA/MSFC continuous wave (CW) focused Doppler lidars obtained in-situ high resolution calibrated backscatter measurements in the upper levels of Hurricane Juliette as part of the 1995 NASA/Multicenter Airborne Coherent Atmospheric Wind Sensor (MACAWS) mission on board NASA's DC8 aircraft. These were also intercompared with in-situ cloud particle size distributions obtained from NASA/Ames Research Center's forward scattering spectrometer probe (FSSP), the DC8 aircraft infrared (IR) surface temperature radiometer data, and the Geostationary Operational Environmental Satellites (GOES-7) 11 micrometer IR emission images with their corresponding estimates of cloud top temperature and height. Two traverses of Hurricane Juliette's eye were made off the west coast of Mexico at altitude approx. 11.7 km on 21 September 1995. During this DC8 flight, late stages of eyewall decay-replacement cycles were observed, giving the appearance of an annular eye with clouds in the central region.

  1. Influence of the spectral distribution of light on the characteristics of photovoltaic panel. Comparison between simulation and experimental

    Science.gov (United States)

    Chadel, Meriem; Bouzaki, Mohammed Moustafa; Chadel, Asma; Petit, Pierre; Sawicki, Jean-Paul; Aillerie, Michel; Benyoucef, Boumediene

    2017-02-01

    We present and analyze experimental results obtained with a laboratory setup based on a hardware and smart instrumentation for the complete study of performance of PV panels using for illumination an artificial radiation source (Halogen lamps). Associated to an accurate analysis, this global experimental procedure allows the determination of effective performance under standard conditions thanks to a simulation process originally developed under Matlab software environment. The uniformity of the irradiated surface was checked by simulation of the light field. We studied the response of standard commercial photovoltaic panels under enlightenment measured by a spectrometer with different spectra for two sources, halogen lamps and sunlight. Then, we bring a special attention to the influence of the spectral distribution of light on the characteristics of photovoltaic panel, that we have performed as a function of temperature and for different illuminations with dedicated measurements and studies of the open circuit voltage and short-circuit current.

  2. Comparison of aluminum sulphonated phthalocyanine with 5-aminolaevulinic-acid-induced protoporphyrin IX: tissue distributions, photodamage, and photodegradation

    Science.gov (United States)

    MacRobert, Alexander J.; Bedwell, Joanne; Loh, C. S.; Chatlani, P. T.; Bown, Stephen G.

    1993-06-01

    Fluorescence spectroscopic studies have been carried out on tissue sensitization by Aluminium Sulphonated Phthalocyanine (AlSPc) and endogenous Protoporphyrin IX induced by administration of exogenous 5-aminolaevulinic acid (ALA). A charge-coupled device (CCD) imaging system has been used to obtain quantitative fluorescence distributions of sensitization in frozen sections taken from rat tumors together with normal adjacent tissues. Using ALA, specific porphyrin sensitization of malignant epithelium is observed with much less sensitization present in connective tissue. Photodegradation of AlSPc and PPIX was studied by monitoring of fluorescence bleaching: in normal rat colon there is a significant reduction in AlSPc fluorescence at the edge of the photonecrosed zone which suggests that photodegradation may provide a means of diagnosing the extent of tissue damage. ALA- induced PPIX fluorescence is also observed to bleach in colon simultaneously with an increase in fluorescence emission near 675 nm which we attribute to a photoprotoporphyrin degradation product.

  3. Study and Comparison of Rural and Urban Household Income Distribution in Khorasan Province and Country during 2007-2012

    Directory of Open Access Journals (Sweden)

    R. Jamshidi

    2013-12-01

    Full Text Available This study examined distrbution of household income in Khorasan Razavi province and the country for urban and rural areas, seprately. Using household income and expenditure statistics compiled by the Statistical Center of Iran during 2007-2012 the Gini index, Tile index, Atkinson index and the tenth docile to the first docile were applied.The study findings indicate that during the studied period income inequality in the country has been decreased. The levels of disparity in the urban areas have been usually higher than its levels in the country. , while the levels of disparity in the rural areas have been always lower than its levels in the country.. Morever, income distributions in the urban areas and the entire province have been always more uneven than what has been seen for the rural areas. Analysing the Tile and Atkinson indicies (ε=1 shows that both ascending and descending trends of the two indicies were consistent with the Gini index and thus, the three indicies are compatible and validate each other. On the other hand, analysing the Gross expenditures per capita for households and the Gini index shows that the levels of welfare in urban and rural areas of Khorasan were almost constant, however the index for the urban areas of the country has been decreased and for the rural areas has been increased. The social welfare often have been lower for the the rural areas than the social welfare for the urban areas. The results indicate significant differences in income distributions among the province, the country's rural areas and the urban areas.The sudy therefore proposes regional plannings to be considered.

  4. Nonparametric pore size distribution using d-PFG: comparison to s-PFG and migration to MRI.

    Science.gov (United States)

    Benjamini, Dan; Komlosh, Michal E; Basser, Peter J; Nevo, Uri

    2014-09-01

    Here we present the successful translation of a pore size distribution (PSD) estimation method from NMR to MRI. This approach is validated using a well-characterized MRI phantom consisting of stacked glass capillary arrays (GCA) having different diameters. By employing a double pulsed-field gradient (d-PFG) MRI sequence, this method overcomes several important theoretical and experimental limitations of previous single-PFG (s-PFG) based MRI methods by allowing the relative diffusion gradients' direction to vary. This feature adds an essential second dimension in the parameters space, which can potentially improve the reliability and stability of the PSD estimation. To infer PSDs from the MRI data in each voxel an inverse linear problem is solved in conjunction with the multiple correlation function (MCF) framework, which can account for arbitrary experimental parameters (e.g., long diffusion pulses). This scheme makes no a priori assumptions about the functional form of the underlying PSD. Creative use of region of interest (ROI) analysis allows us to create different underlying PSDs using the same GCA MRI phantom. We show that an s-PFG experiment on the GCA phantom fails to accurately reconstruct the size distribution, thus demonstrating the superiority of the d-PFG experiment. In addition, signal simulations corrupted by different noise levels were used to generate continuous and complex PSDs, which were then successfully reconstructed. Finally, owing to the reduced q- or b- values required to measure microscopic PSDs via d-PFG MRI, this method will be better suited to biomedical and clinical applications, in which gradient strength of scanners is limited. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Distribution of Taenia saginata metacestodes: a comparison of routine meat inspection and carcase dissection results in experimentally infected calves.

    Science.gov (United States)

    Soares, V E; De Andrade Belo, M A; Rezende, P C B; Soccol, V T; Fukuda, R T; De Ooliveira, G P; Da Costa, A J

    2011-07-01

    A comparison of techniques for detecting the presence of Cysticercus bovis in bovine carcasses was made by using carcass dissection and routine beef inspection guidelines. In the study, 28 calves were used after they were tested and found to be negative for the presence of anti-C. bovis serum antibodies and were inoculated orally with aliquots containing 6×10(4) Taenia saginata eggs. One hundred and twenty days after inoculation, the animals were slaughtered and a post mortem evaluation was done following Brazilian Federal Beef Inspection guidelines. This routine meat inspection was able to identify 71·42% of the assessed infected carcasses as being parasitized. This result implies that 28·58% of the infected carcasses would have been released as fit for human consumption since they would have been considered as free of C. bovis infection when using this method for carcass assessment. Only 3·07% of the total 2311 metacestodes present in the carcasses were identified by the conventional procedures of sanitary inspection. The assessment of different parts of the carcasses showed high infestation rates in shoulder clod (14·37%), head (11·21%), neck+chuck roll (8·05%), heart (7·75%) and top (inside) round (7·18%) which, together, were responsible for housing 48·51% of all the cysts found in the 24 beef cuts assessed. These numbers contrasted to the low incidence of cysts found in organs such as tongue (3·12%), diaphragm (1·69%) and esophagus (1·60%) which are usually described as predilection sites for the parasite.

  6. Pressure broadening and shift coefficients for the nu_ {2} and 3nu_ {2} bands of CH3D : rotational and temperature dependences

    Science.gov (United States)

    Boussin, C.; Regalia, L.; Plateaux, J. J.; Hamdouni, A.; Lutz, B. L.; de Bergh, C.; Barbe, A.

    1998-09-01

    We have measured broadening and shift coefficients for ro-vibrational lines of the nu_ {2} and 3nu_ {2} bands of CH3D, with the most abundant gases in planetary atmospheres (i.e. H2 and He for the giant planets and in the case of Titan, N2) as the foreign buffer gases, using a multispectral fitting technique developed by the Reims group. The spectra of the nu_ {2} band, near 5 microns, were recorded under high resolution and two temperatures (295 and 197K) using a FTS at the G.S.M.A. Reims laboratory. Those of the 3nu_ {2} band, near 1.6 microns, were recorded also under high resolution but only at room temperature with the FTS at Kitt Peak National Observatory. Broadening and shift coefficients were determined for lines of nu_ {2} up to J=20 in the P-branch and up to J=19 in the R-branch. For 3nu_ {2}, measurements were made up to J=14 in the P-branch and up to J=12 in the R-branch. In addition, for nu_ {2}, the temperature dependences of many of these coefficients were derived. Comparisons of the room temperature coefficients for the two bands show strong similarities in both their magnitudes and dependences with J and K. These similarities suggest that the temperature dependence determined for nu_ {2} can be used for 3nu_ {2}.

  7. Cervicothalamic tract termination: a reexamination and comparison with the distribution of monoclonal antibody Cat-301 immunoreactivity in the cat.

    Science.gov (United States)

    Zhang, M; Broman, J

    1998-12-01

    The distribution of cervicothalamic tract (CTT) terminations, labeled with anterogradely transported tracers (WGA-HRP or biotinylated dextran amine) injected into the lateral cervical nucleus of cats, was compared with the distribution of immunoreactivity for a cell-surface antigen detected with the monoclonal antibody Cat-301. The most abundant CTT termination is present in the ventrobasal complex (VB), mainly in its lateral part (VPL) and only sparsely in its medial part (VPM). In the VPL, the CTT preferentially terminates in a Cat-301-sparse peripheral rim of the nucleus and in between its lateral and medial subdivisions (VPLI and VPLm). CTT terminations are sparse in the central Cat-301-dense parts of the VPL. In the ventral periphery of VB (VBvp), situated in between the VPL/VPM and the external medullary lamina, thin CTT fibers with spaced varicosities is seen among the large fibers of passage. The VBvp is essentially devoid of Cat-301 immunoreactivity. Scattered clusters of CTT termination are also seen caudal and dorsal to the VB in the medial division of the posterior complex (POm), which is virtually devoid of Cat-301 immunoreactivity. In the caudal thalamus, dense and focused CTT termination is present in the medial extension of the magnocellular medial geniculate nucleus (MGmc) but absent from its main lateral part. The termination in the MGmc is centered upon clusters of cells displaying dense Cat-301 immunoreactivity. The present study demonstrates previously unrecognized or unconfirmed CTT terminations in the VPM and in the VBvp, and confirm previously described projections to the VPL, POm and MGmc. The preferential termination of the CTT in the Cat-301-sparse peripheral region of the VPL demonstrates that the CTT is related to a chemically defined VPL compartment. In the light of previous data, this observation suggests that the CTT is related to one or more thalamocortical channels that are partly or completely separate from that (those) activated

  8. Comparison of prostate cancer survival in Germany and the USA: can differences be attributed to differences in stage distributions?

    Science.gov (United States)

    Winter, Alexander; Sirri, Eunice; Jansen, Lina; Wawroschek, Friedhelm; Kieschke, Joachim; Castro, Felipe A; Krilaviciute, Agne; Holleczek, Bernd; Emrich, Katharina; Waldmann, Annika; Brenner, Hermann

    2017-04-01

    To better understand the influence of prostate-specific antigen (PSA) screening and other health system determinants on prognosis of prostate cancer, up-to-date relative survival (RS), stage distributions, and trends in survival and incidence in Germany were evaluated and compared with the United States of America (USA). Incidence and mortality rates for Germany and the USA for the period 1999-2010 were obtained from the Centre for Cancer Registry Data at the Robert Koch Institute and the USA Surveillance Epidemiology and End Results (SEER) database. For analyses on stage and survival, data from 12 population-based cancer registries in Germany and from the SEER-13 database were analysed. Patients (aged ≥ 15 years) diagnosed with prostate cancer (1997-2010) and mortality follow-up to December 2010 were included. The 5- and 10-year RS and survival trends (2002-2010) were calculated using standard and model-based period analysis. Between 1999 and 2010, prostate cancer incidence decreased in the USA but increased in Germany. Nevertheless, incidence remained higher in the USA throughout the study period (99.8 vs 76.0 per 100,000 in 2010). The proportion of localised disease significantly increased from 51.9% (1998-2000) to 69.6% (2007-2010) in Germany and from 80.5% (1998-2000) to 82.6% (2007-2010) in the USA. Mortality slightly decreased in both countries (1999-2010). Overall, 5- and 10-year RS was lower in Germany (93.3%; 90.7%) than in the USA (99.4%; 99.6%) but comparable after adjustment for stage. The same patterns were seen in age-specific analyses. Improvements seen in prostate cancer survival between 2002-2004 and 2008-2010 (5-year RS: 87.4% and 91.2%; +3.8% units) in Germany disappeared after adjustment for stage (P = 0.8). The survival increase in Germany and the survival advantage in the USA might be explained by differences in incidence and stage distributions over time and across countries. Effects of early detection or a lead-time bias due to the more

  9. Myocardial blood flow at rest and stress measured with dynamic contrast-enhanced MRI: comparison of a distributed parameter model with a Fermi function model.

    Science.gov (United States)

    Broadbent, David A; Biglands, John D; Larghat, Abdulghani; Sourbron, Steven P; Radjenovic, Aleksandra; Greenwood, John P; Plein, Sven; Buckley, David L

    2013-12-01

    To assess the feasibility of simultaneously measuring blood flow (Fb ), Gd-DTPA extraction fraction (E), and distribution volume (vd ) in healthy myocardium at rest and under adenosine stress using dynamic contrast-enhanced MRI. Sixteen volunteers were examined at 1.5 T and 11 returned for a repeat study. The data were analyzed using a distributed parameter (DP) 2-region model to arrive at estimates of Fb , E, blood volume, and interstitial volume. For comparison, estimates of Fb were also obtained using a Fermi function model. DP model fits were successful in 49 of the 54 data sets. Estimates obtained using DP and Fermi models did not differ for either rest Fb or myocardial perfusion reserve though DP estimates of stress Fb were lower than Fermi estimates. The repeatability of the DP parameters Fb , E, and vd was better than or equal to the repeatability of Fermi-Fb . E at rest and under stress was estimated to be 66% and 57%, respectively. The results suggest that characteristics of the microvasculature of healthy myocardium can be reliably determined using dynamic contrast-enhanced MRI at rest and under stress and that delivery of Gd-DTPA to the myocardium is not flow-limited. Copyright © 2013 Wiley Periodicals, Inc.

  10. Inflammatory cells in minor salivary glands of patients with chronic hepatitis C: immunophenotype, pattern of distribution, and comparison with liver samples.

    Science.gov (United States)

    Caldeira, Patrícia Carlos; Oliveira e Silva, Karla Rachel; Vidigal, Paula Vieira Teixeira; Grossmann, Soraya de Mattos Camargo; do Carmo, Maria Auxiliadora Vieira

    2014-05-01

    To characterize the immunophenotype and the distribution of the inflammatory infiltrate (INF) in salivary glands (SG) of patients with chronic hepatitis C, comparing with laboratorial data (genotype, viral load, METAVIR, and HCV RNA in SG), and liver. INF was classified as diffuse or focal. Immunohistochemistry for CD3, CD20, CD8, CD4, CD57, CD68, and S100 was performed in 61 SG and 59 livers. Diffuse INF was more common in SG than in liver. CD3(+), CD20(+), and CD8(+) were the most frequent cells in both tissues, with few CD57(+), CD68(+), and S100(+) cells. CD4(+) cells were common in liver, but rare in SG. Liver presented higher indexes for all markers, except S100(+) (p<0.05). Higher CD3(+), CD20(+), and CD8(+) (p<0.05) were observed in SG with focal infiltrate than with diffuse infiltrate. In liver, CD20(+) and CD3(+) were higher in focal infiltrate, and CD68(+) in diffuse infiltrate (p<0.05). Comparisons with laboratorial data did not show statistical significance. The INF in SG was mainly composed by T and B lymphocytes, mostly cytotoxic T cells. The glandular INF can present differences in composition according to its distribution. A more intense inflammation was observed in liver, but similar cell types were identified in SG, except for CD4(+). Copyright © 2014 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

  11. The Comparison of Distributed P2P Trust Models Based on Quantitative Parameters in the File Downloading Scenarios

    Directory of Open Access Journals (Sweden)

    Jingpei Wang

    2016-01-01

    Full Text Available Varied P2P trust models have been proposed recently; it is necessary to develop an effective method to evaluate these trust models to resolve the commonalities (guiding the newly generated trust models in theory and individuality (assisting a decision maker in choosing an optimal trust model to implement in specific context issues. A new method for analyzing and comparing P2P trust models based on hierarchical parameters quantization in the file downloading scenarios is proposed in this paper. Several parameters are extracted from the functional attributes and quality feature of trust relationship, as well as requirements from the specific network context and the evaluators. Several distributed P2P trust models are analyzed quantitatively with extracted parameters modeled into a hierarchical model. The fuzzy inferring method is applied to the hierarchical modeling of parameters to fuse the evaluated values of the candidate trust models, and then the relative optimal one is selected based on the sorted overall quantitative values. Finally, analyses and simulation are performed. The results show that the proposed method is reasonable and effective compared with the previous algorithms.

  12. High-accuracy measurements of snow Bidirectional Reflectance Distribution Function at visible and NIR wavelengths – comparison with modelling results

    Directory of Open Access Journals (Sweden)

    M. Dumont

    2010-03-01

    Full Text Available High-accuracy measurements of snow Bidirectional Reflectance Distribution Function (BRDF were performed for four natural snow samples with a spectrogonio-radiometer in the 500–2600 nm wavelength range. These measurements are one of the first sets of direct snow BRDF values over a wide range of lighting and viewing geometry. They were compared to BRDF calculated with two optical models. Variations of the snow anisotropy factor with lighting geometry, wavelength and snow physical properties were investigated. Results show that at wavelengths with small penetration depth, scattering mainly occurs in the very top layers and the anisotropy factor is controlled by the phase function. In this condition, forward scattering peak or double scattering peak is observed. In contrast at shorter wavelengths, the penetration of the radiation is much deeper and the number of scattering events increases. The anisotropy factor is thus nearly constant and decreases at grazing observation angles. The whole dataset is available on demand from the corresponding author.

  13. Comparison of Technological Options for Distributed Generation-Combined Heat and Power in Rajasthan State of India

    Directory of Open Access Journals (Sweden)

    Ram Kumar Agrawal

    2013-01-01

    Full Text Available Distributed generation (DG of electricity is expected to become more important in the future electricity generation system. This paper reviews the different technological options available for DG. DG offers a number of potential benefits. The ability to use the waste heat from fuel-operated DG, known as combined heat and power (CHP, offers both reduced costs and significant reductions of CO2 emissions. The overall efficiency of DG-CHP system can approach 90 percent, a significant improvement over the 30 to 35 percent electric grid efficiency and 50 to 90 percent industrial boiler efficiency when separate production is used. The costs of generation of electricity from six key DG-CHP technologies; gas engines, diesel engines, biodiesel CI engines, microturbines, gas turbines, and fuel cells, are calculated. The cost of generation is dependent on the load factor and the discount rate. It is found that annualized life cycle cost (ALCC of the DG-CHP technologies is approximately half that of the DG technologies without CHP. Considering the ALCC of different DG-CHP technologies, the gas I.C. engine CHP is the most effective for most of the cases but biodiesel CI engine CHP seems to be a promising DG-CHP technology in near future for Rajasthan state due to renewable nature of the fuel.

  14. A comparison of experimental and theoretical results for leakage, pressure distribution, and rotordynamic coefficients for annular gas seals

    Science.gov (United States)

    Nicks, C. O.; Childs, D. W.

    1984-01-01

    The importance of seal behavior in rotordynamics is discussed and current annular seal theory is reviewed. A Nelson's analytical-computational method for determining rotordynamic coefficients for this type of compressible-flow seal is outlined. Various means for the experimental identification of the dynamic coefficients are given, and the method employed at the Texas A and M University (TAMU) test facility is explained. The TAMU test apparatus is described, and the test procedures are discussed. Experimental results, including leakage, entrance-loss coefficients, pressure distributions, and rotordynamic coefficients for a smooth and a honeycomb constant-clearance seal are presented and compared to theoretical results from Nelson's analysis. The results for both seals show little sensitivity to the running speed over the test range. Agreement between test results and theory for leakage through the seal is satisfactory. Test results for direct stiffness show a greater sensitivity to fluid pre-rotation than predicted. Results also indicate that the deliberately roughened surface of the honeycomb seal provides improved stability versus the smooth seal.

  15. Comparison of selenium distribution in mice organs after the supplementation with inorganic and organic selenium compound selenosemicarbazide.

    Science.gov (United States)

    Musik, Irena; Kozioł-Montewka, Maria; Toś-Luty, Sabina; Donica, Helena; Pasternak, Kazimierz; Wawrzycki, Sławomir

    2002-01-01

    Studies on selenium organ content and its function in living organisms just like studies on other elements provide interesting results although their interpretation is not always clear. The aim of our study was to determine the concentration and distribution of selenium in several organs and tissues in mice after supplementation with our newly synthesized organic compound of selenium selenosemicarbazide (4-o-tolyl-selenosemicarbazide of o-chlorobenzoic acid) as compared to the effects of the supplementation with inorganic compounds. SWISS mice were fed with both types of compounds at the dose of 10(-3) g Se per kg for the period of 10 days. The concentrations of selenium in brains of mice treated with selenocarbazide and sodium selenite were higher than in controls (38.04 micrograms g-1 and 32.00 micrograms g-1 vs. 26.18 micrograms g-1). There was a statistically significant increase in the selenium contents in lungs after supplementation with selenosemicarbazide and sodium selenite (11.81 micrograms g-1 and 6.79 micrograms g-1 vs. 1.75 micrograms g-1 in controls). We found a statistically insignificant increase in selenium contents in intercostal muscles after supplementation with inorganic selenium compounds and a statistically significant increase after the supplementation with selenosemicarbazide (10.13 micrograms g-1; 14.21 micrograms g-1 and 28.84 micrograms g-1, respectively). Our investigations lead to a conclusion that 4-o-tolyl-seleno-semicarbazide of o-chlorobenzoic acid, an organic selenium compound may be more easily absorbed than inorganic sodium IV selenite.

  16. Effects of malathion and carbendazim on Amazonian freshwater organisms: comparison of tropical and temperate species sensitivity distributions.

    Science.gov (United States)

    Rico, Andreu; Waichman, Andrea V; Geber-Corrêa, Rachel; van den Brink, Paul J

    2011-06-01

    The risk assessment of pesticides for freshwater ecosystems in the Amazon has relied on the use of toxicity data and water quality criteria derived for temperate regions due to a lack of ecotoxicological studies performed with indigenous species. This leaves an unknown margin of uncertainty for the protection of Amazonian ecosystems, as differences in environmental conditions and species sensitivity are not taken into account. To address this issue, the acute toxic effects of malathion (an organophosphorus insecticide) and carbendazim (a benzimidazole fungicide) were assessed on five fish and five freshwater invertebrates endemic to the Amazonian region. Subsequently, the intrinsic sensitivity of Amazonian and temperate freshwater species was compared using the species sensitivity distribution (SSD) concept. Amazonian species sensitivity to malathion was found to be similar to that of their temperate counterparts, with LC50 values ranging between 111 and 1507 μg/l for fish species and 2.1-426 μg/l for arthropod species. However, Amazonian fish appeared to be slightly less sensitive for carbendazim than temperate fish with LC50 values ranging between 1648 and 4238 μg/l, and Amazonian invertebrates were found to be significantly more resistant than their temperate counterparts, with LC50 values higher than 16000 μg/l. The results of this study suggest that for these compounds, the use of water quality criteria derived with laboratory toxicity data for temperate species will result in a sufficient protection level for Amazonian freshwater organisms. Recommendations for further research include the validation of threshold concentrations derived with temperate standard test species and with the SSD model with semi-field experiments considering larger assemblages of indigenous species under local environmental conditions.

  17. Trace elements and their distribution in protein fractions of camel milk in comparison to other commonly consumed milks.

    Science.gov (United States)

    Al-Awadi, F M; Srikumar, T S

    2001-08-01

    Studies on camels' milk, whether with respect to concentration or bioavailability of trace elements from this milk, are limited and warrant further investigation. The object of this study was to analyse the concentration and distribution of zinc, copper, selenium, manganese and iron in camel milk compared to those in human milk, cows' milk and infant formula under similar experimental conditions. Camels' milk and cows' milk were collected from local farms, human milk samples were obtained from healthy donors in Kuwait and infant formula was purchased locally. Milk fractionation was performed by ultra-centrifugation and gelcolumn chromatography. The concentration of trace elements was analysed by atomic absorption spectrometry and that of protein was determined spectrophotometrically. The concentration of manganese and iron in camels' milk was remarkably higher (7-20-fold and 4-10-fold, respectively) than in human milk, cows' milk and infant formula. The zinc content of camels' milk was higher than that of human milk but slightly lower than in cows' milk and infant formula. The concentration of copper in camels' milk was similar to that of cows' milk but lower than in human milk and infant formula. The selenium content of camels' milk was comparable to those of other types of milk, Approximately 50-80% of zinc, copper and manganese in camels' milk were associated with the casein fraction, similar to that of cows' milk, The majority of selenium and iron in camels' milk was in association with the low molecular weight fraction, It is recommended that camels' milk be considered as a potential source of manganese, selenium and iron, perhaps not only for infants, but also for other groups suspected of mild deficiency of these elements. Further investigations are required to confirm this proposal.

  18. Comparison Studies on the Observation of Raindrop Size Distribution in Strong Precipitation Frontal Case in Northern Taiwan

    Science.gov (United States)

    Lin, Pay-Liam; Chen, Ying-Jhen

    2015-04-01

    In the nighttime of 11th June 2012, a mature Mai-Yu front passed through northern Taiwan. The leading edge of front associated with southwesterly flow produced strong precipitation in a short time. The extreme rainfall event caused multiple areas flooding. In order to investigate the characteristic of drop size distribution (DSD) accompanied with this heavy rainfall event, we used an impact type Joss-Waldgovel disdrometer (JWD), a laser-optical OTT Parsivel disdrometer (Parsivel) and a two dimensional video disdrometer (2DVD) collocated at NCU, and we also used three JWDs in FeiCui, NanGang and XiaYung to investigate the frontal precipitation. In the weak precipitation period, we found the concentration of small raindrops would be underestimated because the velocity detected by Parsivel is faster than the real situation. But we also made sure that before the strong precipitation happens, the three type disdrometers (JWD, 2DVD and Parsivel) operate consistently.During strong precipitation period, we found a significant DSD variation characteristic. As a convective cell passes, the concentration of medium to large drops increases in Parsivel, while decreases in JWD. Due to the limitation of instrument, Parsivel tended to overestimate the concentration of medium to large drops in the strong rainfall intensity. Comparing the rain drops concentration with the rain rate varies with time, Parsivel showed a good agreement but JWD even did not get the most significant characteristic as the strongest rainfall occurred. The rain rates of JWD and Parsivel varied in the same trend, but compared the rain rates with the rain gauge observation in the 10 m tower at NCU, both of them showed obvious underestimation. We suspected the limitation of instrument made the rain rate underestimated.

  19. Spatial variability of phytoplankton pigment distributions in the Subtropical South Pacific Ocean: comparison between in situ and predicted data

    Directory of Open Access Journals (Sweden)

    J. Ras

    2008-03-01

    Full Text Available In the frame of the BIOSOPE cruise in 2004, the spatial distribution and structure of phytoplankton pigments was investigated along a transect crossing the ultra-oligotrophic South Pacific Subtropical Gyre (SPSG between the Marquesas Archipelago (141° W–8° S and the Chilean upwelling (73° W–34° S. A High Performance Liquid Chromatography (HPLC method was improved in order to be able to accurately quantify pigments over such a large range of trophic levels, and especially from strongly oligotrophic conditions. Seven diagnostic pigments were associated to three phytoplankton size classes (pico-, nano and microphytoplankton. The total chlorophyll-α concentrations [TChlα] in surface waters were the lowest measured in the centre of the gyre, reaching 0.017 mg m−3. Pigment concentrations at the Deep Chlorophyll Maximum (DCM were generally 10 fold the surface values. Results were compared to predictions from a global parameterisation based on remotely sensed surface [TChlα]. The agreement between the in situ and predicted data for such contrasting phytoplankton assemblages was generally good: throughout the oligotrophic gyre system, picophytoplankton (prochlorophytes and cyanophytes and nanophytoplankton were the dominant classes. Relative bacteriochlorophyll-α concentrations varied around 2%. The transition zone between the Marquesas and the SPSG was also well predicted by the model. However, some regional characteristics have been observed where measured and modelled data differ. Amongst these features is the extreme depth of the DCM (180 m towards the centre of the gyre, the presence of a deep nanoflagellate population beneath the DCM or the presence of a prochlorophyte-enriched population in the formation area of the high salinity South Pacific Tropical Water. A coastal site sampled in the eutrophic upwelling zone, characterised by recently upwelled water, was significantly and unusually enriched in picoeucaryotes, in

  20. A comparison of additional treatment processes to limit particle accumulation and microbial growth during drinking water distribution.

    Science.gov (United States)

    Liu, G; Lut, M C; Verberk, J Q J C; Van Dijk, J C

    2013-05-15

    Water quality changes, particle accumulation and microbial growth occurring in pilot-scale water distribution systems fed with normally treated and additional treated groundwater were monitored over a period of almost one year. The treatment processes were ranked in the following order: nanofiltration (NF) > (better than) ultrafiltration (UF) > ion exchange (IEX) for limiting particle accumulation. A different order was found for limiting overall microbial growth: NF > IEX > UF. There were strong correlations between particle load and particle accumulation, and between nutrient load and microbial growth. It was concluded that particle accumulation can be controlled by reducing the particle load in water treatment plants; and the microbial growth can be better controlled by limiting organic nutrients rather than removing biomass in water treatment plants. The major focus of this study was on microbial growth. The results demonstrated that growth occurred in all types of treated water, including the phases of bulk water, biofilm and loose deposits. Considering the growth in different phases, similar growth in bulk water was observed for all treatments; NF strongly reduced growth both in loose deposits and in biofilm; UF promoted growth in biofilm, while strongly limiting growth in loose deposits. IEX had good efficiency in between UF and NF, limiting both growths in loose deposits and in biofilm. Significant growth was found in loose deposits, suggesting that loose deposit biomass should be taken into account for growth evaluation and/or prediction. Strong correlations were found between microbial growth and pressure drop in a membrane fouling simulator which proved that a membrane fouling simulator can be a fast growth predictor (within a week). Different results obtained by adenosine triphosphate and flow cytometry cell counts revealed that ATP can accurately describe both suspended and particle-associated biomass, and flow cytometry files of TCC measurements needs

  1. Comparison of the local pulmonary distribution of nanoparticles administered intratracheally to rats via gavage needle or microsprayer delivery devices.

    Science.gov (United States)

    Zhang, Guihua; Shinohara, Naohide; Oshima, Yutaka; Kobayashi, Toshio; Imatanaka, Nobuya; Kawaguchi, Kenji; Gamo, Masashi

    2017-04-01

    Intratracheal administration methods are used to conduct toxicological assessments of inhaled nanoparticles (NPs), and gavage needles or microsprayers are common intratracheal delivery devices. The NP suspension is delivered in a liquid state via gavage needle and as a liquid aerosol via microsprayer. The differences in local pulmonary NP distribution (called the microdistribution) arising from the different states of the NP suspension cause differential pulmonary responses; however, this has yet to be investigated. Herein, using microbeam X-ray fluorescence microscopy, we quantitatively evaluated the TiO2 pulmonary microdistribution (per mesh: 100 μm × 100 μm) in lung sections from rats administered an intratracheal dose of TiO2 NPs (6 mg kg-1 ) via gavage needle or microsprayer. The results revealed that: (i) using a microsprayer appears to reduce the variations in TiO2 content (ng mesh-1 ) among rats (e.g., coefficients of variation, n = 3, microsprayer vs gavage needle: 13% vs 30%, for the entire lungs); (ii) TiO2 appears to be deposited less in the right middle lobes than in the rest of the lung lobes, irrespective of the chosen intratracheal delivery device; and (iii) similar TiO2 contents (ng mesh-1 ) and frequencies are deposited in the lung lobes of rats administered TiO2 NPs via gavage needle or microsprayer. This suggests that the physical state of the administered NP suspension does not markedly alter TiO2 pulmonary microdistribution. The results of this investigation are important for the standardization of intratracheal administration methods. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Comparison of single- and multi-scale models for the prediction of the Culicoides biting midge distribution in Germany

    Directory of Open Access Journals (Sweden)

    Renke Lühken

    2016-05-01

    Full Text Available This study analysed Culicoides presence-absence data from 46 sampling sites in Germany, where monitoring was carried out from April 2007 until May 2008. Culicoides presence-absence data were analysed in relation to land cover data, in order to study whether the prevalence of biting midges is correlated to land cover data with respect to the trapping sites. We differentiated eight scales, i.e. buffer zones with radii of 0.5, 1, 2, 3, 4, 5, 7.5 and 10 km, around each site, and chose several land cover variables. For each species, we built eight single-scale models (i.e. predictor variables from one of the eight scales for each model based on averaged, generalised linear models and two multiscale models (i.e. predictor variables from all of the eight scales based on averaged, generalised linear models and generalised linear models with random forest variable selection. There were no significant differences between performance indicators of models built with land cover data from different buffer zones around the trapping sites. However, the overall performance of multi-scale models was higher than the alternatives. Furthermore, these models mostly achieved the best performance for the different species using the index area under the receiver operating characteristic curve. However, as also presented in this study, the relevance of the different variables could significantly differ between various scales, including the number of species affected and the positive or negative direction. This is an even more severe problem if multi-scale models are concerned, in which one model can have the same variable at different scales but with different directions, i.e. negative and positive direction of the same variable at different scales. However, multi-scale modelling is a promising approach to model the distribution of Culicoides species, accounting much more for the ecology of biting midges, which uses different resources (breeding sites, hosts, etc. at

  3. COMPARISON OF SPATIAL INTERPOLATION METHODS FOR WHEAT WATER REQUIREMENT AND ITS TEMPORAL DISTRIBUTION IN HAMEDAN PROVINCE (IRAN

    Directory of Open Access Journals (Sweden)

    M. H. Nazarifar

    2014-01-01

    Full Text Available Water is the main constraint for production of agricultural crops. The temporal and spatial variations in water requirement for agriculture products are limiting factors in the study of optimum use of water resources in regional planning and management. However, due to unfavorable distribution and density of meteorological stations, it is not possible to monitor the regional variations precisely. Therefore, there is a need to estimate the evapotranspiration of crops at places where meteorological data are not available and then extend the findings from points of measurements to regional scale. Geostatistical methods are among those methods that can be used for estimation of evapotranspiration at regional scale. The present study attempts to investigate different geostatistical methods for temporal and spatial estimation of water requirements for wheat crop in different periods. The study employs the data provided by 16 synoptic and climatology meteorological stations in Hamadan province in Iran. Evapotranspiration for each month and for the growth period were determined using Penman-Mantis and Torrent-White methods for different water periods based on Standardized Precipitation Index (SPI. Among the available geostatistical methods, three methods: Kriging Method, Cokriging Method, and inverse weighted distance were selected, and analyzed, using GS+ software. Analysis and selection of the suitable geostatistical method were performed based on two measures, namely Mean Absolute Error (MAE and Mean Bias Error (MBE. The findings suggest that, in general, during the drought period, Kriging method is the proper one for estimating water requirements for the six months: January, February, April, May, August, and December. However, weighted moving average is a better estimation method for the months March, June, September, and October. In addition, Kriging is the best method for July. In normal conditions, Kriging is suitable for April, August, December

  4. Comparison of growth, biomass and nutrient distribution in five promising clones of Populus deltoides under an agrisilviculture system.

    Science.gov (United States)

    Swamy, S L; Mishra, Alka; Puri, S

    2006-01-01

    Variations in growth, above- and below-ground biomass and nutrient distribution were examined in five clones (G3, G48, 65/27, D121 and S7C1) of Populus deltoides grown under agrisilviculture system in sub-humid tropics of Central India. The monoclonal blocks were planted at 4x5 m in a randomized block design with three replications. Diameter at breast height (dbh) and tree height were consistently higher in clone 65/27 and lowest in clone S7C1. Mean annual increments (MAI) in dbh and height were 1.6 and 1.3 times higher in clone 65/27 compared to clone S7C1. Total biomass varied from 48.5 to 62.2 Mg ha(-1) in six-year-old clones. In rank order, the total biomass of clones was: 65/27>D121>G48>G3>S7C1. Stem wood accounted 60.4-68.9% to total biomass followed by coarse roots (12.2-18.9%), branches (12.3-15%), leaves (3.02-6.9%) and fine roots (1.5-2.7%). Root-shoot ratio ranged from 0.2 to 0.35. It was highest in clone G48 and lowest in clone S7C1. In six-year-old clones, total N ranged from 184.3 to 266.3 kg ha(-1), P from 16.8 to 31.1 kg ha(-1) and K from 81.9 to 128.7 kg ha(-1). Total N and P were highest in clone 65/27, while K in clone G48. Nutrients were lowest in clone S7C1. In general, maximum nutrients (N, P and K) were allocated to above-ground components (leaves>stem>branches) than below-ground components. Available N, P and K in the soil improved significantly after six years of planting. It was higher in 0-20 cm and decreased with soil depth. At 0-20 cm soil depth, N increased from 14.9% to 24.1%, P from 17.2% to 23.3% and K from 3.1% to 5.1% under different clones. The yield of both soybean and wheat reduced under poplar clones. Yield losses in soybean ranged from 10.1% to 33% and wheat from 15% to 30.3% under different clones. The management strategies for reducing tree-crop competition and nutrient export from the site under P. deltoides based agrisilviculture system for achieving sustainable production are discussed.

  5. Calculation of the Doppler broadening function using Fourier analysis;Calculo da funcao de alargamento Doppler utilizando analise de Fourier

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Alessandro da Cruz

    2010-07-01

    An efficient and precise method for calculation of Doppler broadening function is very important to obtain average group microscopic cross sections, self shielding factors, resonance integrals and others reactor physics parameter. In this thesis two different methods for calculation of Doppler broadening function and interference term will be presented. The main method is based on a new integral form for Doppler broadening function {psi}(x,{zeta}) which gives a mathematical interpretation of the approximation proposed by Bethe and Placzek, as the convolution of the Lorentzian function with a Gaussian function. This interpretation besides leading to a new integral form for {psi}(x,{zeta}), enables to obtain a simple analytic solution for the Doppler broadening function. (author)

  6. Comparison of growth, biomass and nutrient distribution in five promising clones of Populus deltoides under an agrisilviculture system

    Energy Technology Data Exchange (ETDEWEB)

    Swamy, S.L.; Mishra, A.; Puri, S. [Indira Gandhi Agricultural Univ., Raipur (India). Dept. of Forestry

    2006-01-15

    Variations in growth, above- and below-ground biomass and nutrient distribution were examined in five clones (G3, G48, 65/27, D121 and S7C1) of Populus deltoides grown under agrisilviculture system in sub-humid tropics of Central India. The monoclonal blocks were planted at 4 x 5 m in a randomized block design with three replications. Diameter at breast height (dbh) and tree height were consistently higher in clone 65/27 and lowest in clone S7C1. Mean annual increments (MAI) in dbh and height were 1.6 and 1.3 times higher in clone 65/27 compared to clone S7C1. Total biomass varied from 48.5 to 62.2 Mg ha{sup -} {sup 1} in six-year-old clones. In rank order, the total biomass of clones was: 65/27 > D121 > G48 > G3 > S7C1. Stem wood accounted 60.4-68.9% to total biomass followed by coarse roots (12.2-18.9%), branches (12.3-15%), leaves (3.02-6.9%) and fine roots (1.5-2.7%). Root-shoot ratio ranged from 0.2 to 0.35. It was highest in clone G48 and lowest in clone S7C1. In six-year-old clones, total N ranged from 184.3 to 266.3 kg ha{sup -1}, P from 16.8 to 31.1 kg ha{sup -1} and K from 81.9 to 128.7 kg ha{sup -1}. Total N and P were highest in clone 65/27, while K in clone G48. Nutrients were lowest in clone S7C1. In general, maximum nutrients (N, P and K) were allocated to above-ground components (leaves > stem > branches) than below-ground components. Available N, P and K in the soil improved significantly after six years of planting. It was higher in 0-20 cm and decreased with soil depth. At 0-20 cm soil depth, N increased from 14.9% to 24.1%, P from 17.2% to 23.3% and K from 3.1% to 5.1% under different clones. The yield of both soybean and wheat reduced under poplar clones. Yield losses in soybean ranged from 10.1% to 33% and wheat from 15% to 30.3% under different clones. The management strategies for reducing tree-crop competition and nutrient export from the site under P. deltoides based agrisilviculture system for achieving sustainable production are

  7. Broadening engineering education: bringing the community in : commentary on "social responsibility in French engineering education: a historical and sociological analysis".

    Science.gov (United States)

    Conlon, Eddie

    2013-12-01

    Two issues of particular interest in the Irish context are (1) the motivation for broadening engineering education to include the humanities, and an emphasis on social responsibility and (2) the process by which broadening can take place. Greater community engagement, arising from a socially-driven model of engineering education, is necessary if engineering practice is to move beyond its present captivity by corporate interests.

  8. Influence of Electron–Acoustic-Phonon Scattering on Intensity Power Broadening in a Coherently Driven Quantum-Dot–Cavity System

    OpenAIRE

    C. Roy; S. Hughes

    2011-01-01

    We present a quantum optics formalism to study the intensity power broadening of a semiconductor quantum dot interacting with an acoustic-phonon bath and a high-Q microcavity. Power broadening is investigated using a time-convolutionless master equation in the polaron frame, which allows for a nonperturbative treatment of the interaction of the quantum dot with the phonon reservoir. We calculate the full non-Lorentzian photoluminescence (PL) line shapes and numerically extract the intensity l...

  9. An Experimental and Theoretical Study of Nitrogen-Broadened Acetylene Lines

    Science.gov (United States)

    Thibault, Franck; Martinez, Raul Z.; Bermejo, Dionisio; Ivanov, Sergey V.; Buzykin, Oleg G.; Ma, Qiancheng

    2014-01-01

    We present experimental nitrogen-broadening coefficients derived from Voigt profiles of isotropic Raman Q-lines measured in the 2 band of acetylene (C2H2) at 150 K and 298 K, and compare them to theoretical values obtained through calculations that were carried out specifically for this work. Namely, full classical calculations based on Gordon's approach, two kinds of semi-classical calculations based on Robert Bonamy method as well as full quantum dynamical calculations were performed. All the computations employed exactly the same ab initio potential energy surface for the C2H2N2 system which is, to our knowledge, the most realistic, accurate and up-to-date one. The resulting calculated collisional half-widths are in good agreement with the experimental ones only for the full classical and quantum dynamical methods. In addition, we have performed similar calculations for IR absorption lines and compared the results to bibliographic values. Results obtained with the full classical method are again in good agreement with the available room temperature experimental data. The quantum dynamical close-coupling calculations are too time consuming to provide a complete set of values and therefore have been performed only for the R(0) line of C2H2. The broadening coefficient obtained for this line at 173 K and 297 K also compares quite well with the available experimental data. The traditional Robert Bonamy semi-classical formalism, however, strongly overestimates the values of half-width for both Qand R-lines. The refined semi-classical Robert Bonamy method, first proposed for the calculations of pressure broadening coefficients of isotropic Raman lines, is also used for IR lines. By using this improved model that takes into account effects from line coupling, the calculated semi-classical widths are significantly reduced and closer to the measured ones.

  10. On the Origin of the Scatter Broadening of Fast Radio Burst Pulses and Astrophysical Implications

    Science.gov (United States)

    Xu, Siyao; Zhang, Bing

    2016-12-01

    Fast radio bursts (FRBs) have been identified as extragalactic sources that can probe turbulence in the intergalactic medium (IGM) and their host galaxies. To account for the observed millisecond pulses caused by scatter broadening, we examine a variety of possible electron density fluctuation models in both the IGM and the host galaxy medium. We find that a short-wave-dominated power-law spectrum of density, which may arise in highly supersonic turbulence with pronounced local dense structures of shock-compressed gas in the host interstellar medium (ISM), can produce the required density enhancements at sufficiently small scales to interpret the scattering timescale of FRBs. This implies that an FRB residing in a galaxy with efficient star formation in action tends to have a broadened pulse. The scaling of the scattering time with the dispersion measure (DM) in the host galaxy varies in different turbulence and scattering regimes. The host galaxy can be the major origin of scatter broadening, but contributes to a small fraction of the total DM. We also find that the sheet-like structure of the density in the host ISM associated with folded magnetic fields in a viscosity-dominated regime of magnetohydrodynamic (MHD) turbulence cannot give rise to strong scattering. Furthermore, valuable insights into the IGM turbulence concerning the detailed spatial structure of density and magnetic field can be gained from the observed scattering timescale of FRBs. Our results favor the suppression of micro-plasma instabilities and the validity of the collisional-MHD description of turbulence properties in the collisionless IGM.

  11. Quantum Memory for Microwave Photons in an Inhomogeneously Broadened Spin Ensemble

    DEFF Research Database (Denmark)

    Julsgaard, Brian; Grezes, Cécile; Bertet, Patrice

    2013-01-01

    We propose a multi-mode quantum memory protocol able to store the quantum state of the field in a microwave resonator into an ensemble of electronic spins. The stored information is protected against inhomogeneous broadening of the spin ensemble by spin-echo techniques resulting in memory times...... orders of magnitude longer than previously achieved. By calculating the evolution of the first and second moments of the spin-cavity system variables for realistic experimental parameters, we show that a memory based on NV center spins in diamond can store a qubit encoded on the |0> and |1> Fock states...

  12. Biexcitonic bound and continuum states of homogeneously and inhomogeneously broadened exciton resonances

    DEFF Research Database (Denmark)

    Langbein, W.; Hvam, Jørn Märcher

    2002-01-01

    We investigate the influence of excitonic localization on the corresponding biexcitonic states in GaAs quantum wells by spectrally resolved four-wave mixing. With increasing localization, the biexciton binding energy increases, while the biexciton continuum shifts to higher energies....... The localization leads to an inhomogeneous broadening of the biexciton binding energy and the biexciton continuum edge. Simultaneously, the oscillator strength of the biexciton continuum-edge is reduced. This is interpreted as a result of the different localization of biexcitonic and excitonic states by the random...

  13. Characterization of film surface treated with ECR plasma by Doppler broadening

    CERN Document Server

    Nishijima, S; Hirata, K; Kobayashi, Y; Honda, Y; Tagawa, S

    2000-01-01

    Doppler broadened positron annihilation measurements were carried out using the positron beam technique on plasma treated polyethylene films as a function of incident positron energy. In addition, surface properties of the treated films also have been measured using other conventional techniques such as FT-IR, SEM and AFM. The surface tension of the films was also determined using sessile drop method. The S-parameter is seen to decrease on the surface upon plasma treatment that introduces polar groups such as hydroxyl and carbonyl on the surface. The results are discussed.

  14. On quantum-mechanical unified theories of collisional spectral line broadening

    OpenAIRE

    Schuller, F.; Nienhuis, G.

    1982-01-01

    We compare the Baranger-type unified theory of line broadening with a quantum version of the binary-collision approach. For the simple model system of a two-state atom, where both treatments are well-defined, the binary-collision theory results only from the exact formalism after an inversion of an integration variable in an integral equation. On the other hand, the binary-collision theory is applicable to more general systems. In the limiting cases of the impact and the quasistatic theories,...

  15. Ultraslow Light Propagation in an Inhomogeneously Broadened Rare-Earth Ion-Doped Crystal

    Science.gov (United States)

    Baldit, E.; Bencheikh, K.; Monnier, P.; Levenson, J. A.; Rouget, V.

    2005-09-01

    We show that coherent population oscillations effect allows us to burn a narrow spectral hole (26 Hz) within the homogeneous absorption line of the optical transition of an erbium ion-doped crystal. The large dispersion of the index of refraction associated with this hole permits us to achieve a group velocity as low as 2.7m/s with a transmission of 40%. We especially benefit from the inhomogeneous absorption broadening of the ions to tune both the transmission coefficient, from 40% to 90%, and the light group velocity from 2.7m/s to 100m/s.

  16. Somatic currents contribute to frequency-dependent spike-broadening in supraoptic neuroendocrine cells.

    Science.gov (United States)

    O'Regan, M H; Cobbett, P

    1993-10-29

    Voltage-gated K and Ca currents were recorded in acutely dissociated neuroendocrine cells of the supraoptic nucleus. The effect of repeated activation of the currents by trains of (10) voltage pulses over a range of pulse-repetition frequencies were examined. There was a significant reduction of K-current amplitude and a significant increase of Ca-current amplitude during trains with high repetition frequencies. Frequency-dependent changes in K and Ca conductances may contribute to frequency-dependent spike-broadening which is exhibited during bursts of action potentials generated by these neurons.

  17. Broadening of a spectrum line by finite spectrometer resolution. [FORTRAN IV; SAL, KAL

    Energy Technology Data Exchange (ETDEWEB)

    Engleman, R. Jr.

    1978-12-01

    The distortion of a spectrum line by the finite resolving power of a spectrometer is discussed in terms of a mathematical model. Particular attention is given to the case where either a Gaussian or Cauchy slit function broadens an isolated Doppler, Lorentz, or Voigt absorption line. Corrections to the peak absorption, the line width, and the integrated absorption coefficient are calculated and discussed for different combinations of slit functions and line shapes. Several new series expansions for the corrections are derived. Two general FORTRAN IV programs that calculate these corrections are described and some sample correction curves are given. 27 references.

  18. Calculation of line parameters of the ν3 band of monodeuterated methane: Nitrogen broadening

    Science.gov (United States)

    Lavrentieva, N. N.; Dudaryonok, A. S.; Buldyreva, J. V.

    2017-09-01

    Halfwidths and shifts of CH3D lines are calculated for the case of nitrogen broadening. The calculations are performed for room temperature (296 K) for vibrational-rotational lines in the ν3 parallel band, with the rotational quantum numbers varying in the ranges of 0 ≤ J ≤ 70 and 0 ≤ K ≤ 20. For each line, the temperature-dependence characteristics are calculated in the range of 200-400 K recommended for the HITRAN database. The calculations are carried out using a semiempirical method with a correction factor the parameters of which are adjusted on a number of experimental values.

  19. Chemical analysis of precipitates in metallic alloys using coincidence Doppler broadening of positron annihilation radiation

    CERN Document Server

    Nagai, Y; Hasegawa, M

    2000-01-01

    Two-detector coincidence Doppler broadening (CDB) method of positron annihilation radiation is applied to the study of precipitates in metals. As the first step, the CDB spectra for many kinds of elements are measured to obtain the 'fingerprint' of each element for the chemical analysis of the precipitates in metals. Utilizing the fingerprint of Cu, we made chemical analysis of nano-particles formed in the initial stage of thermal aging in a Fe-Cu alloy, and found that the particles are consisting of Cu only and free from vacancies, which demonstrates the usefulness of this method in the study of the precipitates.

  20. Spectral broadening of picosecond pulses forming dispersive shock waves in optical fibers.

    Science.gov (United States)

    Parriaux, A; Conforti, M; Bendahmane, A; Fatome, J; Finot, C; Trillo, S; Picqué, N; Millot, G

    2017-08-01

    We investigate analytically, numerically, and experimentally the spectral broadening of pulses that undergo the formation of dispersive shocks, addressing in particular pulses in the range of tens of ps generated via electro-optic modulation of a continuous-wave laser. We give an analytical estimate of the maximal spectral extension and show that super-Gaussian waveforms favor the generation of flat-topped spectra. We also show that the weak residual background of the modulator produces undesired spectral ripples. Spectral measurements confirm our estimates and agree well with numerical integration of the nonlinear Schrödinger equation.

  1. Spectral broadening due to long-range Coulomb interactions in the molecular metal TTF-TCNQ

    Energy Technology Data Exchange (ETDEWEB)

    Koch, E.; Dolfen, A. [Inst. fuer Festkoerperforschung, Forschungszentrum Juelich (Germany); Cano-Cortes, L.; Merino, J. [Univ. Autonona de Madrid (Spain); Behler, J.; Reuter, K. [Fritz-Haber-Inst., Berlin (Germany); Delley, B. [Paul-Scherrer-Inst., Villigen (Switzerland)

    2007-07-01

    We employ density-functional theory to calculate realistic parameters for an extended Hubbard model of the molecular metal TTF-TCNQ. Considering both intra- and intermolecular screening in the crystal, we find that longer-range Coulomb interactions along the molecular stacks, as well as inter-stack coupling are of importance. Contrary to past belief, these terms do not lead to the formation of a Wigner lattice, but simply broaden the spectral function. We show how this can be understood already in perturbation theory. Moreover we calculate the effect of the nearest neighbor repulsion on the Luttinger parameter. (orig.)

  2. A small-scale comparison of Iceland scallop size distributions obtained from a camera based autonomous underwater vehicle and dredge survey.

    Science.gov (United States)

    Singh, Warsha; Örnólfsdóttir, Erla B; Stefansson, Gunnar

    2014-01-01

    An approach is developed to estimate size of Iceland scallop shells from AUV photos. A small-scale camera based AUV survey of Iceland scallops was conducted at a defined site off West Iceland. Prior to height estimation of the identified shells, the distortions introduced by the vehicle orientation and the camera lens were corrected. The average AUV pitch and roll was 1.3 and 2.3 deg that resulted in <2% error in ground distance rendering these effects negligible. A quadratic polynomial model was identified for lens distortion correction. This model successfully predicted a theoretical grid from a frame photographed underwater, representing the inherent lens distortion. The predicted shell heights were scaled for the distance from the bottom at which the photos were taken. This approach was validated by height estimation of scallops of known sizes. An underestimation of approximately 0.5 cm was seen, which could be attributed to pixel error, where each pixel represented 0.24 x 0.27 cm. After correcting for this difference the estimated heights ranged from 3.8-9.3 cm. A comparison of the height-distribution from a small-scale dredge survey carried out in the vicinity showed non-overlapping peaks in size distribution, with scallops of a broader size range visible in the AUV survey. Further investigations are necessary to evaluate any underlying bias and to validate how representative these surveys are of the true population. The low resolution images made identification of smaller scallops difficult. Overall, the observations of very few small scallops in both surveys could be attributed to low recruitment levels in the recent years due to the known scallop parasite outbreak in the region.

  3. A small-scale comparison of Iceland scallop size distributions obtained from a camera based autonomous underwater vehicle and dredge survey.

    Directory of Open Access Journals (Sweden)

    Warsha Singh

    Full Text Available An approach is developed to estimate size of Iceland scallop shells from AUV photos. A small-scale camera based AUV survey of Iceland scallops was conducted at a defined site off West Iceland. Prior to height estimation of the identified shells, the distortions introduced by the vehicle orientation and the camera lens were corrected. The average AUV pitch and roll was 1.3 and 2.3 deg that resulted in <2% error in ground distance rendering these effects negligible. A quadratic polynomial model was identified for lens distortion correction. This model successfully predicted a theoretical grid from a frame photographed underwater, representing the inherent lens distortion. The predicted shell heights were scaled for the distance from the bottom at which the photos were taken. This approach was validated by height estimation of scallops of known sizes. An underestimation of approximately 0.5 cm was seen, which could be attributed to pixel error, where each pixel represented 0.24 x 0.27 cm. After correcting for this difference the estimated heights ranged from 3.8-9.3 cm. A comparison of the height-distribution from a small-scale dredge survey carried out in the vicinity showed non-overlapping peaks in size distribution, with scallops of a broader size range visible in the AUV survey. Further investigations are necessary to evaluate any underlying bias and to validate how representative these surveys are of the true population. The low resolution images made identification of smaller scallops difficult. Overall, the observations of very few small scallops in both surveys could be attributed to low recruitment levels in the recent years due to the known scallop parasite outbreak in the region.

  4. Comparison of 3D dose distributions for HDR 192Ir brachytherapy sources with normoxic polymer gel dosimetry and treatment planning system.

    Science.gov (United States)

    Senkesen, Oznur; Tezcanli, Evrim; Buyuksarac, Bora; Ozbay, Ismail

    2014-01-01

    Radiation fluence changes caused by the dosimeter itself and poor spatial resolution may lead to lack of 3-dimensional (3D) information depending on the features of the dosimeter and quality assurance of dose distributions for high-dose rate (HDR) iridium-192 ((192)Ir) brachytherapy sources is challenging and experimental dosimetry methods used for brachytherapy sources are limited. In this study, we investigated 3D dose distributions of (192)Ir brachytherapy sources for irradiation with single and multiple dwell positions using a normoxic gel dosimeter and compared them with treatment planning system (TPS) calculations. For dose calibration purposes, 100-mL gel-containing vials were irradiated at predefined doses and then scanned in an magnetic resonance (MR) imaging unit. Gel phantoms prepared in 2 spherical glasses were irradiated with (192)Ir for the calculated dwell positions, and MR scans of the phantoms were obtained. The images were analyzed with MATLAB software. Dose distributions and profiles derived with 1-mm resolution were compared with TPS calculations. Linearity was observed between the delivered dose and the reciprocal of the T2 relaxation time constant of the gel. The x-, y-, and z-axes were defined as the sagittal, coronal, and axial planes, respectively, the sagittal and axial planes were defined parallel to the long axis of the source while the coronal plane was defined horizontally to the long axis of the source. The differences between measured and calculated profile widths of 3-cm source length and point source for 70%, 50%, and 30% isodose lines were evaluated at 3 dose levels using 18 profiles of comparison. The calculations for 3-cm source length revealed a difference of > 3mm in 1 coordinate at 50% profile width on the sagittal plane and 3 coordinates at 70% profile width and 2 coordinates at 50% and 30% profile widths on the axial plane. Calculations on the coronal plane for 3-cm source length showed > 3-mm difference in 1 coordinate at

  5. Theory and Simulation of Exoplanetary Atmospheric Haze: Giant Spectral Line Broadening

    Science.gov (United States)

    Sadeghpour, Hossein; Felfeli, Zineb; Kharchenko, Vasili; Babb, James; Vrinceanu, Daniel

    2018-01-01

    Prominent spectral features in observed transmission spectra of exoplanets are obscured. Atmospheric haze is the leading candidate for the flattening of spectral transmission of expolanetray occultation, but also for solar system planets, Earth and cometary atmospheres. Such spectra which carry information about how the planetary atmospheres become opaque to stellar light in transit, show broad absorption where strong absorption lines from sodium or potassium and water are predicted to exist. In this work, we develop a detailed atomistic theoretical model, taking into account interaction between an atomic or molecular radiator with dust and haze particulates. Our model considers a realistic structure of haze particulates from small seed particles up to sub-micron irregularly shaped aggregates. This theory of interaction between haze and radiator particles allows to consider nearly all realistic structure, size and chemical composition of haze particulates. The computed shift and broadening of emission spectra will include both quasi-static (mean field) and collisional (pressure) shift and broadening. Our spectral calculations will be verified with available laboratory experimental data on spectra of alkali atoms in liquid droplet, solid ice, dust and dense gaseous environments. The simplicity, elegance and generality of the proposed model makes it amenable to a broad community of users in astrophysics and chemistry. The verified models can be used for analysis of emission and absorption spectra of alkali atoms from exoplanets, solar system planets, satellites and comets.

  6. Global wild annual Lens collection: a potential resource for lentil genetic base broadening and yield enhancement.

    Science.gov (United States)

    Singh, Mohar; Bisht, Ishwari Singh; Kumar, Sandeep; Dutta, Manoranjan; Bansal, Kailash Chander; Karale, Moreshwar; Sarker, Ashutosh; Amri, Ahmad; Kumar, Shiv; Datta, Swapan Kumar

    2014-01-01

    Crop wild relatives (CWRs) are invaluable gene sources for various traits of interest, yet these potential resources are themselves increasingly threatened by the impact of climate change as well as other anthropogenic and socio-economic factors. The prime goal of our research was to cover all aspects of wild Lens genetic resource management like species characterization, agro-morphological evaluation, diversity assessment, and development of representative sets for its enhanced utilization in lentil base broadening and yield improvement initiatives. We characterized and evaluated extensively, the global wild annual Lens taxa, originating from twenty seven counties under two agro-climatic conditions of India consecutively for three cropping seasons. Results on various qualitative and quantitative characters including two foliar diseases showed wide variations for almost all yield attributing traits including multiple disease resistance in the wild species, L. nigricans and L. ervoides accessions. The core set developed from the entire Lens taxa had maximum representation from Turkey and Syria, indicating rich diversity in accessions originating from these regions. Diversity analysis also indicated wide geographical variations across genepool as was reflected in the core set. Potential use of core set, as an initial starting material, for genetic base broadening of cultivated lentil was also suggested.

  7. Contaminant-State Broadening Mechanism in a Driven Dissipative Rydberg System

    Science.gov (United States)

    Porto, J. V.

    2017-04-01

    The strong interactions in Rydberg atoms make them an ideal system for the study of correlated many-body physics, both in the presence and absence of dissipation. Using such highly excited atomic states requires addressing challenges posed by the dense spectrum of Rydberg levels, the detrimental effects of spontaneous emission, and strong interactions. A full understanding of the scope and limitations of many Rydberg-based proposals requires simultaneously including these effects, which typically cannot be described by a mean-field treatment due to correlations in the quantum coherent and dissipative processes. We study a driven, dissipative system of Rydberg atoms in a 3D optical lattice, and observe substantial deviation from single-particle excitation rates, both on and off resonance. The observed broadened spectra cannot be explained by van der Waals interactions or a mean-field treatment of the system. Based on the magnitude of the broadening and the scaling with density and two-photon Rabi frequency, we attribute these effects to unavoidable blackbody-induced transitions to nearby Rydberg states of opposite parity, which have large, resonant dipole-dipole interactions with the state of interest. Even at low densities of Rydberg atoms, uncontrolled production of atoms in other states significantly modifies the energy levels of the remaining atoms. These off-diagonal exchange interactions result in complex many-body states of the system and have implications for off-resonant Rydberg dressing proposals. This work was partially supported by the ARL-CDQI program.

  8. The effect of density fluctuations on electron cyclotron beam broadening and implications for ITER

    Science.gov (United States)

    Snicker, A.; Poli, E.; Maj, O.; Guidi, L.; Köhn, A.; Weber, H.; Conway, G.; Henderson, M.; Saibene, G.

    2018-01-01

    We present state-of-the-art computations of propagation and absorption of electron cyclotron waves, retaining the effects of scattering due to electron density fluctuations. In ITER, injected microwaves are foreseen to suppress neoclassical tearing modes (NTMs) by driving current at the q=2 and q=3/2 resonant surfaces. Scattering of the beam can spoil the good localization of the absorption and thus impair NTM control capabilities. A novel tool, the WKBeam code, has been employed here in order to investigate this issue. The code is a Monte Carlo solver for the wave kinetic equation and retains diffraction, full axisymmetric tokamak geometry, determination of the absorption profile and an integral form of the scattering operator which describes the effects of turbulent density fluctuations within the limits of the Born scattering approximation. The approach has been benchmarked against the paraxial WKB code TORBEAM and the full-wave code IPF-FDMC. In particular, the Born approximation is found to be valid for ITER parameters. In this paper, we show that the radiative transport of EC beams due to wave scattering in ITER is diffusive unlike in present experiments, thus causing up to a factor of 2–4 broadening in the absorption profile. However, the broadening depends strongly on the turbulence model assumed for the density fluctuations, which still has large uncertainties.

  9. Remembering Collective Violence: Broadening the Notion of Traumatic Memory in Post-Conflict Rehabilitation.

    Science.gov (United States)

    Kevers, Ruth; Rober, Peter; Derluyn, Ilse; De Haene, Lucia

    2016-12-01

    In the aftermath of war and armed conflict, individuals and communities face the challenge of dealing with recollections of violence and atrocity. This article aims to contribute to a better understanding of processes of remembering and forgetting histories of violence in post-conflict communities and to reflect on related implications for trauma rehabilitation in post-conflict settings. Starting from the observation that memory operates at the core of PTSD symptomatology, we more closely explore how this notion of traumatic memory is conceptualized within PTSD-centered research and interventions. Subsequently, we aim to broaden this understanding of traumatic memory and post-trauma care by connecting to findings from social memory studies and transcultural trauma research. Drawing on an analysis of scholarly literature, this analysis develops into a perspective on memory that moves beyond a symptomatic framing toward an understanding of memory that emphasizes its relational, political, moral, and cultural nature. Post-conflict memory is presented as inextricably embedded in communal relations, involving ongoing trade-offs between individual and collective responses to trauma and a complex negotiation of speech and silence. In a concluding discussion, we develop implications of this broadened understanding for post-conflict trauma-focused rehabilitation.

  10. Quantification of tip-broadening in non-contact atomic force microscopy with carbon nanotube tips

    DEFF Research Database (Denmark)

    Meinander, Kristoffer; Jensen, Thomas N.; Simonsen, Soren B.

    2012-01-01

    Carbon nanotube terminated atomic force microscopy (AFM) probes have been used for the imaging of 5 nm wide surface supported Pt nanoclusters by non-contact (dynamic mode) AFM in an ultra-high vacuum. The results are compared to AFM measurements done with conventional Si-tips, as well as with tra......Carbon nanotube terminated atomic force microscopy (AFM) probes have been used for the imaging of 5 nm wide surface supported Pt nanoclusters by non-contact (dynamic mode) AFM in an ultra-high vacuum. The results are compared to AFM measurements done with conventional Si-tips, as well...... as with transmission electron microscopy images, which give accurate measures for cluster widths. Despite their ideal aspect ratio, tip-broadening is concluded to be a severe problem even when imaging with carbon nanotube tips, which overestimates the cluster width by several times the nominal width of the nanotube...... tip. This broadening is attributed to a bending of the carbon nanotubes, and not to pure geometrical factors, which coincidentally results in a significant improvement for relative height measurements of tightly spaced high aspect ratio structures, as compared to what can be achieved...

  11. Spectral broadening measurement of the lower hybrid waves during long pulse operation in Tore Supra

    Science.gov (United States)

    Berger-By, G.; Decampy, J.; Antar, G. Y.; Goniche, M.; Ekedahl, A.; Delpech, L.; Leroux, F.; Tore Supra Team

    2014-02-01

    On many tokamaks (C-Mod, EAST, FTU, JET, HT-7, TS), a decrease in current drive efficiency of the Lower Hybrid (LH) waves is observed in high electron density plasmas. The cause of this behaviour is believed to be: Parametric Instabilities (PI) and Scattering from Density Fluctuations (SDF). For the ITER LH system, our knowledge must be improved to avoid such effects and to maintain the LH current drive efficiency at high density. The ITPA IOS group coordinates this effort [1] and all experimental data are essential to validate the numerical codes in progress. Usually the broadening of the LH wave frequency spectrum is measured by a probe located in the plasma edge. For this study, the frequency spectrum of a reflected power signal from the LH antenna was used. In addition, the spectrum measurements are compared with the density fluctuations observed on RF probes located at the antenna mouth. Several plasma currents (0.6 to 1.4 MA) and densities up to 5.2 × 1019 m-3 have been realised on Tore Supra (TS) long pulses and with high injected RF power, up to 5.4 MW-30s. This allowed using a spectrum analyser to make several measurements during the plasma pulse. The side lobe amplitude, shifted by 20-30MHz with respect to the main peak, grows with increasing density. Furthermore, for an increase of plasma current at the same density, the spectra broaden and become asymmetric. Some parametric dependencies are shown in this paper.

  12. Plasma density characterization at SPARC-LAB through Stark broadening of Hydrogen spectral lines

    Energy Technology Data Exchange (ETDEWEB)

    Filippi, F., E-mail: francesco.filippi@roma1.infn.it [Dipartimento di Scienze di Base e Applicate per l' Ingegneria (SBAI), ‘Sapienza’ Università di Roma, Via A. Scarpa 14-16, 00161 Roma (Italy); INFN-Roma1, Piazzale Aldo Moro, 2 00161 Roma (Italy); Anania, M.P.; Bellaveglia, M.; Biagioni, A.; Chiadroni, E. [Laboratori Nazionali di Frascati, INFN, Via E. Fermi, Frascati (Italy); Cianchi, A. [Dipartimento di Fisica, Universitá di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma (Italy); Di Giovenale, D.; Di Pirro, G.; Ferrario, M. [Laboratori Nazionali di Frascati, INFN, Via E. Fermi, Frascati (Italy); Mostacci, A.; Palumbo, L. [Dipartimento di Scienze di Base e Applicate per l' Ingegneria (SBAI), ‘Sapienza’ Università di Roma, Via A. Scarpa 14-16, 00161 Roma (Italy); INFN-Roma1, Piazzale Aldo Moro, 2 00161 Roma (Italy); Pompili, R.; Shpakov, V.; Vaccarezza, C.; Villa, F. [Laboratori Nazionali di Frascati, INFN, Via E. Fermi, Frascati (Italy); Zigler, A. [Hebrew University of Jerusalem, Jerusalem 91904 (Israel)

    2016-09-01

    Plasma-based acceleration techniques are of great interest for future, compact accelerators due to their high accelerating gradient. Both particle-driven and laser-driven Plasma Wakefield Acceleration experiments are foreseen at the SPARC-LAB Test Facility (INFN National Laboratories of Frascati, Italy), with the aim to accelerate high-brightness electron beams. In order to optimize the efficiency of the acceleration in the plasma and preserve the quality of the accelerated beam, the knowledge of the plasma electron density is mandatory. The Stark broadening of the Hydrogen spectral lines is one of the candidates used to characterize plasma density. The implementation of this diagnostic for plasma-based experiments at SPARC-LAB is presented. - Highlights: • Stark broadening of Hydrogen lines has been measured to determine plasma density. • Plasma density diagnostic tool for plasma-based experiments at SPARC-LAB is presented. • Plasma density in tapered laser triggered ablative capillary discharge was measured. • Results of plasma density measurements in ablative capillaries are shown.

  13. Longitudinal mode selection in a delay-line homogeneously broadened oscillator with a fast saturable amplifier.

    Science.gov (United States)

    Fleyer, Michael; Horowitz, Moshe

    2017-05-01

    Homogeneously broadened delay-line oscillators such as lasers or optoelectronic oscillators (OEOs) can potentially oscillate in a large number of cavity modes that are supported by their amplifier bandwidth. In a continuous wave operating mode, the oscillating mode is selected between one or few cavity modes that experience the highest small-signal gain. In this manuscript, we show that the oscillation mode of a homogeneously broadened oscillator can be selected from a large number of modes in a frequency region that can be broader than the full width at half maximum of the effective cavity filter. The mode is selected by a short-time injection of an external signal into the oscillator. After the external signal is turned off, the oscillation is maintained in the selected mode even if this mode has a significantly lower small-signal gain than that of other cavity modes. The stability of the oscillation is obtained due to nonlinear saturation effect in the oscillator amplifier. We demonstrate, experimentally and theoretically, mode selection in a long cavity OEO. We could select any desired mode between 400 cavity modes while maintaining ultra-low phase noise in the selected mode and in the non-oscillating modes. No mode-hopping was observed during our maximum measurement duration of about 24 hours.

  14. Music-induced positive mood broadens the scope of auditory attention.

    Science.gov (United States)

    Putkinen, Vesa; Makkonen, Tommi; Eerola, Tuomas

    2017-07-01

    Previous studies indicate that positive mood broadens the scope of visual attention, which can manifest as heightened distractibility. We used event-related potentials (ERP) to investigate whether music-induced positive mood has comparable effects on selective attention in the auditory domain. Subjects listened to experimenter-selected happy, neutral or sad instrumental music and afterwards participated in a dichotic listening task. Distractor sounds in the unattended channel elicited responses related to early sound encoding (N1/MMN) and bottom-up attention capture (P3a) while target sounds in the attended channel elicited a response related to top-down-controlled processing of task-relevant stimuli (P3b). For the subjects in a happy mood, the N1/MMN responses to the distractor sounds were enlarged while the P3b elicited by the target sounds was diminished. Behaviorally, these subjects tended to show heightened error rates on target trials following the distractor sounds. Thus, the ERP and behavioral results indicate that the subjects in a happy mood allocated their attentional resources more diffusely across the attended and the to-be-ignored channels. Therefore, the current study extends previous research on the effects of mood on visual attention and indicates that even unfamiliar instrumental music can broaden the scope of auditory attention via its effects on mood. © The Author (2017). Published by Oxford University Press.

  15. Comparison of NMR and Dynamic Light Scattering for Measuring Diffusion Coefficients of Formulated Insulin: Implications for Particle Size Distribution Measurements in Drug Products.

    Science.gov (United States)

    Patil, Sharadrao M; Keire, David A; Chen, Kang

    2017-11-01

    Particle size distribution, a measurable physicochemical quantity, is a critical quality attribute of drug products that needs to be controlled in drug manufacturing. The non-invasive methods of dynamic light scattering (DLS) and Diffusion Ordered SpectroscopY (DOSY) NMR can be used to measure diffusion coefficient and derive the corresponding hydrodynamic radius. However, little is known about their use and sensitivity as analytical tools for particle size measurement of formulated protein therapeutics. Here, DLS and DOSY-NMR methods are shown to be orthogonal and yield identical diffusion coefficient results for a homogenous monomeric protein standard, ribonuclease A. However, different diffusion coefficients were observed for five insulin drug products measured using the two methods. DOSY-NMR yielded an averaged diffusion coefficient among fast exchanging insulin oligomers, ranging between dimer and hexamer in size. By contrast, DLS showed several distinct species, including dimer, hexamer, dodecamer and other aggregates. The heterogeneity or polydisperse nature of insulin oligomers in formulation caused DOSY-NMR and DLS results to differ from each other. DLS measurements provided more quality attributes and higher sensitivity to larger aggregates than DOSY-NMR. Nevertheless, each method was sensitive to a different range of particle sizes and complemented each other. The application of both methods increases the assurance of complex drug quality in this similarity comparison.

  16. Does Maximal External Tibial Component Rotation Influence Tibiofemoral Load Distribution in the Primary Knee Arthroplasty Setting: A Comparison of Neutral vs Maximal Anatomical External Rotatory States.

    Science.gov (United States)

    Manning, William A; Ghosh, Kanishka M; Blain, Alasdair P; Longstaff, Lee M; Rushton, Steven P; Deehan, David J

    2017-06-01

    Tibial component rotation at time of knee arthroplasty can influence conformity, load transmission across the polyethylene surface, and perhaps ultimately determined survivorship. Optimal tibial component rotation on the cut surface is reliant on standard per operative manual stressing. This subjective assessment aims to balance constraint and stability of the articulation through a full arc of movement. Using a cadaveric model, computer navigation and under defined, previously validated loaded conditions mimicking the in vivo setting, the influence of maximal tibial component external rotation compared with the neutral state was examined for changes in laxity and tibiofemoral continuous load using 3D displacement measurement and an orthosensor continuous load sensor implanted within the polyethylene spacer in a simulated single radius total knee arthroplasty. No significant difference was found throughout arc of motion (0-115 degrees of flexion) for maximal varus and/or valgus or rotatory laxity between the 2 states. The neutral state achieved equivalence for mediolateral load distribution at each point of flexion. We have found that external rotation of the tibial component increased medial compartment load in comparison with the neutral position. Compared with the neutral state, external rotation consistently effected a marginal, but not significant reduction in lateral load under similar loading conditions. The effects were most pronounced in midflexion. On the basis of these findings, we would advocate for the midtibial tubercle point to determine tibial component rotation and caution against component external rotation. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. An evaluation of Flickrs distributed classification system, from the perspective of its members, and as an image retrieval tool in comparison with a controlled vocabulary

    CERN Document Server

    Piker, Samuel

    2009-01-01

    The profusion of online digital images presents new challenges for image indexing. Images have always been problematic to describe and catalogue due to lack of inherent textual data and ambiguity of meaning. An alternative to time-consuming professionally-applied metadata has been sought in the form of tags, simple keywords that form a flat structure known as distributed classification, or more popularly as a folksonomy. This research aims to increase understanding of why people tag and how effective they find it for searching, using as the focus. Open-ended questionnaires were sent out to members of the photo-sharing website Flickr, with the opportunity to post comments to an online discussion space. There is also a systematic comparison between a tag-based system and a more traditional controlled vocabulary, to test out the claims made regarding the suitability of tagging for searching and browsing. For this purpose Flickr has been compared with Getty Images using a series of test themes. The small number o...

  18. Comparison of PALSAR-2 Interferometric Estimates of Snow Water Equivalent, Airborne Snow Observatory Snow Depths, and Results from a Distributed Energy Balance Snow Model (iSnobal)

    Science.gov (United States)

    Deeb, E. J.; Marshall, H. P.; Painter, T. H.; Marks, D. G.; Hedrick, A. R.; Havens, S.; Forster, R. R.; Siqueira, P.

    2016-12-01

    The interferometric approach to estimating snow water equivalent (SWE) leverages the fact that at relatively low frequencies ( 1 GHz, L-Band), differences in snow microstructure and layering do not significantly affect the radar backscatter of dry snow. At these frequencies, the main contribution of the radar backscatter is the snow/ground interface, and the difference in the timing of the radar propagation through the snowpack is controlled by snow depth, density and liquid water content. While engineering limitations prevent direct measurement of absolute radar travel-time, interferometric phase shift between acquisitions can be used to monitor changes in radar travel-time, caused by changes in snow properties. PALSAR-2 is a L-Band synthetic aperture radar (SAR) aboard the Japan Aerospace Exploration Agency's (JAXA) ALOS-2 satellite. Launched in 2014, PALSAR-2 interferometric pairs geographically and temporally overlap data collected by the NASA/JPL Airborne Snow Observatory (ASO) which provides spatial distribution of snow depths across basins (e.g. Tuolumne, CA and Grand Mesa, CO) identified as contributing significantly to NASA's multi-year airborne SnowEx campaign. As part of ASO's operational requirements, a spatially distributed energy balance snow model (iSnobal) is run over these domains estimating density (and other snow properties) and providing SWE products for water resource managers as well as other cryospheric science applications. This effort identifies PALSAR-2 satellite pairs closely coincident with ASO collections, processes interferometric products of coherence and phase change, and compares these results with the spatially distributed snow depths from ASO and modeled snow densities from iSnobal. Moreover, for satellite acquisitions not temporally matching the ASO collections, the modeled snow properties (depths and densities) from iSnobal are used for comparison with interferometric estimates of SWE. The integration of ground measurements

  19. Comparison of water distribution mechanisms under two localized irrigation techniques (Drip Irrigation & Buried Diffuser) for one week irrigation period in a sandy soil of southeastern Tunisia

    Science.gov (United States)

    Gasmi, Ines; Kodešová, Radka; Mechergui, Mohamed; Nikodem, Antonín; Moussa, Mohamed

    2017-04-01

    The majority of agricultural ecosystems in the Mediterranean basin of northern Africa suffer from water shortage and positions these regions in a highly vulnerable to climate change. In arid regions of Tunisia and exactly in the Southeastern part, during each growing season, plant productivity in sandy-loamy soils is dramatically reduced by limited availability of soil water and nutrients. Thus, highly permeable soils are unable to retain adequate water and nutrient resource in the plant root zone. Moreover, the investments of supplemental irrigation and agricultural amendments of additional fertilization are not sustainable due to the leaching of water supplies and nutrients, which severely limit agricultural productivity. In addition, inadequate soil water distribution, costly irrigation and fertilization leads to negative responses to plant nutrients added to highly permeable soils. That's why we should use irrigation techniques with high water use efficiency. This paper focuses on the comparison between two localized irrigation techniques which are the Drip Irrigation (DI) and the Buried Diffuser (BD) that has the same flow rates (4 l/h). The BD is buried at 15 cm depths. Experimental data was obtained from Smar-Médenine located in South-East of Tunisia. The water distribution at the soil surface for BD is very important about 195 cm2 while for the DI is about 25.12 cm2. The HYDRUS 2D/3D model helped to evaluate the water distribution and compare the water balance obtained with those two irrigation techniques for one week irrigation period. There is a rapid kinetic which has a duration of 3 hours (irrigation time) and a slow kinetic which is the result of the water distribution in the soil, the plant uptake and the effect of climatic condition. There are two mechanisms that affect the two irrigation techniques: the water distribution and the position of irrigation system. As a result, irrigation with BD goes dipper in the soil. The transmission zone for this

  20. Resonance broadening of argon lines in a micro-scaled atmospheric pressure plasma jet (argon μAPPJ)

    Science.gov (United States)

    Pipa, A. V.; Ionikh, Yu. Z.; Chekishev, V. M.; Dünnbier, M.; Reuter, S.

    2015-06-01

    Optical emission from atmospheric pressure micro-jet operating with pure argon (argon μAPPJ) flow has been detected with a moderate resolution spectrometer. Large broadening of the several argon (Ar) lines has been observed in the near infrared spectral region. This effect was attributed to resonance broadening of the s2 (Paschen notation) level in 3p54s configuration. In the present work, corresponding line profiles are suggested for plasma diagnostics. For this, a general case of resonance broadening coefficient of noble gases is discussed. As broadening reflects the Ar density, and the static gas pressure of the jet is in equilibrium with the ambient, the local gas temperature can be inferred. An estimation of gas temperature from the width of the 750 nm Ar line is in agreement with rotational temperature of OH radicals determined from the A2Σ+ → X2Π (0, 0) band. At low temperatures (300-600 K) and at partial Ar pressure near atmospheric, the resonance width of the suggested lines is very sensitive to small temperature variations. High temperature sensitivity and large width make the resonance broadened lines very attractive for diagnostics of low temperature discharges at elevated pressure, e.g., as they are used in plasma-medicine.

  1. Investigation of the HU-density conversion method and comparison of dose distribution for dose calculation on MV cone beam CT images

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Joo; Lee, Seu Ran; Suh, Tae Suk [Dept. of Biomedical Engineering, The Catholic University of Korea, Bucheon (Korea, Republic of)

    2011-11-15

    Modern radiation therapy techniques, such as Image-guided radiation therapy (IGRT), Adaptive radiation therapy (ART) has become a routine clinical practice on linear accelerators for the increase the tumor dose conformity and improvement of normal tissue sparing at the same time. For these highly developed techniques, megavoltage cone beam computed tomography (MVCBCT) system produce volumetric images at just one rotation of the x-ray beam source and detector on the bottom of conventional linear accelerator for real-time application of patient condition into treatment planning. MV CBCT image scan be directly registered to a reference CT data set which is usually kilo-voltage fan-beam computed tomography (kVFBCT) on treatment planning system and the registered image scan be used to adjust patient set-up error. However, to use MV CBCT images in radiotherapy, reliable electron density (ED) distribution are required. Patients scattering, beam hardening and softening effect caused by different energy application between kVCT, MV CBCT can cause cupping artifacts in MV CBCT images and distortion of Houns field Unit (HU) to ED conversion. The goal of this study, for reliable application of MV CBCT images into dose calculation, MV CBCT images was modified to correct distortion of HU to ED using the relationship of HU and ED from kV FBCT and MV CBCT images. The HU-density conversion was performed on MV CBCT image set using Dose difference map was showing in Figure 1. Finally, percentage differences above 3% were reduced depending on applying density calibration method. As a result, total error co uld be reduced to under 3%. The present study demonstrates that dose calculation accuracy using MV CBCT image set can be improved my applying HU-density conversion method. The dose calculation and comparison of dose distribution from MV CBCT image set with/without HU-density conversion method was performed. An advantage of this study compared to other approaches is that HU

  2. Particle size and strain broadening in energy-dispersive x-ray powder patterns

    DEFF Research Database (Denmark)

    Gerward, Leif; Mørup, Steen; Topsøe, Haldor

    1976-01-01

    An energy-dispersive x-ray method for a rapid analysis of the broadening of diffraction lines in powder patterns has been developed. Experimental results are given for magnetite powders with sizes in the range 50–200 Å and compared with the results of standard angle-dispersive diffractometry and ...... studies. The method should be of special advantage for the study of solid-state reactions and processes such as sintering. Journal of Applied Physics is copyrighted by The American Institute of Physics....... and electron microscopy. The greatest advantages of the energy-dispersive method compared with the angle-dispersive method are the absence of the Kalpha doublet, the simultaneous recording of a large part of the diffraction pattern, the fast data accumulation, and the adaptability of the technique to in situ...

  3. Generation of transport lattice code KARMA library with doppler broadening rejection correction method

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ho Jin; Cho, Jin Young; Park, Sang Yoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Hong, Ser Gi [Kyung Hee Univ., Yongin (Korea, Republic of); Kim, Kang Seog [Oak Ridge National Laboratory, Tennessee (United States)

    2012-10-15

    In order to solve the exact neutron transport equations, the temperature-dependent neutron cross sections including scattering kernel are needed. However, the current cross section generation systems such as NJOY do not generate the temperature dependent scatting kernels. In Monte Carlo (MC) code, the sampling of velocity of target nucleus method is used to determine the energy and direction of outgoing neutron by the approximated constant cross section model. Recently, the Doppler-broadening rejection correction (DBRC) and weight correction method are proposed for the exact sampling. In this study, the KARMA(Kernel Analyzer by Ray tracing Method for fuel Assembly) library system incorporating McCARD calculations with the DBRC method are established and the effect of improved Doppler treatment will be examined.

  4. Pressure Broadening of J=1<-0 Rotational Line of Fluoroform Caused by Spherical Perturbers

    Science.gov (United States)

    Gierszal, S.; Galica, J.; Mis-Kuzmiñska, E.; Liber, A.

    1999-06-01

    The foreign-gas broadening parameter was measured for CHF3 molecule interacting with spherical (SF6, CF4, CH4, CCl4) perturbers and the pressure shift parameter of rotational transition J=1>-0 in the CHF3 molecule was obtained. For the systems of trifluoromethane molecule and four spherical molecules as perturbers the collision cross-sections were determined. Experimental line width parameters are interpreted using Anderson--Tsao--Curnutte as well as Murphy--Boggs theories. Accounting for the dispersive and inductive interactions the cross-section was determined. The theoretical values are in qualitative agreement with the experimental results, but the absolute values of the measured cross-section were larger than these calculated.

  5. Intensities, broadening and narrowing parameters in the ν3 band of methane

    KAUST Repository

    Es-sebbar, Et-touhami

    2014-12-01

    The P-branch of methane\\'s ν3 band is probed to carry out an extensive study of the 2905-2908cm-1 infrared spectral region. Absolute line intensities as well as N2-, O2-, H2-, He-, Ar- and CO2-broadening coefficients are determined for nine transitions at room temperature. Narrowing parameters due to the Dicke effect have also been investigated. A narrow emission line-width (~0.0001cm-1) difference-frequency-generation (DFG) laser system is used as the tunable light source. To retrieve the CH4 spectroscopic parameters, Voigt and Galatry profiles were used to simulate the measured line shape of the individual transitions.

  6. Effect of broadened-specification fuels on aircraft engines and fuel systems

    Science.gov (United States)

    Rudey, R. A.

    1979-01-01

    A wide variety of studies on the potential effects of broadened-specification fuels on future aircraft engines and fuel systems are summarized. The compositions and characteristics of aircraft fuels that may be derived from current and future crude-oil sources are described, and the most critical properties that may affect aircraft engines and fuel systems are identified and discussed. The problems that are most likely to be encountered because of changes in selected fuel properties are described; and the related effects on engine performance, component durability and maintenance, and aircraft fuel-system performance are discussed. The ability of current technology to accept possible future fuel-specification changes is discussed, and selected technological advances that can reduce the severity of the potential problems are illustrated.

  7. FAKTOR-FAKTOR BROADEN BUILD YANG MEMPENGARUHI KINERJA KELEMBAGAAN PADA LEMBAGA SEKURITAS DI MALANG

    Directory of Open Access Journals (Sweden)

    Erna Retna Rahadjeng

    2014-07-01

    Full Text Available This study aims to identify the performing of an agency applying nuturing institutional capital markets through built Broaden approach to improve the performance of securities institution. This phenomenological study was conducted on securities agency in Malang. The data has been collected by using participant observation, indepth interviews, and questionnaires. The data was anlyzed by using content analysis. Based on the result, the researcher concluded that the variables (x1 Emotional Resiliency; (x2 Cognitive Resiliency; (x3 social resiliency; and Financial Resiliency (x4 have jointly significant influence on the performance of securities agency. Similarly, each variable partially has an influence on financial performance. The dominant variable influencing the performance of securities agency is cognitive resiliency variable that has the highest value of regression coefficient. Therefore, the hypothesis stated about there is an influence of emotional resiliency; cognitive resiliency; social resiliency; and financial resiliency variables towards the performance of the securities agency in Malang is accepted.

  8. Benchmarking of alternate theories for Stark broadening against experimental data from DIII-D diagnostics

    Science.gov (United States)

    Brooks, N. H.; Lisgo, S.; Oks, E.; Volodko, D.; Groth, M.; Leonard, A. W.

    2009-02-01

    Spectroscopy of high- n Balmer line transitions provides a means of measuring n e and T e in recombining plasmas [J. L. Terry et al., Phys. Plasmas 5, 1579 (1998)]. The relative intensities of Rydberg series lines near the ionization limit are a sensitive diagnostic of T e , for T e Academic, New York, 1974); E. Oks, Stark Broadening of Hydrogen and Hydrogenlike Spectral Lines in Plasmas: The Physical Insight (Alpha Science International, Oxford, UK, 2006)] is evaluated by comparing values of n e and T e measured on DIII-D by divertor Thomson scattering (DTS) with those deduced from spectral profile analysis of Balmer series deuterium lines. In particular, the detailed dependence of line width on principal quantum number provides a sensitive metric for distinguishing which model best accords with experiment.

  9. Theory and Simulations of Refractive Substructure in Resolved Scatter-broadened Images

    Science.gov (United States)

    Johnson, Michael D.; Gwinn, Carl R.

    2015-06-01

    At radio wavelengths, scattering in the interstellar medium distorts the appearance of astronomical sources. Averaged over a scattering ensemble, the result is a blurred image of the source. However, Narayan & Goodman and Goodman & Narayan showed that for an incomplete average, scattering introduces refractive substructure in the image of a point source that is both persistent and wideband. We show that this substructure is quenched but not smoothed by an extended source. As a result, when the scatter-broadening is comparable to or exceeds the unscattered source size, the scattering can introduce spurious compact features into images. In addition, we derive efficient strategies to numerically compute realistic scattered images, and we present characteristic examples from simulations. Our results show that refractive substructure is an important consideration for ongoing missions at the highest angular resolutions, and we discuss specific implications for RadioAstron and the Event Horizon Telescope.

  10. Bandwidth broadening of a linear polarization converter by near-field metasurface coupling.

    Science.gov (United States)

    Gao, Xi; Singh, Leena; Yang, Wanli; Zheng, Jingjing; Li, Haiou; Zhang, Weili

    2017-07-28

    We experimentally demonstrate a highly efficient, broadband linear polarization converter functioning at terahertz frequencies. The linear polarization converter is composed of three metasurfaces and two dielectric layers interlaced with each other. The neighboring unit cells of the central metasurface layer of the linear polarization converter exhibit strong electromagnetic coupling, which increases the number of resonances and results in significant bandwidth broadening. The simulation and experimental results show that in the frequency range of 0.2 to 0.4 THz, the proposed polarization converter has a flat transmission curve and exhibits a transmission efficiency that is higher than 80%. High performance terahertz polarization conversion is desirable in many fields, such as terahertz spectroscopy, imaging, and communications.

  11. Tropospheric CH4 signals as observed by NDACC FTIR at globally distributed sites and comparison to GAW surface in situ measurements

    Directory of Open Access Journals (Sweden)

    E. Sepúlveda

    2014-07-01

    Full Text Available We present lower/middle tropospheric column-averaged CH4 mole fraction time series measured by nine globally distributed ground-based FTIR (Fourier transform infrared remote sensing experiments of the Network for the Detection of Atmospheric Composition Change (NDACC. We show that these data are well representative of the tropospheric regional-scale CH4 signal, largely independent of the local surface small-scale signals, and only weakly dependent on upper tropospheric/lower stratospheric (UTLS CH4 variations. In order to achieve the weak dependency on the UTLS, we use an a posteriori correction method. We estimate a typical precision for daily mean values of about 0.5% and a systematic error of about 2.5%. The theoretical assessments are complemented by an extensive empirical study. For this purpose, we use surface in situ CH4 measurements made within the Global Atmosphere Watch (GAW network and compare them to the remote sensing data. We briefly discuss different filter methods for removing the local small-scale signals from the surface in situ data sets in order to obtain the in situ regional-scale signals. We find good agreement between the filtered in situ and the remote sensing data. The agreement is consistent for a variety of timescales that are interesting for CH4 source/sink research: day-to-day, monthly, and inter-annual. The comparison study confirms our theoretical estimations and proves that the NDACC FTIR measurements can provide valuable data for investigating the cycle of CH4.

  12. Evaluation of the aerosol vertical distribution in global aerosol models through comparison against CALIOP measurements: AeroCom phase II results: AEROSOL PROFILES IN AEROCOM II GCM

    Energy Technology Data Exchange (ETDEWEB)

    Koffi, Brigitte [European Commission, Joint Research Centre, Institute for Environment and Sustainability, Ispra Italy; Schulz, Michael [Norwegian Meteorological Institute, Oslo Norway; Bréon, François-Marie [Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette France; Dentener, Frank [European Commission, Joint Research Centre, Institute for Environment and Sustainability, Ispra Italy; Steensen, Birthe Marie [Norwegian Meteorological Institute, Oslo Norway; Griesfeller, Jan [Norwegian Meteorological Institute, Oslo Norway; Winker, David [NASA Langley Research Center, MS/475, Hampton Virginia USA; Balkanski, Yves [Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette France; Bauer, Susanne E. [Center for Climate Systems Research, Columbia University, New York New York USA; NASA Goddard Institute for Space Studies, New York New York USA; Bellouin, Nicolas [Department of Meteorology, University of Reading, Reading UK; Berntsen, Terje [Department of Geosciences, University of Oslo, Oslo Norway; Center for International Climate and Environmental Research-Oslo (CICERO), Oslo Norway; Bian, Huisheng [NASA Goddard Space Flight Center, Greenbelt Maryland USA; Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore Country Maryland USA; Chin, Mian [NASA Goddard Space Flight Center, Greenbelt Maryland USA; Diehl, Thomas [European Commission, Joint Research Centre, Institute for Environment and Sustainability, Ispra Italy; Easter, Richard [Pacific Northwest National Laboratory, Richland Washington USA; Ghan, Steven [Pacific Northwest National Laboratory, Richland Washington USA; Hauglustaine, Didier A. [Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette France; Iversen, Trond [Norwegian Meteorological Institute, Oslo Norway; Department of Geosciences, University of Oslo, Oslo Norway; Kirkevåg, Alf [Norwegian Meteorological Institute, Oslo Norway; Liu, Xiaohong [Pacific Northwest National Laboratory, Richland Washington USA; Now at University of Wyoming, Laramie Wyoming USA; Lohmann, Ulrike [ETH-Zentrum, Zürich Switzerland; Myhre, Gunnar [Center for International Climate and Environmental Research-Oslo (CICERO), Oslo Norway; Rasch, Phil [NASA Goddard Space Flight Center, Greenbelt Maryland USA; Seland, Øyvind [Norwegian Meteorological Institute, Oslo Norway; Skeie, Ragnhild B. [Center for International Climate and Environmental Research-Oslo (CICERO), Oslo Norway; Steenrod, Stephen D. [NASA Goddard Space Flight Center, Greenbelt Maryland USA; Stier, Philip [Department of Physics, University of Oxford, Oxford UK; Tackett, Jason [Science Systems and Applications, Inc., Hampton Virginia USA; Takemura, Toshihiko [Research Institute for Applied Mechanics, Kyushu University, Fukuoka Japan; Tsigaridis, Kostas [Center for Climate Systems Research, Columbia University, New York New York USA; NASA Goddard Institute for Space Studies, New York New York USA; Vuolo, Maria Raffaella [Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette France; Now at National Institute for Agronomic Research, Thiverval-Grignon France; Yoon, Jinho [Pacific Northwest National Laboratory, Richland Washington USA; Now at Gwangju Institute of Science and Technology, Gwangju Korea; Zhang, Kai [Pacific Northwest National Laboratory, Richland Washington USA; Max Planck Institute for Meteorology, Hamburg Germany

    2016-06-27

    The ability of eleven models in simulating the aerosol vertical distribution from regional to global scales, as part of the second phase of the AeroCom model inter-comparison initiative (AeroCom II) is assessed and compared to results of the first phase. The evaluation is performed using a global monthly gridded dataset of aerosol extinction profiles built on purpose from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) Layer Product 3.01. Results over 12 sub-continental regions show that five models improved whereas three degraded in reproducing the Zα 0-6 km mean extinction height diagnostic, which is computed over the 0-6 km altitude range for each studied region and season. While the models’ performance remains highly variable, it has generally improved in terms of inter-regional diversity and seasonality. The biases in Zα 0-6 km have notably decreased in the U.S. and European industrial and downwind maritime regions, whereas the timing of the Zα 0-6 km peak season has improved for all but two models. However, most of the models now show a Zα 0-6 km underestimation over land, notably in the dust and biomass burning regions in Asia and Africa. At global scale, the AeroCom II models better reproduce the Zα 0-6 km latitudinal variability over ocean than over land. Hypotheses for the (changes in the) the performance of the individual models and for the inter-model diversity are discussed. We also provide an analysis of the CALIOP limitations and uncertainties that can contribute to the differences between the simulations and observations.

  13. Auger Recombination in Self-Assembled Quantum Dots: Quenching and Broadening of the Charged Exciton Transition.

    Science.gov (United States)

    Kurzmann, Annika; Ludwig, Arne; Wieck, Andreas D; Lorke, Axel; Geller, Martin

    2016-05-11

    In quantum dots (QDs), the Auger recombination is a nonradiative process in which the electron-hole recombination energy is transferred to an additional carrier. It has been studied mostly in colloidal QDs, where the Auger recombination time is in the picosecond range and efficiently quenches the light emission. In self-assembled QDs, on the other hand, the influence of Auger recombination on the optical properties is in general neglected, assuming that it is masked by other processes such as spin and charge fluctuations. Here, we use time-resolved resonance fluorescence to analyze the Auger recombination and its influence on the optical properties of a single self-assembled QD. From excitation-power-dependent measurements, we find a long Auger recombination time of about 500 ns and a quenching of the trion transition by about 80%. Furthermore, we observe a broadening of the trion transition line width by up to a factor of 2. With a model based on rate equations, we are able to identify the interplay between tunneling and Auger rate as the underlying mechanism for the reduced intensity and the broadening of the line width. This demonstrates that self-assembled QDs can serve as an ideal model system to study how the charge recapture process, given by the band-structure surrounding the confined carriers, influences the Auger process. Our findings are not only relevant for improving the emission properties of colloidal QD-based emitters and dyes, which have recently entered the consumer market, but also of interest for more visionary applications, such as quantum information technologies, based on self-assembled quantum dots.

  14. High-temperature argon broadening of CO2 near 2190 cm-1 in a shock tube

    Science.gov (United States)

    Mulvihill, C. R.; Petersen, E. L.

    2017-10-01

    Scanned-wavelength laser absorption measurements of CO2 diluted in Ar were performed behind reflected shock waves at high temperatures (1158-2017 K) and low pressures (5.1-108.4 kPa). High-resolution (0.001 cm-1) scans were conducted in 0.4-cm-1 increments from about 2188.8 to 2191.8 cm-1 at a scan rate of 2 kHz. The HITRAN 2004, HITRAN 2012, and CDSD-296 databases were all found to underestimate the absorption, typically by an order of magnitude or more. The HITEMP database, however, closely predicted the measured data. For the assumed form γ_{{{CO}_{ 2} - {Ar}}} (T) = γ_{{{CO}_{ 2} - {Ar}}} (T0 )(T0 /T)n with T0 = 296 K, an optimization routine was implemented to determine the values of γ_{{{CO}_{ 2} - {Ar}}} (T0 ) and n. From the optimization, values of 0.033 ± 0.004 cm-1 atm.-1 and 0.61 ± 0.04 were determined for γ_{{{CO}_{ 2} - {Ar}}} (T0 ) and n, respectively, which are in good agreement with historical values. These values describe an average CO2-Ar broadening coefficient in the frequency range studied herein and are reliable within the experimental temperature range. In addition, a set of fixed-wavelength measurements at 2190.0175 cm-1 were carried out at 122, 446, and 1115 kPa between 1100 and 2100 K, and the HITEMP predictions incorporating the proposed Ar-broadening parameters showed excellent agreement with these data.

  15. Citizen Science: Broadening Access and Engagement Through Community Partnerships, Aerospace Education and Water Quality Research

    Science.gov (United States)

    Johnson, M. A.

    2016-12-01

    We applied a new approach to the design and development of citizen science learning opportunities to enhance outreach to diverse student populations, while advancing water quality research and aerospace education. This collaborative approach to informal science, technology, engineering, and math (STEM) and aerospace education required innovative partnerships between private general aviation pilots, researchers, teachers, and students. This research explored the development of active partnerships required to facilitate community engaged science, with an emphasis on increased participation of women and girls and people of color, while creating new exploratory pathways for broadening access to and engagement in STEM learning experiences. We developed an outreach program through collaborative planning with local schools to create new STEM learning experiences based upon basic aerospace education concepts and an existing water quality research project designed to track harmful algal blooms (HAB) that can produce toxins called cyanobacteria, also known as blue-green algae, which can impact drinking, fishing, and recreational waters. General aviation pilots functioning as citizen scientists obtained high-resolution aerial images while flying over potentially impacted waters. Aerial data was made available to teachers and students, as well as researchers participating in the existing water quality program lead by NASA Glenn Research Center. Teachers used the images and results to educate in climate change and the dangers of HAB. Students were able to compare aerial data with their own observations, and also gained experience in aeronautical science through field trips to local airports, hands-on experience with private research aircraft, specialized equipment used for data collection, and advanced ground instruction from research pilots. As a result of reaching out to local educators serving diverse student populations and facilitating collaborative planning, we

  16. Complete compensation of pulse broadening in an amplifier-based slow light system using a nonlinear regeneration element.

    Science.gov (United States)

    Chin, Sanghooon; Gonzalez-Herraez, Miguel; Thévenaz, Luc

    2009-11-23

    We experimentally demonstrate complete compensation of pulse broadening in an amplifier-based slow light system. The configuration of the delay line basically consists of two stages: a conventional Brillouin slow light system and a nonlinear regeneration element. Signal pulses experienced both time delay and temporal broadening through the Brillouin delay line and then the delayed pulses were delivered into a nonlinear optical loop mirror. Due to the nonlinear response of the transmission of the fiber loop, the inevitably broadened pulses were moderately compressed in the output of the loop, without loss in the capacity to delay the pulses. The overall result is that, for the maximum delay, the width of the pulse could be kept below the input width while the time delays introduced by the slow light element were preserved. Using this delay line, a signal pulse with duration of 27 ns at full width at half maximum was delayed up to 1.3-bits without suffering from signal distortion.

  17. [Participatory potential and deliberative function: a debate on broadening the scope of democracy through the health councils].

    Science.gov (United States)

    Bispo Júnior, José Patrício; Gerschman, Sílvia

    2013-01-01

    This article reflects upon the relation between democracy and health councils. It seeks to analyze the councils as a space for broadening the scope of democracy. First, some characteristics and principles of the liberal democratic regime are presented, with an emphasis on the minimalist and procedural approach of decision-making. The fragilities of the representative model and the establishment of new relations between the Government and society are then discussed in light of the new social grammar and the complexity of the division between governmental and societal responsibilities. The principles of deliberative democracy and the idea of substantive democracy are subsequently presented. Broadening the scope of democracy is understood not only as the guarantee of civil and political rights, but also especially, of social rights. Lastly, based on discussion of the participation and deliberation categories, the health councils are analyzed as potential mechanisms for broadening the scope of democracy.

  18. Calculations of H2O microwave line broadening in collisions with He atoms - Sensitivity to potential energy surfaces

    Science.gov (United States)

    Green, Sheldon; Defrees, D. J.; Mclean, A. D.

    1991-01-01

    Theoretical computations of broadening parameters are reported for three microwave lines of H2O in a bath of He atoms. The potential-energy surfaces employed are corrected for basis-set superposition error, and their reliability is checked by repeating the calculations with a different basis set for orbital expansion. The results are presented in extensive tables and discussed in detail. The corrections applied are shown to have a significant impact on the accuracy of the room-temperature broadenings determined: 8.9 sq A for the 22.2-GHz line, 11.8 sq A for the 183,3-GHz line, and 10.0 sq A for the 380.2-GHz line, in good agreement with published experimental data. The importance of collisional broadening for the atmospheric transmission of radiation and for remote-sensing applications is indicated.

  19. Quantum Cascade Laser Measurements of Line Intensities, N2-, O2- and Ar- Collisional Broadening Coefficients of N2O in the  3 Band Near 4.5  m

    KAUST Repository

    Es-sebbar, E.-t.

    2016-04-19

    This study deals with precise measurements of absolute line intensities, N2-, O2- and Ar- collisional broadening coefficients of N2O in the P-branch of the ν3 vibrational band near 4.5 μm. Collisional broadening coefficients of N2O-air are derived from the N2- and O2- broadening contributions by considering an ideal atmospheric composition. Studies are performed at room temperature for 10 rotational transitions over 2190-2202 cm-1 spectral range using a distributed-feedback quantum cascade laser. To retrieve spectroscopic parameters for each individual transition, measured absorption line shape is simulated within Voigt and Galatry profiles. The obtained results compare well with previous experimental data available in the literature: the discrepancies being less than 4% for most of the probed transitions. The spectroscopic data reported here are very useful for the design of sensors used to monitor the abundance of N2O in earth\\'s atmosphere. © The Author(s) 2016.

  20. Regulation of the natural gas distribution sector: a comparison of Brazilian and Colombian industries; Regulacao do setor de distribuicao de gas natural: uma comparacao dos casos brasileiro e colombiano

    Energy Technology Data Exchange (ETDEWEB)

    Domingues, Mariana Peralva; Ferraro, Marcelo Colomer [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2008-07-01

    The Bolivia oil industry nationalization in 2006 and the high price of oil on the international market called the public and government attention to the problems of the natural gas industry regulation in Brazil. Recently, the establishment of a specific law for the natural gas industry had been debated in academic circles and in government institutions. In Brazil, the absence of an integrated energy policy and the absence of a homogeneous regulatory framework interfere with natural gas industry development, especially in distribution. Thus, the objective of the work will be contrast the Colombia distribution natural gas regulatory structure sector to the Brazilian natural gas regulatory framework. The comparison of the Brazilian regulatory framework and the Colombian natural gas regulation shows that the existence of different kinds of concession contracts in distribution is one of the explanations for the different levels of investment in Brazil. The contract with exclusive right to explore the distribution service in geographic territories also contributes to explain the low coverage rate of public distribution companies. Thus, the rapid expansion of the natural gas distribution network in Colombia after the regulatory reforms shows the importance of the establishment of a regulatory structure to push private investment. The Colombian case can be considered a good model for other countries in South America, especially to the natural gas distribution regulation. (author)

  1. Simulating groundwater flow in karst aquifers with distributed parameter models—Comparison of porous-equivalent media and hybrid flow approaches

    Science.gov (United States)

    Kuniansky, Eve L.

    2016-09-22

    Understanding karst aquifers, for purposes of their management and protection, poses unique challenges. Karst aquifers are characterized by groundwater flow through conduits (tertiary porosity), and (or) layers with interconnected pores (secondary porosity) and through intergranular porosity (primary or matrix porosity). Since the late 1960s, advances have been made in the development of numerical computer codes and the use of mathematical model applications towards the understanding of dual (primary [matrix] and secondary [fractures and conduits]) porosity groundwater flow processes, as well as characterization and management of karst aquifers. The Floridan aquifer system (FAS) in Florida and parts of Alabama, Georgia, and South Carolina is composed of a thick sequence of predominantly carbonate rocks. Karst features are present over much of its area, especially in Florida where more than 30 first-magnitude springs occur, numerous sinkholes and submerged conduits have been mapped, and numerous circular lakes within sinkhole depressions are present. Different types of mathematical models have been applied for simulation of the FAS. Most of these models are distributed parameter models based on the assumption that, like a sponge, water flows through connected pores within the aquifer system and can be simulated with the same mathematical methods applied to flow through sand and gravel aquifers; these models are usually referred to as porous-equivalent media models. The partial differential equation solved for groundwater flow is the potential flow equation of fluid mechanics, which is used when flow is dominated by potential energy and has been applied for many fluid problems in which kinetic energy terms are dropped from the differential equation solved. In many groundwater model codes (basic MODFLOW), it is assumed that the water has a constant temperature and density and that flow is laminar, such that kinetic energy has minimal impact on flow. Some models have

  2. Image analysis for the quantitative comparison of stress fibers and focal adhesions.

    Directory of Open Access Journals (Sweden)

    Alberto Elosegui-Artola

    Full Text Available Actin stress fibers (SFs detect and transmit forces to the extracellular matrix through focal adhesions (FAs, and molecules in this pathway determine cellular behavior. Here, we designed two different computational tools to quantify actin SFs and the distribution of actin cytoskeletal proteins within a normalized cellular morphology. Moreover, a systematic cell response comparison between the control cells and those with impaired actin cytoskeleton polymerization was performed to demonstrate the reliability of the tools. Indeed, a variety of proteins that were present within the string beginning at the focal adhesions (vinculin up to the actin SFs contraction (non-muscle myosin II (NMMII were analyzed. Finally, the software used allows for the quantification of the SFs based on the relative positions of FAs. Therefore, it provides a better insight into the cell mechanics and broadens the knowledge of the nature of SFs.

  3. Evaluation of scatter-to-primary ratio, grid performance and normalized average glandular dose in mammography by Monte Carlo simulation including interference and energy broadening effects

    Science.gov (United States)

    Cunha, D. M.; Tomal, A.; Poletti, M. E.

    2010-08-01

    In this work, a computational code for the study of imaging systems and dosimetry in conventional and digital mammography through Monte Carlo simulations is described. The developed code includes interference and Doppler energy broadening for simulation of elastic and inelastic photon scattering, respectively. The code estimates the contribution of scattered radiation to image quality through the spatial distribution of the scatter-to-primary ratio (S/P). It allows the inclusion of different designs of anti-scatter grids (linear or cellular), for evaluation of contrast improvement factor (CIF), Bucky factor (BF) and signal difference-to-noise ratio improvement factor (SIF). It also allows the computation of the normalized average glandular dose, \\bar{D}_{g,N} . These quantities were studied for different breast thicknesses and compositions, anode/filter combinations and tube potentials. Results showed that the S/P increases linearly with breast thickness, varying slightly with breast composition or the spectrum used. Evaluation of grid performance showed that the cellular grid provides the highest CIF with smaller BF. The SIF was also greater for the cellular grid, although both grids showed SIF breasts. Results for \\bar{D}_{g,N} showed that it increases with the half-value layer (HVL) of the spectrum, decreases considerably with breast thickness and has a small dependence on the anode/filter combination. Inclusion of interference effects of breast tissues affected the values of S/P obtained with the grid up to 25%, while the energy broadening effect produced smaller variations on the evaluated quantities.

  4. Strategies for Broadening Participation in the Geosciences: Lessons Learned From the UCAR-SOARSr Program

    Science.gov (United States)

    Pandya, R. E.

    2004-12-01

    Broadening participation in the geosciences will advance our research, enhance our education and training, and improve our ability to meet societal needs. By attracting more diverse students, we will be better postioned to provide all our students the increasingly necessary and relevant experience of working in diverse teams. Because some traditionally underrepresented groups, particularly Latinos & Hispanics, are growing much faster than the population as a whole, broader participation will enlarge the pool of talented individuals contributing to the next generation of research. Finally the geosciences will be more effective and credible when the diversity of our nation is reflected in our workforce, especially as civic discourse includes more and more complex decisions about society's interactions with the Earth and its resources. The Significant Opportunities in Atmospheric Research and Science (SOARS) seeks to broaden participation in geosciences by helping undergraduate students successfully transition to graduate programs in the atmospheric and related sciences. SOARS combines multiple research experiences, multifaceted mentoring, an encouraging community, and financial support to help students enter and succeed in graduate school. A central feature of the SOARS program is a ten-week summer immersion program in which protégés (SOARS participants) conduct scientific research at the National Center for Atmospheric Research (NCAR) or at laboratories of SOARS sponsors. During this summer research experience, SOARS protégés are supported by up to four mentors: a science research mentor, a writing mentor, a community mentor, and a peer mentor. SOARS protégés collaborate with their mentors to perform original research, prepare scientific papers, and present their research at a colloquium. SOARS also provides extensive leadership and communication training; support for conference presentations and for graduate school; and a strong scholarly community that

  5. Gas hydrates distribution in the Shenhu area, northern South China Sea: comparisons between the eight drilling sites with gashydrate petroleum system

    Energy Technology Data Exchange (ETDEWEB)

    Su, M.; Yang, R.; Wang, H.; Sha, Z.; Liang, J.; Wu, N.; Qiao, S.; Cong, X.

    2016-07-01

    The results of the first marine gas hydrate drilling expedition of Guangzhou Marine Geological Survey (GMGS-1) in northern continental slope of the South China Sea revealed a variable distribution of gas hydrates in the Shenhu area. In this study, comparisons between the eight sites with gas-hydrate petroleum system were used to analyze and re-examine hydrate potential. In the Shenhu gas hydrate drilling area, all the sites were located in a suitable low-temperature, high-pressure environment. Biogenic and thermogenic gases contributed to the formation of hydrates. Gas chimneys and some small-scale faults (or micro-scale fractures) compose the migration pathways for gas-bearing fluids. Between these sites, there are three key differences: the seafloor temperatures and pressures; geothermal gradient and sedimentary conditions. Variations of seafloor temperatures and pressures related to water depths and geothermal gradient would lead to changes in the thickness of gas hydrate stability zones. Although the lithology and grain size of the sediments were similar, two distinct sedimentary units were identified for the first time through seismic interpretation, analysis of deep-water sedimentary processes, and the Cm pattern (plotted one-percentile and median values from grain-size analyses), implying the heterogeneous sedimentary conditions above Bottom Simulating Reflectors (BSRs). Based on the analyses of forming mechanisms and sedimentary processes, these two fine-grained sedimentary units have different physical properties. Fine-grained turbidites (Unit I) with thin-bedded chaotic reflectors at the bottom acted as the host rocks for hydrates; whereas, finegrained sediments related to soft-sediment deformation (Unit II) characterized by thick continuous reflectors at the top would serve as regional homogeneous caprocks. Low-flux methane that migrated upwards along chimneys could be enriched preferentially in fine-grained turbidites, resulting in the formation of

  6. Strategies for broadening participation in the Maryland Sea Grant REU program

    Science.gov (United States)

    Moser, F. C.; Kramer, J.; Allen, J. R.

    2011-12-01

    A core goal of the ocean science community is to increase gender and ethnic diversity in its scientific workforce. Maryland Sea Grant strives to provide women and students from underrepresented groups in marine science opportunities to participate in its NSF-supported Research Experiences for Undergraduates (REU) program in estuarine processes. While women currently dominate the applicant student pool, and often the accepted student pool, we are trying a variety of strategies to increase the number of applicants and accepted students from underrepresented groups who might not otherwise be lured into marine science research and, ultimately, careers. For example, we have built partnerships with multicultural-focused undergraduate research programs and institutions, which can raise awareness about our REU program and its commitment to broadening diversity. Further, we work to attract first generation college students, students from small colleges with limited marine science opportunities and students from varied racial and ethnic backgrounds using such strategies as: 1) developing trust and partnerships with faculty at minority serving institutions; 2) expanding our outreach in advertising our program; 3) recruiting potential applicants at professional meetings; 4) targeting minority serving institutions within and beyond our region; 5) encouraging our REU alumni to promote our REU program among their peers; and 6) improving our application process. We believe these efforts contribute to the increase in the diversity of our summer-supported students and the change in the composition of our applicant pool over the last decade. Although we cannot definitively identify which strategies are the most effective at broadening participation in our program, we attribute most of our improvements to some combination of these strategies. In addition, pre- and post-surveying of our REU students improves our understanding of effective tools for recruiting and adapting our program

  7. Is it only the regulatory status? Broadening the debate on cisgenic plants.

    Science.gov (United States)

    van Hove, Lilian; Gillund, Frøydis

    2017-01-01

    In current debates on emerging technologies for plant breeding in Europe, much attention has been given to the regulatory status of these techniques and their public acceptance. At present, both genetically modified plants with cisgenic approaches-using genes from crossable species-as well as transgenic approaches-using genes from different species-fall under GMO regulation in the EU and both are mandatorily labelled as GMOs. Researchers involved in the early development of cisgenic GM plants convey the message that the potential use and acceptance of cisgenic approaches will be seriously hindered if GMO regulations are not adjusted. Although the similar treatment and labelling of transgenic and cisgenic plants may be a legitimate concern for the marketability of a cisgenic GM plant, there are concerns around their commercialization that reach beyond the current focus on (de)regulation. In this paper, we will use the development of the cisgenic GM potato that aims to overcome 'late blight'-the most devastating potato disease worldwide-as a case to argue that it is important to recognize, reflect and respond to broader concerns than the dominant focus on the regulatory 'burden' and consumer acceptance. Based on insights we gained from discussing this case with diverse stakeholders within the agricultural sector and potato production in Norway during a series of workshops, we elaborate on additional issues such as the (technical) solution offered; different understandings of the late blight problem; the durability of the potato plant resistance; and patenting and ownership. Hence, this paper contributes to empirical knowledge on stakeholder perspectives on emerging plant breeding technologies, underscoring the importance to broaden the scope of the debate on the opportunities and challenges of agricultural biotechnologies, such as cisgenic GM plants. The paper offers policy-relevant input to ongoing efforts to broaden the scope of risk assessments of agricultural

  8. Pinatubo and Pre-Pinatubo Optical-Depth Spectra: Mauna Loa Measurements, Comparisons, Inferred Particle Size Distributions, Radiative Effects, and Relationship to Lidar Data

    Science.gov (United States)

    Russell, P. B.; Livingston, J. M.; Dutton, E. G.; Pueschel, R. F.; Reagan, J. A.; DeFoor, T. E.; Box, M. A.; Pilewskie, P.; Herman, B. M.; Kinne, S. A.; hide

    1993-01-01

    The Ames airborne tracking sunphotometer was operated at the National Oceanic and Atmospheric Administration (NOAA) Mauna Loa Observatory (MLO) in 1991 and 1992 along with the NOAA Climate Monitoring and Diagnostics Laboratory (CMDL) automated tracking sunphotometer and lidar. June 1991 measurements provided calibrations, optical-depth spectra, and intercomparisons under relatively clean conditions; later measurements provided spectra and comparisons for the Pinatubo cloud plus calibration checks. June 1991 results are similar to previous MLO springtime measurements, with midvisible particle optical depth tau(sub p)(lambda = 0.526 microns) at the near-background level of 0.012 +/- 0.006 and no significant wavelength dependence in the measured range (lambda = 0.38 to 1.06 microns). The arrival of the Pinatubo cloud in July 1991 increased midvisible particle optical depth by more than an order of magnitude and changed the spectral shape of tau(sub p)(lambda) to an approximate power law with an exponent of about -1.4. By early September 1991, the spectrum was broadly peaked near 0.5 microns, and by July 1992, it was peaked near 0.8 microns. Our optical-depth spectra include corrections for diffuse light which increase postvolcanic midvisible tau(sub p) values by 1 to 3% (i.e., 0.0015 to 0.0023). NOAA- and Ames Research Center (ARC)-measured spectra are in good agreement. Columnar size distributions inverted from the spectra show that the initial (July 1991) post-Pinatubo cloud was relatively rich in small particles (r less than 0.25 microns), which were progressively depleted in the August-September 1991 and July 1992 periods. Conversely, both of the later periods had more of the optically efficient medium-sized particles (0.25 less than r less than 1 micron) than did the fresh July 1991 cloud. These changes are consistent with particle growth by condensation and coagulation. The effective, or area-weighted, radius increased from 0.22 +/- 0.06 micron in July 1991 to 0

  9. Linewidth broadening and emission saturation of a resonantly excited quantum dot monitored via an off-resonant cavity mode

    DEFF Research Database (Denmark)

    Ulhaq, A.; Ates, Serkan; Weiler, S.

    2010-01-01

    We report on the robustness of a detuned mode channel for reading out the relevant s-shell properties of a resonantly excited coupled quantum dot (QD) in a pillar microcavity. The line broadening of the QD s-shell is “monitored” by the mode signal with high conformity to the directly measured QD...

  10. Probing transverse momentum broadening via dihadron and hadron-jet angular correlations in relativistic heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    Lin Chen

    2017-10-01

    Full Text Available Dijet, dihadron, hadron-jet angular correlations have been reckoned as important probes of the transverse momentum broadening effects in relativistic nuclear collisions. When a pair of high-energy jets created in hard collisions traverse the quark–gluon plasma produced in heavy-ion collisions, they become de-correlated due to the vacuum soft gluon radiation associated with the Sudakov logarithms and the medium-induced transverse momentum broadening. For the first time, we employ the systematical resummation formalism and establish a baseline calculation to describe the dihadron and hadron-jet angular correlation data in pp and peripheral AA collisions where the medium effect is negligible. We demonstrate that the medium-induced broadening 〈p⊥2〉 and the so-called jet quenching parameter qˆ can be extracted from the angular de-correlations observed in AA collisions. A global χ2 analysis of dihadron and hadron-jet angular correlation data renders 〈p⊥2〉∼13−4+5 GeV2 for a quark jet at RHIC top energy. Further experimental and theoretical efforts along the direction of this work shall significantly advance the quantitative understanding of transverse momentum broadening and help us acquire unprecedented knowledge of jet quenching parameter in relativistic heavy-ion collisions.

  11. BASE (Broadening Access to Science Education): A Research and Mentoring Focused Summer STEM Camp Serving Underrepresented High School Girls

    Science.gov (United States)

    Phelan, Shelley A.; Harding, Shannon M.; Harper-Leatherman, Amanda S.

    2017-01-01

    BASE (Broadening Access to Science Education) Camp is a hands-on, two-week residential summer science experience on the Fairfield University campus in Fairfield CT, USA. The annual program targets 24 young women who attend high school in the neighboring city of Bridgeport, CT, the most economically depressed city in CT. The camp, which is free to…

  12. An Age-Related Mechanism of Emotion Regulation: Regulating Sadness Promotes Children's Learning by Broadening Information Processing

    Science.gov (United States)

    Davis, Elizabeth L.

    2016-01-01

    Emotion regulation predicts positive academic outcomes like learning, but little is known about "why". Effective emotion regulation likely promotes learning by broadening the scope of what may be attended to after an emotional event. One hundred twenty-six 6- to 13-year-olds' (54% boys) regulation of sadness was examined for changes in…

  13. Local Talent: By Tapping into the Resources Just outside Their School Walls, Music Teachers Can Help Broaden Their Students' Horizons

    Science.gov (United States)

    Randall, Mac

    2009-01-01

    Many music teachers across the country have learned how beneficial it can be to tap into the communities around them. The author discusses how music teachers can help broaden their students' horizons by tapping into the resources just outside their school walls. One way is by employing local talents. Another is to put an ad in nearby music stores,…

  14. Mortality Salience and Positive Affect Influence Adolescents' Attitudes toward Peers with Physical Disabilities: Terror Management and Broaden and Build Theories

    Science.gov (United States)

    Taubman-Ben-Ari, Orit; Eherenfreund-Hager, Ahinoam; Findler, Liora

    2011-01-01

    Attitudes toward teenagers with and without physical disabilities, and their social acceptance, were examined from the perspective of terror management theory and the broaden and build theory. Participants (n = 390, aged 13-17) were divided into 3 experimental conditions: positive emotions, mortality salience, and control. Then, they were shown…

  15. Probing transverse momentum broadening via dihadron and hadron-jet angular correlations in relativistic heavy-ion collisions

    Science.gov (United States)

    Chen, Lin; Qin, Guang-You; Wei, Shu-Yi; Xiao, Bo-Wen; Zhang, Han-Zhong

    2017-10-01

    Dijet, dihadron, hadron-jet angular correlations have been reckoned as important probes of the transverse momentum broadening effects in relativistic nuclear collisions. When a pair of high-energy jets created in hard collisions traverse the quark-gluon plasma produced in heavy-ion collisions, they become de-correlated due to the vacuum soft gluon radiation associated with the Sudakov logarithms and the medium-induced transverse momentum broadening. For the first time, we employ the systematical resummation formalism and establish a baseline calculation to describe the dihadron and hadron-jet angular correlation data in pp and peripheral AA collisions where the medium effect is negligible. We demonstrate that the medium-induced broadening 〈 p⊥2 〉 and the so-called jet quenching parameter q ˆ can be extracted from the angular de-correlations observed in AA collisions. A global χ2 analysis of dihadron and hadron-jet angular correlation data renders 〈p⊥ 2 〉 ∼13-4+5 GeV2 for a quark jet at RHIC top energy. Further experimental and theoretical efforts along the direction of this work shall significantly advance the quantitative understanding of transverse momentum broadening and help us acquire unprecedented knowledge of jet quenching parameter in relativistic heavy-ion collisions.

  16. The effects of Doppler broadening and detector resolution on the performance of three-stage Compton cameras

    Energy Technology Data Exchange (ETDEWEB)

    Mackin, Dennis; Polf, Jerimy; Peterson, Steve; Beddar, Sam [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Department of Physics, 145 Physical Sciences II, Oklahoma State University, Stillwater, Oklahoma 74078 (United States); Department of Physics, University of Cape Town, Rondebosch 7701 (South Africa); Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2013-01-15

    Purpose: The authors investigated how the characteristics of the detectors used in a three-stage Compton camera (CC) affect the CC's ability to accurately measure the emission distribution and energy spectrum of prompt gammas (PG) emitted by nuclear de-excitations during proton therapy. The detector characteristics they studied included the material (high-purity germanium [HPGe] and cadmium zinc telluride [CZT]), Doppler broadening (DB), and resolution (lateral, depth, and energy). Methods: The authors simulated three-stage HPGe and CZT CCs of various configurations, detecting gammas from point sources with energies ranging from 0.511 to 7.12 MeV. They also simulated a proton pencil beam irradiating a tissue target to study how the detector characteristics affect the PG data measured by CCs in a clinical proton therapy setting. They used three figures of merit: the distance of closest approach (DCA) and the point of closest approach (PCA) between the measured and actual position of the PG emission origin, and the calculated energy resolution. Results: For CCs with HPGe detectors, DB caused the DCA to be greater than 3 mm for 14% of the 6.13 MeV gammas and 20% of the 0.511 MeV gammas. For CCs with CZT detectors, DB caused the DCA to be greater than 3 mm for 18% of the 6.13 MeV gammas and 25% of the 0.511 MeV gammas. The full width at half maximum (FWHM) of the PCA in the z-caret direction for HPGe and CZT detectors ranged from 1.3 to 0.4 mm for gammas with incident energy ranging from 0.511 to 7.12 MeV. For CCs composed of HPGe detectors, the resolution of incident gamma energy calculated by the CC ranged from 6% to 1% for gammas with true incident energies from 0.511 to 7.12 MeV. For CCs composed of CZT detectors, the resolution of gamma energy calculated by the CC ranged from 10% to 1% for gammas with true incident energies from 0.511 to 7.12 MeV. For HPGe and CZT CCs in which all detector effect were included, the DCA was less than 3 mm for 75% and 68% of

  17. Investigation of the collision line broadening problem as applicable to the NASA Optical Plume Anomaly Detection (OPAD) system, phase 1

    Science.gov (United States)

    Dean, Timothy C.; Ventrice, Carl A.

    1995-01-01

    As a final report for phase 1 of the project, the researchers are submitting to the Tennessee Tech Office of Research the following two papers (reprinted in this report): 'Collision Line Broadening Effects on Spectrometric Data from the Optical Plume Anomaly System (OPAD),' presented at the 30th AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 27-29 June 1994, and 'Calculation of Collision Cross Sections for Atomic Line Broadening in the Plume of the Space Shuttle Main Engine (SSME),' presented at the IEEE Southeastcon '95, 26-29 March 1995. These papers fully state the problem and the progress made up to the end of NASA Fiscal Year 1994. The NASA OPAD system was devised to predict concentrations of anomalous species in the plume of the Space Shuttle Main Engine (SSME) through analysis of spectrometric data. The self absorption of the radiation of these plume anomalies is highly dependent on the line shape of the atomic transition of interest. The Collision Line Broadening paper discusses the methods used to predict line shapes of atomic transitions in the environment of a rocket plume. The Voigt profile is used as the line shape factor since both Doppler and collisional line broadening are significant. Methods used to determine the collisional cross sections are discussed and the results are given and compared with experimental data. These collisional cross sections are then incorporated into the current self absorbing radiative model and the predicted spectrum is compared to actual spectral data collected from the Stennis Space Center Diagnostic Test Facility rocket engine. The second paper included in this report investigates an analytical method for determining the cross sections for collision line broadening by molecular perturbers, using effective central force interaction potentials. These cross sections are determined for several atomic species with H2, one of the principal constituents of the SSME plume environment, and compared with experimental data.

  18. Transformational Partnerships and Learning: broadening the experiences for a community organization, school and university

    Directory of Open Access Journals (Sweden)

    Janette Long

    2012-11-01

    Full Text Available Partnerships between community organizations, schools and universities are becoming more widespread as education faculties seek to broaden the experiences of their preservice teachers (Kruger, Davies, Eckersley, Newell& Cherednichenko, 2009. The following paper reports on one such endeavour where a small group of six preservice teachers, drawn from teaching programs that included secondary, primary and primary/early childhood, were immersed in a primary/secondary rural school in Sola, on the remote island of Vanua Lava, located in the northern province of Vanuatu. Whilst international practicums are not new, what is unique within this endeavour was the nature of the partnership that included the Vanuatu Ministry of Education, the Australian Catholic University (ACU and Rotary Australia World Community Service (RAWCS. Each partner had a layer of active participants represented by Arep Secondary School, the School of Education (ACU, NSW, and the Rotary Club of Winston Hills.  The partnership was therefore able to provide both strategic and practical support to the ongoing project, creating layers of engagement and participation for the various groups.  This partnership was transformational as it was based upon genuine engagement with a focus on common goals and mutual benefits, built on relationships established over many years, which is different to other types of partnerships that often seek to obtain only individual organizational goals rather that mutual goals or shared purposes (Brown et al., 2006.

  19. Broadening not strengthening of the Agulhas Current since the early 1990s

    Science.gov (United States)

    Beal, Lisa M.; Elipot, Shane

    2016-12-01

    Western boundary currents—such as the Agulhas Current in the Indian Ocean—carry heat poleward, moderating Earth’s climate and fuelling the mid-latitude storm tracks. They could exacerbate or mitigate warming and extreme weather events in the future, depending on their response to anthropogenic climate change. Climate models show an ongoing poleward expansion and intensification of the global wind systems, most robustly in the Southern Hemisphere, and linear dynamical theory suggests that western boundary currents will intensify and shift poleward as a result. Observational evidence of such changes comes from accelerated warming and air-sea heat flux rates within all western boundary currents, which are two or three times faster than global mean rates. Here we show that, despite these expectations, the Agulhas Current has not intensified since the early 1990s. Instead, we find that it has broadened as a result of more eddy activity. Recent analyses of other western boundary currents—the Kuroshio and East Australia currents—hint at similar trends. These results indicate that intensifying winds may be increasing the eddy kinetic energy of boundary currents, rather than their mean flow. This could act to decrease poleward heat transport and increase cross-frontal exchange of nutrients and pollutants between the coastal ocean and the deep ocean. Sustained in situ measurements are needed to properly understand the role of these current systems in a changing climate.

  20. Intrinsic homogeneous linewidth and broadening mechanisms of excitons in monolayer transition metal dichalcogenides

    KAUST Repository

    Moody, Galan

    2015-09-18

    The band-edge optical response of transition metal dichalcogenides, an emerging class of atomically thin semiconductors, is dominated by tightly bound excitons localized at the corners of the Brillouin zone (valley excitons). A fundamental yet unknown property of valley excitons in these materials is the intrinsic homogeneous linewidth, which reflects irreversible quantum dissipation arising from system (exciton) and bath (vacuum and other quasiparticles) interactions and determines the timescale during which excitons can be coherently manipulated. Here we use optical two-dimensional Fourier transform spectroscopy to measure the exciton homogeneous linewidth in monolayer tungsten diselenide (WSe2). The homogeneous linewidth is found to be nearly two orders of magnitude narrower than the inhomogeneous width at low temperatures. We evaluate quantitatively the role of exciton–exciton and exciton–phonon interactions and population relaxation as linewidth broadening mechanisms. The key insights reported here—strong many-body effects and intrinsically rapid radiative recombination—are expected to be ubiquitous in atomically thin semiconductors.