[en] Highlights: • The mean visualization length of the Eustachian tube and its bony segment is significantly higher in healthy sides than in pathological sides. • The cross-sectional size of the tympanic orifice may be a specific imaging feature indicating the obstructive Eustachian tube. • However, 3D morphologic measurements of the Eustachian tube are insufficient to yield useful data about its function. To investigate the diagnostic value of three-dimensional morphologic measurements of the Eustachian tube on computed tomography in Eustachian tube dysfunction.

[en] We compare three semimicroscopic theories to the first data on particle production in central Au+Au collisions taken at RHIC by the PHOBOS Collaboration as well as to existing data on central Pb+Pb collisions taken at the SPS by the NA49 Collaboration. The Linear Extrapolation of Ultrarelativistic nucleon-nucleon Scattering to nucleus-nucleus collisions (LEXUS) represents the SPS data quite well but predicts too many particles at RHIC. The wounded nucleon model predicts too few particles at both the SPS and RHIC; the collective tube model predicts fewer particles still. This suggests a transition in the dynamics of particle production between s=17 and 56A GeV as one goes from the SPS to RHIC

[en] The Independent Network Model (INM) has proven to be a useful tool for understanding the development of permanent set in strained elastomers. Our previous work showed the applicability of the INM to our simulations of polymer systems crosslinking in strained states. This study looks at the INM applied to theoretical models incorporating entanglement effects, including Flory's constrained junction model and more recent tube models. The effect of entanglements has been treated as a separate network formed at gelation, with additional curing treated as traditional phantom contributions. Theoretical predictions are compared with large-scale molecular dynamics simulations

[en] Similar to entangled ropes, polymer chains cannot slide through each other. These topological constraints, the so-called entanglements, dominate the viscoelastic behavior of high-molecular-weight polymeric liquids. Tube models of polymer dynamics and rheology are based on the idea that entanglements confine a chain to small fluctuations around a primitive path which follows the coarse-grained chain contour. To establish the microscopic foundation for these highly successful phenomenological models, we have recently introduced a method for identifying the primitive path mesh that characterizes the microscopic topological state of computer-generated conformations of long-chain polymer melts and solutions. Here we give a more detailed account of the algorithm and discuss several key aspects of the analysis that are pertinent for its successful use in analyzing the topology of the polymer configurations. We also present a slight modification of the algorithm that preserves the previously neglected self-entanglements and allows us to distinguish between local self-knots and entanglements between distant sections of the same chain. Our results indicate that the latter make a negligible contribution to the tube and that the contour length between local self-knots, N_1k is significantly larger than the entanglement length N_e

[en] We extend the results on decoherence in the thermodynamic limit [Phys. Lett. A 283 (2001) 271] to general Hamiltonians. It is shown that N independent particles, initially properly prepared, have a set of observables behaving classically in the thermodynamic limit. This particular set of observables is then coupled to a quantum system that in this way decoheres so to have the density matrix in a mixed form. This gives a proof of the generality of this effect

[en] The possibility of Y(2175) as a 2³D₁ss-bar meson is studied. We study the decay of 2³D₁ss-bar from both the ³P₀ model and the flux tube model, and the results are similar in the two models. We show that the decay patterns of 1^-- strangeonium hybrid and 2³D₁ss-bar are very different. The experimental search of the decay modes KK, K*K*, K(1460)K, h₁(1380)η is suggested to distinguish the two pictures. Measuring the K*K* partial width ratios is crucial to discriminate the 2³D₁ from the 3³S₁ss-bar assignment

No abstract available

[en] We construct baryons and hybrid baryons in the non-relativistic flux-tube model of Isgur and Paton. The motion of the flux-tube with the three quark positions fixed, except for centre of mass corrections, is discussed. It is shown that the problem can to an excellent approximation be reduced to the independent motion of a junction and strings

[en] Although screw compressors (dry and wet) have been widely used in many applications (such as HVAC&R, petrochemical and gas transmission, plant air, etc..) for more than half a century, limited information is available regarding the genesis and mechanism of gas pulsations at pocket passing frequency (PPF) dominating at discharge side of these compressors [1]. The understanding of its physical nature, magnitude and affecting parameters, the location and moment of generation, and the velocity it propagates are all of fundamental, and will help to determine how it will interact with downstream components such as silencers and piping system, especially for accurately predicting downstream pulsation levels and excited vibration and noise at the higher multiples of the PPF.

The primary goal of this paper is to apply the shock tube theory [2] to screw compressors during the transient generation phase of gas pulsations at discharge. It will reveal that the nature of gas pulsation is a combination of large amplitude compression waves (CW) and expansion waves (EW) accompanied with an induced fluid flow (IFF). The most dominant gas pulsation at discharge is directly caused by either an over compression (OC) or a under compression (UC) suddenly discharging to compressor outlet. Therefore its exact location and moment of generation, magnitude, travelling directions and velocity can all be predicted based on design parameters and operating conditions of those machines. With this knowledge, its interactions with the compressor cavity and downstream piping and silencer are conducted for a typical UC and case, and results are in good agreement with the test data of previous researchers. The analysis suggests that the shock tube model can provide a pedagogic tool in understanding the physics of the transient phase of pulsation generation and subsequent formation. As such it can provide valuable insight to developers of more precise CFD calculations and a comprehensive algorithm of gas pulsations in the future. (paper)

[en] High-energy hadron-nucleus (hA) collisions provide the exciting possibility of giving information about the spacetime development of hadron-hadron interactions and therefore differentiating various multiparticle production models. Some of the major developments in this field during the past decade, both experimentally and theoretically are reviewed. Several general features of the data are pointed out, and several classes of models are discussed. A recently proposed simple spacetime model for high-energy hA collisions is elaborated. Comments are made on the extension to nucleus-nucleus interactions and the future outlook