Synchronized cluster formation in coupled laser networks

We experimentally investigate the phase dynamics of laser networks with homogenous time-delayed mutual coupling and establish the fundamental rules that govern their state of synchronization. We identified a specific substructure that imposes its synchronization state on the entire network and show that for any coupling configuration the network forms at most two synchronized clusters. Our results indicate that the synchronization state of the network is a nonlocal phenomenon and cannot be deduced by decomposing the network into smaller substructures, each with its individual synchronization state.     

Studies of the out-of-plane emission of pions in symmetric heavy-ion collisions

Triple differential cross-sections of midrapidity pions from ²⁰⁹Bi+²⁰⁹Bi collisions were measured with the Kaon Spectrometer at SIS at incident energies of 400, 700 and 1000 AMeV. The azimuthal emission pattern of the pions has been investigated in dependence of beam energy and impact parameter. An enhanced emission of pions perpendicular to the reaction plane is observed. The strength of the anisotropy increases with beam energy and pion transverse momentum. In contrast to the nucleons the anisotropy varies only little with the impact parameter. No difference in the behaviour of positive and negative pions is observed.     

Characterization of Powder Beds by Thermal Conductivity: Effect of Gas Pressure on the Thermal Resistance of Particle Contact Points

The thermal conductivity of ceramic powder packed beds was measured at temperatures below 100 °C for various powder sizes and compositions and under different gas atmospheres. Measurements at low pressures (down to 10 Pa) combined with a theoretical model allowed the elucidation of geometrical and thermal resistance parameters for the contact points between granules. The gap thickness and contact point size were found to be well correlated with the mean particle size. The thermal conductivities of all powders at low pressure were found to differ at most by a factor of two, whereas the solid‐phase conductivities of the powder materials differed by more than one order of magnitude. A theoretical model accounting for the size‐dependence of contact point conductivity is incorporated to rationalize this trend.     

A cardinal preserving extension making the set of points of countable V cofinality nonstationary

Assuming large cardinals we produce a forcing extension of V which preserves cardinals, does not add reals, and makes the set of points of countable V cofinality in κ⁺ nonstationary. Continuing to force further, we obtain an extension in which the set of points of countable V cofinality in ν is nonstationary for every regular ν ≥ κ⁺. Finally we show that our large cardinal assumption is optimal. This material is based upon work supported by the National Science Foundation under Grant no. DMS-0094174.     

Charge order superstructure with integer iron valence in Fe(2)OBO(3)

Solution-grown single crystals of Fe(2)OBO(3) were characterized by specific heat, M?ssbauer spectroscopy, and x-ray diffraction. A peak in the specific heat at 340 K indicates the onset of charge order. Evidence for a doubling of the unit cell at low temperature is presented. Combining structural refinement of diffraction data and M?ssbauer spectra, domains with diagonal charge order are established. Bond-valence-sum analysis indicates integer valence states of the Fe ions in the charge ordered phase, suggesting Fe(2)OBO(3) is the clearest example of ionic charge order so far.     

Empirical equations to predict flow patterns in two-phase inclined flow

Based on experimental data, flow regime maps were drawn for different inclination angles, including horizontal and vertical flow. Different empirical equations for the flow regime transitions are proposed that are functions of inclination angle for both upflow and downflow. In general, the flow regimes and their transitions for upflow were similar to those proposed by Duns and Ros for vertical upflow. For downflow, the flow regimes and their transitions conformed more to the Mandhane et al. type of flow regime map. The stratified flow region in downflow was found to be affected appreciably by the angle of inclination. A detailed comparison of the proposed transition equations with a number of flow regime maps is also presented.     

Transport and elastic anomalies in ZrTe3

Anomalies were observed in electrical resistivity components, Hall coefficient and Young's modulus of semimetallic ZrTe₃ near 63K. The results suggest that a structural phase transition, e.g. the onset of a charge density wave, occurs. Analysis indicates that the hole band is more strongly affected by the transition, resulting in the strong renormalization of the elastic modulus.     

Thermal conductivity of NbSe3

The thermal conductivity, κ, of NbSe₃ has been measured by novel self-heating techniques that allowed the electric field dependence of κ to also be measured. Measurements were made from 35 K to room temperature. Above the charge density wave transitions, the phonon thermal conductivity is 4–7 times the electron thermal conductivity, and it rises smoothly below the transitions, indicating that phonon-phonon scattering predominates. Phonon mean free parths have been estimated at 187 A° at 60 K and 60 A° at 150 K. No clear anomalies were observed at the phase transitions, giving upper limits to changes in the phonon mean free path. No field dependence of κ was observed.     

Evaluating environmental quality management programmes in which dischargers are grouped

A method is presented for evaluating management programmes in which the dischargers are divided into groups. Analogous non-linear mathematical formulations are presented for direct regulation and effluent charge programmes, and a non-linear branch-and-bound solution procedure is described. A detailed algorithm is described for the effluent charge case; it is shown to be very practical in an application to data for the Delaware estuary.