Simulation Modeling of Prehospital Trauma Care

Prehospital emergency care systems are complex and do not necessarily respond predictably to changes in management. A combined discrete-continuous simulation model focusing on trauma care was designed and implemented in SIMSCRIPT II.5 to allow prediction of the systems response to policy changes in terms of its effect on the system and on patient survival. The utility of the completed model was demonstrated by the results of experiments on triage and helicopter dispatching policies. Experiments on current and two alternate triage policies showed that helicopter utilization is significantly increased by more liberal triage to Level 1 trauma centers, which was expected, but that the waiting time for pending accidents tended to decrease, an unexpected consequence. Experiments on helicopter dispatch policy showed that liberalization of the dispatch policy would have much greater consequences than would changing the triage criteria. Again, this result was unexpected and has received little attention from system planners and administrators, especially with respect to the degree of discussion and controversy surrounding triage criteria

CFD characterization of flow regimes inside open cell foam substrates

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.In this work a combination of micro-CT, image-based modeling and CFD has been applied to investigate the pressure drop in open-cell foams. The analysis covers a range of flow regimes and is aimed at determining the effects of important morphological parameters on the pressure drop. The adoption of micro-CT technology along with detailed CFD modeling allows the investigation of phenomena occurring in real foam micro-structures. Moreover, by means of image processing tools, the geometry can be artificially modified in order to investigate the effects of mathematical transformation of the geometrical parameters of a real foam, one parameter at a time, e.g. varying pore size without affecting the porosity. Non-dimensional coefficients have been defined for the analysis of the results, with the purpose of describing the pressure drop as a function of the Reynolds number. The proposed formulation allows us to relate the permeability properties of an open-cell foam to its morphology alone, without any dependence on the properties of the fluid adopted or on the effective characteristic dimension of the foam micro-structure (pore or cell size). Comparison with experimental results available in the literature is also provided for one of the cases studied

The magnetic manipulation of surface plasmons - Consideration of possible technologies

Copyright © 2008 PIERSAn as yet unexploited mechanism for producing controlled shifts in the frequency of lightwaves via their temporary conversion to surface plasmons propagating on a ferromagnetic surface or under the action of applied magnetic fields is introduced. Indirect evidence of the observation of this phenomena is presented and the technological possibilities it might offer are explored and discussed

Novel magneto-optic behaviour from a polysquaraine

Copyright © 2013 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Synthetic Metals. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Synthetic Metals, Volume 171 (1 May 2013), DOI: 10.1016/j.synthmet.2013.03.010We report that poly((2,5-bis(1-methylpyrrol-2-yl)thiophene)squaraine) can be synthesized as a dark green insoluble powder which when subjected to shear force and pressed as a disk exhibits a gold-green near optical quality surface with semi-metallic behaviour. Reflectivity measurements at a wavelength of 819 nm reveal a high (72°) pseudo-Brewster angle and non-zero p-reflectivity whilst electrical measurements using a four-point probe return a conductivity of 1 × 10−5 S cm−1. Unexpectedly the disks also exhibit magneto-optic (MO) activity which it appears must arise from a weak magnetic component intrinsic to the samples. In both the longitudinal and transverse Kerr configurations large fractional changes in reflectivity (ΔI/I ≈ 2.5 × 10−2) are observed across a wide range of angles of incidence for wavelengths between 400 nm and 1064 nm on application and reversal of a magnetic field. Anomalously for these configurations all the MO effects observed are quadratic in the applied field and no first-order effects linear in applied field are observed for any state of incident polarisation. Examined using conventional magnetometry, disk samples return saturation magnetization values of 4.13 × 10−3 emu g−1 on a vibrating sample magnetometer and smaller samples similarly processed and prepared for examination by Squid magnetometer confirmatory values of 4.9 × 10−3 emu g−1. Magnetization curves from both instruments have a similar form, saturating at about 1.14 kOe, and are also in close correspondence with curves derived by plotting the magneto-optic signal as a function of field after allowance for the quadratic nature of the observed MO response. Similarly, both the magnetic and magneto-optic behaviour of all samples is isotropic in plane. Taken together, all experimental observations on this fully organic polymer appear, surprisingly, to be commensurate with the development at room temperature of some form of magnetic state throughout very limited regions of the material. A very tentative model able to reconcile the magnetic and MO observations on the supposition that the magnetic state may be of a reduced dimensional nature is presented. We are very aware that the appearance of an intrinsic room temperature magnetism in the material studied is highly unlikely and that this interpretation of the results presented is strongly dependent on using MO evidence to support chemical analysis, which included multi-elements scans on an ICP and ESR, in precluding contamination

Localised electro-thermal processing: a new route to the patterning of magnetic recording media

notes: A new route to magnetic nanopatterning demonstrated experimentally and via new theoretical modelpublication-status: Publishedtypes: ArticlePrevious reports have detailed the fabrication of media able to support high density magnetic recording in both longitudinal and perpendicular formats by the global rapid thermal processing of sputtered non-magnetic precursor films. During processing in this manner a magnetic element is released from its nitride and agglomerates to form a random near mono-dispersion of magnetic nano-particles. Here we explore, primarily through modelling and simulation, the feasibility of processing similarly formulated precursor media not globally but locally. We investigate the potential of using conducting nano-probe tips to produce, via electro-thermal (Joule) heating, a nano-patterned recording media in the form of regular arrays of magnetic islands in a non-magnetic host. In the first instance we concentrate on the simplest cobalt based precursor medium for which both initial simulation and experimental studies indicate the formation of magnetic islands with dimensions of the order of the tip diameter is relatively straightforward. The results signify that if practical production scenarios can be devised to produce technologically significant areas of recording media by the rapid multi-probe repetition of this technique, then processing in this manner offers a promising route to areal recording densities of perhaps 5 Terabit/in2 even with the simplest cobalt media. We also note that the electro-thermal processing method is potentially extendable to the production of a wide variety of magnetic materials (eg. PtCo, FeCo, NiFe alloys) and, applied via electrical nano-imprinting type techniques, to the production of a wide variety of patterned structures

Learning from Failure in Systems Engineering: A Panel Discussion

This paper summarizes the discussion of the Learning from Failure in Systems Engineering panel that was held in Huntsville, AL on November 8, 2010. The panel objective was to discuss how systems engineers respond to and learn from failure and identify future directions important to the community. The panel consisted of four representatives with experience in government, industry, and academia: (1) Ronald Kadish from Booz Allen Hamilton and former director of the Missile Defense Agency, (2) Gary Payton, retired Deputy Under Secretary of the Air Force for Space Programs, (3) John Thomas from Booz Allen Hamilton and President-elect of INCOSE, and (4) Michael Griffin from the University of Alabama, Huntsville and former NASA Administrator. Each panelist was asked to (i) provide an opening statement and elaborate on their experience with failure, (ii) describe when failure is appropriate, (iii) describe how we learn and react to failure, and (iv) identify and discuss techniques to improve how systems engineers react to failure. Several common themes arose from the discussion including: failure is an option, the importance of failure to allow reassessment, and more process is not the solution. Each of these is discussed in turn along with future directions identified for reacting to and learning from failure

Promoting Teamwork: An Event-Based Approach to Simulation-Based Teamwork Training for Emergency Medicine Residents

The growing complexity of patient care requires that emergency physicians (EPs) master not only knowledge and procedural skills, but also the ability to effectively communicate with patients and other care providers and to coordinate patient care activities. EPs must become good team players, and consequently an emergency medicine (EM) residency program must systematically train these skills. However, because teamwork-related competencies are relatively new considerations in health care, there is a gap in the methods available to accomplish this goal. This article outlines how teamwork training for residents can be accomplished by employing simulation-based training (SBT) techniques and contributes tools and strategies for designing structured learning experiences and measurement tools that are explicitly linked to targeted teamwork competencies and learning objectives. An event-based method is described and illustrative examples of scenario design and measurement tools are provided

An integrated statistical model of Emergency Department length of stay informed by Resilient Health Care principles

Background Hospital Emergency Departments (EDs) face variable demand and capacity issues affecting timely discharge of patients. This is due in part to a lack of integration of routine monitoring data, affecting anticipation and response. Methods Patient flow was modelled (four hour target breaches; time to decision-to-admit; subsequent time to admit-to-hospital) in a busy ED. Patient and organisational data were collated, screened and conceptualised using Resilient Health Care (RHC) theory. Data were collected for all patients presenting during a 24-month period (May 2014–April 2016; n = 232,920) and analysed via multivariable logistic regression for four hour target breaches, and ordinary least squares regression for time. A measure of effect size was calculated for each independent variable. Overall model fit was assessed using percent concordant. Results Length of stay is related to demand, capacity and process indicators including: number of patients; night shift; first location being resuscitation or major injury area(s); urgent or very urgent triage patients; patients readmitting from up to 7 days previous; bed capacity; recent ambulance arrivals; and patients where the primary presenting complaint (PPC) is related to mental health or difficult to ascertain. Conclusions Understanding variation in performance through RHC theory can support staff and organisations in monitoring, anticipating and responding. A set of reliable core predictors has been identified to help design future ways to facilitate resilient performance through early indicators of pressure