Quantum Cell Model for Bosons

The dynamical properties of simple molten salts are studied with particular attention to cross-correlation between two species. The general formulation of the dynamics in two-component liquids is made by describing partial density fluctuations with the memory function formalism, and thereby introducing effective potentials in response functions. The excitation spectra for charge density and number (or mass) density fluctuations are calculated by assuming the simple relaxation for the polarisation function in simple molten salts, in good agreement with the molecular dynamics calculation. It is found that the dynamical coupling representing cross-correlations is no longer negligible below the wavenumber at the first peak of the static structure factor for number density fluctuations.

Hydrodynamical field fluctuations in a non-equilibrium quasi-stationary state due to a temperature gradient

The balance between grass and clover in mixed sward is highly susceptible to environmental change. Many studies have shown that a sward can become grass-dominant or clover-dominant according to the nutrient status or grazing management imposed on it. In this paper seasonal and yearly changes of botanical composition in mixed sward of orchard grass and ladino clover grown under different treatments in cutting height and amount of nitrogen application, are presented. 1. In all results so far obtained by the author, the percentages of grass are tend to decrease as time passes. It is found that the kind of treatment affects on decreasing rate of grass percentage. Low cut treatment accelerates decreasing rate and high cut treatment makes it slow. Seasonal maximum in grass percentage is found in spring, and then it decreases rapidly through summer to autumn. 2. Yield decrease in grass and yield increase in clover in progress of year are due in part at least to decrease of stem number density in grass and increase of stolon number density in clover progress of year. 3. Spring high yield in grass is due to its high stem number density and plant height. Summer low yield is due to sudden decreasing in stem number density and autumn low yield is due to low stem number density and plant height. 4. Spring high yield in clover is due to its high stolon number density, and summer decrease of yield is in parallel with decrease of stolon number density. It is likely that autumn increase of yield is due to increase of new developed stolon number. 5. By cutting at a high level, yield of grass increases but that of clover decreases. Those are attributed to increase of grass stem number density and the consequent shading of clover, i.e. to decrease of stolon number density. 6. Application of nitrogen gives increased yields of grass and decreased yields of clover especially in spring. In any seasons, much more yields of clover are found in the plots without nitrogen. 7. The responses of clover in pure stand to treatment in height of cutting and nitrogen application are quite different from those in mixed sward. On the other hand, in case of grass, differences to treatment between pure stand and mixed sward are not so much, however the decreasing rates of hill number density in mixed sward are rather faster than those in pure stand. It is likely to be concluded that various aspects of responses found in pure stand are not applicable to phenomena which take place in mixed sward.

Theory unifies. Four superficially differing physical phenomena mentioned in previous chapters are NMR relaxation times, van der Waals forces, diffusion, and number density fluctuations. Underlying these four subjects is a common denominator — the microscopic time-dependent fluctuations of molecular properties. Spin relaxation is normally caused by randomly fluctuating magnetic fields sensed by nuclei or electrons. Van der Waals forces are a consequence of fluctuating dipoles. A diffusing molecule is subject to random forces due to collisions with its neighbors. Number density fluctuations are due to random molecular translations.

We investigate fluctuations of the net-baryon number density in hot hadronic matter. We discuss the interplay between chiral dynamics and repulsive interactions and their influence on the properties of these fluctuations near the chiral crossover. The chiral dynamics is modeled by the parity doublet Lagrangian that incorporates the attractive and repulsive interactions mediated via the exchange of scalar and vector mesons, respectively. The mean-field approximation is employed to account for chiral criticality. We focus on the properties and systematics of the cumulants of the net-baryon number density up to the sixth order. It is shown that the higher-order cumulants exhibit a substantial suppression in the vicinity of the chiral phase transition due to the presence of repulsive interactions. We find, however, that the characteristic properties of cumulants near the chiral crossover observed in lattice QCD results are entirely linked to the critical chiral dynamics and, in general, cannot be reproduced in phenomenological models, which account only for effective repulsive interactions via excluded-volume corrections or van-der-Waals type interactions. Consequently, a description of the higher-order cumulants of the net-baryon density in the chiral crossover requires a self-consistent treatment of the chiral in-medium effects and repulsive interactions.

We spectroscopically investigate a pathway for the conversion of 23Na39K Feshbach molecules into rovibronic ground state molecules via stimulated Raman adiabatic passage. Using photoassociation spectroscopy from the diatomic scattering threshold in the a3Σ+ potential, we locate the resonantly mixed electronically excited intermediate states and which, due to their singlet–triplet admixture, serve as an ideal bridge between predominantly a3Σ+ Feshbach molecules and pure X1Σ+ ground state molecules. We investigate their hyperfine structure and present a simple model to determine the singlet–triplet coupling of these states. Using Autler–Townes spectroscopy, we locate the rovibronic ground state of the 23Na39K molecule () and the second rotationally excited state N = 2 to unambiguously identify the ground state. We also extract the effective transition dipole moment from the excited to the ground state. Our investigations result in a fully characterized scheme for the creation of ultracold bosonic 23Na39K ground state molecules.

We present the results of studying the multifractal structure of intermittency in a developed ionospheric turbulence during special experiments on radio-raying of the midlatitude ionosphere by signals from orbital satellites in 2005–2006. It is shown, in particular, that the determination of multidimensional structural functions of the energy fluctuations of received signals permits one to obtain the necessary information on multifractal spectra of the studied process of radio-wave scattering in the ionosphere. Experimental data on multifractal spectra of slow fluctuations in the received-signal energy under conditions of a developed small-scale turbulence are compared with the existing concept of the radio-wave scattering within the framework of the statistical theory of radio-wave propagation in the ionosphere. It is inferred that under conditions of a developed ionospheric turbulence, the multifractal structure of the intermittency of slow fluctuations in the received-signal energy is a consequence of the intermittency of small-scale fluctuations in the electron number density of the ionospheric plasma on relatively large spatial scales of about several ten kilometers.

Structure of the hydrophilic phase and its impact on the conductivity of graft copolymer ionomers at low hydration level

We present recent lattice results on QCD thermodynamics at non-vanishing baryon number density obtained from a sixth-order Taylor expansion in the chemical potential. Results for bulk thermodynamic observables, in particular for fluctuations in the baryon number density, are found to be well described by a hadron resonance gas model at low temperature and an ideal quark–gluon gas at high temperature. We also analyse the radius of convergence of the Taylor series and discuss the information it provides on the occurrence of a second-order phase transition point in the QCD phase diagram.

Microscopic density fluctuations in a dense helium-neon gas mixture

We consider a simple ‘theory’ of galaxy formation in which the luminosity L of a galaxy is determined by a universal Faber-Jackson law L/L * = (V/V *)4, regardless of formation redshift. One consequence of such a model is that long wavelength density perturbations present in the CDM Gaussian initial conditions naturally induce a positive bias in the galaxy distribution. On large scales we find the bias factor b, the factor by which fluctuations in the galaxy number density are amplified relative to the underlying mass distribution, to be b = 1.4 – 1.5. While identifying rich clusters as recently virialized systems we obtain a factor 3 enhancement for their L/M relative to the global value. Thus the bias we find using this simple model is substantial, though somewhat smaller than seems to be required to reproduce the virial analysis.

A time-dependent two-dimensional (2D) axisymmetric simulation was conducted for arc plasma with dynamically fluctuating fluid generating iron nanoparticles in a direct-current discharge condition. The nonequilibrium process of simultaneous growth and transport of nanoparticles is simulated using a simple model with a low computational cost. To ascertain fluid dynamic instability and steep gradients in plasma temperature and particle distributions, a highly accurate method is adopted for computation. The core region of the arc plasma is almost stationary, whereas the fringe fluctuates because of fluid dynamic instability between the arc plasma and the shielding gas. In the downstream region, the vapor molecules decrease by condensation. The nanoparticles decrease by coagulation. These results suggest that both of the simultaneous processes make important contributions to particle growth. The fluctuation of nanoparticle number density in a distant region exhibits stronger correlation with the temperature fluctuation at the plasma fringe. The correlation analysis results suggest that the distribution of growing nanoparticles distant from the arc plasma can be controlled via control of temperature fluctuation at the arc plasma fringe.

Eukaryotic cells in living tissues form dynamic patterns with spatially varying orientational order that affects important physiological processes such as apoptosis and cell migration. The challenge is how to impart a predesigned map of orientational order onto a growing tissue. Here, we demonstrate an approach to produce cell monolayers of human dermal fibroblasts with predesigned orientational patterns and topological defects using a photoaligned liquid crystal elastomer (LCE) that swells anisotropically in an aqueous medium. The patterns inscribed into the LCE are replicated by the tissue monolayer and cause a strong spatial variation of cells phenotype, their surface density, and number density fluctuations. Unbinding dynamics of defect pairs intrinsic to active matter is suppressed by anisotropic surface anchoring allowing the estimation of the elastic characteristics of the tissues. The demonstrated patterned LCE approach has potential to control the collective behavior of cells in living tissues, cell differentiation, and tissue morphogenesis.

We have studied oil in water microemulsion system comprising Triton X-100 (TX100) as surfactant, cosurfactant (octanol) and oil (decane) by dynamic light scattering at various concentration. In diluted regime, the autocorrelation function exhibits a nearly mono-exponential relaxation. The best fit is obtained by using the method of cumulant up to order 2. The apparent hydrodynamic radius RHapp and polydispersity index σD were deduced. In concentrated regime, the DLS correlation function exhibit two relaxation modes. According to Pusey and Weissman, the fast one corresponds to collective diffusion coefficient (number density fluctuations) and the slow one corresponds to self diffusion coefficient (polydispersity fluctuation). The variation of Dc and Ds with volume fraction Φ reflects that the droplets interact via an overall repulsive potential.

Photon correlation spectroscopy in the polarized (VV) and depolarized (VH) geometries has been utilized in order to investigate the aggregation dynamics in toluene solutions of a hairy-rod polymer, poly(p-phenylene) with flexible dodecyl side chains [Ph-Ph(C 12 H 25 ) 2 -Ph] n . Static and dynamic results from the dilute regime suggest that polymer molecules form small aggregates, typically trimers, even at very low concentrations. In the semidilute regime, results at different scattering wavevectors (q) in both the VV and VH geometry reveal two new relaxation processes (slow and ultra slow), in addition to the faster cooperative diffusion and reorientation of the trimers, respectively. They are attributed to the formation of large anisotropic clusters (of typical size 570 nm), with inherent crystallization, as revealed by X-ray scattering. After about 2 weeks the clusters settle under the action of gravity and form an opaque sediment. Assessment of the aggregation modes has been carried out by sediment redispersion. The first stages of this process, which exhibit multiple scattering, reveal a steeper than exponential relaxation, associated with a sedimentation-induced velocity gradient in a transient pseudonetwork formed by the dispersed clusters. In the single scattering limit, reached at later stages, the two relaxation processes are related to reorientation (slow) and number density fluctuation (ultraslow) of the anisotropic clusters. On the basis of simple thermodynamic arguments, we argue that rodlike macromolecules exhibit a larger activation energy barrier compared to their flexible counterparts, in agreement with the experimental evidence.