Measurement of Both Gas and Particle Velocity in Turbulent Two-Phase Flow

A laser-Doppler anemometer was used to measure the velocity of both the gas and particles in a turbulent two-phase flow for conditions when the distribution of the velocities of the two phases overlaps. The velocities from the two phases are separated by comparing the Doppler amplitude to the pedestal amplitude. Results of the measure of the gas-particle flow downstream of a nozzle mounted in a circular pipe are presented

Innovative practices for special warfare

Special Warfare forces are tasked with conducting operations in uncertain environments defined by rapidly changing environmental elements (instability) and the interaction of many diverse external factors (complexity). In order to succeed, organizations operating in uncertain environments should decentralize decision-making to the appropriate level and emphasize an organic approach that focuses on the importance of people, adaptation, and innovation. The current USASOC bureaucracy, mirroring the conventional Army, is built to maximize internal efficiency and specialize in previously predicted scenarios. Due to persistently high operational tempo, personnel downsizing, and fiscal constraints, redesigning USASOC is not feasible at this time. However, the improvement of processes and incremental enhancement to align better with the operational environment within the existing design is possible. This study explores best practices from innovative and adaptive organizations that ARSOF can draw upon to increase its capability to conduct special warfare. Through the examination of these best practices, the study identified four key factors that lead to innovation: collaboration, organizational structure, incentives, and acceptance. This study recommends that Special Warfare forces apply these factors by increasing career flexibility, internal and external linkages through broadening opportunities and liaisons, and the collective intelligence of the organization through the use of cross-functional teams and increased communication measures. Adopting these enhancements may promote innovation and adaptation and increase Special Warfare forces’ contributions to national defense.http://archive.org/details/innovativepracti1094547858Major, United States ArmyApproved for public release; distribution is unlimited

Pressure coefficients of Raman modes of carbon nanotubes resolved by chirality: Environmental effect on graphene sheet

Studies of the mechanical properties of single-walled carbon nanotubes are hindered by the availability only of ensembles of tubes with a range of diameters. Tunable Raman excitation spectroscopy picks out identifiable tubes. Under high pressure, the radial breathing mode shows a strong environmental effect shown here to be largely independent of the nature of the environment . For the G-mode, the pressure coefficient varies with diameter consistent with the thick-wall tube model. However, results show an unexpectedly strong environmental effect on the pressure coefficients. Reappraisal of data for graphene and graphite gives the G-mode Grueuneisen parameter gamma = 1.34 and the shear deformation parameter beta = 1.34.Comment: Submitted to Physical Review

Cascading failures in networks of heterogeneous node behavior

Variability in the dynamical function of nodes comprising a complex network impacts upon cascading failures that can compromise the network's ability to operate. Node types correspond to sources, sinks or passive conduits of a current ow, applicable to renewable electrical power micro-grids containing a variable number of intermittently operating generators and consumers of power. The resilience to cascading failures of ensembles of synthetic networks with di_erent topology is examined as a function of the edge current carrying capacity and mix of node types, together with exemplar real-world networks. Whilst a network with homogeneous node type can be resilient to failure, one with identical topology but heterogeneous node function can be strongly susceptible to failure. For networks with similar numbers of sources, sinks and passive nodes the mean resilience decreases as networks become more disordered. Nevertheless all network topologies have enhanced regions of resilience, accessible by manipulation of node composition and functionality

Treatment with supplementary arginine, vitamin C and zinc in patients with pressure ulcers: A randomised controlled trial

Background &amp; AimsNutrients putatively implicated in pressure ulcer healing were evaluated in a clinical setting.MethodsSixteen inpatients with a stage 2, 3 or 4 pressure ulcer randomised to receive daily a standard hospital diet; a standard diet plus two high-protein/energy supplements; or a standard diet plus two high-protein/energy supplements containing additional arginine (9 g), vitamin C (500 mg) and zinc (30 mg). Nutritional status measurements (dietary, anthropometric and biochemical) and pressure ulcer size and severity (by PUSH tool; Pressure Ulcer Scale for Healing; 0=completely healed, 17=greatest severity) were measured weekly for 3 weeks.ResultsPatients&rsquo; age and BMI ranges were 37&ndash;92 years and 16.4&ndash;28.1 kg/m2, respectively. Baseline PUSH scores were similar between groups (8.7&plusmn;0.5). Only patients receiving additional arginine, vitamin C and zinc demonstrated a clinically significant improvement in pressure ulcer healing (9.4&plusmn;1.2 vs. 2.6&plusmn;0.6; baseline and week 3, respectively; P&lt;0.01). All patient groups presented with low serum albumin and zinc and elevated C-reactive protein. There were no significant changes in biochemical markers, oral dietary intake or weight in any group.ConclusionsIn this small set of patients, supplementary arginine, vitamin C and zinc significantly improved the rate of pressure ulcer healing. The results need to be confirmed in a larger study.<br /

Grey Literature and Professional Knowledge Making

International audienceWhat does grey literature mean? What role does it play in the production and dissemination of practitioner knowledge? How do reports, presentations and communications, working papers and other un-published material contribute to professional, extra-academic knowledge making? The following paper tries to provide some elements for a better understanding of grey literature, with examples from different collections and disciplines. Moreover, it puts the focus on critical issues like standards, identifiers and quality, and it discusses the impact of open science, i.e. the movement to make scientific research, data and dissemination accessible to all levels of an inquiring society, amateur or professional

Diet and risk of diverticular disease in Oxford cohort of European Prospective Investigation into Cancer and Nutrition (EPIC): prospective study of British vegetarians and non-vegetarians

Objective To examine the associations of a vegetarian diet and dietary fibre intake with risk of diverticular disease

Eulerian simulation of the fluid dynamics of helicopter brownout

A computational model is presented that can be used to simulate the development of the dust cloud that can be entrained into the air when a helicopter is operated close to the ground in desert or dusty conditions. The physics of this problem, and the associated pathological condition known as ‘brownout’ where the pilot loses situational awareness as a result of his vision being occluded by dust suspended in the flow around the helicopter, is acknowledged to be very complex. The approach advocated here involves an approximation to the full dynamics of the coupled particulate-air system. Away from the ground, the model assumes that the suspended particles remain in near equilibrium under the action of aerodynamic forces. Close to the ground, this model is replaced by an algebraic sublayer model for the saltation and entrainment process. The origin of the model in the statistical mechanics of a distribution of particles governed by aerodynamic forces allows the validity of the method to be evaluated in context by comparing the physical properties of the suspended particulates to the local properties of the flow field surrounding the helicopter. The model applies in the Eulerian frame of reference of most conventional Computational Fluid Dynamics codes and has been coupled with Brown’s Vorticity Transport Model. Verification of the predictions of the coupled model against experimental data for particulate entrainment and transport in the flow around a model rotor are encouraging. An application of the coupled model to analyzing the differences in the geometry and extent of the dust clouds that are produced by single main rotor and tandem-rotor configurations as they decelerate to land has shown that the location of the ground vortex and the size of any regions of recirculatory flow, should they exist, play a primary role in governing the extent of the dust cloud that is created by the helicopter