Search results for "Scaling"
showing 10 items of 754 documents
Characteristic time scale of auroral electrojet data
1994
The structure function of the AE time series shows that the AE time series is self-affine such that the scaling exponent changes at the time scale of approximately 113 (±9) minutes. Autocorrelation function is shown to have scaling properties similar to those of the structure function. From this result it can be deduced that the time scale at which the scaling properties of the AE data change should equal the typical autocorrelation time of these data. We find the typical autocorrelation time of the AE data is 118 (±9) minutes. The characteristic time scale of the AE data appears as a spectral break in their power spectrum at a period of about twice the autocorrelation time.
Antiproton over proton and K$^-$ over K$^+$ multiplicity ratios at high $z$ in DIS
2020
The $\bar{\rm p} $ over p multiplicity ratio is measured in deep-inelastic scattering for the first time using (anti-) protons carrying a large fraction of the virtual-photon energy, $z>0.5$. The data were obtained by the COMPASS Collaboration using a 160 GeV muon beam impinging on an isoscalar $^6$LiD target. The regime of deep-inelastic scattering is ensured by requiring $Q^2$ > 1 (GeV/$c$)$^2$ for the photon virtuality and $W > 5$ GeV/$c^2$ for the invariant mass of the produced hadronic system. The range in Bjorken-$x$ is restricted to $0.01 < x < 0.40$. Protons and antiprotons are identified in the momentum range $20 ��60$ GeV/$c$. In the whole studied $z$-region, the $\…
On the convergent validity of two Parental Rearing Behaviour Scales: EIIBU and PBI
1999
The EMBU and PBI are two of the most used Parental Rearing Behaviour questionnaires. The literature assumes a high correlation between homonymous and assimilable factors (PBI Care and EMBU Affectional Warmth, PBI Control and EMBU Overprotection). Using a sample of 796 subjects the authors carried out the joint application of both scales in order to determine their concurrent validity. The correlation obtained between the scales barely reaches significance on average levels of correlation. The same can be deduced for the applied Multidimensional Scaling. In conclusion, the most extreme precaution is recommended when considering the homonymous scales of both questionnaires, and their joint us…
Scaling up strategies of the chronic respiratory disease programme of the European Innovation Partnership on Active and Healthy Ageing (Action Plan B…
2016
Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) focuses on the integrated care of chronic diseases. Area 5 (Care Pathways) was initiated using chronic respiratory diseases as a model. The chronic respiratory disease action plan includes (1) AIRWAYS integrated care pathways (ICPs), (2) the joint initiative between the Reference site MACVIA-LR (Contre les MAladies Chroniques pour un VIeillissement Actif) and ARIA (Allergic Rhinitis and its Impact on Asthma), (3) Commitments for Action to the European Innovation Partnership on Active and Healthy Ageing and the AIRWAYS ICPs network. It is deployed in collaboration with the World Health Organizatio…
Applied multi-pulsed laser in surface treatment and numerical–experimental analysis
2011
International audience; This paper presents a comparison between simulation and experimental results of the melting process of metallic material by a pulsed laser source Nd–YAG. The simulations of temperature and velocity fields of melted material were done by solving the transient heat transfer and fluid-flow equations. Variations of the thermophysical properties were considered. Furthermore, the model included the effects of the surface-tension gradient on the fluid surface and the buoyancy force. The simulation was useful in improving our understanding of the phenomena occurring in the treated material. Using a laser triangulation sensor, an experimental study was also conducted on the s…
Structure and dynamics of polymer brushes near the Θ point: A Monte Carlo simulation
1992
Grafted polymer layers under variable solvent conditions are studied by Monte Carlo simulations using the bond fluctuation model. Structural information such as monomer density profiles, brush thickness, mean‐square displacement of monomers, and positions of the monomers along the chain are obtained for temperatures above, at, and below the Θ point. In particular, the scaling of the brush thickness is formulated and verified by the simulation data. At the Θ point, more extensive simulations are performed to investigate the structural and dynamical properties. While the brush thickness at the Θ point agrees very well with the scaling and self‐consistent field predictions, the latter deviate …
Polymer brushes on flat and curved surfaces: How computer simulations can help to test theories and to interpret experiments
2012
Theoretical descriptions of static properties of polymer brushes are reviewed, with an emphasis on monodisperse macromolecules grafted to planar, cylindrical, or spherical substrates. Blob concepts and resulting scaling relations are outlined, and various versions of the self-consistent field theory are summarized: the classical approximation and the strong stretching limit, as well as the lattice formulation. The physical justification of various inherent assumptions is discussed, and computer simulation results addressing the test of the validity of these approximations are reviewed. Also, alternative theories, such as the single chain mean field theory and the density functional theory, …
Intermolecular structure factors of macromolecules in solution: Integral equation results
1999
The inter-molecular structure of semidilute polymer solutions is studied theoretically. The low density limit of a generalized Ornstein-Zernicke integral equation approach to polymeric liquids is considered. Scaling laws for the dilute-to-semidilute crossover of random phase (RPA) like structure are derived for the inter-molecular structure factor on large distances when inter-molecular excluded volume is incorporated at the microscopic level. This leads to a non-linear equation for the excluded volume interaction parameter. For macromolecular size-mass scaling exponents, $\nu$, above a spatial-dimension dependent value, $\nu_c=2/d$, mean field like density scaling is recovered, but for $\n…
Simulation of Phase Transitions of Single Polymer Chains: Recent Advances
2006
The behaviour of a flexible polymer chain in solvents of variable quality in dilute solution is discussed both in the bulk and in the presence of an adsorbing wall. Monte Carlo simulations of coarse-grained bead-spring models and of the bond fluctuation model are presented and interpreted in terms of phenomenological theories and scaling concepts. Particular attention is paid to the behaviour of the polymer chain when the temperature of the polymer solution gets lower than the Theta temperature. It is argued that the adsorption transition line at the Theta temperature splits into lines of wetting and drying transitions of polymer globules attached to the wall. In addition, it is shown that …
Polyelectrolytes Grafted to Curved Surfaces
1996
We present a scaling theory to describe equilibrium conformations of weakly charged polyelectrolyte molecules grafted at one end onto impermeable surfaces of various morphologies (spheres, cylinders) and of arbitrary curvature. We focus on the case of sufficiently densely grafted chains, i.e., on curved polyelectrolyte brushes. Different regimes of the behavior of curved polyelectrolyte brushes can be distinguished, depending on grafting density, surface curvature, and chain length. We present phase diagrams of the system describing these regimes and discuss the crossover conditions. We also analyze the effect of charge annealing in curved polyelectrolyte brushes.