Hydrodynamics of a Cluster Descending at the Wall of a CFB Riser - Numerical Study

The incompressible hydrodynamics of a single parabolic cluster descending at the wall of a CFB riser was numerically simulated using a 2-D Eulerian-Granular model and a segregated time-dependent unsteady solver. Numerical predictions of the velocity of descent and the evolution of cluster shape are in reasonable agreement with experimental results available in the literature

Yes we can! Improving medical screening for intimate partner violence through self-efficacy

BACKGROUND: Because individual practitioner's commitment to routine screening for IPV is the greatest predictor that women will be screened and referred for services, it is vital that screeners are dedicated, knowledgeable, and confident in their ability to recognize and assist victims of violence. Self-efficacy has been consistently linked in the literature with successful outcomes. Objectives: Intimate partner violence (IPV) constitutes a major public health problem. In the absence of Federal or State regulation, individual hospitals and systems are left to develop their own policies and procedures. This paper describes the policies and procedures developed by an American domestic violence counseling and resource center. Design: Post test surveys were used. Settings: Hospitals, medical offices, and medical schools surrounding an urban area in Pennsylvania participated. Participants: 320 nurses and medical students participated in training provided by a domestic violence center. METHODS: Post test surveys measured self-efficacy, the perceived usefulness of screening the accessibility of victim services, understanding of obstacles faced by victims, and knowledge-level regarding local IPV services. Participants also self-reported their gender, age, race, and position with the hospital system. RESULTS: Nurses and medical interns exhibit a wide range of self-efficacy regarding their ability to screen victims of intimate partner violence. Intimate partner violence (IPV) training yielded participants who were better informed about IPV services and the obstacles faced by victims. CONCLUSIONS: In the absence of uniform screening guidelines, hospitals, systems, and individual practitioners must be vigilant in screening procedures. Partnerships with women's centers may provide valuable resources and training that may ultimately improve patient care

Monitoring Electrostatic Charges in Fluidized Beds

A novel analysis procedure for dynamic collision probes has been developed to monitor the charge density of particles in gas-solids fluidized beds based on the mean and normalized standard deviation of current signals. The contribution from hydrodynamic changes is decoupled from the changes in specific particle charge density based on the principles that the average current is related to charge transfer and/or triboelectrification due to the contact between the probe and particles, whereas the normalized standard deviation of current signals is mainly related to the hydrodynamic changes of the fluidized bed. The correlation between hydrodynamic changes and current signal fluctuations is confirmed from experimental data of both current fluctuations and pressure fluctuations measured from a 0.1 m diameter fluidized bed using polymer particles. Utilizing these findings, dynamic collision probes can potentially be applied in industrial fluidized bed reactors to monitor electrostatic charge build-up

Fluidized Bed Membrane Reactor for Steam Reforming of Higher Hydrocarbons: Model Sensitivity

A fluidized bed membrane reactor (FBMR) was built and operated at temperatures \u3c600°C to reform higher hydrocarbons like propane and heptane. A two-phase reactor model is utilized to simulate the FBMR with hydrogen withdrawn from both phases. The superficial gas velocities in the reactor change because of variations in molar flow due to reaction and hydrogen withdrawal through the membranes, as well as variations in temperature, pressure and cross-sectional area. Sensitivity studies show that the FBMR performance is primarily controlled by chemical equilibrium and hydrogen permeation through the membranes, while being insensitive to errors in accurately characterizing the chemical kinetics and hydrodynamics

Volume Contraction in Liquid Fluidization of Binary Solids Mixtures

When liquid-fluidized particles of radically different sizes and densities mix, the serial (additive volume) model fails to predict the fluidized bed voidage due to contraction of the mixed bed relative to the volumetric sum of the corresponding monocomponent beds. Models are proposed to predict contraction reported in the literature for both upflow and downflow fluidization

The relationship between fluidized bed electrostatics and entrainment

Existing methods of predicting entrainment from gas-fluidized beds, based exclusively on hydrodynamic variables and mechanisms, show extremely wide discrepancies in their predictions and often deviate by many orders of magnitude from experimental values. Based on simultaneous measurement of electrostatic charges in the freeboard region and entrainment, this paper will show that inter-particle electrostatic forces on relatively fine particles can be at least of the same order of magnitude as the gravity forces that must be overcome for entrainment to take place. Moreover, incorporation of a term for inter-particle electrostatic force leads to substantial improvement in the ability to correlate our experimental entrainment data. These results show that it is essential to consider electrostatic forces when predicting entrainment from gas-fluidized beds

Determining energy expenditure in a large seabird using accelerometry

Funding The research was financially supported by the Holsworth Wildlife Research Endowment. Open Access funding provided by La Trobe University. Deposited in PMC for immediate release. Acknowledgements We thank the Victorian Marine Science Consortium, Sea All Dolphin Swims, and Parks Victoria for logistical support. Catherine Hambly and Peter Thomson provided technical support for the DLW isotope analysis. Aspects of the results and discussion in this paper are reproduced from the PhD thesis of L.P.A. (Angel, 2015).Peer reviewedPublisher PD