Effective Rheology of Bubbles Moving in a Capillary Tube

We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

Alignment of the ALICE Inner Tracking System with cosmic-ray tracks

37 pages, 15 figures, revised version, accepted by JINSTALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10^5 charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.Peer reviewe

Particle identification in ALICE : a Bayesian approach

Peer reviewe

清涼飮料税論

The production of J/\).psi\) and $\psi(2S)$ was measured with the ALICE detector in Pb-Pb collisions at the LHC. The measurement was performed at forward rapidity 2.5 < y < 4 \() down to zero transverse momentum \(p_{\rm T} in the dimuon decay channel. Inclusive J/\).psi\) yields were extracted in different centrality classes and the centrality dependence of the average $p_{\rm T}$ is presented. The J/\).psi\) suppression, quantified with the nuclear modification factor $R_{\rm AA}$ , was studied as a function of centrality, transverse momentum and rapidity. Comparisons with similar measurements at lower collision energy and theoretical models indicate that the J/\).psi\) production is the result of an interplay between color screening and recombination mechanisms in a deconfined partonic medium, or at its hadronization. Results on the $\psi(2S)$ suppression are provided via the ratio of $\psi(2S)$ over J/\).psi\) measured in pp and Pb-Pb collisions

Service employee burnout and engagement: the moderating role of power distance orientation

Studies show that service employees are among the most disengaged in the workforce. To better understand service employees’ job engagement, this study broadens the scope of the job demands-resources (JD-R) model to include power distance orientation (PDO). The inclusion of PDO enriches the JD-R model by providing a key piece of information that has been missing in prior JD-R models: employees’ perceptions of the source of job demands (i.e., supervisors) or employees’ views of power and hierarchy within the organization. Study 1 uses a survey-based field study to show that employees with a high (compared to low) PDO feel more burnout due to supervisors when they are closely monitored by their supervisors. Study 1 further supports the finding that employees with high (compared to low) PDO feel less disengagement despite burnout due to supervisors. Study 2, using a lab experiment, and Study 3, relying on a survey-based field study, unveil why these effects were observed. Stress and job satisfaction emerge as mediators that explain the findings from Study 1. Implications of the role of PDO are discussed to improve the current understanding of how job engagement can improve customer service performance

Strategic goal accomplishment in export ventures: the role of capabilities, knowledge, and environment

The management literature suggests that setting strategic goals facilitates the identification of appropriate business strategies and focuses management attention and available resources on their accomplishment, enabling subsequent goal realization. Yet the literature also indicates that firms often find it difficult to realize their strategic goals and may find it even more challenging to do so when operating in foreign markets. However, little is known empirically about the extent to which strategic goals enable desired strategic positions to be achieved and factors that may affect this relationship. We examine this important issue using primary data from a sample of exporting manufacturers. Results support the existence of previously theorized strategic goal–realized strategic position gaps and show that these negatively impact performance. Thus, simply setting strategic goals does not necessarily aid in accomplishing the desired outcomes, and any failure to do so is costly. Drawing on organization theory, we find that internal capabilities and knowledge, and external market factors play important roles in minimizing such strategic goal–realized strategic position gaps. Specifically, we show that businesses with stronger architectural capabilities, those with higher levels of internationalization, and those operating in less dynamic market environments are better able to realize their intended strategic objectives and thereby enjoy superior performance