Application of second-order turbulent modeling to the prediction of radiated aerodynamic sound

The Ribner formulation of the generation of aerodynamic sound is coupled with predictions of second-order velocity correlations and integral scale to estimate the sound radiated from several complicated jet flows. In particular, it is shown that the sound radiated from a cold swirling jet is greater than from its nonswirling equal thrust counterpart. The noise radiated from the flow field of a multitube suppressor was estimated and compared with an equal thrust diameter Gaussian jet. It is shown that the multitube concept is indeed quieter

More, More, More: Reducing Thrombosis in Acute Coronary Syndromes Beyond Dual Antiplatelet Therapy-Current Data and Future Directions.

© 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.Common to the pathogenesis of acute coronary syndromes (ACS) is the formation of arterial thrombus, which results from platelet activation and triggering of the coagulation cascade.1 To attenuate the risk of future thrombotic events, patients with ACS are treated with dual antiplatelet therapy (DAPT), namely, the combination of aspirin with a P2Y12 inhibitor, such as clopidogrel, ticagrelor, or prasugrel. Despite DAPT, some ≈10% of ACS patients experience recurrent major adverse cardiovascular events over the subsequent 30 days,2 driving the quest for more effective inhibition of thrombotic pathways. In this review, we provide an overview of studies to date and those ongoing that aim to deliver more effective combinations of antithrombotic agents to patients with recent ACS. We have chosen to confine the review to ACS patients without atrial fibrillation because those with atrial fibrillation have a clear indication for combination therapy that includes oral anticoagulation and should, we feel, be treated as a separate cohort. In this article, we discuss the limitations of the currently available clinical trial data and future directions, with suggestions for how practice might change to reduce the risk of coronary thrombosis in those at greatest risk, with minimal impact on bleeding.Peer reviewedFinal Published versio

To what extent do the Classical Equations of Motion Determine the Quantization Scheme?

A simple example of one particle moving in a (1+1) space-time is considered. As an example we take the harmonic oscillator. We confirm the statement that the classical Equations of Motion do not determine at all the quantization scheme. To this aim we use two inequivalent Lagrange functions, yielding Euler-Lagrange Equations, having the same set of solutions. We present in detail the calculations of both cases to emphasize the differences occuring between them.Comment: LaTeX 20 page

Atmospheric-wake vortex interactions

The interactions of a vortex wake with a turbulent stratified atmosphere are investigated with the computer code WAKE. It is shown that atmospheric shear, turbulence, and stratification can provide the dominant mechanisms by which vortex wakes decay. Computations included the interaction of a vortex wake with a viscous ground plane. The observed phenomenon of vortex bounce is explained in terms of secondary vorticity produced on the ground. This vorticity is swept off the ground and advected about the vortex pair, thereby altering the classic hyperbolic trajectory. The phenomenon of the solitary vortex is explained as an interaction of a vortex with crosswind shear. Here, the vortex having the sign opposite that of the sign of the vorticity in the shear is dispersed by a convective instability. This instability results in the rapid production of turbulence which in turn disperses the smoke marking the vortex

Development of a Short Trauma Screening Tool (STST) to Measure Child Trauma Symptoms: Establishing Content Validity

Purpose: The purpose of the study was to identify major symptom domain variables common to child trauma and create a prototype short trauma symptom screening tool (STST) intended for use in pediatric medical settings. Methods: This manuscript describes the first two phases of an on-going prospective mixed-method instrument development study. Phase 1 exploratory factor analysis was conducted with an archived LONGSCAN CBCL dataset to: (1) identify behavioral symptoms endorsed by children with known trauma exposure; and (2) generate a preliminary STST item pool. During Phase 2, researchers convened an expert panel (N = 10) and conducted Content Validity Index (CVI) procedures with the 20-item preliminary STST item pool, to further inform item retention, elimination and modification for an updated prototype STST. Findings: Expert quantitative scores yielded a CVI of 0.90 for the overall preliminary STST. The first two phases of this study assisted researchers with identifying 12 items that represent nine child trauma symptom domain variables, which include: (1) aggression/anger; (2) anxiety/fear; (3) sexual concerns; (4) elimination concerns; (5) somatic concerns; (6) depression; (7) dissociation; (8) physical acting out; and (9) dysregulation. Conclusions: The first two phases of STST development resulted in development of a brief, empirically-derived prototype screening tool that features 12 items operationalizing nine domains of child trauma symptoms. Developers can now advance to the next phase of STST development; feasibility assessment and psychometric testing

Magnon-Paramagnon Effective Theory of Itinerant Ferromagnets

The present work is devoted to the derivation of an effective magnon-paramagnon theory starting from a microscopic lattice model of ferromagnetic metals. For some values of the microscopic parameters it reproduces the Heisenberg theory of localized spins. For small magnetization the effective model describes the physics of weak ferromagnets in accordance with the experimental results. It is written in a way which keeps O(3) symmetry manifest,and describes both the order and disordered phases of the system. Analytical expression for the Curie temperature,which takes the magnon fluctuations into account exactly, is obtained. For weak ferromagnets $T_c$ is well below the Stoner's critical temperature and the critical temperature obtained within Moriya's theory.Comment: 14 pages, changed content,new result

Impact of Race and Sex on Pain Management by Medical Trainees: A Mixed Methods Pilot Study of Decision Making and Awareness of Influence

Objective Previous research suggests female and black patients receive less optimal treatment for their chronic pain compared with male and white patients. Provider-related factors are hypothesized to contribute to unequal treatment, but these factors have not been examined extensively. This mixed methods investigation examined the influence of patients' demographic characteristics on providers' treatment decisions and providers' awareness of these influences on their treatment decisions. Methods Twenty medical trainees made treatment decisions (opioid, antidepressant, physical therapy) for 16 virtual patients with chronic low back pain; patient sex and race were manipulated across patients. Participants then indicated from a provided list the factors that influenced their treatment decisions, including patient demographics. Finally, individual interviews were conducted to discuss the role of patient demographics on providers' clinical decisions. Results Individual regression analyses indicated that 30% of participants were reliably influenced by patient sex and 15% by patient race when making their decisions (P < 0.05 or P < 0.10). Group analyses indicated that white patients received higher antidepressant recommendations, on average, than black patients (P < 0.05). Half of the medical trainees demonstrated awareness of the influence of demographic characteristics on their decision making. Participants, regardless of whether they were influenced by patients' demographics, discussed themes related to patient sex and race; however, participants' discussion of patient demographics in the interviews did not always align with their online study results. Conclusions These findings suggest there is a considerable variability in the extent to which medical trainees are influenced by patient demographics and their awareness of these decision making influences

Intelligence for Human-Assistant Planetary Surface Robots

The central premise in developing effective human-assistant planetary surface robots is that robotic intelligence is needed. The exact type, method, forms and/or quantity of intelligence is an open issue being explored on the ERA project, as well as others. In addition to field testing, theoretical research into this area can help provide answers on how to design future planetary robots. Many fundamental intelligence issues are discussed by Murphy [2], including (a) learning, (b) planning, (c) reasoning, (d) problem solving, (e) knowledge representation, and (f) computer vision (stereo tracking, gestures). The new "social interaction/emotional" form of intelligence that some consider critical to Human Robot Interaction (HRI) can also be addressed by human assistant planetary surface robots, as human operators feel more comfortable working with a robot when the robot is verbally (or even physically) interacting with them. Arkin [3] and Murphy are both proponents of the hybrid deliberative-reasoning/reactive-execution architecture as the best general architecture for fully realizing robot potential, and the robots discussed herein implement a design continuously progressing toward this hybrid philosophy. The remainder of this chapter will describe the challenges associated with robotic assistance to astronauts, our general research approach, the intelligence incorporated into our robots, and the results and lessons learned from over six years of testing human-assistant mobile robots in field settings relevant to planetary exploration. The chapter concludes with some key considerations for future work in this area

C-axis Optical Sum Rule in Josephson Coupled Vortex State

Observed violations of the $c$-axis optical sum rule can give important information on deviations from in-plane Fermi liquid behavior and on the nature of interlayer coupling between adjacent copper oxide planes. Application of a magnetic field perpendicular to these planes is another way to probe in-plane dynamics. We find that the optical sum rule is considerably modified in the presence of the $c$-axis magnetic field. Interlayer correlation of pancake vortices is involved in the sum rule modification; however, details of the vortex distribution in the plane are less important.Comment: one figure. To be published in PRB (Sep. 20001

Spin-Wave Theory of the Spiral Phase of the t-J Model

A graded H.P,realization of the SU(2|1) algebra is proposed.A spin-wave theory with a condition that the sublattice magnetization is zero is discussed.The long-range spiral phase is investigated.The spin-spin correlator is calculated.Comment: 17 page