Sudden Collapse of a Granular Cluster

Single clusters in a vibro-fluidized granular gas in N connected compartments become unstable at strong shaking. They are experimentally shown to collapse very abruptly. The observed cluster lifetime (as a function of the driving intensity) is analytically calculated within a flux model, making use of the self-similarity of the process. After collapse, the cluster diffuses out into the uniform distribution in a self-similar way, with an anomalous diffusion exponent 1/3.Comment: 4 pages, 4 figures. Figure quality has been reduced in order to decrease file-siz

Longtitudinal electron beam diagnostics via upconversion of THz to visible radiation

Longitudinal electro-optic electron bunch diagnostics has been successfully applied at several accelerators. The electro-optic effect can be seen as an upconversion of the Coulomb field of the relativistic electron bunch (THz radiation) to the visible spectral range, where a variety of standard diagnostic tools are available. Standard techniques to characterise femtosecond optical laser pulses (auto- and cross-correlators) have led to the schemes that can measure electron bunch profiles with femtosecond resolution. These techniques require, however, well synchronized femtosecond laser pulses, in order to obtain the desired temporal resolution. Currently, we are exploring other electro-optic variants which require less advanced laser systems and will be more amenable to beam based longitudinal feedback applications. The first results of one such new scheme will be presented in this paper

Evaluation of an adaptive implementation program for cognitive adaptation training for people with severe mental ilness:A cluster-randomized controlled trial

Introduction Cognitive Adaptation Training (CAT) is a psychosocial intervention focusing on reducing the impact of cognitive disorders on daily functioning in people with severe mental illness (SMI). Similar to many evidence based practices (EBP), implementation of CAT in routine care lags behind, despite the established effectiveness of the intervention. This so called ‘science-to-service gap’ is a widespread problem in mental health care. We developed an innovative implementation program to facilitate implementation of CAT and similar interventions in routine care. Objectives The aim of this study is to evaluate the effectiveness of the implementation program and to determine factors that impede or facilitate the implementation process. Methods We conducted a multicenter cluster randomized controlled trial comparing the implementation program to a single training program in four mental health institutions (a total of 21 rehabilitation teams) in The Netherlands. Focus groups, semistructured interviews and questionnaires were used at multiple levels of service delivery (service user, professional, team, organization). Assessments took place before, during and after implementation and at follow-up, adding up to a total duration of 14 months. Data were analyzed using multilevel modeling. Results Data collection is complete and analyses on the effectiveness of the implementation program are ongoing. Preliminary analyses show that team climate (p<.008) and organizational climate (p<.043) significantly predict the attitudes of mental health providers toward EBP. Conclusions This implementation research may provide important information about the implementation of psychosocial interventions in practice and may result in a program that is useful for Cognitive Adaptation Training, and possibly for psychosocial interventions in general

Relative equilibria and bifurcations in the generalized van der Waals 4-D oscillator

A uniparametric 4-DOF family of perturbed Hamiltonian oscillators in 1:1:1:1 resonance is studied as a generalization for several models for perturbed Keplerian systems. Normalization by Lie-transforms (only first order is considered here) as well as geometric reduction related to the invariants associated to the symmetries is used based on previous work of the authors. A description is given of the lower dimensional relative equilibria in such normalized systems. In addition bifurcations of relative equilibria corresponding to three dimensional tori are studied in some particular cases where we focus on Hamiltonian Hopf bifurcations and bifurcations in the 3-D van der Waals and Zeeman systems

The pattern of interleukin-1ß (IL-1ß) and its modulating agents IL-1 receptor antagonist and IL-1 soluble receptor type II in acute meningococcal infections

Contains fulltext : 4930.pdf (publisher's version ) (Open Access

A numerical investigation on the vortex formation and flow separation of the oscillatory flow in jet pumps

A two-dimensional computational fluid dynamics model is used to predict the oscillatory flow through a tapered cylindrical tube section (jet pump) placed in a larger outer tube. Due to the shape of the jet pump, there will exist an asymmetry in the hydrodynamic end effects which will cause a time-averaged pressure drop to occur that can be used to cancel Gedeon streaming in a closed-loop thermoacoustic device. The performance of two jet pump geometries with different taper angles is investigated. A specific time-domain impedance boundary condition is implemented in order to simulate traveling acoustic wave conditions. It is shown that by scaling the acoustic displacement amplitude to the jet pump dimensions, similar minor losses are observed independent of the jet pump geometry. Four different flow regimes are distinguished and the observed flow phenomena are related to the jet pump performance. The simulated jet pump performance is compared to an existing quasi-steady approximation which is shown to only be valid for small displacement amplitudes compared to the jet pump length.Comment: The following article has been accepted by the Journal of the Acoustical Society of America. After it is published, it will be found at: http://scitation.aip.org/JAS