WorldWideScience

Sample records for 1000au scale properties

  1. Observations of Infalling and Rotational Motions on a 1,000-AU Scale around 17 Class 0 and 0/I Protostars: Hints of Disk Growth and Magnetic Braking?

    Yen, Hsi-Wei; Takakuwa, Shigehisa; Ho, Paul T P; Ohashi, Nagayoshi; Tang, Ya-Wen

    2014-01-01

    We perform imaging and analyses of SMA 1.3 mm continuum, C18O (2-1) and 12CO (2-1) line data of 17 Class 0 and 0/I protostars to study their gas kinematics on a 1,000-AU scale. Continuum and C18O (2-1) emission are detected toward all the sample sources and show central primary components with sizes of ~600-1,500 AU associated with protostars. The velocity gradients in C18O (2-1) have wide ranges of orientations from parallel to perpendicular to the outflows, with magnitudes from ~1 to ~530 km/s/pc. We construct a simple kinematic model to reproduce the observed velocity gradients, estimate the infalling and rotational velocities, and infer the disk radii and the protostellar masses. The inferred disk radii range from 500 AU with estimated protostellar masses from 1 Msun. Our results hint that both large and small disks are possibly present around Class 0 protostars, which could be a sign of disk growth at the Class 0 stage. In addition, the directions of the overall velocity gradients in 7 out of the 17 sour...

  2. FOCAL mission to 550 thru 1000 AU: Status review 2009

    Maccone, Claudio

    2010-09-01

    This paper presents a 2009 status review of the "FOCAL" space mission studied by this author and others since 1992 and formally proposed to ESA for consideration after the year 2000. The FOCAL probe is intended to reach distances between 550 and 1000 AU to exploit the huge radio magnification provided there by the gravitational lens of the Sun, as predicted by the general theory of relativity. However, the alignment between the radio source (any star, for instance), the center of the Sun and the FOCAL spacecraft is rather strict, and so it will be necessary to send a FOCAL probe in the opposite sky direction for any stellar system we wish to observe. For instance, before humanity ever embarked in a true interstellar mission even to the closest stars, the Alpha Centauri three stars system at 4.40 light-years from us, it plainly appears that before launching a really interstellar spacecraft it will be better to send a FOCAL probe in the opposite direction of the sky. In fact, the distance it must reach is 278 times smaller than 4.40 light-years, or, in other words, assuming equal engineering problems, FOCAL will take 278 times less than the trip to Alpha Centauri. This makes the Sun focus a reasonable target for our probes to reach within this century already. This paper describes the gravitational lens of the Sun and an updated status review of FOCAL including:(1) The new book by the author, published in March 2009 and entitled "Deep Space Flight and Communications".(2) The utilization of the relativistic KLT (Karhunen-Loève Transform) instead of the classical FFT to insure optimal telecommunications with the Earth during such a relativistic flight.

  3. EARLY STAGES OF CLUSTER FORMATION: FRAGMENTATION OF MASSIVE DENSE CORES DOWN TO {approx}< 1000 AU

    Palau, Aina; Girart, Josep M. [Institut de Ciencies de l' Espai (CSIC-IEEC), Campus UAB-Facultat de Ciencies, Torre C5-parell 2, E-08193 Bellaterra, Catalunya (Spain); Fuente, Asuncion [Observatorio Astronomico Nacional, P.O. Box 112, E-28803 Alcala de Henares, Madrid (Spain); Estalella, Robert [Departament d' Astronomia i Meteorologia (IEEC-UB), Institut de Ciencies del Cosmos, Universitat de Barcelona, Marti Franques, 1, E-08028 Barcelona (Spain); Ho, Paul T. P.; Zhang, Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Sanchez-Monge, Alvaro; Fontani, Francesco; Cesaroni, Riccardo [Osservatorio Astrofisico di Arcetri, INAF, Lago E. Fermi 5, I-50125 Firenze (Italy); Busquet, Gemma [INAF-Istituto di Astrofisica e Planetologia Spaziali, Area di Recerca di Tor Vergata, Via Fosso Cavaliere 100, I-00133 Roma (Italy); Commercon, Benoit; Hennebelle, Patrick [Laboratoire de Radioastronomie, UMR CNRS 8112, Ecole Normale Superieure et Observatoire de Paris, 24 rue Lhomond, F-75231 Paris Cedex 05 (France); Boissier, Jeremie [Istituto di Radioastronomia, INAF, Via Gobetti 101, I-40129 Bologna (Italy); Zapata, Luis A., E-mail: palau@ieec.uab.es [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, P.O. Box 3-72, 58090 Morelia, Michoacan (Mexico)

    2013-01-10

    In order to study the fragmentation of massive dense cores, which constitute the cluster cradles, we observed the continuum at 1.3 mm and the CO (2-1) emission of four massive cores with the Plateau de Bure Interferometer in the most extended configuration. We detected dust condensations down to {approx}0.3 M {sub Sun} and separate millimeter sources down to 0.''4 or {approx}< 1000 AU, comparable to the sensitivities and separations reached in optical/infrared studies of clusters. The CO (2-1) high angular resolution images reveal high-velocity knots usually aligned with previously known outflow directions. This, in combination with additional cores from the literature observed at similar mass sensitivity and spatial resolution, allowed us to build a sample of 18 protoclusters with luminosities spanning three orders of magnitude. Among the 18 regions, {approx}30% show no signs of fragmentation, while 50% split up into {approx}> 4 millimeter sources. We compiled a list of properties for the 18 massive dense cores, such as bolometric luminosity, total mass, and mean density, and found no correlation of any of these parameters with the fragmentation level. In order to investigate the combined effects of the magnetic field, radiative feedback, and turbulence in the fragmentation process, we compared our observations to radiation magnetohydrodynamic simulations and found that the low-fragmented regions are reproduced well in the magnetized core case, while the highly fragmented regions are consistent with cores where turbulence dominates over the magnetic field. Overall, our study suggests that the fragmentation in massive dense cores could be determined by the initial magnetic field/turbulence balance in each particular core.

  4. High Contrast Imaging with Spitzer: Constraining the Frequency of Giant Planets out to 1000 au Separations

    Durkan, Stephen; Janson, Markus; Carson, Joseph C.

    2016-06-01

    We report results of a re-analysis of archival Spitzer IRAC direct imaging surveys encompassing a variety of nearby stars. Our sample is generated from the combined observations of 73 young stars (median age, distance, spectral type = 85 Myr, 23.3 pc, G5) and 48 known exoplanet host stars with unconstrained ages (median distance, spectral type = 22.6 pc, G5). While the small size of Spitzer provides a lower resolution than 8 m class AO-assisted ground-based telescopes, which have been used for constraining the frequency of 0.5–13 M J planets at separations of 10–102 au, its exquisite infrared sensitivity provides the ability to place unmatched constraints on the planetary populations at wider separations. Here we apply sophisticated high-contrast techniques to our sample in order to remove the stellar point-spread function and to open up sensitivity to planetary mass companions down to 5″ separations. This enables sensitivity to 0.5–13 M J planets at physical separations on the order of 102–103 au, allowing us to probe a parameter space that has not previously been systematically explored to any similar degree of sensitivity. Based on a color and proper motion analysis, we do not record any planetary detections. Exploiting this enhanced survey sensitivity, employing Monte Carlo simulations with a Bayesian approach, and assuming a mass distribution of {dn}/{dm}\\propto {m}-1.31, we constrain (at 95% confidence) a population of 0.5–13 M J planets at separations of 100–1000 au with an upper frequency limit of 9%.

  5. EARLY STAGES OF CLUSTER FORMATION: FRAGMENTATION OF MASSIVE DENSE CORES DOWN TO ∼< 1000 AU

    In order to study the fragmentation of massive dense cores, which constitute the cluster cradles, we observed the continuum at 1.3 mm and the CO (2-1) emission of four massive cores with the Plateau de Bure Interferometer in the most extended configuration. We detected dust condensations down to ∼0.3 M ☉ and separate millimeter sources down to 0.''4 or ∼ 4 millimeter sources. We compiled a list of properties for the 18 massive dense cores, such as bolometric luminosity, total mass, and mean density, and found no correlation of any of these parameters with the fragmentation level. In order to investigate the combined effects of the magnetic field, radiative feedback, and turbulence in the fragmentation process, we compared our observations to radiation magnetohydrodynamic simulations and found that the low-fragmented regions are reproduced well in the magnetized core case, while the highly fragmented regions are consistent with cores where turbulence dominates over the magnetic field. Overall, our study suggests that the fragmentation in massive dense cores could be determined by the initial magnetic field/turbulence balance in each particular core.

  6. An HST Survey for 100–1000 au Companions around Young Stellar Objects in the Orion Molecular Clouds: Evidence for Environmentally Dependent Multiplicity

    Kounkel, M.; Megeath, S. T.; Poteet, C. A.; Fischer, W. J.; Hartmann, L.

    2016-04-01

    We present a near-infrared survey for the visual multiples in the Orion molecular clouds region at separations between 100 and 1000 au. These data were acquired at 1.6 μm with the NICMOS and WFC3 cameras on the Hubble Space Telescope. Additional photometry was obtained for some of the sources at 2.05 μm with NICMOS and in the L‧ band with NSFCAM2 on NASA’s InfraRed Telescope Facility. Toward 129 protostars and 197 pre-main-sequence stars with disks observed with WFC3, we detect 21 and 28 candidate companions between the projected separations of 100–1000 au, of which less than 5 and 8, respectively, are chance line-of-sight coincidences. The resulting companion fraction (CF) after the correction for the line-of-sight contamination is {14.4}-1.3+1.1% for protostars and {12.5}-0.8+1.2% for the pre-main-sequence stars. These values are similar to those found for main-sequence stars, suggesting that there is little variation in the CF with evolution, although several observational biases may mask a decrease in the CF from protostars to the main-sequence stars. After segregating the sample into two populations based on the surrounding surface density of young stellar objects, we find that the CF in the high stellar density regions (ΣYSO > 45 pc‑2) is approximately 50% higher than that found in the low stellar density regions (ΣYSO < 45 pc‑2). We interpret this as evidence for the elevated formation of companions at 100–1000 au in the denser environments of Orion. We discuss possible reasons for this elevated formation.

  7. An HST Survey for 100-1000 AU Companions around Young Stellar Objects in the Orion Molecular Clouds: Evidence for Environmentally Dependent Multiplicity

    Kounkel, M; Poteet, C A; Fischer, W J; Hartmann, L

    2016-01-01

    We present a near-IR survey for the visual multiples in the Orion molecular clouds region at separations between 100 and 1000 AU. These data were acquired at 1.6~$\\mu$m with the NICMOS and WFC3 cameras on the Hubble Space Telescope. Additional photometry was obtained for some of the sources at 2.05~$\\mu$m with NICMOS and in the $L'$-band with NSFCAM2 on the IRTF. Towards 129 protostars and 197 pre-main sequence stars with disks observed with WFC3, we detect 21 and 28 candidate companions between the projected separations of 100---1000 AU, of which less than 5 and 8, respectively, are chance line of sight coincidences. The resulting companion fraction ($CF$) after the correction for the line of sight contamination is 14.4$^{+1.1}_{-1.3}$% for protostars and 12.5$^{+1.2}_{-0.8}$% for the pre-main sequence stars. These values are similar to those found for main sequence stars, suggesting that there is little variation in the $CF$ with evolution, although several observational biases may mask a decrease in the $C...

  8. Relating Biophysical Properties Across Scales

    Flenner, Elijah; Neagu, Adrian; Kosztin, Ioan; Forgacs, Gabor

    2007-01-01

    A distinguishing feature of a multicellular living system is that it operates at various scales, from the intracellular to organismal. Very little is known at present on how tissue level properties are related to cell and subcellular properties. Modern measurement techniques provide quantitative results at both the intracellular and tissue level, but not on the connection between these. In the present work we outline a framework to address this connection. We specifically concentrate on the morphogenetic process of tissue fusion, by following the coalescence of two contiguous multicellular aggregates. The time evolution of this process can accurately be described by the theory of viscous liquids. We also study fusion by Monte Carlo simulations and a novel Cellular Particle Dynamics (CPD) model, which is similar to the earlier introduced Subcellular Element Model (Newman, 2005). Using the combination of experiments, theory and modeling we are able to relate the measured tissue level biophysical quantities to s...

  9. Scale dependence of effective media properties

    For problems where media properties are measured at one scale and applied at another, scaling laws or models must be used in order to define effective properties at the scale of interest. The accuracy of such models will play a critical role in predicting flow and transport through the Yucca Mountain Test Site given the sensitivity of these calculations to the input property fields. Therefore, a research program has been established to gain a fundamental understanding of how properties scale with the aim of developing and testing models that describe scaling behavior in a quantitative manner. Scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas permeability data measured over a range of discrete scales. Also, various physical characteristics of property heterogeneity and the means by which the heterogeneity is measured and described are systematically investigated to evaluate their influence on scaling behavior. This paper summarizes the approach that is being taken toward this goal and presents the results of a scoping study that was conducted to evaluate the feasibility of the proposed research

  10. Scale dependence of effective media properties

    For problems where media properties are measured at one scale and applied at another, scaling laws or models must be used in order to define effective properties at the scale of interest. The accuracy of such models will play a critical role in predicting flow and transport through the Yucca Mountain Test Site given the sensitivity of these calculations to the input property fields. Therefore, a research programhas been established to gain a fundamental understanding of how properties scale with the aim of developing and testing models that describe scaling behavior in a quantitative-manner. Scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas permeability data measured over a range of discrete scales. Also, various physical characteristics of property heterogeneity and the means by which the heterogeneity is measured and described are systematically investigated to evaluate their influence on scaling behavior. This paper summarizes the approach that isbeing taken toward this goal and presents the results of a scoping study that was conducted to evaluate the feasibility of the proposed research

  11. Scaling properties of marathon races

    Alvarez-Ramirez, Jose; Rodriguez, Eduardo

    2006-06-01

    Some regularities in popular marathon races are identified in this paper. It is found for high-performance participants (i.e., racing times in the range [2:15,3:15] h), the average velocity as a function of the marathoner's ranking behaves as a power-law, which may be suggesting the presence of critical phenomena. Elite marathoners with racing times below 2:15 h can be considered as outliers with respect to this behavior. For the main marathon pack (i.e., racing times in the range [3:00,6:00] h), the average velocity as a function of the marathoner's ranking behaves linearly. For this racing times, the interpersonal velocity, defined as the difference of velocities between consecutive runners, displays a continuum of scaling behavior ranging from uncorrelated noise for small scales to correlated 1/f-noise for large scales. It is a matter of fact that 1/f-noise is characterized by correlations extended over a wide range of scales, a clear indication of some sort of cooperative effect.

  12. The Relationship Satisfaction scale – Psychometric properties

    Espen Røysamb

    2014-12-01

    Full Text Available The aim of this study was to establish the psychometric properties of the new Relationship Satisfaction (RS scale. Two population based samples were used: The Norwegian Mother and Child Cohort Study (MoBa, N=117,178 and The Quality of Life study (N=347. Convergent and discriminant validity was investigated in relation to the Quality of Marriage Index (QMI, the Satisfaction With Life Scale (SWLS, Relationship Satisfaction of partner, Big Five personality traits (IPIP50 and future relationship dissolution. The full scale with ten items (RS10 and a short version with five items (RS5 showed good psychometric properties. The scale has high internal and test-retest reliability and high structural, convergent, and discriminant validity. Measurement invariance across gender was established. Additionally, predictive validity was evidenced by prediction of future relationship dissolution. We conclude that the RS scale is highly useful as a generic measure of global relationship satisfaction.

  13. Scaling in stratocumulus fields: an emergent property

    Yuan, Tianle

    2015-01-01

    Marine stratocumulus clouds play a critical role in the Earth's climate system. They display an amazing array of complex behaviors at many different spatiotemporal scales. Precipitation in these clouds is in general very light, but it is vital for clouds' systematic evolution and organization. Here we identify areas of high liquid water path within these clouds as potentially precipitating, or pouches. They are breeding grounds for stratocumuli to change their organization form. We show, using different satellite data sets, that the size distribution of these pouches show a universal scaling. We argue that such scaling is an emergent property of the cloud system, which results from numbers interactions at the microscopic scale.

  14. Scaling properties of European research units

    Jamtveit, Bjørn; Jettestuen, Espen; Mathiesen, Joachim

    2009-01-01

    A quantitative characterization of the scale-dependent features of research units may provide important insight into how such units are organized and how they grow. The relative importance of top-down versus bottom-up controls on their growth may be revealed by their scaling properties. Here we show that the number of support staff in Scandinavian research units, ranging in size from 20 to 7,800 staff members, is related to the number of academic staff by a power law. The scaling exponent of ...

  15. Scaling in topological properties of brain networks

    Singh, Soibam Shyamchand; Singh, Khundrakpam Budhachandra; Ishrat, Romana; Sharma, B. Indrajit; Singh, R. K. Brojen

    2015-01-01

    The organization in brain networks shows highly modular features with weak inter-modular interaction. The topology of the networks involves emergence of modules and sub-modules at different levels of constitution governed by fractal laws. The modular organization, in terms of modular mass, inter-modular, and intra-modular interaction, also obeys fractal nature. The parameters which characterize topological properties of brain networks follow one parameter scaling theory in all levels of netwo...

  16. Scale-Free Properties in Traffic System

    LI Ke-Ping

    2006-01-01

    In this work, we propose a new model of evolution networks, which is based on the evolution of the traffic flow. In our method, the network growth does not take into account preferential attachment, and the attachment of new node is independent of the degree of nodes. Our aim is that employing the theory of evolution network, we give a further understanding about the dynamical evolution of the traffic flow. We investigate the probability distributions and scaling properties of the proposed model. The simulation results indicate that in the proposed model, the distribution of the output connections can be well described by scale-free distribution. Moreover, the distribution of the connections is largely related to the traffic flow states, such as the exponential distribution (i.e., the scale-free distribution) and random distribution etc.

  17. Scaling properties of percolation models for multifragmentation

    We have used scaling properties of nuclear multifragmentation, which have been observed with emulsion data, to investigate the properties of some approaches based on percolation. We have studied different percolation models on a cubic lattice and shown that they can rather well reproduce the data except for binary break up. We have described what the mean field approximation would give in this context and showed that it cannot reproduce the experimental results. Most of the paper is focused on the restructured aggregation model introduced earlier which allows to well reproduce the scaling properties observed experimentally. This model has been studied in details and extended to take account of bonds breaking. It is shown that, in some cases, a nucleus can break up in two pieces. This process cannot be obtained in conventional percolation or aggregation but is observed experimentally in the emulsion data. Other features like the dimensionality of the aggregation model, the restructuration of the clusters and a schematic constraint in momentum space have also been investigated. (orig.)

  18. Scaling properties of percolation models for multifragmentation

    Ngo, H.; Ighezou, F.Z.; Desbois, J. (Paris-11 Univ., 91 - Orsay (France). Div. de Physique Theorique); Ngo, C.; Leray, S. (Laboratoire National Saturne, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)); Zheng, Y.M. (China Center of Advanced Science and Technology, Beijing, BJ (China) Academia Sinica, Beijing (China). Inst. of Atomic Energy)

    1990-09-01

    We have used scaling properties of nuclear multifragmentation, which have been observed with emulsion data, to investigate the properties of some approaches based on percolation. We have studied different percolation models on a cubic lattice and shown that they can rather well reproduce the data except for binary break up. We have described what the mean field approximation would give in this context and showed that it cannot reproduce the experimental results. Most of the paper is focused on the restructured aggregation model introduced earlier which allows to well reproduce the scaling properties observed experimentally. This model has been studied in details and extended to take account of bonds breaking. It is shown that, in some cases, a nucleus can break up in two pieces. This process cannot be obtained in conventional percolation or aggregation but is observed experimentally in the emulsion data. Other features like the dimensionality of the aggregation model, the restructuration of the clusters and a schematic constraint in momentum space have also been investigated. (orig.).

  19. Children's separation anxiety scale (CSAS: psychometric properties.

    Xavier Méndez

    Full Text Available This study describes the psychometric properties of the Children's Separation Anxiety Scale (CSAS, which assesses separation anxiety symptoms in childhood. Participants in Study 1 were 1,908 schoolchildren aged between 8 and 11. Exploratory factor analysis identified four factors: worry about separation, distress from separation, opposition to separation, and calm at separation, which explained 46.91% of the variance. In Study 2, 6,016 children aged 8-11 participated. The factor model in Study 1 was validated by confirmatory factor analysis. The internal consistency (α = 0.82 and temporal stability (r = 0.83 of the instrument were good. The convergent and discriminant validity were evaluated by means of correlations with other measures of separation anxiety, childhood anxiety, depression and anger. Sensitivity of the scale was 85% and its specificity, 95%. The results support the reliability and validity of the CSAS.

  20. Time-scaling properties of city fires

    Highlights: → AnShan city fire sequence is featured by mono- and multi-fractal dynamics. → The monofractal scaling exponent α ∼ 1.0 indicates high degree of time-clusterization, decreasing with the loss. → The city-fire process is highly heterogeneous. → The appearance of the daily oscillation could be connected with the daily cycle of the anthropic activity. - Abstract: Time-scaling scale-invariant approaches have been used to feature the temporal distribution of city fire sequences recorded in the city of AnShan (China). Our findings reveal that the point process of the city fires is a fractal process with a high degree of time-clusterization of the events. The time-clustering phenomenon is visible for timescales larger than few hours. Furthermore, the fire process tends to be less time-clusterized with the increase of the loss. The application of multifractal detrended fluctuation analysis to the series of city-fires has revealed that the sequence is dynamically heterogeneous due to the different long-range time correlation properties for small and large interevent fluctuations.

  1. Outflow structure within 1000 au of high-mass YSOs. I. First results from a combined study of maser and radio continuum emission

    Moscadelli, L.; Sánchez-Monge, Á.; Goddi, C.; Li, J. J.; Sanna, A.; Cesaroni, R.; Pestalozzi, M.; Molinari, S.; Reid, M. J.

    2016-01-01

    Context. In high-mass (≥7 M⊙) star formation (SF) studies, high-angular resolution is crucial for resolving individual protostellar outflows (and possibly accretion disks) from the complex contribution of nearby (high- and low-mass) young stellar objects (YSO). Previous interferometric studies have focused mainly on single objects. Aims: A sensitive survey at high angular resolution is required to investigate outflow processes in a statistically significant sample of high-mass YSOs and on spatial scales relevant to testing theories. Methods: We selected a sample of 40 high-mass YSOs from water masers observed within the BeSSeL Survey. We investigated the 3D velocity and spatial structures of the molecular component of massive outflows at milli-arcsecond angular resolution using multi-epoch Very Long Baseline Array (VLBA) observations of 22 GHz water masers. We also characterize the ionized component of the flows using deep images of the radio continuum emission with resolutions of ~0."2, at 6, 13, and 22 GHz with the Jansky Very Large Array (JVLA). Results: We report the first results obtained for a subset of 11 objects from the sample. The water maser measurements provide us with a very accurate description of the molecular gas kinematics. This in turn enables us to estimate the momentum rate of individual outflows, varying in the range 10-3-100M⊙ yr-1 km s-1, among the highest values reported in the literature. In all the observed objects, the continuum emission at 13 and 22 GHz has a compact structure, with its position coincident with that of the water masers. The 6 GHz continuum consists of either compact components (mostly well aligned with the 13 and/or 22 GHz sources) or extended emission (either highly elongated or approximately spherical), which can be offset by up to a few arcseconds from the water masers. The unresolved continuum emission associated with the water masers likely points to the YSO location. The comparison of the radio continuum

  2. Scale Invariant Properties in Heart Rate Signals

    The rate of heart beat is controlled by autonomic nervous system: accelerated by the sympathetic system and slowed by the parasympathetic system. Scaling properties in heart rate are usually related to the intrinsic dynamics of this physiological regulatory system. The two packages calculating local exponent spectra: Wavelet Transform Modulus Maxima and Multifractal Detrended Fluctuation Analysis (accessible from Physionet home page http://circ.ahajournals.org/cgi/content/full/101/23/e215) are tested, and then used to investigate the spectrum of singularity exponents in series of heart rates obtained from patients suffering from reduced left ventricle systolic function. It occurs that this state of a heart could be connected to some perturbation in the regulatory system, because the heart rate appears to be less controlled than in a healthy human heart. The multifractality in the heart rate signal is weakened: the spectrum is narrower and moved to higher values what indicate the higher activity of the sympatethic nervous system. (author)

  3. Scaling properties of paleomagnetic reversal sequence

    S. S. Ivanov

    1996-01-01

    Full Text Available The history of reversals of main geomagnetic field during last 160 My is analyzed as a sequence of events, presented as a point set on the time axis. Different techniques were applied including the method of boxcounting, dispersion counter-scaling, multifractal analysis and examination of attractor behaviour in multidimensional phase space. The existence of a crossover point at time interval 0.5-1.0 My was clearly identified, dividing the whole time range into two subranges with different scaling properties. The long-term subrange is characterized by monofractal dimension 0.88 and by an attractor, whose correlation dimension converges to 1.0, that provides evidence of a deterministic dynamical system in this subrange, similar to most existing dynamo models. In the short-term subrange the fractal dimension estimated by different methods varies from 0.47 to 0.88 and the dimensionality of the attractor is obtained to be about 3.7. These results are discussed in terms of non-linear superposition of processes in the Earth's geospheres.

  4. Scaling in topological properties of brain networks.

    Singh, Soibam Shyamchand; Khundrakpam, Budhachandra; Reid, Andrew T; Lewis, John D; Evans, Alan C; Ishrat, Romana; Sharma, B Indrajit; Singh, R K Brojen

    2016-01-01

    The organization in brain networks shows highly modular features with weak inter-modular interaction. The topology of the networks involves emergence of modules and sub-modules at different levels of constitution governed by fractal laws that are signatures of self-organization in complex networks. The modular organization, in terms of modular mass, inter-modular, and intra-modular interaction, also obeys fractal nature. The parameters which characterize topological properties of brain networks follow one parameter scaling theory in all levels of network structure, which reveals the self-similar rules governing the network structure. Further, the calculated fractal dimensions of brain networks of different species are found to decrease when one goes from lower to higher level species which implicates the more ordered and self-organized topography at higher level species. The sparsely distributed hubs in brain networks may be most influencing nodes but their absence may not cause network breakdown, and centrality parameters characterizing them also follow one parameter scaling law indicating self-similar roles of these hubs at different levels of organization in brain networks. The local-community-paradigm decomposition plot and calculated local-community-paradigm-correlation co-efficient of brain networks also shows the evidence for self-organization in these networks. PMID:27112129

  5. POLY-SCALE REFINABLE FUNCTION AND THEIR PROPERTIES

    YANG Shou-zhi

    2006-01-01

    Poly-scale refinable function with dilation factor a is introduced. The existence of solution of poly-scale refinable equation is investigated. Specially, necessary and sufficient conditions for the orthonormality of solution function φ of poly-scale refinable equation with integer dilation factor a are established. Some properties of poly-scale refinable function are discussed. Several examples illustrating how to use the method to construct poly-scale refinable function are given.

  6. Large scale properties of the Webgraph

    Donato, D.; Laura, L.; Leonardi, S.; Millozzi, S.

    2004-03-01

    In this paper we present an experimental study of the properties of web graphs. We study a large crawl from 2001 of 200M pages and about 1.4 billion edges made available by the WebBase project at Stanford[CITE]. We report our experimental findings on the topological properties of such graphs, such as the number of bipartite cores and the distribution of degree, PageRank values and strongly connected components.

  7. Electrical properties of random checkerboards at finite scales

    Bharath V. Raghavan

    2015-01-01

    Full Text Available Under investigation is the scale dependent electrical conductivity (and resistivity of two-phase random checkerboards at arbitrary volume fractions and phase contrasts. Using variational principles, rigorous mesoscale bounds are obtained on the electrical properties at finite scales by imposing a boundary condition that is either uniform electric potential or uniform current density. We demonstrate the convergence of these bounds to the effective properties with increasing length scales. This convergence gives rise to the notion of a scalar-valued scaling function that accounts for the statistical nature of the mesoscale responses. A semi-analytical closed form solution for the scaling function is obtained as a function of phase contrast, volume fraction and the mesoscale. Finally, a material scaling diagram is constructed with which the convergence to the effective properties can be assessed for any random checkerboard with arbitrary phase contrast and volume fraction.

  8. Scaling in topological properties of brain networks

    Soibam Shyamchand Singh; Budhachandra Khundrakpam; Andrew T. Reid; Lewis, John D.; Evans, Alan C.; Romana Ishrat; B. Indrajit Sharma; R K Brojen Singh

    2016-01-01

    The organization in brain networks shows highly modular features with weak inter-modular interaction. The topology of the networks involves emergence of modules and sub-modules at different levels of constitution governed by fractal laws that are signatures of self-organization in complex networks. The modular organization, in terms of modular mass, inter-modular, and intra-modular interaction, also obeys fractal nature. The parameters which characterize topological properties of brain networ...

  9. Scale-invariant properties of the APM-Stromlo survey

    Labini, F. Sylos; Montuori, M.

    1997-01-01

    We investigate the statistical properties of the APM-Stromlo redshift survey by using the concepts and methods of modern Statistical Physics. We find that galaxy distribution in this survey exhibits scale invariant properties with fractal dimension $D = 2.1 \\pm 0.1$, up to $\\sim 40 \\hmp$, i.e. the limit of its statistical validity, without any tendency towards homogenization. No intrinsic characteristic scales are definitely found in this galaxy sample. We present several tests to study the s...

  10. Psychometric properties of Frustration Discomfort Scale in a Turkish sample.

    Ozer, Bilge Uzun; Demir, Ayhan; Harrington, Neil

    2012-08-01

    The present study assessed the psychometric properties of the Frustration Discomfort Scale for Turkish college students. The Frustration Discomfort Scale (FDS), Procrastination Assessment Scale-Student, and Rosenberg Self-Esteem Scale were administered to a sample of 171 (98 women, 73 men) Turkish college students. The results of the confirmatory factor analysis yielded fit index values demonstrating viability of the four-dimensional solution as in the original. Findings also revealed that, as predicted, the Discomfort Intolerance subscale of Turkish FDS was most strongly correlated with procrastination. Overall results provided evidence for the factor validity and reliability of the Turkish version of the scale for use in a Turkish population. PMID:23045854

  11. The Chinese Mental Resilience Scale and its psychometric properties.

    Sun, Xin-Yang; Kong, Ling-Ming; Zhang, Qi-Jun; Tao, Feng-Yan; Ma, Ai-Guo; Liu, Yun; Gao, Yu-Fang; Tu, De-Hua; Bai, Xiang-Hui; Su, Wei-Ji; Wang, Li-Jie; Lu, Fang; Song, Wen-Dang; Zhang, Xin-Zhong; Meng, Xin-Zhen; Wang, Yi-Niu; Xie, Hong-Bo; Zhou, Xiao-Dong; Zhang, Li-Yi

    2016-07-01

    This study aimed to develop a Chinese Mental Resilience Scale. A total of 2500 healthy participants, in two representative samples of the Chinese population, were administered the scale. Exploratory factor analysis, confirmatory factor analysis, and correlation analysis were used to obtain the relevant coefficients and verify the reliability and validity of the scale. Five factors were extracted: willpower, family support, optimism and self-confidence, problem solving, and interpersonal interaction, plus a lying subscale, which together accounted for 54 percent of the total variance. The Chinese Mental Resilience Scale demonstrated good psychometric properties. It can be used to evaluate the mental resilience level of general Chinese population. PMID:27357924

  12. Scaling laws and properties of compositional data

    Buccianti, Antonella; Albanese, Stefano; Lima, AnnaMaria; Minolfi, Giulia; De Vivo, Benedetto

    2016-04-01

    Many random processes occur in geochemistry. Accurate predictions of the manner in which elements or chemical species interact each other are needed to construct models able to treat presence of random components. Geochemical variables actually observed are the consequence of several events, some of which may be poorly defined or imperfectly understood. Variables tend to change with time/space but, despite their complexity, may share specific common traits and it is possible to model them stochastically. Description of the frequency distribution of the geochemical abundances has been an important target of research, attracting attention for at least 100 years, starting with CLARKE (1889) and continued by GOLDSCHMIDT (1933) and WEDEPOHL (1955). However, it was AHRENS (1954a,b) who focussed on the effect of skewness distributions, for example the log-normal distribution, regarded by him as a fundamental law of geochemistry. Although modeling of frequency distributions with some probabilistic models (for example Gaussian, log-normal, Pareto) has been well discussed in several fields of application, little attention has been devoted to the features of compositional data. When compositional nature of data is taken into account, the most typical distribution models for compositions are the Dirichlet and the additive logistic normal (or normal on the simplex) (AITCHISON et al. 2003; MATEU-FIGUERAS et al. 2005; MATEU-FIGUERAS and PAWLOWSKY-GLAHN 2008; MATEU-FIGUERAS et al. 2013). As an alternative, because compositional data have to be transformed from simplex space to real space, coordinates obtained by the ilr transformation or by application of the concept of balance can be analyzed by classical methods (EGOZCUE et al. 2003). In this contribution an approach coherent with the properties of compositional information is proposed and used to investigate the shape of the frequency distribution of compositional data. The purpose is to understand data-generation processes

  13. Scale invariant cosmology II: model equations and properties

    Maeder, Andre

    2016-01-01

    We want to establish the basic properties of a scale invariant cosmology, that also accounts for the hypothesis of scale invariance of the empty space at large scales. We write the basic analytical properties of the scale invariant cosmological models. The hypothesis of scale invariance of the empty space at large scale brings interesting simplifications in the scale invariant equations for cosmology. There is one new term, depending on the scale factor of the scale invariant cosmology, that opposes to gravity and favours an accelerated expansion. We first consider a zero-density model and find an accelerated expansion, going like t square. In models with matter present, the displacements due to the new term make a significant contribution Omega_l to the energy-density of the Universe, satisfying an equation of the form Omega_m + Omega_k + Omega_l = 1. Unlike the Friedman's models, there is a whole family of flat models (k=0) with different density parameters Omega_m smaller than 1. We examine the basic relat...

  14. Does Size Really Matter? Landfill Scale Impacts on Property Values

    Lim, Jong Seok; Missios, Paul

    2005-01-01

    The economic advantage of constructing and operating large-scale landfills over small-scale landfills has been used to justify regional landfills as a solution to the municipal waste disposal problem. In addition to the dampening effects on social efforts to divert waste away from landfills, higher external costs of larger landfills may in fact offset the private cost advantages. In this study, the negative effects of a landfill that are capitalized in property values of houses located in the...

  15. Recursive graphs with small-world scale-free properties

    Comellas, Francesc; Fertin, Guillaume; Raspaud, André

    2004-03-01

    We discuss a category of graphs, recursive clique trees, which have small-world and scale-free properties and allow a fine tuning of the clustering and the power-law exponent of their discrete degree distribution. We determine relevant characteristics of those graphs: the diameter, degree distribution, and clustering parameter. The graphs have also an interesting recursive property, and generalize recent constructions with fixed degree distributions.

  16. Scaling properties of sea ice deformation during winter and summer

    Hutchings, J. K.; Heil, P.; Roberts, A.

    2009-12-01

    We investigate sea ice deformation observed with ice drifting buoy arrays during two field campaigns. Ice Station POLarstern [ISPOL], deployed in the western Weddell Sea during November 2004 to January 2005, included a study of small-scale (sub-synoptic) variability in sea ice velocity and deformation using an array of 24 buoys. Upon deployment the ISPOL buoy array measured 70 km in both zonal and meridional extent, and consisted of sub-arrays that resolved sea ice deformation on scales from 10 to 70 km. The Sea Ice Experiment: Dynamic Nature of the Arctic (SEDNA) used two nested arrays of six buoys each as a backbone for the experiment, that were deployed in late March 2007. The two arrays were circular with diameter 140 km and 20 km. ISPOL and SEDNA provide insight into the scaling properties of sea ice deformation over scales of 10 to 200 km during early Astral summer and late Boreal winter. The ISPOL and SEDNA arrays were split into sets of sub-arrays with varying length scales. We find that variance of divergence decreases as the length scale increases. The mean divergence for each length scale set follows a log-linear scaling relationship with length scale. This is an independent verification of a previous result of Marsden, Stern, Lindsay and Weiss (2004). This scaling is indicative of a fractal process. Deformation occurs at linear features (cracks, leads and ridges) in the ice pack, that are distributed with scales that range from meter to hundreds of kilometers in length. The magnitude of deformation at these linear features varies by two orders of magnitude across scales. We demonstrate that the deformation at all these scales is important in the mass balance of sea ice. Which has important implications for the design of sea ice deformation monitoring systems.

  17. Contrasting scaling properties of interglacial and glacial climates

    Shao, Zhi-Gang; Ditlevsen, Peter D.

    2016-03-01

    Understanding natural climate variability is essential for assessments of climate change. This is reflected in the scaling properties of climate records. The scaling exponents of the interglacial and the glacial climates are fundamentally different. The Holocene record is monofractal, with a scaling exponent H~0.7. On the contrary, the glacial record is multifractal, with a significantly higher scaling exponent H~1.2, indicating a longer persistence time and stronger nonlinearities in the glacial climate. The glacial climate is dominated by the strong multi-millennial Dansgaard-Oeschger (DO) events influencing the long-time correlation. However, by separately analysing the last glacial maximum lacking DO events, here we find the same scaling for that period as for the full glacial period. The unbroken scaling thus indicates that the DO events are part of the natural variability and not externally triggered. At glacial time scales, there is a scale break to a trivial scaling, contrasting the DO events from the similarly saw-tooth-shaped glacial cycles.

  18. Homework Emotion Regulation Scale: Psychometric Properties for Middle School Students

    Xu, Jianzhong; Fan, Xitao; Du, Jianxia

    2016-01-01

    The goal of the present investigation is to evaluate the psychometric properties of the Homework Emotion Regulation Scale (HERS) using 796 middle school students in China. Confirmatory factor analyses (CFAs) supported the existence of two distinct yet related subscales for the HERS: Emotion Management and Cognitive Reappraisal. Concerning the…

  19. Psychometric Properties of the Commitment to Physical Activity Scale

    DeBate, Rita DiGioacchino; Huberty, Jennifer; Pettee, Kelley

    2009-01-01

    Objective: To assess psychometric properties of the Commitment to Physical Activity Scale (CPAS). Methods: Girls in third to fifth grades (n = 932) completed the CPAS before and after a physical activity intervention. Psychometric measures included internal consistency, factor analysis, and concurrent validity. Results: Three CPAS factors emerged:…

  20. Scaling properties of crack branching and brittle fragmentation

    Uvarov S.

    2011-01-01

    Full Text Available The present study is focused on the correlation of scaling properties of crack branching and brittle fragmentation with damage accumulation and a change in the fracture mechanism. The experimental results obtained from the glass fragmentation tests indicate that the size distribution of fragments has a fractal character and is described by a power law.

  1. Scaling relations for galaxy clusters: properties and evolution

    Giodini, S; Pointecouteau, E; Ettori, S; Reiprich, T H; Hoekstra, H

    2013-01-01

    Well-calibrated scaling relations between the observable properties and the total masses of clusters of galaxies are important for understanding the physical processes that give rise to these relations. They are also a critical ingredient for studies that aim to constrain cosmological parameters using galaxy clusters. For this reason much effort has been spent during the last decade to better understand and interpret relations of the properties of the intra-cluster medium. Improved X-ray data have expanded the mass range down to galaxy groups, whereas SZ surveys have openened a new observational window on the intracluster medium. In addition,continued progress in the performance of cosmological simulations has allowed a better understanding of the physical processes and selection effects affecting the observed scaling relations. Here we review the recent literature on various scaling relations, focussing on the latest observational measurements and the progress in our understanding of the deviations from self...

  2. Scaling Properties of Force Networks for Compressed Particulate Systems

    Kovalcinova, Lenka; Kondic, Lou

    2015-01-01

    We consider, computationally and experimentally, the scaling properties of force networks in the systems of circular particles exposed to compression in two spatial dimensions. The simulations consider polydisperse and monodisperse particles, both frictional and frictionless, and in experiments we use monodisperse and bidisperse particles. While for some of the considered systems we observe consistent scaling exponents describing the behavior of the force networks, we find that this behavior is it not universal. In particular, monodisperse frictionless systems that partially crystallize under compression, show scaling properties that are significantly different compared to the other considered systems. The findings of non-universality are confirmed by explicitly computing fractal dimension for the considered systems. The results of physical experiments are consistent with the results obtained in simulations of frictional particles.

  3. Scaling properties of dislocation simulations in the similitude regime

    Dislocation systems exhibit well-known scaling properties such as the Taylor relationship between flow stress and dislocation density, and the ‘law of similitude’ linking the flow stress to the characteristic wavelength of dislocation patterns. Here, we discuss the origin of these properties, which can be related to generic invariance properties of the equations of evolution of discrete dislocation systems, and their implications for a wide class of models of dislocation microstructure evolution. We demonstrate that under certain conditions dislocation simulations carried out at different stress, dislocation density and strain rate can be considered to be equivalent, and we study the range of deformation conditions (‘similitude regime’) over which this equivalence can be expected to hold. In addition, we discuss restrictions imposed by the stated invariance properties for density-based, non-local or stochastic models of dislocation microstructure evolution, and for dislocation patterns and size effects. (paper)

  4. PROPERTIES IMPORTANT TO MIXING FOR WTP LARGE SCALE INTEGRATED TESTING

    Koopman, D.; Martino, C.; Poirier, M.

    2012-04-26

    Large Scale Integrated Testing (LSIT) is being planned by Bechtel National, Inc. to address uncertainties in the full scale mixing performance of the Hanford Waste Treatment and Immobilization Plant (WTP). Testing will use simulated waste rather than actual Hanford waste. Therefore, the use of suitable simulants is critical to achieving the goals of the test program. External review boards have raised questions regarding the overall representativeness of simulants used in previous mixing tests. Accordingly, WTP requested the Savannah River National Laboratory (SRNL) to assist with development of simulants for use in LSIT. Among the first tasks assigned to SRNL was to develop a list of waste properties that matter to pulse-jet mixer (PJM) mixing of WTP tanks. This report satisfies Commitment 5.2.3.1 of the Department of Energy Implementation Plan for Defense Nuclear Facilities Safety Board Recommendation 2010-2: physical properties important to mixing and scaling. In support of waste simulant development, the following two objectives are the focus of this report: (1) Assess physical and chemical properties important to the testing and development of mixing scaling relationships; (2) Identify the governing properties and associated ranges for LSIT to achieve the Newtonian and non-Newtonian test objectives. This includes the properties to support testing of sampling and heel management systems. The test objectives for LSIT relate to transfer and pump out of solid particles, prototypic integrated operations, sparger operation, PJM controllability, vessel level/density measurement accuracy, sampling, heel management, PJM restart, design and safety margin, Computational Fluid Dynamics (CFD) Verification and Validation (V and V) and comparison, performance testing and scaling, and high temperature operation. The slurry properties that are most important to Performance Testing and Scaling depend on the test objective and rheological classification of the slurry (i

  5. Properties Important To Mixing For WTP Large Scale Integrated Testing

    Large Scale Integrated Testing (LSIT) is being planned by Bechtel National, Inc. to address uncertainties in the full scale mixing performance of the Hanford Waste Treatment and Immobilization Plant (WTP). Testing will use simulated waste rather than actual Hanford waste. Therefore, the use of suitable simulants is critical to achieving the goals of the test program. External review boards have raised questions regarding the overall representativeness of simulants used in previous mixing tests. Accordingly, WTP requested the Savannah River National Laboratory (SRNL) to assist with development of simulants for use in LSIT. Among the first tasks assigned to SRNL was to develop a list of waste properties that matter to pulse-jet mixer (PJM) mixing of WTP tanks. This report satisfies Commitment 5.2.3.1 of the Department of Energy Implementation Plan for Defense Nuclear Facilities Safety Board Recommendation 2010-2: physical properties important to mixing and scaling. In support of waste simulant development, the following two objectives are the focus of this report: (1) Assess physical and chemical properties important to the testing and development of mixing scaling relationships; (2) Identify the governing properties and associated ranges for LSIT to achieve the Newtonian and non-Newtonian test objectives. This includes the properties to support testing of sampling and heel management systems. The test objectives for LSIT relate to transfer and pump out of solid particles, prototypic integrated operations, sparger operation, PJM controllability, vessel level/density measurement accuracy, sampling, heel management, PJM restart, design and safety margin, Computational Fluid Dynamics (CFD) Verification and Validation (V and V) and comparison, performance testing and scaling, and high temperature operation. The slurry properties that are most important to Performance Testing and Scaling depend on the test objective and rheological classification of the slurry (i

  6. Semi industrial scale RVNRL preparation, products manufacturing and properties

    Zin, Wan Manshol Bin W.

    1998-06-01

    Natural rubber latex vulcanisation by radiation aims towards the preparation of prevulcanised natural rubber latex in the name of RVNRL for use to produce chemical-free and environment-friendly latex products. Scale up RVNRL preparation is proven possible when a semi-commercial latex irradiator was commissioned in MINT in March 1996. The plant is designed to irradiate up to 6 000 cubic meters per annum of natural rubber latex. RVNRL has the required properties and successfully used on industrial scale production of quality gloves and balloons.

  7. The scaling properties of dynamical fluctuations in temporal networks

    Chi, Liping

    2015-01-01

    The factorial moments analyses are performed to study the scaling properties of the dynamical fluctuations of contacts and nodes in temporal networks based on empirical data sets. The intermittent behaviors are observed in the fluctuations for all orders of the moments. It indicates that the interaction has self-similarity structure in time interval and the fluctuations are not purely random but dynamical and correlated. The scaling exponents for contacts in Prostitution data and nodes in Conference data are very close to that for 2D Ising model undergoing a second-order phase transition.

  8. Scaling of Folding Properties in Go Models of Proteins

    Cieplak, Marek; Xuan Hoang, Trinh

    2000-01-01

    Insights about scaling of folding properties of proteins are obtained bystudying folding in heteropolymers described by Go-like Hamiltonians. Bothlattice and continuum space models are considered. In the latter case, themonomer-monomer interactions correspond to the Lennard-Jones potential.Several statistical ensembles of the two- and three-dimensional targetnative conformations are considered. Among them are maximally compactconformations which are confined to a lattice and those which are o...

  9. Psychometric Properties of the Scale for Suicide Ideation in China

    Jie ZHANG; Brown, Gregory K.

    2007-01-01

    The Chinese version of Scale for Suicide Ideation (SSI; Beck, Kovacs, & Weissman, 1979) was examined with high school students (n = 292) in rural China, Results indicated that the SSI had high internal reliability and high item-total correlations. The SSI was highly correlated with measures of trait anxiety, hopelessness, and favorable attitude towards suicide. These findings indicated that the Chinese version of the SSI has excellent psychometric properties for measuring suicidal ideation in...

  10. Universal scaling properties of extremal cohesive holographic phases

    Goutéraux, B. [Nordita, KTH Royal Institute of Technology and Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden)

    2014-01-16

    We show that strongly-coupled, translation-invariant holographic IR phases at finite density can be classified according to the scaling behaviour of the metric, the electric potential and the electric flux introducing four critical exponents, independently of the details of the setup. Solutions fall into two classes, depending on whether they break relativistic symmetry or not. The critical exponents determine key properties of these phases, like thermodynamic stability, the (ir)relevant deformations around them, the low-frequency scaling of the optical conductivity and the nature of the spectrum for electric perturbations. We also study the scaling behaviour of the electric flux through bulk minimal surfaces using the Hartnoll-Radicevic order parameter, and characterize the deviation from the Ryu-Takayanagi prescription in terms of the critical exponents.

  11. Universal scaling properties of extremal cohesive holographic phases

    We show that strongly-coupled, translation-invariant holographic IR phases at finite density can be classified according to the scaling behaviour of the metric, the electric potential and the electric flux introducing four critical exponents, independently of the details of the setup. Solutions fall into two classes, depending on whether they break relativistic symmetry or not. The critical exponents determine key properties of these phases, like thermodynamic stability, the (ir)relevant deformations around them, the low-frequency scaling of the optical conductivity and the nature of the spectrum for electric perturbations. We also study the scaling behaviour of the electric flux through bulk minimal surfaces using the Hartnoll-Radicevic order parameter, and characterize the deviation from the Ryu-Takayanagi prescription in terms of the critical exponents

  12. Scaling Properties in Time-Varying Networks with Memory

    Kim, Hyewon; Jeong, Hawoong

    2015-01-01

    The formation of network structure is influenced by individual node's activity and its memory. Usually activity can be interpreted as the inherent property of node and memory can be represented by the interaction strength among nodes. In our study, we define the activity through the appearance pattern in the time-aggregated network representation, and quantify the memory through the contact pattern of empirical temporal networks. To address the role of activity and memory in epidemics on temporal networks, we propose temporal-pattern coarsening of activity-driven growing networks with memory. In particular, we focus on the relation between coarsening time scale and spreading dynamics in the context of dynamic scaling and finite-size scaling. Finally, we discuss the universality issue of spreading dynamics on time-varying networks for various memory causality aspects.

  13. Properties of Cosmic Shock Waves in Large Scale Structure Formation

    Miniati, F; Kang, H; Jones, T W; Cen, R; Ostriker, J P; Miniati, Francesco; Ryu, Dongsu; Kang, Hyesung; Cen, Renyue; Ostriker, Jeremiah P.

    2000-01-01

    We have examined the properties of shock waves in simulations of large scale structure formation for two cosmological scenarios (a SCDM and a LCDM with Omega =1). Large-scale shocks result from accretion onto sheets, filaments and Galaxy Clusters (GCs) on a scale of circa 5 Mpc/h in both cases. Energetic motions, both residual of past accretion history and due to current asymmetric inflow along filaments, generate additional, common shocks on a scale of about 1 Mpc/h, which penetrate deep inside GCs. Also collisions between substructures inside GCs form merger shocks. Consequently, the topology of the shocks is very complex and highly connected. During cosmic evolution the comoving shock surface density decreases, reflecting the ongoing structure merger process in both scenarios. Accretion shocks have very high Mach numbers (10-10^3), when photo-heating of the pre-shock gas is not included. The typical shock speed is of order v_{sh}(z) =H(z)lambda_{NL}(z), with lambda_{NL}(z) the wavelength scale of the nonli...

  14. Psychometric properties of the Interaction on Supervised Classes Scale (ISCS

    Adrián Pastor-Barceló

    2016-06-01

    Full Text Available Purpose: This research focuses on the construction and validation of a scale designed to assess the quality of the supervised classes: Interaction on Supervised Classes Scale (ISCS. Design/methodology/approach: This is a descriptive correlational study. For the construction of the scale three phases were performed in which different experts assessed the adequacy of the items. Finally, the psychometric properties of the final version were studied in a sample of 314 consumers (69.1% women aged between 18 and 77 with an average of 39.33 years (SD=12.25. Findings: The scale presents adequate validity and reliability, being a useful tool for measuring the interaction in Supervised Classes. Research limitations/implications: The sampling, non-probabilistic or convenience, have taken the sample of a unique sports facility and the small sample size. Practical implications: The ISCS allows managers to receive better feedback, allowing them to obtain deeper insight into the quality and satisfaction of the service. According to its results, the managers may implement different strategies to improve quality in a key service within sports centers. Originality/value: For the first time the interaction between customers and between customers and employees is evaluated both inside and outside the center, a topic that had not yet been studied in the scientific literature. The scale can be applied to any type of directed activity, and will allow a greater understanding of the quality of service.

  15. Scaling Properties of Superoscillations and the Extension to Periodic Signals

    Tang, Eugene; Kempf, Achim

    2015-01-01

    Superoscillatory wave forms, i.e., waves that locally oscillate faster than their highest Fourier component, possess unusual properties that make them of great interest from quantum mechanics to signal processing. However, the more pronounced the desired superoscillatory behavior is to be, the more difficult it becomes to produce, or even only calculate, such highly fine-tuned wave forms in practice. Here, we investigate how this sensitivity to preparation errors scales for a method for constructing superoscillatory functions which is optimal in the sense that it minimizes the energetic expense. We thereby also arrive at very accurate approximations of functions which are so highly superoscillatory that they cannot be calculated numerically. We then investigate to what extent the scaling and sensitivity results for superoscillatory functions on the real line extend to the experimentally important case of superoscillatory functions that are periodic.

  16. Scaling properties of superoscillations and the extension to periodic signals

    Tang, Eugene; Garg, Lovneesh; Kempf, Achim

    2016-08-01

    Superoscillatory wave forms, i.e., waves that locally oscillate faster than their highest Fourier component, possess unusual properties that make them of great interest from quantum mechanics to signal processing. However, the more pronounced the desired superoscillatory behavior is to be, the more difficult it becomes to produce, or even only calculate, such highly fine-tuned wave forms in practice. Here, we investigate how this sensitivity to preparation errors scales for a method for constructing superoscillatory functions which is optimal in the sense that it minimizes the energetic expense. We thereby also arrive at very accurate approximations of functions which are so highly superoscillatory that they cannot be calculated numerically. We then investigate to what extent the scaling and sensitivity results for superoscillatory functions on the real line extend to the experimentally important case of superoscillatory functions that are periodic.

  17. ECG scaling properties of cardiac arrhythmias using detrended fluctuation analysis

    We applied detrended fluctuation analysis to characterize at very short time scales during episodes of cardiac arrhythmias the raw electrocardiogram (ECG) waveform, aiming to get a global insight into its dynamical behaviour in patients who experienced sudden death. We found that in 15 recordings involving different types of arrhythmias (taken from PhysioNet's Sudden Cardiac Death Holter Database), the ECG waveform, besides showing a less-random dynamics, becomes more regular during bigeminy, ventricular tachycardia or even atrial fibrillation and ventricular fibrillation. The ECG waveform scaling properties thus suggest that reduced complexity dominates the underlying mechanisms of arrhythmias. Among other explanations, this may result from shorted or restricted (i.e. less diverse) pathways of conduction of the electrical activity within ventricles

  18. Psychometric Properties of the Adolescent Sleep Hygiene Scale (ASHS)

    Storfer-Isser, A; LeBourgeois, MK; Harsh, J.; Tompsett, CJ; Redline, S.

    2013-01-01

    This study evaluated the psychometric properties of the Adolescent Sleep Hygiene Scale (ASHS), a self-report measure assessing sleep practices theoretically important for optimal sleep. Data were collected on a community sample of 514 adolescents (16-19 years; 17.7±0.4 years; 50% female) participating in the late adolescent examination of a longitudinal study on sleep and health. Self-reports of sleep hygiene and daytime sleepiness, caretaker-reports of behavior, and sleep-wake estimation on ...

  19. The psychometric properties of the Schutte emotional intelligence scale

    Cara S. Jonker; Christel Vosloo

    2008-01-01

    the objective of this study was to investigate the psychometric properties of the Schutte Emotional Intelligence Scale (SEiS). the psychometric soundness of the SEiS was tested. A cross-sectional survey design was used for this study. A sample (n = 341) was taken from Economical Science students from a higher-education institution. The results obtained using the cross-sectional design supported a six- dimensional factor structure of the SEiS. the six factors are Positive Affect, Emotion-...

  20. Psychometric Properties of the Dutch Rosenberg Self-Esteem Scale

    Erik Franck

    2008-01-01

    Full Text Available Interest in self-esteem has been fuelled by the suggestion that level of self-esteem is associated with psychological well-being. In the present study, we translated the Rosenberg Self-Esteem Scale (RSES into the Dutch language and evaluated its psychometric properties in a sample of 442 adults. The results of both exploratory and confirmatory factor analyses confirmed that a single-factor solution provides the best fit. In addition, the Dutch RSES showed high internal consistency as well as high congruent validity. Overall, these findings support the usefulness of the Dutch RSES as a measure for global self-esteem.

  1. Psychometric Properties of the Dutch Rosenberg Self-Esteem Scale

    Erik Franck; Rudi De Raedt; Catherine Barbez; Yves Rosseel

    2008-01-01

    Interest in self-esteem has been fuelled by the suggestion that level of self-esteem is associated with psychological well-being. In the present study, we translated the Rosenberg Self-Esteem Scale (RSES) into the Dutch language and evaluated its psychometric properties in a sample of 442 adults. The results of both exploratory and confirmatory factor analyses confirmed that a single-factor solution provides the best fit. In addition, the Dutch RSES showed high internal consistency as well as...

  2. Mechanical Properties of Materials with Nanometer Scale Microstructures

    William D. Nix

    2004-10-31

    We have been engaged in research on the mechanical properties of materials with nanometer-scale microstructural dimensions. Our attention has been focused on studying the mechanical properties of thin films and interfaces and very small volumes of material. Because the dimensions of thin film samples are small (typically 1 mm in thickness, or less), specialized mechanical testing techniques based on nanoindentation, microbeam bending and dynamic vibration of micromachined structures have been developed and used. Here we report briefly on some of the results we have obtained over the past three years. We also give a summary of all of the dissertations, talks and publications completed on this grant during the past 15 years.

  3. Kpc-scale Properties of Emission-line Galaxies

    Hemmati, Shoubaneh; Mobasher, Bahram; Nayyeri, Hooshang; Ferguson, Henry C; Guo, Yicheng; Koekemoer, Anton M; Koo, David C; Papovich, Casey

    2014-01-01

    We perform a detailed study of the resolved properties of emission-line galaxies at kpc-scale to investigate how small-scale and global properties of galaxies are related. 119 galaxies with high-resolution Keck/DEIMOS spectra are selected to cover a wide range in morphologies over the redshift range 0.2

  4. Matching spatial property rights fisheries with scales of fish dispersal.

    White, Crow; Costello, Christopher

    2011-03-01

    Regulation of fisheries using spatial property rights can alleviate competition for high-value patches that hinders economic efficiency in quota-based, rights-based, and open-access management programs. However, efficiency gains erode when delineation of spatial rights constitutes incomplete ownership of the resource, thereby degrading its local value and promoting overexploitation. Incomplete ownership may be particularly prevalent in the spatial management of mobile fishery species. We developed a game-theoretic bioeconomic model of spatial property rights representing territorial user rights fisheries (TURF) management of nearshore marine fish and invertebrate species with mobile adult and larval life history stages. Strategic responses by fisheries in neighboring management units result in overexploitation of the stock and reduced yields for each fishery compared with those attainable without resource mobility or with coordination or sole control in fishing effort. High dispersal potential of the larval stage, a common trait among nearshore fishery species, coupled with scaling of management units to only capture adult mobility, a common characteristic of many nearshore TURF programs, in particular substantially reduced stock levels and yields. In a case study of hypothetical TURF programs of nearshore fish and invertebrate species, management units needed to be tens of kilometers in alongshore length to minimize larval export and generate reasonable returns to fisheries. Cooperation and quota regulations represent solutions to the problem that need to be quantified in cost and integrated into the determination of the acceptability of spatial property rights management of fisheries. PMID:21563568

  5. Arecibo Multi-Epoch HI Absorption Measurements Against Pulsars: Tiny-Scale Atomic Structure

    Stanimirovic, S; Pei, Z; Tuttle, K; Green, J T

    2010-01-01

    We present results from multi-epoch neutral hydrogen (HI) absorption observations of six bright pulsars with the Arecibo telescope. Moving through the interstellar medium (ISM) with transverse velocities of 10--150 AU/yr, these pulsars have swept across 1--200 AU over the course of our experiment, allowing us to probe the existence and properties of the tiny scale atomic structure (TSAS) in the cold neutral medium (CNM). While most of the observed pulsars show no significant change in their HI absorption spectra, we have identified at least two clear TSAS-induced opacity variations in the direction of B1929+10. These observations require strong spatial inhomogeneities in either the TSAS clouds' physical properties themselves or else in the clouds' galactic distribution. While TSAS is occasionally detected on spatial scales down to 10 AU, it is too rare to be characterized by a spectrum of turbulent CNM fluctuations on scales of 10-1000 AU, as previously suggested by some work. In the direction of B1929+10, an...

  6. Scaling properties of phase-change line memory

    Du Xiao-Feng; Song San-Nian; Song Zhi-Tang; Liu Wei-Li; Lü Shi-Long; Gu Yi-Feng; Xue Wei-Jia; Xi Wei

    2012-01-01

    Phase-change line memory cells with different line widths are fabricated using focused-ion-beam deposited C-Pt as a hard mask.The electrical performance of these memory devices was characterized.The current-voltage (I-V) and resistance-voltage (R-V) characteristics demonstrate that the power consumption decreases with the width of the phase-change line.A three-dimensional simulation is carried out to further study the scaling properties of the phase-change line memory.The results show that the resistive amorphous (RESET) power consumption is proportional to the cross-sectional area of the phase-change line,but increases as the line length decreases.

  7. The psychometric properties of the Schutte Emotional Intelligence Scale

    Cara S. Jonker

    2008-11-01

    Full Text Available the objective of this study was to investigate the psychometric properties of the Schutte Emotional Intelligence Scale (SEiS. the psychometric soundness of the SEiS was tested. A cross-sectional survey design was used for this study. A sample (n = 341 was taken from Economical Science students from a higher-education institution. The results obtained using the cross-sectional design supported a six- dimensional factor structure of the SEiS. the six factors are Positive Affect, Emotion-Others, happy Emotions, Emotions-Own, Non-verbal Emotions and Emotional Management. A multi-analysis of variance (MANOVA was used to determine differences in terms of biographical data. the results indicated signifcant differences between gender and language groups.

  8. Multiwavelength and parsec-scale properties of extragalactic jets

    Cornelia, Müller

    2016-01-01

    Extragalactic jets originating from the central supermassive black holes of active galaxies are powerful, highly relativistic plasma outflows, emitting light from the radio up to the gamma-ray regime. The details of their formation, composition and emission mechanisms are still not completely clear. The combination of high-resolution observations using very long baseline interferometry (VLBI) and multiwavelength monitoring provides the best insight into these objects. Here, such a combined study of sources of the TANAMI sample is presented, investigating the parsec-scale and high-energy properties. The TANAMI program is a multiwavelength monitoring program of a sample of the radio and gamma-ray brightest extragalactic jets in the southern sky, below -30deg declination. We obtain the first-ever VLBI images for most of the sources, providing crucial information on the jet kinematics and brightness distribution at milliarcsecond resolution. Two particular sources are discussed in detail: PMN J1603-4904, which ca...

  9. Synthetic melanin films: Assembling mechanisms, scaling behavior, and structural properties

    Lorite, Gabriela S.; Coluci, Vitor R.; da Silva, Maria Ivonete N.; Dezidério, Shirlei N.; Graeff, Carlos Frederico O.; Galva~O, Douglas S.; Cotta, Mônica A.

    2006-06-01

    In this work we report on the surface characterization of melanin thin films prepared using both water-based and organic solvent-based melanin syntheses. Atomic force microscopy (AFM) analysis of these films suggests that the organic solvent synthesis provides relatively planar basic melanin structures; these basic structures generate surface steps with height in the range of 2-3 nm and small tendency to form larger aggregates. The scaling properties obtained from the AFM data were used to infer the assembling mechanisms of these thin films which depend on the solvent used for melanin synthesis. The behavior observed in organic solvent-based melanin suggests a diffusion-limited aggregation process. Thus films with good adhesion to the substrate and smoother morphologies than water-prepared melanin films are obtained. Electronic structure calculations using a conductorlike screening model were also performed in order to elucidate the microscopic processes of thin film formation. Our results suggest that the agglomerates observed in hydrated samples originate from reaction with water at specific locations on the surface most likely defects on the planar structure.

  10. Weighted Scale-Free Network Properties of Ecological Network

    We investigate the scale-free network properties of the bipartite ecological network, in particular, the plant-pollinator network. In plant-pollinator network, the pollinators visit the plant to get the nectars. In contrast to the other complex network, the plant-pollinator network has not only the trophic relationships among the interacting partners but also the complexities of the coevolutionary effects. The interactions between the plant and pollinators are beneficial relations. The plant-pollinator network is a bipartite and weighted network. The networks have two types of the nodes: plant and pollinator. We consider the visiting frequency of a pollinator to a plant as the weighting value of the link. We defined the strength of a node as the sum of the weighting value of the links. We reported the cumulative distribution function (CDF) of the degree and the strength of the plant-pollinator network. The CDF of the plants followed stretched exponential functions for both degree and strength, but the CDF of the pollinators showed the power law for both degree and strength. The average strength of the links showed the nonlinear dependence on the degree of the networks.

  11. What exactly are the properties of scale-free and other networks?

    Judd, Kevin; Small, Michael; Stemler, Thomas

    2013-01-01

    The concept of scale-free networks has been widely applied across natural and physical sciences. Many claims are made about the properties of these networks, even though the concept of scale-free is often vaguely defined. We present tools and procedures to analyse the statistical properties of networks defined by arbitrary degree distributions and other constraints. Doing so reveals the highly likely properties, and some unrecognised richness, of scale-free networks, and casts doubt on some p...

  12. Scaling soil hydraulic properties: concepts and a research example

    Scale issues remain central to hydrological science, and targeted land management decisions depend on predictions of space-time process interactions in complex terrain. Spatial variability in soils above the measurement scale must be quantified and typically scaled up to determine “effective” hydrau...

  13. Calculation of large scale relative permeabilities from stochastic properties of the permeability field and fluid properties

    Lenormand, R.; Thiele, M.R. [Institut Francais du Petrole, Rueil Malmaison (France)

    1997-08-01

    The paper describes the method and presents preliminary results for the calculation of homogenized relative permeabilities using stochastic properties of the permeability field. In heterogeneous media, the spreading of an injected fluid is mainly sue to the permeability heterogeneity and viscosity fingering. At large scale, when the heterogeneous medium is replaced by a homogeneous one, we need to introduce a homogenized (or pseudo) relative permeability to obtain the same spreading. Generally, is derived by using fine-grid numerical simulations (Kyte and Berry). However, this operation is time consuming and cannot be performed for all the meshes of the reservoir. We propose an alternate method which uses the information given by the stochastic properties of the field without any numerical simulation. The method is based on recent developments on homogenized transport equations (the {open_quotes}MHD{close_quotes} equation, Lenormand SPE 30797). The MHD equation accounts for the three basic mechanisms of spreading of the injected fluid: (1) Dispersive spreading due to small scale randomness, characterized by a macrodispersion coefficient D. (2) Convective spreading due to large scale heterogeneities (layers) characterized by a heterogeneity factor H. (3) Viscous fingering characterized by an apparent viscosity ration M. In the paper, we first derive the parameters D and H as functions of variance and correlation length of the permeability field. The results are shown to be in good agreement with fine-grid simulations. The are then derived a function of D, H and M. The main result is that this approach lead to a time dependent . Finally, the calculated are compared to the values derived by history matching using fine-grid numerical simulations.

  14. USING ENSEMBLE PREDICTIONS TO SIMULATE FIELD-SCALE SOIL WATER TIME SERIES WITH UPSCALED AND DOWNSCALED SOIL HYDRAULIC PROPERTIES

    Simulations of soil water flow require measurements of soil hydraulic properties which are particularly difficult at field scale. Laboratory measurements provide hydraulic properties at scales finer than the field scale, whereas pedotransfer functions (PTFs) integrate information on hydraulic prope...

  15. Fixed point SU(3) gauge actions: scaling properties and glueballs

    We present a new parametrization of a SU(3) fixed point (FP) gauge action using smeared ('fat') gauge links. We report on the scaling behaviour of the FP action on coarse lattices by means of the static quark-antiquark potential, the hadronic scale r0, the string tension σ and the critical temperature Tc of the deconfining phase transition. In addition, we investigate the low lying glueball masses where we observe no scaling violations within the statistical errors

  16. Serbian translation of the 20-item toronto alexithymia scale: Psychometric properties and the new methodological approach in translating scales

    Trajanović Nikola N.

    2013-01-01

    Full Text Available Introduction. Since inception of the alexithymia construct in 1970’s, there has been a continuous effort to improve both its theoretical postulates and the clinical utility through development, standardization and validation of assessment scales. Objective. The aim of this study was to validate the Serbian translation of the 20-item Toronto Alexithymia Scale (TAS-20 and to propose a new method of translation of scales with a property of temporal stability. Methods. The scale was expertly translated by bilingual medical professionals and a linguist, and given to a sample of bilingual participants from the general population who completed both the English and the Serbian version of the scale one week apart. Results. The findings showed that the Serbian version of the TAS-20 had a good internal consistency reliability regarding total scale (α=0.86, and acceptable reliability of the three factors (α=0.71-0.79. Conclusion. The analysis confirmed the validity and consistency of the Serbian translation of the scale, with observed weakness of the factorial structure consistent with studies in other languages. The results also showed that the method of utilizing a self-control bilingual subject is a useful alternative to the back-translation method, particularly in cases of linguistically and structurally sensitive scales, or in cases where a larger sample is not available. This method, dubbed as ‘forth-translation’, could be used to translate psychometric scales measuring properties which have temporal stability over the period of at least several weeks.

  17. The Alzheimer's Disease Knowledge Scale: Development and Psychometric Properties

    Carpenter, Brian D.; Balsis, Steve; Otilingam, Poorni G.; Hanson, Priya K.; Gatz, Margaret

    2009-01-01

    Purpose: This study provides preliminary evidence for the acceptability, reliability, and validity of the new Alzheimer's Disease Knowledge Scale (ADKS), a content and psychometric update to the Alzheimer's Disease Knowledge Test. Design and Methods: Traditional scale development methods were used to generate items and evaluate their psychometric…

  18. Multiscale properties of DNA primary structure: cross-scale correlations

    Cross-scale correlations of wavelet coefficients of the DNA coding sequences are calculated and compared to that of the generated random sequence of the same length. The coding sequences are shown to have strong correlation between large and small scale structures, while random sequences have not

  19. Laboratory investigation of constitutive property up-scaling in volcanic tuffs

    Tidwell, V.C. [Sandia National Labs., Albuquerque, NM (United States). Geohydrology Dept.

    1996-08-01

    One of the critical issues facing the Yucca Mountain site characterization and performance assessment programs is the manner in which property up-scaling is addressed. Property up-scaling becomes an issue whenever heterogeneous media properties are measured at one scale but applied at another. A research program has been established to challenge current understanding of property up-scaling with the aim of developing and testing improved models that describe up-scaling behavior in a quantitative manner. Up-scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas-permeability data measured over a range of discrete scales. To date, up-scaling studies have been performed on a series of tuff and sandstone (used as experimental controls) blocks. Samples include a welded, anisotropic tuff (Tiva Canyon Member of the Paintbrush Tuff, upper cliff microstratigraphic unit), and a moderately welded tuff (Tiva Canyon Member of the Paintbrush Tuff, Caprock microstratigraphic unit). A massive fluvial sandstone (Berea Sandstone) was also investigated as a means of evaluating the experimental program and to provide a point of comparison for the tuff data. Because unsaturated flow is of prime interest to the Yucca Mountain Program, scoping studies aimed at investigating the up-scaling of hydraulic properties under various saturated conditions were performed to compliment these studies of intrinsic permeability. These studies focused on matrix sorptivity, a constitutive property quantifying the capillarity of a porous medium. 113 refs.

  20. Laboratory investigation of constitutive property up-scaling in volcanic tuffs

    One of the critical issues facing the Yucca Mountain site characterization and performance assessment programs is the manner in which property up-scaling is addressed. Property up-scaling becomes an issue whenever heterogeneous media properties are measured at one scale but applied at another. A research program has been established to challenge current understanding of property up-scaling with the aim of developing and testing improved models that describe up-scaling behavior in a quantitative manner. Up-scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas-permeability data measured over a range of discrete scales. To date, up-scaling studies have been performed on a series of tuff and sandstone (used as experimental controls) blocks. Samples include a welded, anisotropic tuff (Tiva Canyon Member of the Paintbrush Tuff, upper cliff microstratigraphic unit), and a moderately welded tuff (Tiva Canyon Member of the Paintbrush Tuff, Caprock microstratigraphic unit). A massive fluvial sandstone (Berea Sandstone) was also investigated as a means of evaluating the experimental program and to provide a point of comparison for the tuff data. Because unsaturated flow is of prime interest to the Yucca Mountain Program, scoping studies aimed at investigating the up-scaling of hydraulic properties under various saturated conditions were performed to compliment these studies of intrinsic permeability. These studies focused on matrix sorptivity, a constitutive property quantifying the capillarity of a porous medium. 113 refs

  1. Scale invariant alternatives to General Relativity II: Dilaton properties

    Karananas, Georgios K

    2016-01-01

    In the present paper we revisit gravitational theories which are invariant under TDiffs - transverse (volume preserving) diffeomorphisms and global scale transformations. It is known that these theories can be rewritten in an equivalent diffeomorphism-invariant form with an action including an integration constant (cosmological constant for the particular case of non scale-invariant unimodular gravity). The presence of this integration constant, in general, breaks explicitly scale invariance and induces a run-away potential for (otherwise massless) dilaton, associated with the determinant of the metric tensor. We show, however, that if the metric carries mass dimension $\\left[\\text{GeV}\\right]^{-2}$, the scale invariance of the system is preserved, unlike the situation in theories in which the metric has mass dimension different from $-2$. The dilaton remains massless and couples to other fields only through derivatives, without any conflict with observations. We observe that one can define a specific limit f...

  2. Scaling properties of image textures: A detrending fluctuation analysis approach

    Alvarez-Ramirez, Jose; Rodriguez, Eduardo; Cervantes, Ilse; Carlos Echeverria, Juan

    2006-03-01

    The aim of this paper is to explore the application of detrended fluctuation analysis (DFA) to study roughness features of images. Unidimensional sequences at different image orientations are extracted and their average scaling exponent is estimated. In this form, the existence of anisotropies can be detected when considerable variations in the scaling exponent at different image orientation are observed. Different images from grass to solar granulation are analyzed and the underlying physics of such results is briefly commented.

  3. The Determination Of Scaling Factor of Clay Properties

    Agus Sulaeman

    2015-05-01

    Full Text Available The observations and tests under small scale in 1-gravity condition is intended to obtain a comparative behavior of model and prototype of geotechnical case by imposing the scaling relations. Simulation to represent related structure, sub-soil and failure mechanism need to be prepared prior to do observations in this modelling. To obtain the new parameter for sub-soil simulation and inter-dependency with scaling relationship, the  ten samples with different water content of prototype clay soil were consolidated in the triaxial CU test.  After consolidation, each sample were given the arbitrarily initial mean stress po =1/3 (σ1+σ2+σ3 at the same time each corresponding void ratio were recorded. The data was plotted and numbered in the e Ln p’ axises to adopt critical state line concept. Further shear stage in triaxial CU test were done to record the stress and strain of each ten samples. Among those of ten stress strain curves there were 3 similar curves (1, 6 and 8 observed when the deviatoric stress was normalized with its po, this showed similar behavior among them. The further observation revealed that void ratio in the clay soil no. 8 (ep corresponded with void ratio of the sample no. 1 (em, stress ratio N and critical state line parameter l in the form of  em= ep+ l Ln N. To support the expression of  em= ep+ l Ln N,  The “pile loading test” case was prepared in small scale and full scale modeling, em   represented void ratio of clay in small scale and ep represented void ratio of clay at original project location. Load settlement curves were obtained from both “pile loading test” in small and full scale simulation and the result showed closely good agreement.

  4. Assessment of heterogeneous hydraulic properties in natural aquifers at the intermediate scale

    Zovi, Francesco

    2014-01-01

    One of the most relevant issues in groundwater hydrology is the assessment of heterogeneous hydraulic properties of natural aquifers at the intermediate scale. The intermediate scale includes, as a general definition, aquifers characterized by a ratio L/B, L being a linear measure of the horizontal extent, and B the average thickness, between one (local scale) and approximately one thousand (regional scale). In Italy groundwater represents almost eighty percent of drinkable water supply, ther...

  5. Returns-to-scale properties in DEA models: The fundmantal role of interior points

    Krivonozhko, Vladimir; Førsund, Finn R.

    2009-01-01

    Attempts can be found in the DEA literature to identify returns to scale at efficient interior points of the production possibility set on the basis of returns to scale at points of the corresponding reference sets. However, an opposite approach is put forward in this paper, advocating that returns-to-scale properties of efficient reference units should be found by identifying first returns to scale of an efficient interior unit that is a radial projection to the frontier of an inefficient un...

  6. Returms-to-scale Properties in DEA Models: The Fundamental Role of Interior Points

    Krivonozhko, Vladimir; Førsund, Finn R.

    2009-01-01

    Attempts can be found in the DEA literature to identify returns to scale at efficient interior points of the production possibility set on the basis of returns to scale at points of the corresponding reference sets. However, an opposite approach is put forward in this paper, advocating that returns-to-scale properties of efficient reference units should be found by identifying first returns to scale of an efficient interior unit that is a radial projection to the frontier of an inefficient un...

  7. Stroke detection based on the scaling properties of human EEG

    Hwa, Rudolph C.; Ferree, Thomas C.

    2004-07-01

    We propose a new method of detecting stroke by use of electroencephalogram (EEG) time series. When detrended fluctuation analysis is applied to the data, it is found that there exist two scaling regions for every channel. Thus with the geodesic sensor nets used there are as many as 128 paris of scaling exponents for each subject. We then determine a stroke index S that is based on the normalized variances of those scaling exponents. It is shown that S=1.3 distinctly separates the 28 normal and stroke subjects we have studied. We also show that the effect of stroke on EEG signals is global, in contrast to the local effect revealed by radiological studies such as MRI.

  8. Power Moments and Scaling Properties of Nuclear Emulsion Data

    Lee, S J

    1994-01-01

    Various features of the charge yield in heavy ion collisions are studied. Considered here are the nuclear emulsion data of $^{84}$Kr, $^{131}$Xe, $^{197}$Au, $^{238}$U in the energy range of 1 GeV/A. Mean charge yields and multiplicity distribution of these data indicate that the nuclear fragmentation at this energy is a multiprocess phenomena. Power moments of the charge distribution exhibit a scale invariance. While small nuclei (Kr and Xe) show a nuclear size dependence, large nuclei (Au and U) exhibit scale independence in their charge distribution.

  9. Psychometric Properties of a Social Abilities Evaluation Scale: C-scale

    María José Rabazo Méndez

    2004-11-01

    Full Text Available In this paper the psychometric data of a scale of evaluation of the social abilities (social expression and motor skills are presented. The scale was constructed to investigate social competence and antisocial conduct in adolescence. The process of the scale’s construction is explained; and the data on its internal consistency, its test-retest reliability, and its concurrent validity are presented. The scale was filled out by 325 teachers from different schools in the city of Badajoz (Spain; however, 20 scales were rejected because they were not properly completed. As well, the scale was analyzed, giving as a result 9 factors that explain 59.4% of the total variance. With the results obtained, the position of situational specificity with regard to social abilities is supported.

  10. Scale-invariant alternatives to general relativity. II. Dilaton properties

    Karananas, Georgios K.; Shaposhnikov, Mikhail

    2016-04-01

    In the present paper, we revisit gravitational theories which are invariant under TDiffs—transverse (volume-preserving) diffeomorphisms and global scale transformations. It is known that these theories can be rewritten in an equivalent diffeomorphism-invariant form with an action including an integration constant (cosmological constant for the particular case of non-scale-invariant unimodular gravity). The presence of this integration constant, in general, breaks explicitly scale invariance and induces a runaway potential for the (otherwise massless) dilaton, associated with the determinant of the metric tensor. We show, however, that if the metric carries mass dimension [GeV] -2 , the scale invariance of the system is preserved, unlike the situation in theories in which the metric has mass dimension different from -2 . The dilaton remains massless and couples to other fields only through derivatives, without any conflict with observations. We observe that one can define a specific limit for fields and their derivatives (in particular, the dilaton goes to zero, potentially related to the small distance domain of the theory) in which the only singular terms in the action correspond to the Higgs mass and the cosmological constant. We speculate that the self-consistency of the theory may require the regularity of the action, leading to the absence of the bare Higgs mass and cosmological constant, whereas their small finite values may be generated by nonperturbative effects.

  11. Development and Psychometric Properties Gender Roles Attitude Scale

    Zeyneloglu, Simge; Terzioglu, Fusun

    2011-01-01

    This research was conducted for the purpose of developing a scaling tool to determine university students' attitudes towards gender roles. University students' attitudes should first be determined in order to change this traditional view to gender and to achieve a more egalitarian view. The research sample was comprised of one university's…

  12. Scaling properties of ionospheric, solar, and geomagnetic data

    Mošna, Zbyšek

    Magurele : Institute of Space Science, 2015. s. 51. [International Workshop and School on solar system plasma turbulence, intermittency and multifractals (STORM 2015). 06.09.2015-13.09.2015, Mamaia] Institutional support: RVO:68378289 Keywords : Scaling analysis * ionosphere * solar and geomagnetic activity Subject RIV: DG - Athmosphere Sciences, Meteorology http://www. space science.ro/conferences/storm2015/storm2015_book.pdf

  13. Fundamental scaling properties of electro-mechanical switches

    We discuss the fundamental processes including electron conduction and adhesion of metallic contacts pertaining to the scaling of the performance metrics of nano-electro-mechanical switches. In particular, we show that under most circumstances, the switching energy is governed by the force that is needed in order to break the electrical contact when opening the switch. For an optimally designed parallel plate capacitor switch, the energy consumption does not depend on the actuation voltage. However, stray capacitances degrade the energy efficiency if a high operating voltage is chosen. The limit is of the order of 1 V for an aggressively scaled Si device, for which an overall switching energy of the order of 150 eV, a footprint area of 2500 nm2 and a switching time of 200 ps are predicted. The scaling analysis also stipulates that materials with a low free electron density and high effective mass should be used for the electrical contact, which is counter-intuitive, as such materials are known to be poor conductors on the macroscopic scale. (paper)

  14. Psychometric properties of the Swedish version of the Resilience Scale.

    Lundman, Berit; Strandberg, Gunilla; Eisemann, Martin; Gustafson, Yngve; Brulin, Christine

    2007-06-01

    The aim of this study was to investigate resilience in relation to age and gender, and to elucidate the underlying structure of the Swedish version of the Resilience Scale (RS). The RS, originally created by Wagnild and Young is a 25 items scale of Lickert type with possible scores ranges from 25 to 175, the higher the score, the stronger resilience. A standardized procedure was used for translation. The analysis was based on 1719 participants, 1248 women and 471 men, from eight different samples, aged from 19 to 103 years. We found that the participants estimated their resilience as relatively high. There was a significant relationship between age and resilience, for every year RS score increased with 0.134 units. There was no relation between gender and resilience. From a factor analyses five factors emerged, equanimity, meaningfulness, perseverance, existential aloneness and self-reliance reflecting the five dimensions described by Wagnild and Young. We concluded that the resilience is related to age, the older, the stronger resilience. Five underlying dimensions was identified, which can be seen as reflection of the theoretical assumptions behind the RS scale. The RS scale seems applicable to a Swedish population. PMID:17559442

  15. Psychometric properties of the Social Comparison Motives Scale.

    Tigges, Beth Baldwin

    2009-01-01

    This article describes the 19-item Social Comparison Motive Scale [SCMS], a measure of adolescents' motives for social comparison related to pregnancy. Dimensions and items were developed based on adolescent focus groups. The instrument was reviewed for content validity, pilot tested, and administered to 431 adolescents aged 14-18 years. Principal axis factor analysis with oblique rotation supported five dimensions. Convergent and discriminant validity were demonstrated by moderate correlations (r = .50) between the SCMS and the Iowa-Netherlands Comparison Orientation Measure and low correlations (r = .15) between the SCMS and the Rosenberg Self-Esteem Scale. Cronbach's alphas were .91 overall and .71 to .85 for the subscales. The SCMS demonstrated reliability and validity as a measure of adolescents' motives for comparing themselves with others about pregnancy. PMID:19902658

  16. Approximate scaling properties of RNA free energy landscapes

    Baskaran, S.; Stadler, P. F.; Schuster, P.

    1996-01-01

    RNA free energy landscapes are analysed by means of "time-series" that are obtained from random walks restricted to excursion sets. The power spectra, the scaling of the jump size distribution, and the scaling of the curve length measured with different yard stick lengths are used to describe the structure of these "time series". Although they are stationary by construction, we find that their local behavior is consistent with both AR(1) and self-affine processes. Random walks confined to excursion sets (i.e., with the restriction that the fitness value exceeds a certain threshold at each step) exhibit essentially the same statistics as free random walks. We find that an AR(1) time series is in general approximately self-affine on timescales up to approximately the correlation length. We present an empirical relation between the correlation parameter rho of the AR(1) model and the exponents characterizing self-affinity.

  17. Properties of Brownian Image Models in Scale-Space

    Pedersen, Kim Steenstrup

    2003-01-01

    law that apparently governs natural images. Furthermore, the distribution of Brownian images mapped into jet space is Gaussian and an analytical expression can be derived for the covariance matrix of Brownian images in jet space. This matrix is also a good approximation of the covariance matrix...... Brownian images) will be discussed in relation to linear scale-space theory, and it will be shown empirically that the second order statistics of natural images mapped into jet space may, within some scale interval, be modeled by the Brownian image model. This is consistent with the 1/f 2 power spectrum...... of natural images in jet space. The consequence of these results is that the Brownian image model can be used as a least committed model of the covariance structure of the distribution of natural images....

  18. LCAO approximation for scaling properties of the Menger sponge fractal.

    Sakoda, Kazuaki

    2006-11-13

    The electromagnetic eigenmodes of a three-dimensional fractal called the Menger sponge were analyzed by the LCAO (linear combination of atomic orbitals) approximation and a first-principle calculation based on the FDTD (finite-difference time-domain) method. Due to the localized nature of the eigenmodes, the LCAO approximation gives a good guiding principle to find scaled eigenfunctions and to observe the approximate self-similarity in the spectrum of the localized eigenmodes. PMID:19529555

  19. Density scaling as a property of strongly correlating viscous liquids

    Schrøder, Thomas; Pedersen, Ulf Rørbæk; Bailey, Nicholas; Toxværd, Søren; Dyre, J.C.

    2008-01-01

    Results from molecular dynamics simulations of two viscous molecular model liquids -- the Lewis-Wahnstrom model of ortho-terphenyl and an asymmetric dumbbell model -- are reported. We demonstrate that the liquids have a ``hidden'' approximate scale invariance: Equilibrium potential energy fluctuations are accurately described by inverse power law (IPL) potentials, the radial distribution functions are accurately reproduced by the IPL's, and the radial distribution functions obey the IPL predi...

  20. Characteristic Length Scale of Electric Transport Properties of Genomes

    Shih, C T

    2005-01-01

    A tight-binding model together with a novel statistical method are used to investigate the relation between the sequence-dependent electric transport properties and the sequences of protein-coding regions of complete genomes. A correlation parameter $\\Omega$ is defined to analyze the relation. For some particular propagation length $w_{max}$, the transport behaviors of the coding and non-coding sequences are very different and the correlation reaches its maximal value $\\Omega_{max}$. $w_{max}$ and \\omax are characteristic values for each species. The possible reason of the difference between the features of transport properties in the coding and non-coding regions is the mechanism of DNA damage repair processes together with the natural selection.

  1. Scale-by-scale analysis of probability distributions for global MODIS-AQUA cloud properties: how the large scale signature of turbulence may impact statistical analyses of clouds

    M. de la Torre Juárez

    2011-03-01

    Full Text Available Means, standard deviations, homogeneity parameters used in models based on their ratio, and the probability distribution functions (PDFs of cloud properties from the MODerate resolution Infrared Spectrometer (MODIS are estimated globally as function of averaging scale varying from 5 to 500 km. The properties – cloud fraction, droplet effective radius, and liquid water path – all matter for cloud-climate uncertainty quantification and reduction efforts. Global means and standard deviations are confirmed to change with scale. For the range of scales considered, global means vary only within 3% for cloud fraction, 7% for liquid water path, and 0.2% for cloud particle effective radius. These scale dependences contribute to the uncertainties in their global budgets. Scale dependence for standard deviations and generalized flatness are compared to predictions for turbulent systems. Analytical expressions are identified that fit best to each observed PDF. While the best analytical PDF fit to each variable differs, all PDFs are well described by log-normal PDFs when the mean is normalized by the standard deviation inside each averaging domain. Importantly, log-normal distributions yield significantly better fits to the observations than gaussians at all scales. This suggests a possible approach for both sub-grid and unified stochastic modeling of these variables at all scales. The results also highlight the need to establish an adequate spatial resolution for two-stream radiative studies of cloud-climate interactions.

  2. Properties of large-scale methane/hydrogen jet fires

    A future economy based on reduction of carbon-based fuels for power generation and transportation may consider hydrogen as possible energy carrier Extensive and widespread use of hydrogen might require a pipeline network. The alternatives might be the use of the existing natural gas network or to design a dedicated network. Whatever the solution, mixing hydrogen with natural gas will modify the consequences of accidents, substantially The French National Research Agency (ANR) funded project called HYDROMEL focuses on these critical questions Within this project large-scale jet fires have been studied experimentally and numerically The main characteristics of these flames including visible length, radiation fluxes and blowout have been assessed. (authors)

  3. Dimensional scaling effects on transport properties of ultrathin body p-i-n diodes

    Rajasekharan, B.; van der Salm, C.; Hueting, R.J.E.; Hoang, Van T.; Schmitz, J.

    2008-01-01

    Device scaling has been a subject of research for both optoelectronics and electronics. In order to investigate the electronic properties of scaled devices we studied lateral p-i-n structures using thin silicon on insulator (SOI) or poly-Si layers of varying dimension. With the help of these structures we try to explain the size dependencies on electronic transport properties. Further, we also propose a new device concept called charge plasma diode.

  4. The effects of scales, flows and filters on property rights and collective action in watershed management:

    Swallow, Brent M.; Garrity, Dennis P.; van Noordwijk, Meine

    2001-01-01

    Research and policy on property rights, collective action and watershed management requires good understanding of ecological and socio-political processes at different social-spatial scales. On-farm soil erosion is a plot or farm-level problem that can be mitigated through more secure property rights for individual farmers, while the sedimentation of streams and deterioration of water quality are larger-scale problems that may require more effective collective action and / or more secure prop...

  5. Bibliometric statistical properties of the 100 largest European universities: prevalent scaling rules in the science system

    van Raan, Anthony F. J.

    2007-01-01

    For the 100 largest European universities we studied the statistical properties of bibliometric indicators related to research performance, field citation density and journal impact. We find a size-dependent cumulative advantage for the impact of universities in terms of total number of citations. In previous work a similar scaling rule was found at the level of research groups. Therefore we conjecture that this scaling rule is a prevalent property of the science system. We observe that lower...

  6. The attitudes toward transgendered individuals scale: psychometric properties.

    Walch, Susan E; Ngamake, Sakkaphat T; Francisco, Jacquelyn; Stitt, Rashunda L; Shingler, Kimberly A

    2012-10-01

    Gay, lesbian, bisexual, and transgendered individuals are sexual and gender minorities subject to stigma in a heteronormative culture with binary gender role norms. Although much research has examined sexual stigma in the form of homophobia, or negative attitudes and reactions to homosexuals and homosexuality, little is known about the stigma experienced by transgendered individuals. Transgendered people are those whose gender identity (sense of oneself as a man or a woman) or gender expression (expression of oneself as a man or a woman in behavior, manner, and/or dress) differ from conventional expectations for their physical sex. Although a scale exists to measure transphobia or negative attitudes and reactions to transgendered individuals, it includes items tapping into overt behavioral expression of this stigma, or gender-bashing, and fails to identify or define transgendered persons as the attitudinal target of the items. A new scale was developed and evaluated in an effort to assess transgender-related stigma, separately from discrimination and violence, among members of the general population. Using two separate samples of college students ranging in age from 18-64 years, exploratory (N = 134) and confirmatory factor analyses (N = 237) were performed. The resulting 20-item, self-report measure demonstrated a single-factor structure, high internal consistency reliability, and evidence of convergent and discriminant construct validity. PMID:22810996

  7. Soil properties and preferential solute transport at the field scale

    Koestel, J K; Minh, Luong Nhat; Nørgaard, Trine;

    An important fraction of water flow and solute transport through soil takes place through preferential flow paths. Although this had been already observed in the nineteenth century, it had been forgotten by the scientific community until it was rediscovered during the 1970s. The awareness of the...... relevance of preferential flow was broadly re-established in the community by the early 1990s. However, since then, the notion remains widespread among soil scientists that the occurrence and strength of preferential flow cannot be predicted from measurable proxy variables such as soil properties or land...

  8. The Severe Sexual Sadism Scale: Cross-Validation and Scale Properties

    Mokros, Andreas; Schilling, Frank; Eher, Reinhard; Nitschke, Joachim

    2012-01-01

    The Severe Sexual Sadism Scale (SSSS) is a screening device for the file-based assessment of forensically relevant sexual sadism. The SSSS consists of 11 dichotomous (yes/no) items that code behavioral indicators of severe sexual sadism within sexual offenses. Based on an Austrian sample of 105 sexual offenders, the present study replicated the…

  9. Rating scale analysis and psychometric properties of the Caregiver Self-Efficacy Scale for Transfers

    Cipriani, D.J.; Hensen, Fenna; McPeck, D.L.; Kubec, G.L.; Thomas, J.J.

    2012-01-01

    Parents and caregivers faced with the challenges of transferring children with disability are at risk of musculoskeletal injuries and/or emotional stress. The Caregiver Self-Efficacy Scale for Transfers (CSEST) is a 14-item questionnaire that measures self-efficacy for transferring under common cond

  10. Psychometric properties of the Perceptual Aberration Scale and the Magical Ideation Scale in Spanish college students

    Eduardo Fonseca-Pedrero

    2009-01-01

    Magical Ideation Scale seem to be useful self-reports for the identification of subjects with a higher risk of developing schizophrenia-spectrum disorders. Future research should replicate these findings in samples of other nationalities, determine the contribution of each dimension in the transition to psychosis, as well as apply them in clinical practice along with endophenotypes.

  11. Psychometric properties of the satisfaction with food-related Life Scale

    Schnettler, Berta; Miranda, Horacio; Sepúlveda, José;

    2013-01-01

    Objective: To evaluate the psychometric properties of the Satisfaction with Food-related Life (SWFL) scale and its relation to the Satisfaction with Life Scale (SWLS) in southern Chile. Methods: A survey was applied to a sample of 316 persons in the principal cities of southern Chile distributed...

  12. Properties of large-scale TIDs observed in Central China

    TANG; Qiulin(汤秋林); WAN; Weixing(万卫星); NING; Baiqi(宁百齐); YUAN; Hong(袁洪)

    2002-01-01

    This paper investigates the large scale travelling ionospheric disturbances (LSTIDs) using the observation data of an HF Doppler array located in Central China. The data observed in a high solar activity year (year 1989) are analyzed to obtain the main propagation parameters of LSTIDs such as period, horizontal phase velocity and propagating direction. Results are outlined as follows: Most of the LSTIDs propagate southward; others tend to propagate northward, mostly in summer; dispersion of most LSTIDs is matched with that of Lamb pseudomode, while others have the dispersion of long period gravity wave mode. The horizontal phase velocities of these two modes are about 220 and 450 m/s respectively. The analysis shows that LSTIDs are strongly pertinent to solar activity and space magnetic storms; thus the results presented here are significant for the research of ionospheric weather in mid-low latitude region.

  13. Symmetric scaling properties in global surface air temperature anomalies

    Varotsos, Costas A.; Efstathiou, Maria N.

    2015-08-01

    We have recently suggested "long-term memory" or internal long-range correlation within the time-series of land-surface air temperature (LSAT) anomalies in both hemispheres. For example, an increasing trend in the LSAT anomalies is followed by another one at a different time in a power-law fashion. However, our previous research was mainly focused on the overall long-term persistence, while in the present study, the upward and downward scaling dynamics of the LSAT anomalies are analysed, separately. Our results show that no significant fluctuation differences were found between the increments and decrements in LSAT anomalies, over the whole Earth and over each hemisphere, individually. On the contrary, the combination of land-surface air and sea-surface water temperature anomalies seemed to cause a departure from symmetry and the increments in the land and sea surface temperature anomalies appear to be more persistent than the decrements.

  14. Scaling properties of Wilson loops pierced by P-vortices

    Dunn, Patrick; Greensite, Jeffrey Paul

    2012-01-01

    P-vortices, in an SU(N) lattice gauge theory, are excitations on the center-projected Z(N) lattice. We study the ratio of expectation values of SU(2) Wilson loops, on the unprojected lattice, linked to a single P-vortex, to that of Wilson loops which are not linked to any P-vortices. When these...... ratios are plotted versus loop area in physical units, for a range of lattice couplings, it is found that the points fall approximately on a single curve, consistent with scaling. We also find that the ratios are rather insensitive to the point where the minimal area of the loop is pierced by the P-vortex....

  15. Scaling properties of cavity-enhanced atom cooling

    Horak, P; Horak, Peter; Ritsch, Helmut

    2001-01-01

    We extend an earlier semiclassical model to describe the dissipative motion of N atoms coupled to M modes inside a coherently driven high-finesse cavity. The description includes momentum diffusion via spontaneous emission and cavity decay. Simple analytical formulas for the steady-state temperature and the cooling time for a single atom are derived and show surprisingly good agreement with direct stochastic simulations of the semiclassical equations for N atoms with properly scaled parameters. A thorough comparison with standard free-space Doppler cooling is performed and yields a lower temperature and a cooling time enhancement by a factor of M times the square of the ratio of the atom-field coupling constant to the cavity decay rate. Finally it is shown that laser cooling with negligible spontaneous emission should indeed be possible, especially for relatively light particles in a strongly coupled field configuration.

  16. Ternary eutectic dendrites: Pattern formation and scaling properties

    Extending previous work [Pusztai et al., Phys. Rev. E 87, 032401 (2013)], we have studied the formation of eutectic dendrites in a model ternary system within the framework of the phase-field theory. We have mapped out the domain in which two-phase dendritic structures grow. With increasing pulling velocity, the following sequence of growth morphologies is observed: flat front lamellae → eutectic colonies → eutectic dendrites → dendrites with target pattern → partitionless dendrites → partitionless flat front. We confirm that the two-phase and one-phase dendrites have similar forms and display a similar scaling of the dendrite tip radius with the interface free energy. It is also found that the possible eutectic patterns include the target pattern, and single- and multiarm spirals, of which the thermal fluctuations choose. The most probable number of spiral arms increases with increasing tip radius and with decreasing kinetic anisotropy. Our numerical simulations confirm that in agreement with the assumptions of a recent analysis of two-phase dendrites [Akamatsu et al., Phys. Rev. Lett. 112, 105502 (2014)], the Jackson-Hunt scaling of the eutectic wavelength with pulling velocity is obeyed in the parameter domain explored, and that the natural eutectic wavelength is proportional to the tip radius of the two-phase dendrites. Finally, we find that it is very difficult/virtually impossible to form spiraling two-phase dendrites without anisotropy, an observation that seems to contradict the expectations of Akamatsu et al. Yet, it cannot be excluded that in isotropic systems, two-phase dendrites are rare events difficult to observe in simulations

  17. Ternary eutectic dendrites: Pattern formation and scaling properties

    Rátkai, László; Szállás, Attila; Pusztai, Tamás [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, P.O. Box 49, H-1525 Budapest (Hungary); Mohri, Tetsuo [Center for Computational Materials Science, Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Gránásy, László, E-mail: granasy.laszlo@wigner.mta.hu [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, P.O. Box 49, H-1525 Budapest (Hungary); Brunel University, Uxbridge, Middlesex UB8 3PH (United Kingdom)

    2015-04-21

    Extending previous work [Pusztai et al., Phys. Rev. E 87, 032401 (2013)], we have studied the formation of eutectic dendrites in a model ternary system within the framework of the phase-field theory. We have mapped out the domain in which two-phase dendritic structures grow. With increasing pulling velocity, the following sequence of growth morphologies is observed: flat front lamellae → eutectic colonies → eutectic dendrites → dendrites with target pattern → partitionless dendrites → partitionless flat front. We confirm that the two-phase and one-phase dendrites have similar forms and display a similar scaling of the dendrite tip radius with the interface free energy. It is also found that the possible eutectic patterns include the target pattern, and single- and multiarm spirals, of which the thermal fluctuations choose. The most probable number of spiral arms increases with increasing tip radius and with decreasing kinetic anisotropy. Our numerical simulations confirm that in agreement with the assumptions of a recent analysis of two-phase dendrites [Akamatsu et al., Phys. Rev. Lett. 112, 105502 (2014)], the Jackson-Hunt scaling of the eutectic wavelength with pulling velocity is obeyed in the parameter domain explored, and that the natural eutectic wavelength is proportional to the tip radius of the two-phase dendrites. Finally, we find that it is very difficult/virtually impossible to form spiraling two-phase dendrites without anisotropy, an observation that seems to contradict the expectations of Akamatsu et al. Yet, it cannot be excluded that in isotropic systems, two-phase dendrites are rare events difficult to observe in simulations.

  18. Psychometric Properties of the Depression Anxiety and Stress Scale-21 in Older Primary Care Patients

    Gloster, Andrew T.; Rhoades, Howard M.; Novy, Diane; Klotsche, Jens; Senior, Ashley; Kunik, Mark; Wilson, Nancy; Stanley, Melinda A.

    2008-01-01

    The Depression Anxiety Stress Scale (DASS) was designed to efficiently measure the core symptoms of anxiety and depression and has demonstrated positive psychometric properties in adult samples of anxiety and depression patients and student samples. Despite these findings, the psychometric properties of the DASS remain untested in older adults, for whom the identification of efficient measures of these constructs is especially important.

  19. Silver nanoparticles: Large scale solvothermal synthesis and optical properties

    Silver nanoparticles have been successfully synthesized by a simple and modified solvothermal method at large scale using ethanol as the refluxing solvent and NaBH4 as reducing agent. The nanopowder was investigated by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-visible and BET surface area studies. XRD studies reveal the monophasic nature of these highly crystalline silver nanoparticles. Transmission electron microscopic studies show the monodisperse and highly uniform nanoparticles of silver of the particle size of 5 nm, however, the size is found to be 7 nm using dynamic light scattering which is in good agreement with the TEM and X-ray line broadening studies. The surface area was found to be 34.5 m2/g. UV-visible studies show the absorption band at ∼425 nm due to surface plasmon resonance. The percentage yield of silver nanoparticles was found to be as high as 98.5%.

  20. Soil properties and preferential solute transport at the field scale

    Koestel, J. K.; Luong, N. M.; Nørgaard, T.; Vendelboe, A. L.; Moldrup, P.; Jarvis, N. J.; Lamandé, M.; Iversen, B. V.; Wollesen de Jonge, L.

    2012-04-01

    An important fraction of water flow and solute transport through soil takes place through preferential flow paths. Although this had been already observed in the nineteenth century, it had been forgotten by the scientific community until it was rediscovered during the 1970s. The awareness of the relevance of preferential flow was broadly re-established in the community by the early 1990s. However, since then, the notion remains widespread among soil scientists that the occurrence and strength of preferential flow cannot be predicted from measurable proxy variables such as soil properties or land management practices (e.g. Beven, K., 1991, Modeling preferential flow - an uncertain future, Preferential Flow, 1-11). In our study, we present evidence that disproves this notion. We evaluated breakthrough curve experiments under a constant irrigation rate of 1 cm/h conducted on 65 soil columns (20 cm diameter and 20 height) which had been sampled from an approximately 1 ha large loamy field-site in Silstrup, Denmark. We show that the holdback factor, which is an indicator for the strength of preferential transport, is strongly correlated to the bulk density, which in turn is correlated to the organic matter content. By applying multiple linear regression in a bootstrapping framework, we could estimate the holdback factor from the bulk density and the very fine sand fraction with a coefficient of determination of 0.65. Our results raise hopes that it is indeed possible to establish pedotransfer functions for soil susceptibility to preferential flow and transport.

  1. Electronic transport properties of copper and gold at atomic scale

    Mohammadzadeh, Saeideh

    2010-11-23

    The factors governing electronic transport properties of copper and gold atomic-size contacts are theoretically examined in the present work. A two-terminal conductor using crystalline electrodes is adopted. The non-equilibrium Green's function combined with the density functional tight-binding method is employed via gDFTB simulation tool to calculate the transport at both equilibrium and non-equilibrium conditions. The crystalline orientation, length, and arrangement of electrodes have very weak influence on the electronic characteristics of the considered atomic wires. The wire width is found to be the most effective geometric aspect determining the number of conduction channels. The obtained conductance oscillation and linear current-voltage curves are interpreted. To analyze the conduction mechanism in detail, the transmission channels and their decomposition to the atomic orbitals are calculated in copper and gold single point contacts. The presented results offer a possible explanation for the relation between conduction and geometric structure. Furthermore, the results are in good agreement with available experimental and theoretical studies. (orig.)

  2. Scaled down physical properties of semiconductor nanowires for nanoelectronics scaling up

    Carapezzi, Stefania

    2014-01-01

    Semiconductor nanowires (NWs) are one- or quasi one-dimensional systems whose physical properties are unique as compared to bulk materials because of their nanoscaled sizes. They bring together quantum world and semiconductor devices. NWs-based technologies may achieve an impact comparable to that of current microelectronic devices if new challenges will be faced. This thesis primarily focuses on two different, cutting-edge aspects of research over semiconductor NW arrays as pivotal component...

  3. Development and examination of the psychometric properties of the Learning Experience Scale in nursing.

    Takase, Miyuki; Imai, Takiko; Uemura, Chizuru

    2016-06-01

    This paper examines the psychometric properties of the Learning Experience Scale. A survey method was used to collect data from a total of 502 nurses. Data were analyzed by factor analysis and the known-groups technique to examine the construct validity of the scale. In addition, internal consistency was evaluated by Cronbach's alpha, and stability was examined by test-retest correlation. Factor analysis showed that the Learning Experience Scale consisted of five factors: learning from practice, others, training, feedback, and reflection. The scale also had the power to discriminate between nurses with high and low levels of nursing competence. The internal consistency and the stability of the scale were also acceptable. The Learning Experience Scale is a valid and reliable instrument, and helps organizations to effectively design learning interventions for nurses. PMID:26373632

  4. Scaling properties of evolutionary paths in a biophysical model of protein adaptation

    Manhart, Michael; Morozov, Alexandre V.

    2015-07-01

    The enormous size and complexity of genotypic sequence space frequently requires consideration of coarse-grained sequences in empirical models. We develop scaling relations to quantify the effect of this coarse-graining on properties of fitness landscapes and evolutionary paths. We first consider evolution on a simple Mount Fuji fitness landscape, focusing on how the length and predictability of evolutionary paths scale with the coarse-grained sequence length and alphabet. We obtain simple scaling relations for both the weak- and strong-selection limits, with a non-trivial crossover regime at intermediate selection strengths. We apply these results to evolution on a biophysical fitness landscape that describes how proteins evolve new binding interactions while maintaining their folding stability. We combine the scaling relations with numerical calculations for coarse-grained protein sequences to obtain quantitative properties of the model for realistic binding interfaces and a full amino acid alphabet.

  5. Psychometric properties of a single-item scale to assess sleep quality among individuals with fibromyalgia

    Sadosky Alesia B; McDermott Anne M; Bushmakin Andrew G; Cappelleri Joseph C; Petrie Charles D; Martin Susan

    2009-01-01

    Abstract Background Sleep disturbances are a common and bothersome symptom of fibromyalgia (FM). This study reports psychometric properties of a single-item scale to assess sleep quality among individuals with FM. Methods Analyses were based on data from two randomized, double-blind, placebo-controlled trials of pregabalin (studies 1056 and 1077). In a daily diary, patients reported the quality of their sleep on a numeric rating scale ranging from 0 ("best possible sleep") to 10 ("worst possi...

  6. Psychometric properties of a short form of the Affective Lability Scale (ALS-18)

    Look, Amy E.; Flory, Janine D.; Harvey, Philip D.; Siever, Larry J.

    2010-01-01

    Psychometric properties of a short form of the Affective Lability Scale (ALS) that was developed in a nonclinical sample (i.e., undergraduate students) were examined in a sample of people diagnosed with Cluster B DSM-IV Axis II personality disorders (n=236), other personality disorders (n=180), and healthy comparison participants (n=164). The total score of the ALS-18 score correlated strongly with the original 54-item scale (r = .97) and aspects of convergent and discriminant validity of the...

  7. Testing properties of potato starch from different scales of isolations - A ringtest

    Wischmann, Bente; Ahmt, T.; Bandsholm, O.;

    2007-01-01

    Five different procedures were used to isolate potato starch from the same batch at three different scales in order to analyse what influence scaling up of the starch process had on the starch physical/chemical properties. Common to the five isolation processes was the steps of washing and...... maceration of potato tubers followed by separation of starch and cell debris by sieving, filtration or sedimentation. The properties of the processed starch were analysed both in water-based systems of 10 mM NaCl as well as in a milk based food model, dutch vla. Analysis of chemical and physical properties...... by a rapid visco analyser (RVA) and freeze/thaw stability and retrogradation characteristics analysed by pulse-NMR. Various theological flow properties were included in the analysis of the starch samples in the food model. Only the sample of starch isolated in distilled water showed significant...

  8. Depth dependence of seismic source scaling properties beneath Vrancea, Romania region

    Previous research focused on seismicity, tomography and seismic source scaling in the Vrancea region revealed significant plate subducting irregularity which was assumed to be in connection with multiple parameter and multi-scale fields, reflecting differences in the physical, geochemical and tectonic processes at different scale lengths. A substantial new amount of high-quality earthquake data have been recently gained through the progress of seismic networks on the Romanian territory within the cooperation programme with the University of Karlsruhe (Germany): Collaborative Research Centre 461 programme (Bonjer et al., 2000) and the tomography experiment CALIXTO'99 (Wenzel et al., 1999). The main purpose of the present study is to study the depth dependence of the seismic source scaling in the Vrancea subducting slab on the basis of these new data. Spectral ratios and empirical Green's function deconvolution methods are applied for a set of 130 earthquakes with magnitudes 2.9 ≤ Mw ≤ 6.0, occurred between 1996 and 2005. The two relative methods are employed to pairs of collocated events and similar focal mechanism, in order to inspect the scaling properties over the seismic active depth domain (60-220 km). The results are discussed in connection with previous studies based on fractal statistics analysis. The clustering properties of time, space and size distributions as well as the scaling variations in the subducting lithosphere are ascribed to differences in specific source mechanisms or/and structural inhomogeneity properties with hierarchical distribution. (authors)

  9. Physical and functional properties of chromatography media : a down-scale study

    Hansson, Emma

    2013-01-01

    During down scale of column chromatography a phenomenon called wall effect appears.This supports the gel bed and gives it better flow properties. Using three different media infive different sized columns this effect was investigated regarding the physical andfunctional properties of the media. The conclusion of this study is that the effect appears incolumns below 26 mm in diameter and that the impact of the wall effect is larger the morerigid the used media is.

  10. Measurement properties of the Minimal Insomnia Symptom Scale (MISS) in an elderly population in Sweden.

    Fagerström Cecilia; Hagell Peter; Hellström Amanda; Willman Ania

    2010-01-01

    Abstract Background Insomnia is common among elderly people and associated with poor health. The Minimal Insomnia Symptom Scale (MISS) is a three item screening instrument that has been found to be psychometrically sound and capable of identifying insomnia in the general population (20-64 years). However, its measurement properties have not been studied in an elderly population. Our aim was to test the measurement properties of the MISS among people aged 65 + in Sweden, by replicating the ori...

  11. Multi-scale modeling in heterogeneous material properties : An application to porous piezoelectric material

    Asai, Mitsuteru

    2012-01-01

    Many engineering problems involve different scale in space or time. The main interest for engineering designer is to find an optimum macroscopic response of structure, although the macroscopic response is strongly dependent on the microscopic material properties. The material itself has an individual microstructure, and the optimum material is fabricated by controlling the microstructure. Usually, the macroscopic material properties are measured by the experimental material tests. The asympto...

  12. Length Scales and Turbulent Properties of Magnetic Fields in Simulated Galaxy Clusters

    Egan, Hilary; Hallman, Eric; Burns, Jack; Xu, Hao; Collins, David; Li, Hui; Norman, Michael L

    2016-01-01

    Additional physics beyond standard hydrodynamics is needed to fully model the intracluster medium (ICM); however, as we move to more sophisticated models, it is important to consider the role of magnetic fields and the way the fluid approximation breaks down. This paper represents a first step towards developing a self-consistent model of the ICM by characterizing the statistical properties of magnetic fields in cosmological simulations of galaxy clusters. We find that plasma conditions are largely homogeneous across a range of cluster masses and relaxation states. We also find that the magnetic field length scales are resolution dependent and not based on any particular physical process. Energy transfer mechanisms and scales are also identified, and imply the existence of small scale dynamo action. The scales of the small scale dynamo are resolution limited and driven by numerical resistivity and viscosity.

  13. Scaling of material properties for Yucca Mountain: literature review and numerical experiments on saturated hydraulic conductivity

    McKenna, S.A.; Rautman, C.A.

    1996-08-01

    A review of pertinent literature reveals techniques which may be practical for upscaling saturated hydraulic conductivity at Yucca Mountain: geometric mean, spatial averaging, inverse numerical modeling, renormalization, and a perturbation technique. Isotropic realizations of log hydraulic conductivity exhibiting various spatial correlation lengths are scaled from the point values to five discrete scales through these techniques. For the variances in log{sub 10} saturated hydraulic conductivity examined here, geometric mean, numerical inverse and renormalization adequately reproduce point scale fluxes across the modeled domains. Fastest particle velocities and dispersion measured on the point scale are not reproduced by the upscaled fields. Additional numerical experiments examine the utility of power law averaging on a geostatistical realization of a cross-section similar to the cross-sections that will be used in the 1995 groundwater travel time calculations. A literature review on scaling techniques for thermal and mechanical properties is included. 153 refs., 29 figs., 6 tabs.

  14. Scaling of material properties for Yucca Mountain: literature review and numerical experiments on saturated hydraulic conductivity

    A review of pertinent literature reveals techniques which may be practical for upscaling saturated hydraulic conductivity at Yucca Mountain: geometric mean, spatial averaging, inverse numerical modeling, renormalization, and a perturbation technique. Isotropic realizations of log hydraulic conductivity exhibiting various spatial correlation lengths are scaled from the point values to five discrete scales through these techniques. For the variances in log10 saturated hydraulic conductivity examined here, geometric mean, numerical inverse and renormalization adequately reproduce point scale fluxes across the modeled domains. Fastest particle velocities and dispersion measured on the point scale are not reproduced by the upscaled fields. Additional numerical experiments examine the utility of power law averaging on a geostatistical realization of a cross-section similar to the cross-sections that will be used in the 1995 groundwater travel time calculations. A literature review on scaling techniques for thermal and mechanical properties is included. 153 refs., 29 figs., 6 tabs

  15. Development and Psychometric Properties of the Emotional Intelligence Admission Essay Scale

    Sharon A. Gutman

    2016-07-01

    Full Text Available The purpose was to describe the development and psychometric properties of the Emotional Intelligence Admission Essay scale. The authors developed an admission essay question and rating scale designed to provide information about applicants’ emotional intelligence (EI. Content validity, convergent validity, interrater reliability, and internal consistency were established. The scale was also examined to determine if it could discriminate between students with and without professional behavior problems in the academic and fieldwork settings. Content validity was found to be high by a panel of three experts in EI (content validity index = 1.0. Convergent validity with the Assessing Emotions Scale was moderate (r = .46, p < .02. Interrater reliability between two trained faculty raters was high (ICC = .91, p < .000. Internal consistency of the scale was high with a Cronbach’s alpha of .95. This version of the scale was not able to discriminate between students with and without professional behavior problems. The moderate to strong psychometric properties suggest that the EI Admission Essay Scale has the ability to provide information about applicants’ EI. The wording of the essay question must be modified to better instruct applicants to address interpersonal conflict.

  16. Multi-scales modeling of reactive transport mechanisms. Impact on petrophysical properties during CO2 storage

    The geo-sequestration of carbon dioxide (CO2) is an attractive option to reduce the emission of greenhouse gases. Within carbonate reservoirs, acidification of brine in place can occur during CO2 injection. This acidification leads to mineral dissolution which can modify the transport properties of a solute in porous media. The aim of this study is to quantify the impact of reactive transport on a solute distribution and on the structural modification induced by the reaction from the pore to the reservoir scale. This study is focused on reactive transport problem in the case of single phase flow in the limit of long time. To do so, we used a multi-scale up-scaling method that takes into account (i) the local scale, where flow, reaction and transport are known; (ii) the pore scale, where the reactive transport is addressed by using averaged formulation of the local equations; (iii) the Darcy scale (also called core scale), where the structure of the rock is taken into account by using a three-dimensions network of pore-bodies connected by pore-throats; and (iv) the reservoir scale, where physical phenomenon, within each cell of the reservoir model, are taken into account by introducing macroscopic coefficients deduced from the study of these phenomenon at the Darcy scale, such as the permeability, the apparent reaction rate, the solute apparent velocity and dispersion. (author)

  17. Assessing Psychometric Properties of the Sex-Role Egalitarianism Scale (SRES) with African Americans.

    McGhee, Melissa R.; Johnson, NeSonya; Liverpool, Joan

    2001-01-01

    Examined the psychometric properties of the Sex-Role Egalitarianism Scale in a group of African American college students, comparing scores from this sample to scores of a predominantly white norming base. While there were no significant differences between the norming sample and study sample, significant differences were found between African…

  18. Psychometric Properties of the MMPI-2-RF Somatic Complaints (RC1) Scale

    Thomas, Michael L.; Locke, Dona E. C.

    2010-01-01

    The MMPI-2 Restructured Form (MMPI-2-RF; Tellegen & Ben-Porath, 2008) was designed to be psychometrically superior to its MMPI-2 counterpart. However, the test has yet to be extensively evaluated in diverse clinical settings. The purpose of this study was to examine the psychometric properties of the MMPI-2-RF Somatic Complaints (RC1) scale in a…

  19. Measuring Grief Following Miscarriage: Psychometric Properties of the Chinese Version of the Perinatal Grief Scale

    Lai, Beatrice P. Y.; Chung, Tony K. H.; Lee, Dominic T. S.; Kong, Grace W. S.; Lok, Ingrid H.

    2013-01-01

    Grief following miscarriage is a complex psychological response. This study was conducted to examine the psychometric properties of the Chinese version of the Perinatal Grief Scale (PGS). A total of 280 Chinese women completed the PGS immediately following a diagnosis of miscarriage (baseline) and were reassessed at 12 months follow-up. The factor…

  20. Nonlinear option pricing models for illiquid markets: scaling properties and explicit solutions

    Bordag, Ljudmila A.; Ruediger Frey

    2007-01-01

    Several models for the pricing of derivative securities in illiquid markets are discussed. A typical type of nonlinear partial differential equations arising from these investigation is studied. The scaling properties of these equations are discussed. Explicit solutions for one of the models are obtained and studied.

  1. The axiomatic definition of a linguistic scale fuzziness degree, its major properties, and applications

    Ryjov, Alexander P.

    1992-01-01

    A model that makes use of fuzzy linguistic scales (FLS) is considered in this report. The definition of FLS fuzziness and its major properties are given in the report. Definitions that are concerned with information loss and noise are also presented.

  2. Psychometric Properties of the Teachers' Sense of Efficacy Scale within the Greek Educational Context

    Tsigilis, Nikolaos; Koustelios, Athanasios; Grammatikopoulos, Vasilios

    2010-01-01

    Many concerns have been raised about the validity of the existing instruments measuring teachers' efficacy. Recently, a new instrument to measure teachers' perceived efficacy has been presented, namely, the Teachers' Sense of Efficacy Scale (TSES). The purpose of the present study is to examine the psychometric properties of the TSES in the Greek…

  3. Investigating the Measurement Properties of the Social Responsiveness Scale in Preschool Children with Autism Spectrum Disorders

    Duku, Eric; Vaillancourt, Tracy; Szatmari, Peter; Georgiades, Stelios; Zwaigenbaum, Lonnie; Smith, Isabel M.; Bryson, Susan; Fombonne, Eric; Mirenda, Pat; Roberts, Wendy; Volden, Joanne; Waddell, Charlotte; Thompson, Ann; Bennett, Teresa

    2013-01-01

    The purpose of this study was to examine the measurement properties of the Social Responsiveness Scale in an accelerated longitudinal sample of 4-year-old preschool children with the complementary approaches of categorical confirmatory factor analysis and Rasch analysis. Measurement models based on the literature and other hypothesized measurement…

  4. Psychometric Properties of the Chinese Version of the Social Responsiveness Scale

    Gau, Susan Shur-Fen; Liu, Li-Ting; Wu, Yu-Yu; Chiu, Yen-Nan; Tsai, Wen-Che

    2013-01-01

    This study evaluated the psychometric properties of the Chinese version of the Social Responsiveness Scale (Chinese SRS). We assessed 1419 grade 1 to grade 8 students from northern Taiwan and 401 clinic-based participants (aged 3-20, male 90.3%). All clinic-based participants were clinically diagnosed with autism spectrum disorders (ASDs),…

  5. Psychometric Properties of a Korean Translation of the "Scales of Independent Behavior--Revised"

    Cho, Su-Je; Paik, Eunhee; Lee, Byoung-In; Yi, Joonsuk

    2010-01-01

    This study explores the psychometric properties of data drawn from the Korean translation of the full "Scales of Independent Behavior--Revised" (SIB-R). In addition, semantic, content, conceptual, and technical equivalence are examined. The participants include 2,763 typically developing children and 406 children with intellectual disabilities…

  6. Psychometric Properties of the "Reminiscence Functions Scale" for the Portuguese Population: A Preliminary Report

    Goncalves, Daniela C.; Guedes, Joana Martins; Fonseca, Antonio M.; Martin, Inacio

    2010-01-01

    The aim of the present study was to assess the psychometric properties of a version in Portuguese of the "Reminiscence Functions Scale." Total sample was composed of 628 participants aged between 18 and 92 years, divided into three groups according to their age (18-24 years, "n" = 249; 26-54 years, "n" = 174; 55 and older, "n" = 205). Results…

  7. Factor Structure and Psychometric Properties of the Injection Phobia Scale-Anxiety

    Olatunji, Bunmi O.; Sawchuk, Craig N.; Moretz, Melanie W.; David, Bieke; Armstrong, Thomas; Ciesielski, Bethany G.

    2010-01-01

    The present investigation examined the factor structure and psychometric properties of the Injection Phobia Scale-Anxiety (IPS-Anx). Principal components analysis of IPS-Anx items in Study 1 (n = 498) revealed a 2-factor structure consisting of Distal Fear and Contact Fear. However, CFA results in Study 2 (n = 567) suggest that a 1-factor…

  8. Constraints on dark-matter properties from large-scale structure

    Kunz, Martin; Sawicki, Ignacy

    2016-01-01

    We use large-scale cosmological observations to place constraints on the dark matter pressure, sound speed and viscosity, and infer a limit on the mass of warm dark matter particles. Measurements of the cosmic microwave background (CMB) anisotropies constrain the equation of state and sound speed of the dark matter at last scattering at the per mille level. Since the redshifting of collisionless particles universally implies that these quantities scale like $a^{-2}$ absent shell crossing, we infer that today $w_{\\rm (DM)} 70$ eV, assuming it decoupled while relativistic around the same time as the neutrinos; for a cold relic, we show that $m>100$ eV. We separately constrain the properties of the DM fluid on linear scales at late times, and find upper bounds $c_{\\rm s, (DM)}^2<10^{-5.9}$, $c_{\\rm vis, (DM)}^{2} < 10^{-5.7}$, with no detection of non-dust properties for the DM.

  9. Remarks on Some Mechanical Small-Scale Tests Applied to Properties of Materials

    Cardu, Marilena; Seccatore, Jacopo

    2016-06-01

    The paper presents the results of test campaigns on small-scale strength properties (particularly, micro-hardness) performed on two homogeneous materials: calcite, a very common and widespread mineral that is characterized by its relatively low Mohs hardness and its high reactivity with even weak acids; and glass, an amorphous solid characterized by the absence of the long-range order which defines crystalline materials. After a synthetic description of the principles underlying two of the three classical comminution laws, known as Kick's law and Rittinger's law, experimental results are discussed. The results of the tests performed show that both scale effect and size effect contribute to the non-constancy of mechanical properties at small scale for crystalline materials. On the other hand, for amorphous materials, a theoretical law considering size effects gives considerably different results from empirical measurements. Considerations and an extended discussion address these findings.

  10. Dynamical properties of fractal networks: Scaling, numerical simulations, and physical realizations

    This article describes the advances that have been made over the past ten years on the problem of fracton excitations in fractal structures. The relevant systems to this subject are so numerous that focus is limited to a specific structure, the percolating network. Recent progress has followed three directions: scaling, numerical simulations, and experiment. In a happy coincidence, large-scale computations, especially those involving array processors, have become possible in recent years. Experimental techniques such as light- and neutron-scattering experiments have also been developed. Together, they form the basis for a review article useful as a guide to understanding these developments and for charting future research directions. In addition, new numerical simulation results for the dynamical properties of diluted antiferromagnets are presented and interpreted in terms of scaling arguments. The authors hope this article will bring the major advances and future issues facing this field into clearer focus, and will stimulate further research on the dynamical properties of random systems

  11. The scaling properties of stock markets based on modified multiscale multifractal detrended fluctuation analysis

    Lin, Aijing; Ma, Hui; Shang, Pengjian

    2015-10-01

    Here we propose the new method DH-MMA, based on multiscale multifractal detrended fluctuation analysis(MMA), to investigate the scaling properties in stock markets. It is demonstrated that our approach can provide a more stable and faithful description of the scaling properties in comprehensive range rather than fixing the window length and slide length. It allows the assessment of more universal and subtle scaling characteristics. We illustrate DH-MMA by selecting power-law artificial data sets and six stock markets from US and China. The US stocks exhibit very strong multifractality for positive values of q, however, the Chinese stocks show stronger multifractality for negative q than positive q. In general, the US stock markets show similar behaviors, but Chinese stock markets display distinguishing characteristics.

  12. Luminescence properties of II/VI semiconductor colloidal nanocrystals at collective and single scales

    Vion, Celine; Barthou, Carlos; Coolen, Laurent; Bennaloul, Paul; MaItre, Agnes [Institut des NanoSciences de Paris, Unite Mixte de Recherche-CNRS 7588, Universite Pierre et Marie Curie, Paris (France); Vu Duc Chinh; Pham Thuy Linh; Vu Thi Bich; Pham Thu Nga [Institute of Materials Science, Vietnam Academy of Science and Technology, Hanoi (Viet Nam)], E-mail: celine.vion@insp.jussieu.fr

    2009-09-01

    Colloidal nanocrystals are crystalline spheres of semiconductors of a few nanometers, obtained by chemical synthesis. At this size scale, lower than Bohr radius of the exciton, emission properties are dominated by quantum confinement effects and depend crucially on the nanocrystal radius, which can be controlled by adjusting the synthesis parameters. Nanocrystals present high photostability and good quantum efficiency, even at room temperature. Their emission wavelength can be tuned over the whole visible range, making them very attractive solid state light sources which are already used in optoelectronic devices or for biological labeling. The luminescence properties of CdSe colloidal nanocrystals synthesized at the Institute of Materials Science in Hanoi are presented. At collective scale, the emission properties reveal the synthesis quality. Temperature effects from ambient to 4 K on spectra and decay rates will be presented and analyzed in terms of emitting level fine structure. The study of CdSe colloidal quantum dots at the single emitter scale is of great interest as it reveals properties which are hidden by collective studies, such as luminescence 'blinking', a random switching from a fluorescent to a non fluorescent state, which is closely related to the crystalline defects of a nanocrystal and its interaction with its environment. We will present the blinking properties of the prepared nanocrystals, and relate them to the nanocrystals synthesis quality and shell quality.

  13. Thermophysical Properties of Lignocellulose: A Cell-scale Study down to 41K

    Cheng, Zhe; Zhang, Lei; Wang, Xinwei

    2014-01-01

    Thermal energy transport is of great importance in lignocellulose pyrolysis for bio-fuels. The thermophysical properties of lignocellulose significantly affect the overall properties of bio-composites and the related thermal transport. In this work, cell-scale lignocellulose (mono-layer plant cells) is prepared to characterize their thermal properties from room temperature down to 41 K. The thermal conductivities of cell-scale lignocellulose along different directions show a little anisotropy due to the cell structure anisotropy. It is found that with temperature going down, the volumetric specific heat of the lignocellulose shows a slower decreasing trend against temperature than that of microcrystalline cellulose, and its value is always higher than that of microcrystalline cellulose. The thermal conductivity of lignocellulose decreases with temperature from 243 K to 317 K due to increasing phonon-phonon scatterings. From 41 K to 243 K, the thermal conductivity rises with temperature and its change mainly d...

  14. Thermophysical properties of lignocellulose: a cell-scale study down to 41 K.

    Zhe Cheng

    Full Text Available Thermal energy transport is of great importance in lignocellulose pyrolysis for biofuels. The thermophysical properties of lignocellulose significantly affect the overall properties of bio-composites and the related thermal transport. In this work, cell-scale lignocellulose (mono-layer plant cells is prepared to characterize their thermal properties from room temperature down to ∼ 40 K. The thermal conductivities of cell-scale lignocellulose along different directions show a little anisotropy due to the cell structure anisotropy. It is found that with temperature going down, the volumetric specific heat of the lignocellulose shows a slower decreasing trend against temperature than microcrystalline cellulose, and its value is always higher than that of microcrystalline cellulose. The thermal conductivity of lignocellulose decreases with temperature from 243 K to 317 K due to increasing phonon-phonon scatterings. From 41 K to 243 K, the thermal conductivity rises with temperature and its change mainly depends on the heat capacity's change.

  15. The Influence of the Large-scale Environment on Galaxy Property

    Wei, Y. Q.; Wang, L.; Dai, C. P.

    2016-03-01

    The properties of star formation in galaxies and their dependence on environment play an important role in understanding the formation and evolution of galaxies.Using the galaxy sample of the Sloan Digital Sky Survey (SDSS), different groups have studied the physical property and the large-scale environment of galaxies. Here we use the filament catalog from Tempel et al. and classified galaxies catalog from Wang et al., considering the affect of shape of galaxies, high and low local density environment, and central (satellite) galaxies. It is found that the properties of galaxies and the large-scale environment are related: the SSFR (specific star formation rate) and SFR (star formation rate) strongly depend on large-scale environment only for spiral galaxies and satellite galaxies, but this dependence is very weak for elliptical galaxies and the central galaxies, and the influence of large-scale environment on galaxies in low density region is more sensitive than that in high density region. The above conclusion remains valid even for the galaxies with the same mass. In addition, the SSFR distributions from Tempel et al.'s catalog and Wang et al.'s catalog are not entirely consistent.

  16. Multi-dimensional scattering properties diagnosis system of scale aircraft model in an anechoic chamber

    Chufeng Hu; Zhou Zhou; Nanjing Li; Kun Zhang

    2014-01-01

    Aiming at the concept of “diagnosis”, a simple and ef-fective broadband radar cross section (RCS) measurement system is constructed, and some multi-dimensional scattering properties diagnosis techniques are presented based on the system. Firstly, a stepped-frequency signal is employed to achieve high range resolution, combining with a variety of signal processing tech-niques. Secondly, cross-range resolution is gained with a rotating table, and the high-resolution two-dimensional (2-D) imaging of the scale model is obtained by the microwave imaging theory. Fi-nal y, two receiving antennas with a smal distance in altitude are used, and the three-dimensional (3-D) height distribution of scattering points on the scale model is extracted from the phase of images. Some typical bodies and a scale aircraft model are diagnosed in an anechoic chamber. The experimental results show that, after scaling with a metal sphere, the accurate one-dimensional (1-D) RCS pattern of the model is obtained, and it has a large dynamic range. When the bandwidth of the transmit-ting signal is 4 GHz, the resolution of the 2-D image can reach to 0.037 5 m. The 3-D height distribution of scattering points is given by interferometric measurement. This paper provides a feasible way to obtain high-precision scattering properties parameters of the scale aircraft model in a conventional rectangular anechoic chamber.

  17. Psychometric properties of the Turkish version of the internalized homophobia scale.

    Gençöz, Tülin; Yüksel, Murat

    2006-10-01

    The current study examined the psychometric properties of the Turkish version of the Internalized Homophobia Scale (IHS; Herek, Cogan, Gillis, & Glunt, 1997) in gay men living in Turkey. Participants were 132 men in romantic, intimate, or sexual relationships with men, and they identified themselves as homosexual (n=112) or bisexual (n=20). Alpha and split-half reliability coefficients revealed good internal consistency of the scale. Consistent with the original scale, the construct validity revealed a single factor for the scale. Regarding convergent validity, the IHS had significant correlations with psychological problems, particularly with symptoms of depression and anxiety; the scale also had a significant positive correlation with negative affect and a negative correlation with self-esteem. Regarding discriminant validity, the IHS had very low correlations with positive affect and hostility attitudes. The association between internalized homophobia and psychological problems remained significant even after controlling for the variance explained by self-esteem, negative affect, and positive affect. Hence, the psychometric properties of the Turkish version of IHS appear quite promising. PMID:17031586

  18. Bayley-III Scales of Infant and Toddler Development: Transcultural Adaptation and Psychometric Properties

    Vanessa Madaschi

    2016-08-01

    Full Text Available Abstract Scales with evidence of validity and reliability are important to evaluate child development. In Brazil, there is a lack of standardized instruments to evaluate young children. This study investigated the psychometric properties of the Bayley Scales of Infant Development, Third Edition (Bayley-III. It was translated into Brazilian Portuguese, culturally adapted and tested on 207 children (12-42 months of age. Evidence of convergent validity was obtained from correlations of the Bayley-III with the: Peabody Developmental Motor Scale 2, Leiter International Performance Scale-R, Expressive Vocabulary Assessment List and Peabody Picture Vocabulary Test. Exploratory factor analyses showed a single component explaining 86% of the variance, supported by goodness-of-fit indexes in confirmatory factor analysis. The Bailey-III demonstrated good internal consistency with alpha coefficients greater than or equal to .90 and stability for fine motor scale only. These robust psychometric properties support the use of this tool in future national studies on child development.

  19. Investigating the elastic properties of sedimentary basins on different spatial scales

    Krause, Martin; Methe, Pascal; Goepel, Andreas; Bleibinhaus, Florian; Kukowski, Nina

    2014-05-01

    The study of subsurface fluid motion is important e.g. for understanding ground water motion or processes of compaction, diagenesis, and hydrocarbon migration in sedimentary basins. The multidisciplinary project INFLUINS (INtegrated FLUid dynamics IN Sedimentary basins) aims for investigating the coupled dynamics of near surface and deep fluid patterns and material transport in the Thuringian Basin (Germany). In order to gain information on how fluid flow processes depend on basin architecture, and therefore its physical properties, we first image the subsurface structure of the Thuringian Basin using seismic methods. Then, relations between hydraulic and elastic material parameters are required to also image the hydraulic structure of the basin's subsurface. As hydraulic properties often significantly vary with spatial scales, such a study requires a combination of small- to large-scale seismic data sets. In the framework of INFLUINS a variety of seismic data sets aiming for different subsurface parameters and spatial scales have been acquired. Basin scale seismic data sets are available from a set of 2D reflection seismic profiles as well as 2.5D and 3D seismic travel time tomography. Laboratory scale seismic data characterizing the basin's rocks is provided by ultrasound experiments on drill cores from the Thuringian Basin. Deep drilling conducted in the framework of INFLUINS in 2013 provides further useful data sets for our purpose: we acquired core material for laboratory ultrasound analysis and sonic-log data. As the drill site is located at the cross point of two seismic reflection profiles and also within the array of seismic stations we used for the 3D travel time tomography, it serves a direct transfer of elastic properties between different scales.

  20. Atomic-scale structure of grain boundaries: Correlations to grain boundary properties

    It is generally believed that many properties of solid interfaces are ultimately determined by their structure and composition at the atomic level. We report here on work in two areas of grain boundary (GB) research in which structure-property correlations have been investigated recently. HREM observations in connection with computer modeling of GBs in fcc metals have given considerable insight into correlations between GB energy and atomic-scale GB structure. Efforts to understand and possibly control the supercurrent transport behavior across GBs in high-temperature superconductors require the combination of microstructure characterizations with investigations of electric transport properties. In both areas considerable progress is being made and has already lead to important insights concerning interfacial properties

  1. Biomimic design of multi-scale fabric with efficient heat transfer property

    Fan Jie

    2012-01-01

    Full Text Available Wool fiber has a complex hierarchic structure. The multi-scale fibrils are assembled to form a tree-like channel net in wool fiber, providing an efficient heat transfer property. The optimal inner configuration of wool fiber can also be invited to biomimic design of textile fabrics to improve the thermal comfort of cloth. A heat transfer model of biomimic multi-scale fabric using the fractal derivative is established. Theoretical analysis indicates that the heat flux efficiency in the biomimic fabric can be 2 orders of magnitude comparing with that of the continuous medium.

  2. Psychometric properties of the faces version of the Malay-modified child dental anxiety scale

    Esa, Rashidah; Hashim, Noratikah Awang; Ayob, Yuliana; Yusof, Zamros Yuzadi Mohd

    2015-01-01

    Background To evaluate the psychometric properties of the faces version of the Modified Child Dental Anxiety Scale (MCDASf) Malay version in 5–6 and 9–12 year-old children. Methods The MCDASf was cross culturally adapted from English into Malay. The Malay version was tested for reliability and validity in 3 studies. In the Study 1, to determine test-retest reliability of MCDASf scale, 166 preschool children aged 5–6 years were asked to rank orders five cartoons faces depicting emotions from ‘...

  3. Psychometric properties of the Revised Male Body Attitudes Scale among Irish men.

    Ryan, Travis A

    2011-01-01

    The psychometric properties of a revised version of the Male Body Attitudes Scale (Tylka, Bergeron, & Schwartz, 2005) were investigated using two independent online samples of Irish men (ns=241 and 253, respectively). Exploratory factor analyses suggested that a 15-item, 3-factor solution representing men\\'s attitudes toward their body fat, muscularity, and height best described the data. The internal consistency and construct validity of scores on the Revised Male Body Attitudes Scale suggest that this measure holds promise as an indicant of men\\'s attitudes toward their physical appearance. Limitations and strengths associated with the current research are discussed and directions for future research are outlined.

  4. Psychometric properties of the finnish version of the resilience scale and its short version

    Heidi Losoi; Senni Turunen; Minna Wäljas; Mika Helminen; Juha Öhman; Juhani Julkunen; Eija Rosti-Otajärvi

    2013-01-01

    Aim: To investigate the psychometric properties of the Finnish version of the Resilience Scale (RS) and its short version (RS-14), as well as the relationship of resilience with demographic variables and self-perceived health. Method: A standard procedure was used for translation of the scale, and 243 participants (75% women, mean age = 41.0; SD = 17.8) were evaluated with the RS, the RS-14, and the EuroQol 5D. Results: The mean level of resilience was found to be moderate. Both the RS and th...

  5. Wavelength dependence of scattering properties in the VIS-NIR and links with grain-scale physical and compositional properties

    Pilorget, C.; Fernando, J.; Ehlmann, B. L.; Schmidt, F.; Hiroi, T.

    2016-03-01

    Surface scattered sunlight carries important information about the composition and microtexture of surface materials, thus enabling tracing back the geological and climatic processes that occurred on the planetary body. Here we perform laboratory spectro-goniometric measurements of granular samples (45-75 μ m fraction) with different composition and physical properties over the VIS-NIR spectral range (0.4-2.5 μ m). To quantify the evolution of the scattering properties over the VIS-NIR, we use an inversion procedure based on a Bayesian approach to estimate photometric parameters from the Hapke radiative transfer model. The granular samples are also carefully characterized by optical and SEM techniques in order to link these scattering variations with the grains' physical properties. Results show that the scattering properties are wavelength-dependent and can vary significantly over the VIS-NIR spectral range. In particular, the phase function of a granular material is affected by both the absorptivity and the external and internal structure of the grains, from the millimeter scale down to the wavelength scale. Our results also confirm that the macroscopic roughness parameter, as defined by Hapke, is to first order correlated with the absorptivity of the particles, through multiple scattering effects, and thus mostly corresponds to a measurement of the particles shadowing. Photometric datasets, typically obtained at a given wavelength that can vary from one study to another, should therefore be compared and interpreted with caution when extrapolating across wavelengths. Our results also suggest that multi-wavelength photometry could potentially provide a much richer signature than with single-wavelength photometry, opening new perspectives into the characterization of surface materials.

  6. Psychometric Properties of the Persian Version of Self-Transcendence Scale: Adolescent Version

    AzamShirinabadi Farahani

    2016-04-01

    Full Text Available Background: Given the greater tendency during adolescence toward risk-taking, identifying and measuring the factors affecting the adolescents’ health is highly important to ensure the efficacy of health promoting interventions. One of these factors is self-transcendence. The aim of this study was to assess the psychometric features of the Self-Transcendence Scale (adolescents’ version in students in Tehran, the capital city of Iran. Methods: This research was conducted in 2015. For this purpose, 1210 high school students were selected through the multistage cluster sampling method. After the backward-forward translation, the psychometric properties of the scale were examined through the assessment of the (face and construct validity and reliability (internal consistency and stability of the scale. The construct validity was assessed using two methods, factor analysis, and convergence of the scale with the Hopefulness Scale for Adolescents. Results: The result of face validity was minor modifications in some words. The exploratory factor analysis resulted in the extraction of two dimensions, with explaining 52.79% of the variance collectively. In determining the convergent validity, the correlation between hopefulness score and self-transcendence score was r=0.47 (P<0.001. The internal consistency of the scale was determined using Cronbach’s alpha of 0.82 for the whole scale and 0.75 and 0.70 for each of the sub-scales. The stability reliability was found to have an ICC of 0.86 and a confidence interval of 95%. Conclusion: The Persian version of the Adolescents’ Self-Transcendence Scale showed an acceptable validity and reliability and can be used in the assessment of self-transcendence in Iranian adolescents.

  7. Psychometric Properties of the Persian Version of Self-Transcendence Scale: Adolescent Version

    Farahani, Azam Shirinabadi; Rassouli, Maryam; Yaghmaie, Farideh; Majd, Hamid Alavi; Sajjadi, Moosa

    2016-01-01

    Background: Given the greater tendency during adolescence toward risk-taking, identifying and measuring the factors affecting the adolescents’ health is highly important to ensure the efficacy of health promoting interventions. One of these factors is self-transcendence. The aim of this study was to assess the psychometric features of the Self-Transcendence Scale (adolescents’ version) in students in Tehran, the capital city of Iran. Methods: This research was conducted in 2015. For this purpose, 1210 high school students were selected through the multistage cluster sampling method. After the backward-forward translation, the psychometric properties of the scale were examined through the assessment of the (face and construct) validity and reliability (internal consistency and stability) of the scale. The construct validity was assessed using two methods, factor analysis, and convergence of the scale with the Hopefulness Scale for Adolescents. Results: The result of face validity was minor modifications in some words. The exploratory factor analysis resulted in the extraction of two dimensions, with explaining 52.79% of the variance collectively. In determining the convergent validity, the correlation between hopefulness score and self-transcendence score was r=0.47 (P<0.001). The internal consistency of the scale was determined using Cronbach’s alpha of 0.82 for the whole scale and 0.75 and 0.70 for each of the sub-scales. The stability reliability was found to have an ICC of 0.86 and a confidence interval of 95%. Conclusion: The Persian version of the Adolescents’ Self-Transcendence Scale showed an acceptable validity and reliability and can be used in the assessment of self-transcendence in Iranian adolescents. PMID:27218113

  8. Scale-free and small-world properties of earthquake network in Chile

    Pasten, Denisse; Munoz, Victor; Suzuki, Norikazu

    2010-01-01

    The properties of earthquake networks have been studied so far mainly for the seismic data sets taken from California, Japan and Iran, and features common in these regions have been reported in the literature. Here, an earthquake network is constructed and analyzed for the Chilean data to examine if the scale-free and small-world properties of the earthquake networks constructed in the other geographical regions can also be found in seismicity in Chile. It is shown that the result is affirmative: in all the regions both the exponent "gamma" of the power-law connectivity distribution and the clustering coefficient C take the universal invariant values "gamma ~1" and "C~0.85", respectively, as the cell size becomes larger than a certain value, which is the scale of coarse graining needed for constructing earthquake network. An interpretation for this remarkable result is presented based on physical considerations.

  9. Ionic conduction in solids: Comparing conductivity and modulus representations with regard to scaling properties

    In the literature, the electric modulus representation has been used to provide comparative analysis of the ion transport properties in different ion-conducting materials. In this paper we show that the modulus representation is not a suitable tool for such purposes. Our arguments derive from an examination of the scaling properties of both the ac conductivity σ*(ν) and the modulus M*(ν) which demonstrates how scaling that is inherent in σ*(ν) is lost in M*(ν) by inclusion of the high frequency permittivity ε'(∞), the latter quantity being unrelated to ion transport processes. Furthermore, we show how highly regarded shape changes of the modulus that occur with varying ion concentration are merely a manifestation of including ε'(∞) in the definition of M*(ν). We conclude then that the electric modulus formalism has resulted in misleading interpretations of the ion dynamics and, hence, should be discouraged

  10. Psychometric properties of the Drive for Muscularity Scale in Malay men.

    Swami, Viren; Barron, David; Lau, Poh Li; Jaafar, Jas Laile

    2016-06-01

    The Drive for Muscularity Scale (DMS) is a widely used measure in studies of men's body image, but few studies have examined its psychometric properties outside English-speaking samples. Here, we assessed the factor structure of a Malay translation of the DMS. A community sample of 159 Malay men from Kuala Lumpur, Malaysia, completed the DMS, along with measures of self-esteem, body appreciation, and muscle discrepancy. Exploratory factor analysis led to the extraction of two factors, differentiating attitudes from behaviours, which mirrors the parent scale. Both factors also loaded on to a higher-order drive for muscularity factor. The subscales of the Malay DMS had adequate internal consistencies and good convergent validity, insofar as significant relationships were reported with self-esteem, body appreciation, muscle discrepancy, and body mass index. These results indicate that the Malay DMS has acceptable psychometric properties and can be used to assess body image concerns in Malay men. PMID:27037873

  11. Thermal properties at Aespoe HRL. Analysis of distribution and scale factors

    A thermal model for the Aespoe HRL as well as a general strategy for thermal modelling is under development. As a part of that work, thermal conductivities have been modelled from reference values of thermal conductivity of different minerals and from the mineral composition of all Aespoe samples in the Sicada database. The produced thermal conductivity database has been analysed in terms of frequency, type of distribution, spatial distribution, variogram etc. A correction factor has been estimated to compensate for discrepancies between measured and calculated values. The calculated values have been corrected according to measured values. The data has been analysed according to different rock types. However, there are uncertainties in the base material of rock classification, mainly due to problem to distinguish between Aespoe diorite and Aevroe granite, but also because of different classification systems. There is a relationship between thermal conductivity and density for the rock types at Aespoe. Equations of the relationship have been developed based on all thermal conductivity, heat capacity and density measurements. The equations have been tested on two bore holes at Aespoe with promising results. It may be possible to evaluate the spatial distribution of the thermal properties from density loggings. However, more work is needed to develop a complete model including the handling of high and low density zones. There is an insufficient knowledge in the variation of thermal properties at different scales. If the whole variation within a rock type is in the cm-m scale the thermal influence on the canister is small. This is due to the fact that the small-scale variation in thermal properties is mainly averaged out in the 5-10 m scale. If the main variation within rock types is in the 5-10 m scale there is probably a significant effect on the canister temperature. However, it is likely that the observed variation occurs in both these scales. Simulation has been

  12. Scale-free and multifractal properties of fMRI signals during rest and task

    PhilippeCIUCIU

    2012-06-01

    Full Text Available Scale-free (or 1/f spectral properties in functional MRI (fMRI signals have been evidenced for a decade as intrinsic characteristics of ongoing brain activity [46]. Recently, they were shown to fluctuate across brain networks and to be modulated between rest and task [26]: Notably, Hurst exponent, quantifying long memory, decreases during task in activating and deactivating brain regions. Such results were obtained using tools assuming Gaussianity and self-similar models, while fMRI signals may significantly depart from those two assumptions [16] and were often based on voxelwise or regionwise independent analysis, hence showing large inter-subject variability. The present article aims at contributing to the analysis of scale-free properties of fMRI signals in two respects. First, a recent statistical analysis tool, the Wavelet Leader-based Multifractal formalism (WLMF, is used [45,3]. It shows improved estimation performance, and it is framed within a richer and more versatile class of models, that of multifractal processes. Second, scale-free properties are not investigated at the voxel or region scale. Instead, resting-state brain networks are extracted using a Multi-Subject Dictionary Learning (MSDL algorithm [40]: It produces both a set of spatial components, and a set of times series, for each component and each subject, that conveys ongoing dynamics in functional networks but also in artifacts. These combined tools are applied to an fMRI dataset comprising 12-subjects with resting-state and activation runs [36]. This dataset enabled us to confirm the task-related decrease of long memory in functional networks but also in artifacts making this feature not specific to functional networks. Also, most of fMRI signals appear multifractal at rest except in non-cortical regions. Task-related modulation of multifractality appears only significant in functional networks and thus becomes the key property to disentangle functional networks from

  13. Estimating local scaling properties for the classification of interstitial lung disease patterns

    Huber, Markus B.; Nagarajan, Mahesh B.; Leinsinger, Gerda; Ray, Lawrence A.; Wismueller, Axel

    2011-03-01

    Local scaling properties of texture regions were compared in their ability to classify morphological patterns known as 'honeycombing' that are considered indicative for the presence of fibrotic interstitial lung diseases in high-resolution computed tomography (HRCT) images. For 14 patients with known occurrence of honeycombing, a stack of 70 axial, lung kernel reconstructed images were acquired from HRCT chest exams. 241 regions of interest of both healthy and pathological (89) lung tissue were identified by an experienced radiologist. Texture features were extracted using six properties calculated from gray-level co-occurrence matrices (GLCM), Minkowski Dimensions (MDs), and the estimation of local scaling properties with Scaling Index Method (SIM). A k-nearest-neighbor (k-NN) classifier and a Multilayer Radial Basis Functions Network (RBFN) were optimized in a 10-fold cross-validation for each texture vector, and the classification accuracy was calculated on independent test sets as a quantitative measure of automated tissue characterization. A Wilcoxon signed-rank test was used to compare two accuracy distributions including the Bonferroni correction. The best classification results were obtained by the set of SIM features, which performed significantly better than all the standard GLCM and MD features (p < 0.005) for both classifiers with the highest accuracy (94.1%, 93.7%; for the k-NN and RBFN classifier, respectively). The best standard texture features were the GLCM features 'homogeneity' (91.8%, 87.2%) and 'absolute value' (90.2%, 88.5%). The results indicate that advanced texture features using local scaling properties can provide superior classification performance in computer-assisted diagnosis of interstitial lung diseases when compared to standard texture analysis methods.

  14. The impact of dust on the scaling properties of galaxy clusters

    da Silva, Antonio C.; Catalano, Andrea; Montier, Ludovic; Pointecouteau, Etienne; Lanoux, Joseph; Giard, Martin

    2008-01-01

    We investigate the effect of dust on the scaling properties of galaxy clusters based on hydrodynamic N-body simulations of structure formation. We have simulated five dust models plus a radiative cooling and adiabatic models using the same initial conditions for all runs. The numerical implementation of dust was based on the analytical computations of Montier and Giard (2004). We set up dust simulations to cover different combinations of dust parameters that put in evidence the effects of siz...

  15. Pilot study of the psychometric properties of the Emotional Exhaustion Scale for university students

    Fontana, Silvia Alicia

    2011-01-01

    The stated goal is to analyze the psychometric properties of the Emotional Exhaustion Scale (EES) (González-Ramírez and Landero-Hernández, 2007) in university students in Argentina. The results obtained in the EES were the verification of the unifactorial structure (KMO = .880; test of sphericity of Barttlet = 568,59, p< .001) and a high level of reliability (α = .86).

  16. Psychometric properties of the satisfaction with life scale (SWLS) in Iranian infertile women

    Maroufizadeh, Saman; Ghaheri, Azadeh; Omani Samani, Reza; Ezabadi, Zahra

    2016-01-01

    Background: Infertility is a global public health issue and may adversely affect life satisfaction. One of the most widely instruments used to assess life satisfaction is the Satisfaction with Life Scale (SWLS). Objective: The objective of this study was to examine the psychometric properties of the SWLS in Iranian infertile women. Materials and Methods: In this descriptive cross-sectional study, a total of 125 infertile women referring to Royan Institute in Tehran were selected by convenienc...

  17. Development and Datametric Properties of a Scale Measuring Students' Perceptions of The Classroom Assessment Environment

    Hussain Alkharusi

    2011-01-01

    Each classroom has its own assessment environment perceived by the students and springs from the teacher's assessment practices. Although students' perceptions of the assessment environment may influence their achievement-related outcomes, little attention has been given to the measurement of perceived classroom assessment environment. This study reports on the development and datametric properties of a scale measuring students' perceptions of the classroom assessment environment. A total of ...

  18. Development and Psychometric Properties of the Yoga Self-Efficacy Scale (YSES)

    Birdee, Gurjeet S.; Sohl, Stephanie J.; Wallston, Ken

    2016-01-01

    Background Yoga is a behavioral practice that uses physical movement, breathing, and meditation to improve health and promote personal transformation. Ancient yoga philosophy proposed that an individual’s confidence about yoga, a concept similar to self-efficacy, will affect the likelihood of improved health from yoga practice. The purpose of this study was to develop and examine the psychometric properties of a self-efficacy measure for yoga practice (the Yoga Self-Efficacy Scale; YSES). Met...

  19. The MUSIC of Galaxy Clusters II: X-ray global properties and scaling relations

    Biffi, Veronica; De Petris, Marco; Valdarnini, Riccardo; Yepes, Gustavo; Gottlöber, Stefan

    2014-01-01

    We present the X-ray properties and scaling relations of a large sample of clusters extracted from the Marenostrum MUltidark SImulations of galaxy Clusters (MUSIC) dataset. We focus on a sub-sample of 179 clusters at redshift z~0.11, with 3.2e14M_sun/hproperties of the intracluster medium (ICM), as X-ray temperature (T_X) and luminosity (L_X). T_X is found to slightly under-estimate the true mass-weighted temperature, although tracing fairly well the cluster total mass. We also study the effects of T_X on scaling relations with cluster intrinsic properties: total (M_500) and gas (M_g500) mass; integrated Compton parameter (Y_SZ) of the Sunyaev-Zel'dovich (SZ) thermal effect; Y_X=M_g500 T_X. We confirm that Y_X is a very good mass proxy, with a scatter on M_500-Y_X and Y_SZ-Y_X lower than 5%. The study of scaling relations among X-ray, intrinsic and S...

  20. Psychometric Properties of the Parent and Teacher ADHD Rating Scale (ADHD-RS)

    Makransky, Guido; Bilenberg, Niels

    2014-01-01

    Attention deficit/hyperactivity disorder (ADHD) is one of the most common psychiatric disorders in childhood and adolescence. Rating the severity of psychopathology and symptom load is essential in daily clinical practice and in research. The parent and teacher ADHD-Rating Scale (ADHD-RS) includes...... inattention and hyperactivity/impulsivity subscales and is one of the most frequently used scales in treatment evaluation of children with ADHD. An extended version, mADHD-RS, also includes an oppositional defiant disorder subscale. The partial credit Rasch model, which is based on item response theory, was...... used to test the psychometric properties of this scale in a sample of 566 Danish school children between 6 and 16 years of age. The results indicated that parents and teachers had different frames of reference when rating symptoms in the mADHD-RS. There was support for the unidimensionality of the...

  1. Scaling Properties of Rainfall-Induced Landslides Predicted by a Physically Based Model

    Alvioli, M; Rossi, M

    2013-01-01

    Natural landslides exhibit scaling properties, including the frequency of the size of the landslides, and the rainfall conditions responsible for landslides. Reasons for the scaling behavior of landslides are poorly known, and only a few attempts were made to describe the empirical evidences of the self-similar scaling behavior of landslides with physically based models. We investigate the possibility of using the TRIGRS code, a consolidated, physically motivated, numerical model to describe the stability conditions of natural slopes forced by rainfall, to determine the frequency of the area of the unstable slopes and the rainfall intensity-duration (I-D) conditions that result in landslides in a region.We apply TRIGRS in a portion of the Upper Tiber River Basin, Central Italy. The spatially distributed model predicts the stability conditions of individual grid cells, given the terrain and rainfall conditions. We run TRIGRS using multiple rainfall histories, and we compare the results to empirical evidences o...

  2. The necessary and sufficient conditions for returns to scale properties in generalized data envelopment analysis model

    WEI; Quanling(魏权龄); YU; Gang(于刚); LU; Jianshou(陆剑受)

    2002-01-01

    We give definitions on increasing, constant and decreasing returns to scale under thegeneralized data envelopment analysis (GDEA) model. The GDEA model possesses cone structures fordescribing evaluators' preferences toward different decision making units (DMU) and toward differentinput/output categories. The GDEA model contains many important DEA models as its subclasses.Based upon the definition, we discuss and rigorously prove the necessary and sufficient conditionsfor a DMU to have increasing, constant and decreasing returns to scale under a GDEA model, anddiscuss and clarify the differences and relationships of these conditions under different subclasses ofthe GDEA model. Furthermore, we describe a method based on a two-stage linear program to testreturns to scale properties.

  3. Tabulated In-Drift Geometric and Thermal Properties Used In Drift-Scale Models for TSPA-SR

    The objective of this calculation is to provide in-drift physical properties required by the drift-scale models (both two- and three-dimensional) used in total system performance assessments (TSPA). The physical properties include waste package geometry, waste package thermal properties, emplacement drift geometry including backfill and invert geometry and properties (both thermal and hydrologic), drip shield geometry and thermal properties, all tabulated in a single source

  4. Effect of personality item writing on psychometric properties of ideal-point and likert scales.

    Huang, Jialin; Mead, Alan D

    2014-12-01

    The present study was designed to investigate personality item-writing practices and their effect on the psychometric properties of personality items and scales. Personality items were developed based on ideal-point and dominance models, analyzed using the generalized graded unfolding model, and empirically classified as having an ideal-point or dominance form. Results suggested that writing dominance items were slightly easier (more successful) than writing ideal-point items, but this varied slightly by personality dimensions. Of 3 ideal-point item writing tactics, the "neutral" tactic was least successful; success writing "double-barreled" and "average" ideal-point items was comparable to that of dominance items. Three personality scales were then constructed using successful ideal-point and dominance items. Scales constructed using ideal-point items had substantially inferior psychometric properties, including lower score reliability, lower correlations with important criteria, and mixed test information results. However, lower predictive validity of ideal-point scale scores may be due to lower reliability of the scores. Practical and methodological implications were also discussed. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:24999752

  5. Effects of galactic disc inclination and resolution on observed GMC properties and Larson's scaling relations

    Pan, Hsi-An; Fujimoto, Yusuke; Tasker, Elizabeth J.; Rosolowsky, Erik; Colombo, Dario; Benincasa, Samantha M.; Wadsley, James

    2016-05-01

    With ALMA (Atacama Large Millimeter/submillimeter Array) making it possible to resolve giant molecular clouds (GMCs) in other galaxies, it is becoming necessary to quantify the observational bias on measured GMC properties. Using a hydrodynamical simulation of a barred spiral galaxy, we compared the physical properties of GMCs formed in position-position-position (PPP) space to the observational position-position-velocity (PPV) space. We assessed the effect of disc inclination: face-on (PPVface) and edge-on (PPVedge), and resolution: 1.5 pc versus 24 pc, on GMC properties and the further implications of using Larson's scaling relations for mass-radius and velocity dispersion-radius. The low-resolution PPV data are generated by simulating ALMA Cycle 3 observations using the CASA package. Results show that the median properties do not differ strongly between PPP and PPVface under both resolutions, but PPVedge clouds deviate from these two. The differences become magnified when switching to the lower, but more realistic resolution. The discrepancy can lead to opposite results for the virial parameter's measure of gravitational binding, and therefore the dynamical state of the clouds. The power-law indices for the two Larson's scaling relations decrease going from PPP, PPVedge to PPVface and decrease from high to low resolutions. We conclude that the relations are not entirely driven by the underlying physical origin and therefore have to be used with caution when considering the environmental dependence, dynamical state, and the extragalactic CO-to-H2 conversion factor of GMCs.

  6. Dependency structure and scaling properties of financial time series are related

    Morales, Raffaello; Di Matteo, T.; Aste, Tomaso

    2014-04-01

    We report evidence of a deep interplay between cross-correlations hierarchical properties and multifractality of New York Stock Exchange daily stock returns. The degree of multifractality displayed by different stocks is found to be positively correlated to their depth in the hierarchy of cross-correlations. We propose a dynamical model that reproduces this observation along with an array of other empirical properties. The structure of this model is such that the hierarchical structure of heterogeneous risks plays a crucial role in the time evolution of the correlation matrix, providing an interpretation to the mechanism behind the interplay between cross-correlation and multifractality in financial markets, where the degree of multifractality of stocks is associated to their hierarchical positioning in the cross-correlation structure. Empirical observations reported in this paper present a new perspective towards the merging of univariate multi scaling and multivariate cross-correlation properties of financial time series.

  7. Atomic scale properties of magnetic Mn-based alloys probed by Emission Mössbauer spectroscopy

    Mn-based alloys are characterized by a wealth of properties, which are of interest both from fundamental physics point of view and particularly attractive for different applications in modern technology: from magnetic storage to sensing and spin-based electronics. The possibility to tune their magnetic properties through post-growth thermal processes and/or stoichiometry engineering is highly important in order to target different applications (i.e. Mn$_{x}$Ga) or to increase their Curie temperature above room temperature (i.e. off-stoichiometric MnSi). In this project, the Mössbauer effect will be applied at $^{57}$Fe sites following implantation of radioactive $^{57}$Mn, to probe the micro-structure and magnetism of Mn-based alloys at the most atomic-scale. The proposed experimental plan is devoted to establish a direct correlation between the local structure and bulk magnetism (and other physical properties) of Mn-based alloys.

  8. Microstructure, mechanical, and biomimetic properties of fish scales from Pagrus major.

    Ikoma, Toshiyuki; Kobayashi, Hisatoshi; Tanaka, Junzo; Walsh, Dominic; Mann, Stephen

    2003-06-01

    The fish scale of Pagrus major has an orthogonal plywood structure of stratified lamellae, 1-2 microm in thickness, consisting of closely packed 70- to 80-nm-diameter collagen fibers. X-ray diffraction, energy-dispersive X-ray analysis, and infrared spectroscopy indicate that the mineral phase in the scale is calcium-deficient hydroxyapatite containing a small amount of sodium and magnesium ions, as well as carbonate anions in phosphate sites of the apatite lattice. The tensile strength of the scale is high (approximately 90 MPa) because of the hierarchically ordered structure of mineralized collagen fibers. Mechanical failure occurs by sliding of the lamellae and associated pulling out and fracture of the collagen fibers. In contrast, demineralized scales have significantly lower tensile strength (36 MPa), indicating that interactions between the apatite crystals and collagen fibers are of fundamental importance in determining the mechanical properties. Thermal treatment of fish scales to remove the organic components produces remarkable inorganic replicas of the native orthogonal plywood structure of the fibrillary plate. The biomimetic replica produced by heating to 873 K consists of stratified porous lamellae of c-axis-aligned apatite crystals that are long, narrow plates, 0.5-0.6 microm in length and 0.1-0.2 microm in width. The textured inorganic material remains intact when heated to 1473 K, although the size of the constituent crystals increases as a result of thermal sintering. PMID:12781659

  9. Deep Acting and Surface Acting Scale (DASAS – Adaptation of the metod and preliminary psychometric properties

    Maria Finogenow

    2015-07-01

    Full Text Available Background: This article presents the results of the study on the Polish version of the revised Emotional Labor Scale (ELS, developed by Lee and Brotheridge. The ELS measures deep acting and 2 aspects of surface acting (hiding feelings and faking emotions. Material and Methods: Psychometric characteristics of the Polish version of the ELS, named Deep Acting and Surface Acting Scale (DASAS, were analyzed in the preliminary study on 332 people working in various service professions. We verified factor structure of the scale, its reliability, and construct validity (that is, the relationships between its subscales and other measures of workplace functioning. Results: The results indicated that the DASAS has good psychometric properties which are comparable with the characteristics of the original scale. We replicated a 3-factor structure of the scale and confirmed its satisfying internal consistency and construct validity. Conclusions: The preliminary findings suggest that the DASAS is an adequate measure of deep and surface acting. Med Pr 2015;66(3:359–371

  10. A Brief Scale to Measure Problematic Sexually Explicit Media Consumption: Psychometric Properties of the Compulsive Pornography Consumption (CPC) Scale among Men who have Sex with Men

    Noor, Syed WB; Simon Rosser, B. R.; Erickson, Darin J.

    2015-01-01

    Although the phenomenon of hypersexuality has been described in the literature, and scales of compulsive sexual behavior have been published, the existing measures do not assess compulsive sexually explicit media (SEM) consumption. This study tested the psychometric properties of a new scale, the Compulsive Pornography Consumption (CPC). Exploratory and confirmatory factor analyses results showed good psychometric performance of a five item two factor preoccupation-compulsivity solution. As hypothesized, the scale correlates positively with compulsive sexual behavior, internalized homonegativity, and negatively with sexual self-esteem. The scale will enable researchers to investigate the etiologic factors of compulsive SEM use, and enable clinicians to assess problematic consumption. PMID:25838755

  11. Bio-inspired dual surface modification to improve tribological properties at small-scale

    Singh, R. Arvind; Pham, Duc-Cuong; Kim, Jinseok; Yang, Sungwook; Yoon, Eui-Sung

    2009-02-01

    In miniaturized devices like micro/nano-electro-mechanical systems (MEMS/NEMS), the critical forces, namely adhesion and friction restrict the smooth operation of the elements that are in relative motion. MEMS/NEMS are traditionally made of silicon, whose tribological properties are not good. In this paper, we present an investigation on the approach of dual surface modification of silicon surfaces and their tribological properties at micro-scale. The dual surface modification is a combination of topographical and chemical modifications. As the topographical modification, micro-patterns with varying shapes of pillars and channels were fabricated on Si(1 0 0) wafer surfaces using photolithography method. Chemical modification included the coating of micro-patterns with diamond-like carbon (DLC) and Z-DOL (perfluoropolyether, PFPE) thin films. The surfaces with combined modification were evaluated for their micro-friction behavior in comparison with those of bare Si(1 0 0) flat surfaces and the topographically/chemically modified silicon surfaces. Results showed that the surfaces with dual modification exhibited superior tribological properties. These results indicate that a combination of topographical and chemical modification is very effective in enhancing tribological properties at small-scale. The combined surface treatments such as the ones investigated in the current work could be useful for tribological applications in small-scale devices such as MEMS/NEMS. The motivation for undertaking the dual modification approach comes from an earlier observation made on the significant influence of the surface characteristics of lotus leaf on its micro-friction behavior.

  12. Biome-Scale Forest Properties in Amazonia Based on Field and Satellite Observations

    Liana O. Anderson

    2012-05-01

    Full Text Available Amazonian forests are extremely heterogeneous at different spatial scales. This review intends to present the large-scale patterns of the ecosystem properties of Amazonia, and focuses on two parts of the main components of the net primary production: the long-lived carbon pools (wood and short-lived pools (leaves. First, the focus is on forest biophysical properties, and secondly, on the macro-scale leaf phenological patterns of these forests, looking at field measurements and bringing into discussion the recent findings derived from remote sensing dataset. Finally, I discuss the results of the three major droughts that hit Amazonia in the last 15 years. The panorama that emerges from this review suggests that slow growing forests in central and eastern Amazonia, where soils are poorer, have significantly higher above ground biomass and higher wood density, trees are higher and present lower proportions of large-leaved species than stands in northwest and southwest Amazonia. However, the opposite pattern is observed in relation to forest productivity and dynamism, which is higher in western Amazonia than in central and eastern forests. The spatial patterns on leaf phenology across Amazonia are less marked. Field data from different forest formations showed that new leaf production can be unrelated to climate seasonality, timed with radiation, timed with rainfall and/or river levels. Oppositely, satellite images exhibited a large-scale synchronized peak in new leaf production during the dry season. Satellite data and field measurements bring contrasting results for the 2005 drought. Discussions on data processing and filtering, aerosols effects and a combined analysis with field and satellite images are presented. It is suggested that to improve the understanding of the large-scale patterns on Amazonian forests, integrative analyses that combine new technologies in remote sensing and long-term field ecological data are imperative.

  13. Psychometric properties and construct validity of the Muscle Appearance Satisfaction Scale among Hungarian men.

    Babusa, Bernadett; Urbán, Róbert; Czeglédi, Edit; Túry, Ferenc

    2012-01-01

    Limited studies have evaluated the psychometric properties of the Muscle Appearance Satisfaction Scale (MASS), a measure of muscle dysmorphia, in different cultures and languages. The aims were to examine the psychometric properties of the Hungarian version of the MASS (MASS-HU), and to investigate its relationship with self-esteem and exercise-related variables. Two independent samples of male weight lifters (ns=289 and 43), and a sample of undergraduates (n=240) completed the MASS, Eating Disorder Inventory, and Rosenberg Self-esteem Scale. Exploratory factor analysis supported the original five-factor structure of the MASS only in the weight lifter sample. The MASS-HU had excellent scale score reliability and good test-retest reliability. The construct validity of the MASS-HU was tested with multivariate regression analyses which indicated an inverse relationship between self-esteem and muscle dysmorphia. The 18-item MASS-HU was found to be a useful measure for the assessment of muscle dysmorphia among male weight lifters. PMID:21962394

  14. Some psychometric properties of the Chinese version of the Modified Dental Anxiety Scale with cross validation

    Lahti Satu

    2008-03-01

    Full Text Available Abstract Objective To assess the factorial structure and construct validity for the Chinese version of the Modified Dental Anxiety Scale (MDAS. Materials and methods A cross-sectional survey was conducted in March 2006 from adults in the Beijing area. The questionnaire consisted of sections to assess for participants' demographic profile and dental attendance patterns, the Chinese MDAS and the anxiety items from the Hospital Anxiety and Depression Scale (HADS. The analysis was conducted in two stages using confirmatory factor analysis and structural equation modelling. Cross validation was tested with a North West of England comparison sample. Results 783 questionnaires were successfully completed from Beijing, 468 from England. The Chinese MDAS consisted of two factors: anticipatory dental anxiety (ADA and treatment dental anxiety (TDA. Internal consistency coefficients (tau non-equivalent were 0.74 and 0.86 respectively. Measurement properties were virtually identical for male and female respondents. Relationships of the Chinese MDAS with gender, age and dental attendance supported predictions. Significant structural parameters between the two sub-scales (negative affectivity and autonomic anxiety of the HADS anxiety items and the two newly identified factors of the MDAS were confirmed and duplicated in the comparison sample. Conclusion The Chinese version of the MDAS has good psychometric properties and has the ability to assess, briefly, overall dental anxiety and two correlated but distinct aspects.

  15. Diffusion in time-dependent random environments: mass fluctuations and scaling properties

    A mass-ejection model in a time-dependent random environment with both temporal and spatial correlations is introduced. When the environment has a finite correlation length, individual particle trajectories are found to diffuse at large times with a displacement distribution that approaches a Gaussian. The collective dynamics of diffusing particles reaches a statistically stationary state, which is characterized in terms of a fluctuating mass density field. The probability distribution of density is studied numerically for both smooth and non-smooth scale-invariant random environments. Competition between trapping in the regions where the ejection rate of the environment vanishes and mixing due to its temporal dependence leads to large fluctuations of mass. These mechanisms are found to result in the presence of intermediate power-law tails in the probability distribution of the mass density. For spatially differentiable environments, the exponent of the right tail is shown to be universal and equal to -3/2. However, at small values, it is found to depend on the environment. Finally, spatial scaling properties of the mass distribution are investigated. The distribution of the coarse-grained density is shown to possess some rescaling properties that depend on the scale, the amplitude of the ejection rate and the Hölder exponent of the environment. (paper)

  16. Constraints on dark-matter properties from large-scale structure

    Kunz, Martin; Nesseris, Savvas; Sawicki, Ignacy

    2016-07-01

    We use large-scale cosmological observations to place constraints on the dark-matter pressure, sound speed and viscosity and infer a limit on the mass of warm-dark-matter particles. Measurements of the cosmic microwave background anisotropies constrain the equation of state and sound speed of the dark matter (DM) at last scattering at the per mille level. Since the redshifting of collisionless particles universally implies that these quantities scale like a-2 absent shell crossing, we infer that today w(DM )dark-matter models: For warm dark matter these constraints imply m >70 eV , assuming it decoupled while relativistic around the same time as the neutrinos; for a cold relic, we show that m >100 eV . We separately constrain the properties of the DM fluid on linear scales at late times and find upper bounds cs,(DM ) 2<1 0-5.9 and cvis,(DM) 2<1 0-5.7 , with no detection of nondust properties for the DM.

  17. Pre-scaled two-parameter Gauss-Newton image reconstruction to reduce property recovery imbalance

    Gauss-Newton image reconstruction in microwave imaging can be formulated in terms of a single complex quantity, the wave number squared (k2), with the understanding that the relative permittivity and conductivity images can be extracted afterwards through a simple constitutive relationship. However, this approach ignores the fact that the magnitude of the average real and imaginary components can be considerably out of balance depending on the operating frequency and tissue characteristics which can inadvertently imbalance the process in favour of one parameter over the other. In an effort to achieve property recovery which is balanced, we introduce a pre-scaling procedure at the property update stage of the reconstruction. Utilization of this concept in conjunction with our two-step regularization process for both simulation and phantom experiments demonstrates that the penalty term weighting parameters for the optimal mean-squared property errors for the two recovered distributions (relative permittivity and conductivity) together with that yielding the lowest least-squared electric field error coincide only when the scaling is applied. The scheme provides a means for simultaneous optimization of the two permittivity and conductivity images. (author)

  18. Ecosystem functional properties - useful links to organism and to global scale?

    Reichstein, M.

    2015-12-01

    Classical biogeographical observations tell us that ecosystems (vegetation and soils) strongly respond to climate variation in terms of their structure and function. On the other hand the influence of vegetation function on climate via exchange of matter and energy with the atmosphere has become evident in the last decades via observational and modeling studies. Recent continuous observations of this exchange of CO2, H2O and sensible heat within the global observation network FLUXNET have enabled us to quantify ecosystem function in response to large eco-climatological spatio-temporal variability of climate. We see that ecosystem function co-varies strongly with climate, but that climate alone does not suffice to explain the variation in total. Instead vegetation biophysical and structural parameters co-determine the exchange of carbon, water and energy between the ecosystem and the atmosphere. By combining ecosystem level observation and information of spatial meteorological and vegetation remote sensing covariates we can infer global patterns of ecosystem atmosphere fluxes and derive key ecosystem functional properties globally. While this approach is powerful and meteorological and vegetation structural predictors explain more than 70% of the spatial variation of monthly fluxes at FLUXNET sites, it ignores the effect of ecophysiological vegetation properties, which is expected from plant physiological leaf or whole-plant studies. Hence, future research has to more strongly link the organismic trait information with ecosystem functional properties. For this we propose a framework that involves 1) the correlation of community aggregated traits with flux-derived ecosystem properties across a range of ecosystems, 2) the up-scaling of vegetation traits using spatially distributed geo-ecological co-variates and the comparison with global ecosystem functional properties and their co-variation with climate, 3) the use of vegetation traits instead of vegetation classes

  19. What drives basin scale spatial variability of snowpack properties in northern Colorado?

    Sexstone, G. A.; Fassnacht, S. R.

    2014-03-01

    This study uses a combination of field measurements and Natural Resource Conservation Service (NRCS) operational snow data to understand the drivers of snow density and snow water equivalent (SWE) variability at the basin scale (100s to 1000s km2). Historic snow course snowpack density observations were analyzed within a multiple linear regression snow density model to estimate SWE directly from snow depth measurements. Snow surveys were completed on or about 1 April 2011 and 2012 and combined with NRCS operational measurements to investigate the spatial variability of SWE near peak snow accumulation. Bivariate relations and multiple linear regression models were developed to understand the relation of snow density and SWE with terrain variables (derived using a geographic information system (GIS)). Snow density variability was best explained by day of year, snow depth, UTM Easting, and elevation. Calculation of SWE directly from snow depth measurement using the snow density model has strong statistical performance, and model validation suggests the model is transferable to independent data within the bounds of the original data set. This pathway of estimating SWE directly from snow depth measurement is useful when evaluating snowpack properties at the basin scale, where many time-consuming measurements of SWE are often not feasible. A comparison with a previously developed snow density model shows that calibrating a snow density model to a specific basin can provide improvement of SWE estimation at this scale, and should be considered for future basin scale analyses. During both water year (WY) 2011 and 2012, elevation and location (UTM Easting and/or UTM Northing) were the most important SWE model variables, suggesting that orographic precipitation and storm track patterns are likely driving basin scale SWE variability. Terrain curvature was also shown to be an important variable, but to a lesser extent at the scale of interest.

  20. Scaling behavior and morphological properties of the interfaces obtained by the multilayer deposition process

    The aim of the present work was to study numerically the scaling behavior and the morphological properties of the interfaces generated by the multilayer deposition process. We have noticed that, in the case where the ratio of the surface diffusion coefficient to the deposition rate reaches high values D/F > > 1, the interface consists of mound structures. By using the dynamic scaling, we have shown that the height–height correlation function scales with time t and length l as G(l,t) ∼ lαf(t/lα/β) with β = 0.25 ± 0.05 and α = 0.51 ± 0.02. These exponent values are equal to the ones predicted by the Edwards–Wilkinson approach. Besides, our results are in agreement with the growth system of Cu/Cu(100) at 300 K which has been characterized in more detail by a combined scanning tunneling microscopy and spot profile analysis — low energy electronic diffusion study. Moreover, by considering two different methods, we have examined the fractal aspect of the obtained interfaces. - Highlights: • The adlayer interfaces present mound morphologies. • The adlayer interfaces scale with the Family–Vicsek law. • The critical exponents (α, β) are in agreement with those of Edwards–Wilkinson approach

  1. Scaling Behavior and Magnetic Properties for SmxCo5 Films

    2006-01-01

    SmxCo5 (x=1.3, 0.7, 0.4) thin films were prepared by magnetron co-sputtering technique. The samples were annealed at 723 K under Ar atmosphere. The annealed time was chosen as 30 min. The hysteresis loops of the samples were measured under the ac applied magnetic field with the period Tp (2π/ω), H(t)=H0sin(ωt), by vibrating sample magnetometer (VSM). The experimental results indicate that, (1) the average hysteresis loop areas as functions of the values of H0 and ω display a power scaling law with the exponents, A=A0+H0αωβ; (2) the x composition of SmxCo5 film has evident effect on the scaling behavior and magnetic properties; (3) the anisotropy scaling exponents exist clearly in the anisotropy SmxCo5 thin films. Moreover, the scaling behavior of the anisotropy magnetic film was also simulated with Monte Carlo method. The simulated results are consistent with the experimental fact.

  2. Effects of baryons on the statistical properties of large scale structure of the Universe

    Observations of weak gravitational lensing will provide strong constraints on the cosmic expansion history and the growth rate of large scale structure, yielding clues to the properties and nature of dark energy. Their interpretation is impacted by baryonic physics, which are expected to modify the total matter distribution at small scales. My work has focused on determining and modeling the impact of baryons on the statistics of the large scale matter distribution in the Universe. Using numerical simulations, I have extracted the effect of baryons on the power spectrum, variance and skewness of the total density field as predicted by these simulations. I have shown that a model based on the halo model construction, featuring a concentrated central component to account for cool condensed baryons, is able to reproduce accurately, and down to very small scales, the measured amplifications of both the variance and skewness of the density field. Because of well-known issues with baryons in current cosmological simulations, I have extended the central component model to rely on as many observation-based ingredients as possible. As an application, I have studied the effect of baryons on the predictions of the upcoming Euclid weak lensing survey. During the course of this work, I have also worked at developing and extending the RAMSES code, in particular by developing a parallel self-gravity solver, which offers significant performance gains, in particular for the simulation of some astrophysical setups such as isolated galaxy or cluster simulations. (author)

  3. Psychometric properties of the Family Resilience Assessment Scale: A Singaporean perspective.

    Chew, Judith; Haase, Anne M

    2016-08-01

    Families of young people with chronic illnesses are more likely to experience higher levels of stress. In turn, their ability to cope with multiple demands is likely to affect young people's adaptation. The purpose of this study was to examine psychometric properties of the Family Resilience Assessment Scale (FRAS), an assessment tool that measures the construct of family resilience. A total of 152 young people with epilepsy, aged 13 to 16years old, from KK Women's and Children's Hospital, Singapore, completed the FRAS along with the Rosenberg Self-Esteem Scale. Factor structure of the FRAS was examined. Exploratory factor analysis resulted in a 7-factor solution - meaning-making and positive outlook, transcendence and spirituality, flexibility and connectedness, social and economic resources (community), social and economic resources (neighbors), clarity and open emotional expression, and collaborative problem-solving - accounting for 83.0% of the variance. Internal consistency of the scale was high (α=0.92). Family resilience was significantly correlated with higher levels of self-esteem. Our study provides preliminary findings that suggest that FRAS is a reliable and valid scale for assessing the construct of family resilience among young people with epilepsy in Singapore. PMID:27337164

  4. Microstructure and mechanical properties of large-scale ingots of the Zr-1Mo alloy

    A large-scale ingot of Zr-1Mo alloy was produced for industrial manufacturing to investigate whether it is possible to produce an ingot with homogeneity. The homogeneous ingot with a chemical composition of Zr-1 mass%Mo was prepared successfully. The microstructure, mechanical properties, and magnetic susceptibility were evaluated. The microstructure showed a coarse colony structure of a plate-like α phase and a thin β phase. An ω phase precipitation was observed in the β phase. Elongation of 23% and magnetic susceptibility of 12.4 × 10−9 m3 kg−1 (0.98 × 10−6 cm3 g−1) were achieved. We found that it is possible to produce a homogeneous large-scale ingot of Zr-1Mo with high elongation and low magnetic susceptibility. (author)

  5. Scaling of Macroscopic Properties of Porous Sediments Experiencing Compaction: Implications for Geothermal Gradient and Methane Inventory

    Goldobin, Denis S

    2011-01-01

    Porous sediments in geological systems experience stress by the above-laying mass and consequent compaction, which may be significantly nonuniform across the massif. We derive scaling laws for the compaction of sediments of similar geological origin. With these laws, we evaluate the dependence of the transport properties of a fluid-saturated porous medium (permeability, effective molecular diffusivity, hydrodynamic dispersion, and thermal conductivity) on its porosity. In particular, we demonstrate irrelevance of the assumption of a uniform geothermal gradient for systems with nonuniform compaction and importance of the derived scaling laws for mathematical modelling of methane hydrate deposits, which are believed to have potential for impact on global climate change and Glacial-Interglacial cycles.

  6. Using two scaling exponents to describe the mechanical properties of swollen elastomers

    Okumura, Dai; Kondo, Akifumi; Ohno, Nobutada

    2016-05-01

    We study the ability of two scaling exponents to describe the mechanical properties of swollen elastomers. Swelling effects on the Young's modulus and osmotic pressure of swollen elastomers at equilibrium swelling are investigated using literature data and the Flory-Rehner free energy function. An extended model is developed by introducing two scaling exponents into elastic strain energy functions that are separated into deviatoric and volumetric components. This extended model satisfactorily reproduces the two different swelling effects, and also predicts swelling-induced rupture. The predicted tendency readily explains experimental observations well, i.e., swelling-induced rupture occurs when small extensions are applied in good solvents, and elucidates the mechanism of swelling-induced rupture of elastomers.

  7. Psychometric properties of the Chinese translation of the proactive personality scale.

    Zhou, Le; Shi, Junqi

    2009-08-01

    The purpose of the present study was to examine the psychometric properties of the Chinese translation of the Proactive Personality Scale. Four samples were surveyed. In Sample 1 and Sample 2, exploratory and confirmatory factor analysis results confirmed the unidimensional structure of the 10-item abbreviated version of the scale. In Sample 2, Proactive Personality scores were found to be positively correlated with the personality factors of Extraversion, Conscientiousness, Openness, and Agreeableness, and negatively correlated with Neuroticism. In Sample 3, Proactive Personality was found to be positively related to self-efficacy and political skill. In Sample 4, demographics controlled, Proactive Personality explained significant incremental variance in the employees' self-rated career satisfaction and job performance as rated by immediate supervisors. PMID:19810432

  8. Large-Scale Sunyaev-Zeldovich Effect Measuring Statistical Properties with Multifrequency Maps

    Cooray, A R; Tegmark, M; Cooray, Asantha R.; Hu, Wayne; Tegmark, Max

    2000-01-01

    We study the prospects for extracting detailed statistical properties of theSunyaev-Zel'dovich (SZ) effect associated with large scale structure usingupcoming multifrequency CMB experiments. The greatest obstacle to detecting thelarge-angle signal is the confusion noise provided by the primary anisotropiesthemselves, and to a lesser degree galactic and extragalactic foregrounds. Weemploy multifrequency subtraction techniques and the latest foregrounds modelsto determine the detection threshold for the Boomerang, MAP (several \\muK) andPlanck CMB (sub \\muK) experiments. Calibrating a simplified biased-tracer modelof the gas pressure off recent hydrodynamic simulations, we estimate the SZpower spectrum, skewness and bispectrum through analytic scalings and N-bodysimulations of the dark matter. We show that the Planck satellite should beable to measure the SZ effect with sufficient precision to determine its powerspectrum and higher order correlations, e.g. the skewness and bispectrum.Planck should also be able t...

  9. Constraints on Dark Energy, Observable-mass Scaling Relations, Neutrino Properties and Gravity from Galaxy Clusters

    Rapetti Serra, David Angelo

    Using a data set of 238 cluster detections drawn from the ROSAT All-Sky Survey and X-ray follow-up observations from the Chandra X-ray Observatory and/or ROSAT for 94 of those clusters we obtain tight constraints on dark energy, both luminosity-mass and temperature-mass scaling relations, neutrino...... properties and gravity. I will present the novel statistical framework we employed to self-consistently and simultaneously constrain cosmology and observable-mass scaling relations accounting for survey biases, parameter covariances and systematic uncertainties. Allowing the dark energy equation of state...... and the linear growth index to take any constant values, we find no evidence for departures from the standard cosmological paradigm – General Relativity plus a cosmological constant and cold dark matter. I will review in detail our results and demonstrate the power of X-ray cluster studies to constrain both...

  10. Psychometric properties of the Spanish Human System Audit Short-Scale of transformational leadership.

    Berger, Rita; Romeo, Marina; Guardia, Joan; Yepes, Montserrat; Soria, Miguel Angel

    2012-03-01

    The aim of this research is to examine the psychometric properties of a Spanish version of the Human System Audit transformational leadership short-scale (HSA-TFL-ES). It is based on the concept of Bass developed in 1985. The HSA-TFL is a part of the wider Human System Audit frame. We analyzed the HSA-TFL-ES in five different samples with a total number of 1,718 workers at five sectors. Exploratory Factor Analysis corroborated a single factor in all samples that accounted for 66% to 73% of variance. The internal consistency in all samples was good (alpha = .92 - .95). Evidence was found for the convergent validity of the HSA-TFL-ES and the Multifactor Leadership Questionnaire. These results suggested that the HSA-TFL short-scale is a psychometrically sound measure of this construct and can be used for a combined and first overall measurement. PMID:22379726

  11. Psychometric properties of the Mexican version of the Maternal Antenatal Attachment Scale

    Ruth Eunice Castro Mata

    2015-07-01

    Full Text Available Pregnancy is the period for fetal development and growth. In parallel, for the mother is also a complex adaptation time, which in addition to experience physical changes, there is a greater awareness about their child that creates an affectively approach to his or her. The bond between mother and fetus helps to mitigate physical and emotional problems in this stage, preparing them for the future relationship between mother and child attachment. The objective in this study is to evaluate the psychometric properties of the Spanish translation of the MAAS. Reverse translation process was used in order to achieve a conceptual equivalence of the scale. The study included 169 pregnant women attending prenatal care. Exploratory factor analysis indicated two factors with 36.8% of the explained variance, along with 5 items that were removed. The total scale showed a Cronbach’s alpha of 0.694, Quality subscale obtained an alpha of .771 and .550 Preocupation subscale.

  12. Psychometric properties of the Thai version of the Diabetes Distress Scale in diabetic seniors

    Thanakwang K

    2014-08-01

    Full Text Available Kattika Thanakwang, Wantana Thinganjana, Roumporn Konggumnerd Institute of Nursing, Suranaree University of Technology, Nakhon Ratchasima, Thailand Background: The Diabetes Distress Scale (DDS is an important measure of diabetes-related emotional distress that has been widely used in the Western world. In Thailand, there is a lack of reliable and valid scales for assessing distress levels in diabetes patients, specifically in older adults.Objectives: The main objectives of this study were to adapt the DDS for use in Thai diabetic elderly and to evaluate its psychometric properties. Methods: The 17-item DDS was linguistically adapted using forward–backward translation and administered to 170 diabetic patients ≥60 years selected from diabetes outpatient clinics of four hospitals in Buriram, Thailand. Statistical analyses included exploratory factor analysis, internal consistency, convergent validity, and test–retest reliability. Results: During factor analysis, a three-factor solution was found to be reasonable for the sub-dimensions of emotional and regimen-related burden (ten items, physician- and nurse-related distress (four items, and diabetes-related interpersonal distress (three items. The Cronbach’s alpha coefficient for the total score was 0.95 and varied between 0.85 and 0.96 in the three subscales. The results provided evidence that supports the convergent validity of the Thai version of the DDS as well as its stability. Conclusion: The Thai version of the DDS has acceptable psychometric properties. It enables assessment of diabetes-specific distress in elderly patients and has the advantage of being easy to use in both clinical and research settings. Keywords: diabetes distress scale, psychometric properties, diabetes-related stress, diabetic elderly

  13. The MUSIC of galaxy clusters - II. X-ray global properties and scaling relations

    Biffi, V.; Sembolini, F.; De Petris, M.; Valdarnini, R.; Yepes, G.; Gottlöber, S.

    2014-03-01

    We present the X-ray properties and scaling relations of a large sample of clusters extracted from the Marenostrum MUltidark SImulations of galaxy Clusters (MUSIC) data set. We focus on a sub-sample of 179 clusters at redshift z ˜ 0.11, with 3.2 × 1014 h-1 M⊙ MUSIC clusters reasonably resemble the self-similar prediction, especially for correlations involving TX. The observational approach also allows for a more direct comparison with real clusters, from which we find deviations mainly due to the physical description of the ICM, affecting TX and, particularly, LX.

  14. Atomic-Scale Magnetic Properties of Truly 3d-Diluted ZnO

    Mantovan, Roberto; Gunnlaugsson, Haraldur Pall; Johnston, Karl; Masenda, Hilary; Mølholt, Torben Esmann; Naidoo, Deena; Ncube, Mehluli; Shayestehaminzadeh, Seyedmohammad; Bharuth-Ram, Krish; Fanciulli, Marco; Gislason, Haflidi Petur; Langouche, Guido; Olafsson, Sveinn; Pereira, Lino M. C.; Wahl, Ulrich; Torelli, Piero; Weyer, Gerd

    In search for dilute magnetic semiconductors, the magnetic properties at the atomic-scale of Fe atoms incorporated in ZnO, in a concentration range of more than five orders of magnitude from 1 x 10(-5) to 2.2 at% have been probed using emission 57 Fe Mossbauer spectroscopy on implanted Mn-57 and Co...... any signature of magnetic ordering up to 2.2 at%. Despite the many reports of dilute magnetism in 3d-doped ZnO, this atomic level study shows no evidence of any long-range magnetic ordering between isolated Fe atoms incorporated in the ZnO lattice....

  15. Effect of Nano Scale Fe Doping on Superconducting Properties of MgB2

    S. X. Dou; Soltanian, S.; Zhao, Y.; Getin, E.; Chen, Z.; Horvat, J.

    2004-01-01

    Iron is an important sheath material for fabrication of MgB2 wires. However, the effect of Fe doping on the superconducting properties of MgB2 remains controversial. In this work, we present results of nano-scale Fe particle doping in to MgB2. The Fe doping experiments were performed using both bulk and thin film form. It was found that Fe doping did not affect the lattice parameters of MgB2, as evidenced by the lack of change in the XRD peak positions for MgB2. Because of the high reactivity...

  16. Perceived Autonomy in Old Age scale: Factor structure and psychometric properties of the Polish adaptation

    Aleksandra Kroemeke

    2015-01-01

    Objectives Sense of autonomy – the possibility to choose and decide – is one of the markers of positive and active aging. The goal of this study was to examine the Polish adaptation of the Perceived Autonomy in Old Age (PAA) scale and to determine its internal structure and psychometric properties: reliability, as well as construct and discriminant validity. Methods 277 seniors (female=187; male=90), without cognitive function disorders aged 60 to 100 (M=77.4; SD=9.2) took part in t...

  17. Psychometric Properties of the Spanish Human System Audit Short-Scale of Transformational Leadership

    Berger, Rita; Romeo Delgado, Marina; Guàrdia Olmos, Joan; Yepes i Baldó, Montserrat; Soria Verde, Miguel Ángel

    2012-01-01

    The aim of this research is to examine the psychometric properties of a Spanish version of the Human System Audit transformational leadership short-scale (HSA-TFL-ES). It is based on the concept of Bass developed in 1985. The HSA-TFL is a part of the wider Human System Audit frame. We analyzed the HSA-TFL-ES in five different samples with a total number of 1,718 workers at five sectors. Exploratory Factor Analysis corroborated a single factor in all samples that accounted for 66% to 73% of va...

  18. Analysis of Carbon Nanotubes on the Mechanical Properties at Atomic Scale

    Xiaowen Lei

    2011-01-01

    Full Text Available This paper aims at developing a mathematic model to characterize the mechanical properties of single-walled carbon nanotubes (SWCNTs. The carbon-carbon (C–C bonds between two adjacent atoms are modeled as Euler beams. According to the relationship of Tersoff-Brenner force theory and potential energy acting on C–C bonds, material constants of beam element are determined at the atomic scale. Based on the elastic deformation energy and mechanical equilibrium of a unit in graphite sheet, simply form ED equations of calculating Young's modulus of armchair and zigzag graphite sheets are derived. Following with the geometrical relationship of SWCNTs in cylindrical coordinates and the structure mechanics approach, Young's modulus and Poisson's ratio of armchair and zigzag SWCNTs are also investigated. The results show that the approach to research mechanical properties of SWCNTs is a concise and valid method. We consider that it will be useful technique to progress on this type of investigation.

  19. Effects of Galactic Disc Inclination and Resolution on Observed GMC Properties and Larson's Scaling Relations

    Pan, Hsi-An; Tasker, Elizabeth J; Rosolowsky, Erik; Colombo, Dario; Benincasa, Samantha M; Wadsley, James

    2016-01-01

    With ALMA making it possible to resolve giant molecular clouds (GMCs) in other galaxies, it is becoming necessary to quantify the observational bias on measured GMC properties. Using a hydrodynamical simulation of a barred spiral galaxy, we compared the physical properties of GMCs formed in position-position-position space (PPP) to the observational position-position-velocity space (PPV). We assessed the effect of disc inclination: face-on (PPV_face) and edge-on (PPV_edge), and resolution: 1.5 pc versus 24 pc, on GMC properties and the further implications of using Larson's scaling relations for mass-radius and velocity dispersion-radius. The low-resolution PPV data are generated by simulating ALMA Cycle 3 observations using the CASA package. Results show that the median properties do not differ strongly between PPP and PPV_face under both resolutions, but PPV_edge clouds deviate from these two. The differences become magnified when switching to the lower, but more realistic resolution. The discrepancy can le...

  20. Magnetic properties and scale-up of nanostructured cobalt carbide permanent magnetic powders

    Zamanpour, Mehdi, E-mail: zamanpour.m@husky.neu.edu; Bennett, Steven; Taheri, Parisa; Chen, Yajie [Center for Microwave Magnetic Materials and Integrated Circuits, Northeastern University, Boston, Massachusetts 02115 (United States); Harris, Vincent G. [Center for Microwave Magnetic Materials and Integrated Circuits, Northeastern University, Boston, Massachusetts 02115 (United States); Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts 02115 (United States)

    2014-05-07

    Co{sub x}C magnetic nanoparticles were successfully synthesized via a modified polyol process without using a rare-earth catalyst during the synthesis process. The present results show admixtures of Co{sub 2}C and Co{sub 3}C phases possessing magnetization values exceeding 45 emu/g and coercivity values exceeding 2.3 kOe at room temperature. Moreover, these experiments have illuminated the important role of surfactants, reaction temperature, and reaction duration on the crystallographic structure and magnetic properties of Co{sub x}C, while tetraethylene glycol was employed as a reducing agent. The role of the ratios of Co{sub 2}C and Co{sub 3}C phases in the admixture magnetic properties is discussed. The crystallographic structure and particle size of the Co{sub x}C nanoparticles were characterized by X-ray diffractometry and scanning electron microscopy. Vibrating sample magnetometry was used to determine magnetic properties. Scale-up of synthesis to more than 5 g per batch was demonstrated with no significant degradation of magnetic properties.

  1. A Brief Scale to Measure Problematic Sexually Explicit Media Consumption: Psychometric Properties of the Compulsive Pornography Consumption (CPC) Scale among Men who have Sex with Men

    Noor, Syed WB; Simon Rosser, B. R.; Erickson, Darin J.

    2014-01-01

    Although the phenomenon of hypersexuality has been described in the literature, and scales of compulsive sexual behavior have been published, the existing measures do not assess compulsive sexually explicit media (SEM) consumption. This study tested the psychometric properties of a new scale, the Compulsive Pornography Consumption (CPC). Exploratory and confirmatory factor analyses results showed good psychometric performance of a five item two factor preoccupation-compulsivity solution. As h...

  2. Commercial Properties, parcel data base attribute, Published in 2006, 1:1200 (1in=100ft) scale, Washoe County.

    NSGIC GIS Inventory (aka Ramona) — This Commercial Properties dataset, published at 1:1200 (1in=100ft) scale, was produced all or in part from Published Reports/Deeds information as of 2006. It is...

  3. Short scales to assess cannabis-related problems: a review of psychometric properties

    Klempova Danica

    2008-12-01

    Full Text Available Abstract Aims The purpose of this paper is to summarize the psychometric properties of four short screening scales to assess problematic forms of cannabis use: Severity of Dependence Scale (SDS, Cannabis Use Disorders Identification Test (CUDIT, Cannabis Abuse Screening Test (CAST and Problematic Use of Marijuana (PUM. Methods A systematic computer-based literature search was conducted within the databases of PubMed, PsychINFO and Addiction Abstracts. A total of 12 publications reporting measures of reliability or validity were identified: 8 concerning SDS, 2 concerning CUDIT and one concerning CAST and PUM. Studies spanned adult and adolescent samples from general and specific user populations in a number of countries worldwide. Results All screening scales tended to have moderate to high internal consistency (Cronbach's α ranging from .72 to .92. Test-retest reliability and item total correlation have been reported for SDS with acceptable results. Results of validation studies varied depending on study population and standards used for validity assessment, but generally sensitivity, specificity and predictive power are satisfactory. Standard diagnostic cut-off points that can be generalized to different populations do not exist for any scale. Conclusion Short screening scales to assess dependence and other problems related to the use of cannabis seem to be a time and cost saving opportunity to estimate overall prevalences of cannabis-related negative consequences and to identify at-risk persons prior to using more extensive diagnostic instruments. Nevertheless, further research is needed to assess the performance of the tests in different populations and in comparison to broader criteria of cannabis-related problems other than dependence.

  4. Psychometric properties of a single-item scale to assess sleep quality among individuals with fibromyalgia

    Sadosky Alesia B

    2009-06-01

    Full Text Available Abstract Background Sleep disturbances are a common and bothersome symptom of fibromyalgia (FM. This study reports psychometric properties of a single-item scale to assess sleep quality among individuals with FM. Methods Analyses were based on data from two randomized, double-blind, placebo-controlled trials of pregabalin (studies 1056 and 1077. In a daily diary, patients reported the quality of their sleep on a numeric rating scale ranging from 0 ("best possible sleep" to 10 ("worst possible sleep". Test re-test reliability of the Sleep Quality Scale was evaluated by computing intraclass correlation coefficients. Pearson correlation coefficients were computed between baseline Sleep Quality scores and baseline pain diary and Medical Outcomes Study (MOS Sleep scores. Responsiveness to treatment was evaluated by standardized effect sizes computed as the difference between least squares mean changes in Sleep Quality scores in the pregabalin and placebo groups divided by the standard deviation of Sleep Quality scores across all patients at baseline. Results Studies 1056 and 1077 included 748 and 745 patients, respectively. Most patients were female (study 1056: 94.4%; study 1077: 94.5% and white (study 1056: 90.2%; study 1077: 91.0%. Mean ages were 48.8 years (study 1056 and 50.1 years (study 1077. Test re-test reliability coefficients of the Sleep Quality Scale were 0.91 and 0.90 in the 1056 and 1077 studies, respectively. Pearson correlation coefficients between baseline Sleep Quality scores and baseline pain diary scores were 0.64 (p Conclusion These results provide evidence of the reproducibility, convergent validity, and responsiveness to treatment of the Sleep Quality Scale and provide a foundation for its further use and evaluation in FM patients.

  5. Point contact tunneling spectroscopy apparatus for large scale mapping of surface superconducting properties

    Groll, Nickolas; Pellin, Michael J.; Zasadzinksi, John F.; Proslier, Thomas

    2015-09-01

    We describe the design and testing of a point contact tunneling spectroscopy device that can measure material surface superconducting properties (i.e., the superconducting gap Δ and the critical temperature TC) and density of states over large surface areas with size up to mm2. The tip lateral (X,Y) motion, mounted on a (X,Y,Z) piezo-stage, was calibrated on a patterned substrate consisting of Nb lines sputtered on a gold film using both normal (Al) and superconducting (PbSn) tips at 1.5 K. The tip vertical (Z) motion control enables some adjustment of the tip-sample junction resistance that can be measured over 7 orders of magnitudes from a quasi-ohmic regime (few hundred Ω) to the tunnel regime (from tens of kΩ up to few GΩ). The low noise electronic and LabVIEW program interface are also presented. The point contact regime and the large-scale motion capabilities are of particular interest for mapping and testing the superconducting properties of macroscopic scale superconductor-based devices.

  6. Point contact tunneling spectroscopy apparatus for large scale mapping of surface superconducting properties

    We describe the design and testing of a point contact tunneling spectroscopy device that can measure material surface superconducting properties (i.e., the superconducting gap Δ and the critical temperature TC) and density of states over large surface areas with size up to mm2. The tip lateral (X,Y) motion, mounted on a (X,Y,Z) piezo-stage, was calibrated on a patterned substrate consisting of Nb lines sputtered on a gold film using both normal (Al) and superconducting (PbSn) tips at 1.5 K. The tip vertical (Z) motion control enables some adjustment of the tip-sample junction resistance that can be measured over 7 orders of magnitudes from a quasi-ohmic regime (few hundred Ω) to the tunnel regime (from tens of kΩ up to few GΩ). The low noise electronic and LabVIEW program interface are also presented. The point contact regime and the large-scale motion capabilities are of particular interest for mapping and testing the superconducting properties of macroscopic scale superconductor-based devices

  7. Rural to urban population density scaling of crime and property transactions in English and Welsh Parliamentary Constituencies

    Hanley, Quentin S; Ribeiro, Haroldo V

    2016-01-01

    Urban population scaling of resource use, creativity metrics, and human behaviors has been widely studied. These studies have not looked in detail at the full range of human environments which represent a continuum from the most rural to heavily urban. We examined monthly police crime reports and property transaction values across all 573 Parliamentary Constituencies in England and Wales, finding that scaling models based on population density provided a far superior framework to traditional population scaling. We found four types of scaling: i) non-urban scaling in which a single power law explained the relationship between the metrics and population density from the most rural to heavily urban environments, ii) accelerated scaling in which high population density was associated with an increase in the power-law exponent, iii) inhibited scaling where the urban environment resulted in a reduction in the power-law exponent but remained positive, and iv) collapsed scaling where transition to the high density en...

  8. Psychometric Properties of the Pediatric Emotional Distress Scale in a Diverse Sample of Children Exposed to Interpersonal Violence

    Spilsbury, James C.; Drotar, Dennis; Burant, Christopher; Flannery, Daniel; Creeden, Rosemary; Friedman, Steve

    2005-01-01

    This study determined psychometric properties of the Pediatric Emotional Distress Scale (PEDS) with an ethnically diverse sample of 383 children 2 to 7 years of age exposed to interpersonal violence and participating in a community-based intervention. Means and alpha coefficients for the total scale and 3 subscales fell within previously reported…

  9. Scaling Properties of a Complete X-ray Selected Galaxy Group Sample

    Lovisari, Lorenzo; Schellenberger, Gerrit

    2014-01-01

    Upcoming X-ray surveys like eROSITA require precise calibration between X-ray observables and mass down to the low mass regime to set tight constraints on the fundamental cosmological parameters. Since an individual mass measurement is only possible for a relatively small number of objects it is crucial to have robust and well understood scaling relations that relate the total mass to easily observable quantities. The main goal of this work is to constrain the galaxy group scaling relations corrected for selection effects, and to quantify the influence of non-gravitational physics at the low-mass regime. We analyzed XMM-Newton observations for a complete sample of galaxy groups selected from the ROSAT All-Sky Survey and we compared the derived scaling properties with a galaxy cluster sample. To investigate the role played by the different non-gravitational processes we then compared the observational data with the predictions of hydrodynamical simulations. After applying the correction for selection effects (...

  10. Psychometric Properties of the Intolerance of Uncertainty Scale (IUS in a Lithuanian-speaking population

    Augustinas Rotomskis

    2014-03-01

    Full Text Available Research suggests that intolerance of uncertainty may be important in understanding worry and may play a key role in the etiology and maintenance of worry. Intolerance of uncertainty is measured using the Intolerance of Uncertainty Scale (IUS, which has been shown to be reliable and valid in many studies. The aim of the present study was to develop a Lithuanian version of this instrument. 228 university students completed the scale. The Lithuanian version of the IUS was found to have good psychometric properties. The IUS showed high internal consistency and good test-retest reliability over a five-week period, and good convergent and divergent validity when assessed with measures of trait anxiety, situational anxiety, and depression. Factor analysis indicated that the IUS has a two-factor structure that represents the beliefs that “uncertainty about the future is unfair” and that “uncertainty has negative behavioral and self-referent implications”. In conclusion, it was found that the Lithuanian version of the IUS is a sound scale for assessing intolerance of uncertainty.

  11. Cold gas properties of the Herschel Reference Survey. II. Molecular and total gas scaling relations

    Boselli, A; Boquien, M; Boissier, S; Catinella, B; Lagos, C; Saintonge, A

    2014-01-01

    We study the properties of the cold gas component of the interstellar medium of the Herschel Reference Survey, a complete volume-limited (15 10^10 Mo) from the COLD GASS survey down to stellar masses M* ~ 10^9 Mo. As scaling variables we use M*, the stellar surface density mu*, the specific star formation rate SSFR, and the metallicity of the target galaxies. By comparing molecular gas masses determined using a constant or a luminosity dependent conversion factor, we estimate the robustness of these scaling relations on the very uncertain assumptions used to transform CO line intensities into molecular gas masses. The molecular gas distribution of a K-band-selected sample is different from that of a far-infrared-selected sample since it includes a significantly smaller number of objects with M(H2) < 6 10^9 Mo. In spiral galaxies the molecular gas phase is only 25-30% of the atomic gas. The analysis also indicates that the slope of the main scaling relations depends on the adopted conversion factor. Among t...

  12. Psychometric Properties of the Intolerance of Uncertainty Scale (IUS in a Lithuanian-speaking population

    Augustinas Rotomskis

    2014-03-01

    Full Text Available Research suggests that intolerance of uncertainty may be important in understanding worry and may play a key role in the etiology and maintenance of worry. Intolerance of uncertainty is measured using the Intolerance of Uncertainty Scale (IUS, which has been shown to be reliable and valid in many studies. The aim of the present study was to develop a Lithuanian version of this instrument. 228 university students completed the scale. The Lithuanian version of the IUS was found to have good psychometric properties. The IUS showed high internal consistency and good test-retest reliability over a five-week period, and good convergent and divergent validity when assessed with measures of trait anxiety, situational anxiety, and depression. Factor analysis indicated that the IUS has a two-factor structure that represents the beliefs that “uncertainty about the future is unfair” and that “uncertainty has negative behavioral and self-referent implications”. In conclusion, it was found that the Lithuanian version of the IUS is a sound scale for assessing intolerance of uncertainty. 

  13. Seeking Observable Imprints of Small-Scale Structure on the Properties of Dark Matter Haloes

    Power, Chris

    2013-01-01

    The characteristic prediction of the Cold Dark Matter (CDM) model of cosmological structure formation is that the Universe should contain a wealth of small-scale structure -- low-mass dark matter haloes and subhaloes. However, galaxy formation is inefficient in their shallow potential wells and so we expect these low-mass haloes and subhaloes to be dark. Can we tell the difference between a Universe in which low-mass haloes are present but dark and one in which they never formed, thereby providing a robust test of the CDM model? We address this question using cosmological simulations to examine how properties of low-mass haloes that are potentially accessible to observation, such as their spatial clustering, rate of accretions and mergers onto massive galaxies and the angular momentum content of massive galaxies, differ between a LCDM model and dark matter models in which low-mass halo formation is suppressed. Adopting an effective cut-off mass scale M_cut below which small-scale power is suppressed in the in...

  14. Spatial structure of soil properties at different scales of Mt. Kilimanjaro, Tanzania

    Kühnel, Anna; Huwe, Bernd

    2013-04-01

    Soils of tropical mountain ecosystems provide important ecosystem services like water and carbon storage, water filtration and erosion control. As these ecosystems are threatened by global warming and the conversion of natural to human-modified landscapes, it is important to understand the implications of these changes. Within the DFG Research Unit "Kilimanjaro ecosystems under global change: Linking biodiversity, biotic interactions and biogeochemical ecosystem processes", we study the spatial heterogeneity of soils and the available water capacity for different land use systems. In the savannah zone of Mt. Kilimanjaro, maize fields are compared to natural savannah ecosystems. In the lower montane forest zone, coffee plantations, traditional home gardens, grasslands and natural forests are studied. We characterize the soils with respect to soil hydrology, emphasizing on the spatial variability of soil texture and bulk density at different scales. Furthermore soil organic carbon and nitrogen, cation exchange capacity and the pH-value are measured. Vis/Nir-Spectroscopy is used to detect small scale physical and chemical heterogeneity within soil profiles, as well as to get information of soil properties on a larger scale. We aim to build a spectral database for these soil properties for the Kilimanjaro region in order to get rapid information for geostatistical analysis. Partial least square regression with leave one out cross validation is used for model calibration. Results for silt and clay content, as well as carbon and nitrogen content are promising, with adjusted R² ranging from 0.70 for silt to 0.86 for nitrogen. Furthermore models for other nutrients, cation exchange capacity and available water capacity will be calibrated. We compare heterogeneity within and across the different ecosystems and state that spatial structure characteristics and complexity patterns in soil parameters can be quantitatively related to biodiversity and functional diversity

  15. Testing the suitability of geologic frameworks for extrapolating hydraulic properties across regional scales

    Mirus, Benjamin B.; Halford, Keith; Sweetkind, Don; Fenelon, Joe

    2016-08-01

    The suitability of geologic frameworks for extrapolating hydraulic conductivity ( K) to length scales commensurate with hydraulic data is difficult to assess. A novel method is presented for evaluating assumed relations between K and geologic interpretations for regional-scale groundwater modeling. The approach relies on simultaneous interpretation of multiple aquifer tests using alternative geologic frameworks of variable complexity, where each framework is incorporated as prior information that assumes homogeneous K within each model unit. This approach is tested at Pahute Mesa within the Nevada National Security Site (USA), where observed drawdowns from eight aquifer tests in complex, highly faulted volcanic rocks provide the necessary hydraulic constraints. The investigated volume encompasses 40 mi3 (167 km3) where drawdowns traversed major fault structures and were detected more than 2 mi (3.2 km) from pumping wells. Complexity of the five frameworks assessed ranges from an undifferentiated mass of rock with a single unit to 14 distinct geologic units. Results show that only four geologic units can be justified as hydraulically unique for this location. The approach qualitatively evaluates the consistency of hydraulic property estimates within extents of investigation and effects of geologic frameworks on extrapolation. Distributions of transmissivity are similar within the investigated extents irrespective of the geologic framework. In contrast, the extrapolation of hydraulic properties beyond the volume investigated with interfering aquifer tests is strongly affected by the complexity of a given framework. Testing at Pahute Mesa illustrates how this method can be employed to determine the appropriate level of geologic complexity for large-scale groundwater modeling.

  16. Testing the suitability of geologic frameworks for extrapolating hydraulic properties across regional scales

    Mirus, Benjamin B.; Halford, Keith; Sweetkind, Don; Fenelon, Joe

    2016-02-01

    The suitability of geologic frameworks for extrapolating hydraulic conductivity (K) to length scales commensurate with hydraulic data is difficult to assess. A novel method is presented for evaluating assumed relations between K and geologic interpretations for regional-scale groundwater modeling. The approach relies on simultaneous interpretation of multiple aquifer tests using alternative geologic frameworks of variable complexity, where each framework is incorporated as prior information that assumes homogeneous K within each model unit. This approach is tested at Pahute Mesa within the Nevada National Security Site (USA), where observed drawdowns from eight aquifer tests in complex, highly faulted volcanic rocks provide the necessary hydraulic constraints. The investigated volume encompasses 40 mi3 (167 km3) where drawdowns traversed major fault structures and were detected more than 2 mi (3.2 km) from pumping wells. Complexity of the five frameworks assessed ranges from an undifferentiated mass of rock with a single unit to 14 distinct geologic units. Results show that only four geologic units can be justified as hydraulically unique for this location. The approach qualitatively evaluates the consistency of hydraulic property estimates within extents of investigation and effects of geologic frameworks on extrapolation. Distributions of transmissivity are similar within the investigated extents irrespective of the geologic framework. In contrast, the extrapolation of hydraulic properties beyond the volume investigated with interfering aquifer tests is strongly affected by the complexity of a given framework. Testing at Pahute Mesa illustrates how this method can be employed to determine the appropriate level of geologic complexity for large-scale groundwater modeling.

  17. Scaling properties in the adsorption of ionic polymeric surfactants on generic nanoparticles of metallic oxides by mesoscopic simulation

    Mayoral, E

    2014-01-01

    We study the scaling of adsorption isotherms of polyacrylic dispersants on generic surfaces of metallic oxides $XnOm$ as a function of the number of monomeric units, using Electrostatic Dissipative Particle Dynamics simulations. The simulations show how the scaling properties in these systems emerge and how the isotherms rescale to a universal curve, reproducing reported experimental results. The critical exponent for these systems is also obtained, in perfect agreement with the scaling theory of deGennes. Some important applications are mentioned.

  18. Psychometric Properties of the Patient Self-Advocacy Scale: The Persian Version

    Shaghayegh Vahdat

    2015-07-01

    Full Text Available Background: Advances in science and technology and the changes in lifestyle have changed the concept of health in terms of etiology and mortality. The aim of this study was to test the psychometric properties of the original Patient Self-Advocacy Scale for use with an Iranian population. Methods: In the current study, 50 chronic patients between the ages of 25 and 75 were selected as samples. This study was conducted in May 2013 at Bou Ali Sina Hospital in Sari. The translation process and cultural adaptation of the Patient Self-Advocacy Scale were conducted. The face validity and content validity of the instrument were formally verified by analyzing the feedback of patients and health professionals. In order to evaluate questionnaire’s reliability, the intraclass correlation coefficient (ICC was calculated for each item and each domain; and the Cronbach’s alpha was calculated for the entire instruments and each domain. Results: Of the 50 patients participating in the study, 36% were male and 64% were female. The mean age of the patients was 42.5. To comply with the Iranian culture and the study target population, slight changes were applied to the process of translation and validation. In the present study, intraclass correlation coefficient for each item was 0.8-1, which demonstrates excellent reliability of the questionnaire. The Cronbach’s alpha value was 0.75 for overall scale. Conclusion: The Persian version of Patient Self-Advocacy Scale was valid and reliable. Hence, it can be used by public health researchers and health system policy makers for programming and offering patient-oriented health services based on patients’ comments, needs, and preferences.

  19. Psychometric properties of the Danish versions of headache-specific locus of control scale and headache management self-efficacy scale

    Hansen, Jacob Sander; Bendtsen, Lars; Jensen, Rigmor

    2009-01-01

    The purpose of the study is to test the cross-cultural adaptation and psychometric properties of a Danish version of the Headache-Specific Locus of Control Scale (HSLC) and the Headache Management Self-Efficacy Scale (HMSE) in a tertiary headache centre. HSLC and HMSE are headache-specific measures...... with other self-report measures concerning general distress, anxiety, depression, and health-related quality of life. Internal stability of the HSLC subscales and the HMSE were analysed using Chronbach's alpha coefficient. The psychometric properties of the Danish version of the HSLC and the HMSE were....... The results are consistent with the earlier findings of the original American versions of HMSE and HSLC. These scales seem to be valid and valuable tools for testing of psychological aspects related to level of functioning and quality of life for headache patients across different cultures of Western...

  20. Visualization of micro-scale phase displacement processes in retention and outflow experiments: Non-uniqueness of unsaturated flow properties

    MORTENSEN,ANNETTE P.; GLASS JR.,ROBERT J.; HOLLENBECK,KARL; JENSEN,KARSTEN H.

    2000-03-09

    Methods to determine unsaturated hydraulic properties can exhibit random and non-unique behavior. The authors assess the causes for these behaviors by visualizing micro-scale phase displacement processes during equilibrium retention and transient outflow experiments. They observe that the drainage process is composed of a fast fingering followed by a slower backfilling. The influence of each these processes is controlled by the size and the speed of the applied boundary step, the initial saturation and its structure and by small-scale heterogeneities. Because the mixture of these micro-scale processes yields macro-scale effective behavior, measured unsaturated flow properties are also a function of these controls. These results suggest limitations on the current definitions and uniqueness of unsaturated hydraulic properties.

  1. Measurement Properties of the Lower Extremity Functional Scale: A Systematic Review.

    Mehta, Saurabh P; Fulton, Allison; Quach, Cedric; Thistle, Megan; Toledo, Cesar; Evans, Neil A

    2016-03-01

    Study Design Systematic review of measurement properties. Background Many primary studies have examined the measurement properties, such as reliability, validity, and sensitivity to change, of the Lower Extremity Functional Scale (LEFS) in different clinical populations. A systematic review summarizing these properties for the LEFS may provide an important resource. Objective To locate and synthesize evidence on the measurement properties of the LEFS and to discuss the clinical implications of the evidence. Methods A literature search was conducted in 4 databases (PubMed, MEDLINE, Embase, and CINAHL), using predefined search terms. Two reviewers performed a critical appraisal of the included studies using a standardized assessment form. Results A total of 27 studies were included in the review, of which 18 achieved a very good to excellent methodological quality level. The LEFS scores demonstrated excellent test-retest reliability (intraclass correlation coefficients ranging between 0.85 and 0.99) and demonstrated the expected relationships with measures assessing similar constructs (Pearson correlation coefficient values of greater than 0.7). The responsiveness of the LEFS scores was excellent, as suggested by consistently high effect sizes (greater than 0.8) in patients with different lower extremity conditions. Minimal detectable change at the 90% confidence level (MDC90) for the LEFS scores varied between 8.1 and 15.3 across different reassessment intervals in a wide range of patient populations. The pooled estimate of the MDC90 was 6 points and the minimal clinically important difference was 9 points in patients with lower extremity musculoskeletal conditions, which are indicative of true change and clinically meaningful change, respectively. Conclusion The results of this review support the reliability, validity, and responsiveness of the LEFS scores for assessing functional impairment in a wide array of patient groups with lower extremity musculoskeletal

  2. Dynamic scaling and optical properties of Zn(S, O,OH) thin film grown by chemical bath deposition

    Zhang Yi; Li Bo-Yan; Dang Xiang-Yu; Wu Li; Jin Jing; Li Feng-Yan; Ao Jian-Ping; Sun Yun

    2011-01-01

    The scaling behavior and optical properties of Zn(S,O and OH) thin films deposited on soda-lime glass substrates by chemical bath deposition method were studied by combined roughness measurements,scanning electron microscopy and optical properties measurement.From the scaling behaviour,the value of growth scaling exponent β,0.38±0.06,was determined.This value indicated that the Zn(S,O,OH) film growth in the heterogeneous process was influenced by the surface diffusion and shadowing effect.Results of the optical properties measurements disclosed that the transmittance of the film was in the region of 70%-88% and the optical properties of the film grown for 40 min were better than those grown under other conditions.The energy band gap of the film deposited with 40 min was around 3.63 eV.

  3. Fabrication and characterization of multi-scale microlens arrays with anti-reflection and diffusion properties

    Chen, Yung-Pin; Lee, Chih-Hsien; Wang, Lon A, E-mail: lon@ntu.edu.tw [Photonics and Nano-Structure Laboratory, Department of Electrical Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan (China)

    2011-05-27

    In this paper, an effective method for fabricating artificial compound-eye structures is demonstrated. The fabrication of high fill factor microlens arrays (MLAs) with sub-wavelength structures (SWSs) on a polycarbonate (PC) substrate involves nanoimprint and thermo-extrusion techniques by using two different scales of nano/micromolds. In addition, the MLAs with SWSs on the PC substrate would be replicated on a polymethylmethacrylate (PMMA) millimeter concave surface by hot-embossing, forming three-level compound-eye structures. The optical properties of these samples are characterized. The transmittances of two-level PC and three-level PMMA compound structures are increased by 2.5% and 2%, and the uniformities are enhanced by 18% and 24%, respectively.

  4. Correlation between surface properties and wettability of multi-scale structured biocompatible surfaces

    Gorodzha, S. N.; Surmeneva, M. A.; Prymak, O.; Wittmar, A.; Ulbricht, M.; Epple, M.; Teresov, A.; Koval, N.; Surmenev, R. A.

    2015-11-01

    The influence of surface properties of radio-frequency (RF) magnetron deposited hydroxyapatite (HA) and Si-containing HA coatings on wettability was studied. The composition and morphology of the coatings fabricated on titanium (Ti) were characterized using atomic force microscopy (AFM) and X-ray diffraction (XRD). The surface wettability was studied using contact angle analysis. Different geometric parameters of acid-etched (AE) and pulse electron beam (PEB)-treated Ti substrates and silicate content in the HA films resulted in the different morphology of the coatings at micro- and nano- length scales. Water contact angles for the HA coated Ti samples were evaluated as a combined effect of micro roughness of the substrate and nano-roughness of the HA films resulting in higher water contact angles compared with acid-etched (AE) or pulse electron beam (PEB) treated Ti substrates.

  5. Isolation of nano-meso scale detergent resistant membrane that has properties expected of lipid 'rafts'.

    Morris, Roger J; Jen, Angela; Warley, Alice

    2011-03-01

    This review assesses problems that confound attempts to isolate 'raft' domains from cell membranes, focusing in particular upon the isolation of detergent resistant membrane (DRM). Despite its widespread use, this technique is rightly viewed with skepticism by many membrane biochemists and biophysics for reasons that include the inability to isolate DRMs at 37°C, the temperature at which their lipids are supposed to be ordered and so exclude detergents. If solubilization is done in an ionic buffer that preserves the lamellar phase of the metastable inner leaflet lipids, DRMs can readily be isolated at 37°C, and these have many properties expected of lipid rafts. However, to date these DRMs have remained somewhat larger than current concepts of rafts. We describe an adaptation of this method that purifies nano-meso scale DRMs, and could be a significant step towards purifying the membrane of individual 'rafts'. PMID:21214574

  6. Psychometric properties of the Hebrew version of the Dutch Work Addiction Scale (DUWAS-10).

    Littman-Ovadia, Hadassah; Balducci, Cristian; Ben-Moshe, Tali

    2014-01-01

    The present study examined the psychometric properties of the Hebrew version of the Dutch Work Addiction Scale (DUWAS-10), developed by Schaufeli, Shimazu, and Taris (2009). Three hundred fifty-one employees completed a questionnaire measuring workaholism; of these, 251 employees completed questionnaires measuring work engagement, job satisfaction, overcommitment, and burnout. The results confirmed the expected two-factor structure of workaholism: working excessively and working compulsively. Strong correlations were obtained between self-reports and peer-reports, and satisfactory correlations were obtained between the first and second administrations of the DUWAS-10. Furthermore, DUWAS-10 scores showed predictable relations with actual number of hours worked per week, work engagement, job satisfaction, overcommitment, and burnout. Interestingly, despite working fewer hours per week, women reported higher levels of workaholism in comparison to men, and managers reported higher levels of workaholism in comparison to nonmanagerial employees. PMID:24839730

  7. Polish Version of the Managing the Emotions of Others Scale (MEOS): Psychometric Properties and Validation.

    Jankowski, Konrad S; Zajenkowski, Marcin; Stolarski, Maciej; Styła, Rafał; Zajenkowska, Anna; Jędrasik-Styła, Małgorzata; Linke, Magdalena

    2016-04-01

    The present study aimed to test the psychometric properties of the Polish version of the managing the emotions of others scale (MEOS). MEOS consists of six dimensions: mood enhancing (Enhance), mood worsening (Worsen), concealing emotions from others (Conceal), use of inauthentic displays for self-serving purposes (Inauthentic), poor emotion skills (Poor skills), and use of diversion to enhance another's mood (Divert). The results showed that among MEOS dimensions, Enhance was the most strongly related to performance-based emotional intelligence. Among the Dark Triad, Narcissism was related to the greatest number of MEOS subscales-all except Poor skills. The results indicated that the MEOS has a similar factor structure, reliability, and pattern of correlations with personality and emotional intelligence in Poland as in previous studies. PMID:27154378

  8. Effects of Atomic-Scale Structure on the Fracture Properties of Amorphous Carbon - Carbon Nanotube Composites

    Jensen, Benjamin D.; Wise, Kristopher E.; Odegard, Gregory M.

    2015-01-01

    The fracture of carbon materials is a complex process, the understanding of which is critical to the development of next generation high performance materials. While quantum mechanical (QM) calculations are the most accurate way to model fracture, the fracture behavior of many carbon-based composite engineering materials, such as carbon nanotube (CNT) composites, is a multi-scale process that occurs on time and length scales beyond the practical limitations of QM methods. The Reax Force Field (ReaxFF) is capable of predicting mechanical properties involving strong deformation, bond breaking and bond formation in the classical molecular dynamics framework. This has been achieved by adding to the potential energy function a bond-order term that varies continuously with distance. The use of an empirical bond order potential, such as ReaxFF, enables the simulation of failure in molecular systems that are several orders of magnitude larger than would be possible in QM techniques. In this work, the fracture behavior of an amorphous carbon (AC) matrix reinforced with CNTs was modeled using molecular dynamics with the ReaxFF reactive forcefield. Care was taken to select the appropriate simulation parameters, which can be different from those required when using traditional fixed-bond force fields. The effect of CNT arrangement was investigated with three systems: a single-wall nanotube (SWNT) array, a multi-wall nanotube (MWNT) array, and a SWNT bundle system. For each arrangement, covalent bonds are added between the CNTs and AC, with crosslink fractions ranging from 0-25% of the interfacial CNT atoms. The SWNT and MWNT array systems represent ideal cases with evenly spaced CNTs; the SWNT bundle system represents a more realistic case because, in practice, van der Waals interactions lead to the agglomeration of CNTs into bundles. The simulation results will serve as guidance in setting experimental processing conditions to optimize the mechanical properties of CNT

  9. Full-scale computation for all the thermoelectric property parameters of half-Heusler compounds.

    Hong, A J; Li, L; He, R; Gong, J J; Yan, Z B; Wang, K F; Liu, J-M; Ren, Z F

    2016-01-01

    The thermoelectric performance of materials relies substantially on the band structures that determine the electronic and phononic transports, while the transport behaviors compete and counter-act for the power factor PF and figure-of-merit ZT. These issues make a full-scale computation of the whole set of thermoelectric parameters particularly attractive, while a calculation scheme of the electronic and phononic contributions to thermal conductivity remains yet challenging. In this work, we present a full-scale computation scheme based on the first-principles calculations by choosing a set of doped half-Heusler compounds as examples for illustration. The electronic structure is computed using the WIEN2k code and the carrier relaxation times for electrons and holes are calculated using the Bardeen and Shockley's deformation potential (DP) theory. The finite-temperature electronic transport is evaluated within the framework of Boltzmann transport theory. In sequence, the density functional perturbation combined with the quasi-harmonic approximation and the Klemens' equation is implemented for calculating the lattice thermal conductivity of carrier-doped thermoelectric materials such as Ti-doped NbFeSb compounds without losing a generality. The calculated results show good agreement with experimental data. The present methodology represents an effective and powerful approach to calculate the whole set of thermoelectric properties for thermoelectric materials. PMID:26947395

  10. The size distribution, scaling properties and spatial organization of urban clusters: a global and regional perspective

    Fluschnik, Till; Ros, Anselmo García Cantú; Zhou, Bin; Reusser, Dominik E; Kropp, Jürgen P; Rybski, Diego

    2014-01-01

    Human development has far-reaching impacts on the surface of the globe. The transformation of natural land cover occurs in different forms and urban growth is one of the most eminent transformative processes. We analyze global land cover data and extract cities as defined by maximally connected urban clusters. The analysis of the city size distribution for all cities on the globe confirms Zipf's law. Moreover, by investigating the percolation properties of the clustering of urban areas we assess the closeness to criticality for various countries. At the critical thresholds, the urban land cover of the countries undergoes a transition from separated clusters to a gigantic component on the country scale. We study the Zipf-exponents as a function of the closeness to percolation and find a systematic decrease with increasing scale, which could be the reason for deviating exponents reported in literature. Moreover, we investigate the average size of the clusters as a function of the proximity to percolation and fi...