The experience of positive psychology coaching following unconscious bias training: An Interpretative Phenomenological Analysis

This study explored the lived experience of four professionals who engaged in positive psychology coaching following an implicit association test and unconscious bias training. Unconscious bias training focuses on a human limitation, avoidance goals, and can result in defensiveness. In contrast, positive psychology coaching leverages strengths, intrinsically motivated approach goals and positive affect. Interpretative phenomenological analysis was applied to analyse data gathered via semi-structured interviews. Findings reveal that participants were self-conscious about being perceived negatively and they experienced deep introspection and reflexivity. Participants also reported increased self-efficacy, motivation to improve and feeling safe to discuss previously avoided personal issues

The free compressible viscous vortex

The effects of compressibility on free (unsteady) viscous heat-conducting vortices are investigated. Analytical solutions are found in the limit of large, but finite, Reynolds number, and small, but finite, Mach number. The analysis shows that the spreading of the vortex causes a radial flow. This flow is given by the solution of an ordinary differential equation (valid for any Mach number), which gives the dependence of the radial velocity on the tangential velocity, density, and temperature profiles of the vortex; estimates of the radial velocity found by solving this equation are found to be in good agreement with numerical solutions of the full equations. The experiments of Mandella (1987) also report a radial flow in the vortex, but their estimates are much larger than the analytical predictions, and it is found that the flow inferred from the experiments violates the Second Law of Thermodynamics for two-dimensional axisymmetric flow. It is speculated that three-dimensionality is the cause of this discrepancy. To obtain detailed analytical solutions, the equations for the viscous evolution are expanded in powers of Mach number, M. Solutions valid to O(M^2), are discussed for vortices with finite circulation. Two specific initial conditions - vortices with initially uniform entropy and with initially uniform density - are analysed in detail. It is shown that swirling axisymmetric compressible flows generate negative radial velocities far from the vortex core owing to viscous effects, regardless of the initial distributions of vorticity, density and entropy

Scattering of Sound Waves by a Compressible Vortex

Scattering of plane sound waves by a compressible vortex is investigated by direct computation of the 2-d Navier-Stokes equations. Non-reflecting boundary conditions are utilized, and their accuracy is established by comparing results on different sized domains. Scattered waves are directly measured from the computations. The resulting amplitude and directivity pattern of the scattered waves is discussed, and compared to various theoretical predictions. For compact vortices (zero circulation), the scattered waves directly computed are in good agreement with predictions based on an acoustic analogy. Strong scattering at about ±30° from the direction of incident wave propagation is observed. Back scattering is an order of magnitude smaller than forward scattering. For vortices with finite circulation refraction of the sound by the mean flow field outside the vortex core is found to be important in determining the amplitude and directivity of the scattered wave field

Boundary Conditions for Direct Computation of Aerodynamic Sound Generation

Accurate computation of the far-field sound along with the near-field source terms associated with a free shear flow requires that the Navier-Stokes equations be solved using accurate numerical differentiation and time-marching schemes, with nonreflecting boundary conditions. Nonreflecting boundary conditions have been developed for two-dimensional linearized Euler equations by Giles. These conditions are modified for use with nonlinear Navier-Stokes computations of open flow problems. At an outflow, vortical structures are found to produce large reflections due to nonlinear effects; these reflection errors cannot be improved by increasing the accuracy of the linear boundary conditions. An exit zone just upstream of an outflow where disturbances are significantly attenuated through grid stretching and filtering is developed for use with the nonreflecting boundary conditions; reflections from vortical structures are decreased by 3 orders of magnitude. The accuracy and stability of the boundary conditions are investigated in several model flows that include sound radiation by an energy source in a uniformly sheared viscous flow, the propagation of vortices in a uniform flow, and the spatial evolution of a compressible mixing layer

The Sound Generated by a Two-Dimensional Shear Layer: A Comparison of Direct Computations and Acoustic Analogies

The sound generated by vortex pairing in a two-dimensional mixing layer is studied by solving the Navier-Stokes equations (DNS) for the layer and a portion of its acoustic field, and by solving acoustic analogies with source terms determined from the DNS. Predictions for the acoustic field based on Lilley’s equation are in excellent agreement with the DNS results giving detailed verification of Lilley’s acoustic analogy for the first time. We show that parts of the full source term which arise when the left-hand-side of Lilley’s equation is linearized should not be neglected solely because they are attributable to refraction and scattering, nor because they are proportional to the dilatation. Lilley’s source, -2u_(i,j)u_(j,k)u_(k,i), appears to be mainly responsible for the overall directivity of the acoustic field produced by the vortex pairings, which is highly focused at shallow angles to the streamwise axis. Scattering of the waves by the flow appears also to be significant, causing the directivity to be more omnidirectional than the Lilley source alone would predict. We also show how small errors in determining the sources, especially those due to scattering, can sometimes lead to large errors in the predictions

The Sound Generated by a Two-Dimensional Shear Layer: The Far Field Directivity from Computations and Acoustic Analogies

The sound generated by vortex pairing in a two- dimensional mixing layer is studied by direct numerical simulation of the Navier-Stokes equations (DNS) for the layer and a portion of its acoustic field, and by solving Lilley's equation (with source terms determined from the DNS) for the entire acoustic field. Predictions for the acoustic field based on Lilley's equation are in good agreement with the DNS results. The radiated acoustic field at the pairing frequencies is highly directive and cannot be produced by point quadrupole sources. Instead, it is of the superdirective character considered by Crighton and Huerre (1990, J. Fluid Mech., 220), where the magnitude of the pressure varies like the exponential of the cosine of the angle between the observation point and the downstream axis. By making modifications to this basic directivity, we account, in part, for shear in the mean velocity and the convection of the acoustic waves by the different freestream velocities on either side of the layer, and obtain a good overall agreement between the theory and the computations

Nuchal cord: from dread towards confident management

Background: This study was aimed at observing the outcomes of pregnancies with sonographically detected nuchal cord or cord around the neck at term. Early studies on nuchal cord showed many maternal and neonatal complications. But several recent studies have suggested that maternal and neonatal complications do not increase with nuchal cord at delivery. This ambiguity increases anxiety in treating obstetricians and relatives of pregnant women, thus leading to unnecessary caesarean sections. This study is intended to observe the maternal and neonatal outcomes of 300 pregnant women with sonographically detected nuchal cord at term.Methods: Prospective observational study where 300 term pregnant women with sonographically detected nuchal cord were observed through delivery at Shri Venkata Sai Medical College, Mahabubnagar, Telangana, during October 2016 to April 2018.Results: In this study 80.6% women had normal vaginal delivery, 8.3% had LSCS, 11% had instrumental deliveries. 54% had loose nuchal cord, 46% had tight loop of cord.60% had normal CTG, 8% had variable deceleration, 2% late deceleration. Neonatal morbidity was 9.6% and zero neonatal mortality.Conclusions: The study concluded that the presence of nuchal cord does not adversely affect the mother and the neonate. Presence of nuchal cord per se is not an indication for LSCS. Effect of nuchal cord on neonate is only transient. These women can be allowed for vaginal delivery with routine labour room protocols. Routine sonographycal detection of nuchal cord is not required and if it is reported, it should not dictate obstetric management

Evaluation of Noise Radiation Mechanisms in Turbulent Jets

Data from the direct numerical simulation (DNS) of a turbulent, compressible (Mach = 1.92) jet has been analyzed to investigate the process of sound generation. The overall goals are to understand how the different scales of turbulence contribute to the acoustic field, and to understand the role that linear instability waves play in the noise produced by supersonic turbulent jets. Lighthill’s acoustic analogy was used to predict the radiate sound from turbulent source terms computed from the DNS data. Preliminary computations (for the axisymmetric mode of the acoustic field) showgood agreement between the acoustic field determined from DNS and acoustic analogy. Further work is needed to refine the calculations and investigate the source terms. Work was also begun to test the validity of linear stability wave models of sound generation in supersonic jets. An adjoint-based method was developed to project the DNS data onto the most unstable linear stability mode at different streamwise positions. This will allow the evolution of the wave and its radiated acoustic field, determined by solving the linear equations, to be compared directly with the evolution of the near and far-field fluctuations in the DNS