On the onset of three-dimensionality and time-dependence in the Goertler vortex problem

The instability of large amplitude Goertler vortices in a growing boundary layer is discussed in the fully nonlinear regime. It is shown that a three-dimensional breakdown to a flow with wavy vortex boundaries similar to that which occurs in the Taylor vortex problem takes place. However, the instability is confined to the thin shear layers which have been shown to trap the region of vortex activity. The disturbance eigenfunctions decay exponentially away from the center of these layers so that the upper and lower shear layers can support independent modes of instability. The structure of the instability, in particular its location and speed of downstream propagation, is found to be entirely consistent with recent experimental results. Furthermore, it is shown that the upper and lower layers support wavy vortex instabilities with quite different frequencies. This result is again consistent with the available experimental observations

Wave interactions in a three-dimensional attachment line boundary layer

The 3-D boundary layer on a swept wing can support different types of hydrodynamic instability. Attention is focused on the so-called spanwise contamination problem, which occurs when the attachment line boundary layer on the leading edge becomes unstable to Tollmien-Schlichting waves. In order to gain insight into the interactions important in that problem, a simplified basic state is considered. This simplified flow corresponds to the swept attachment line boundary layer on an infinite flat plate. The basic flow here is an exact solution of the Navier-Stokes equations and its stability to 2-D waves propagating along the attachment can be considered exactly at finite Reynolds number. This has been done in the linear and weakly nonlinear regimes. The corresponding problem is studied for oblique waves and their interaction with 2-D waves is investigated. In fact, oblique modes cannot be described exactly at finite Reynolds number so it is necessary to make a high Reynolds number approximation and use triple deck theory. It is shown that there are two types of oblique wave which, if excited, cause the destabilization of the 2-D mode and the breakdown of the disturbed flow at a finite distance from the leading edge. First, a low frequency mode related to the viscous stationary crossflow mode is a possible cause of breakdown. Second, a class of oblique wave with frequency comparable with that of the 2-D mode is another cause of breakdown. It is shown that the relative importance of the modes depends on the distance from the attachment line

On the receptivity problem for Goertler vortices: Vortex motions induced by wall roughness

The receptivity problem for Goertler vortices induced by wall roughness is investigated. The roughness is modelled by small amplitude perturbations to the curved wall over which the flow takes place. The amplitude of these perturbations is taken to be sufficiently small for the induced Goertler vortices to be described by linear theory. The roughness is assumed to vary in the spanwise direction on the boundary layer lengthscale, while in the flow direction the corresponding variation is on the lengthscale over which the wall curvature varies. In fact the latter condition can be relaxed to allow for a faster streamwise roughness variation so long as the variation does not become as fast as that in the spanwise direction. The function which describes the roughness is assumed to be such that its spanwise and streamwise dependences can be separated; this enables progress by taking Fourier or Laplace transforms where appropriate. The cases of isolated and distributed roughness elements are investigated and the coupling coefficient which relates the amplitude of the forcing and the induced vortex amplitude is found asymptotically in the small wavelength limit. It is shown that this coefficient is exponentially small in the latter limit so that it is unlikely that this mode can be stimulated directly by wall roughness. The situation at 0(1) wavelengths is quite different and this is investigated numerically for different forcing functions. It is found that an isolated roughness element induces a vortex field which grows within a wedge at a finite distance downstream of the element. However, immediately downstream of the obstacle the disturbed flow produced by the element decays in amplitude. The receptivity problem at larger Goertler numbers appropriate to relatively large wall curvature is discussed in detail

Implementation of Best Practice of Simulation Design

The use of simulation has increased in the academic setting. The placement for nursing students for clinical sites has become increasingly difficult. In order to meet the demands of clinical sites, State Boards of Nursing have created standards where simulation can replace clinical rotation. Most State Board of Nursing require the school of nursing to meet the International Association for Clinical Simulation and Learning (INACSL) Standards of Best Practice: SimulationSM, use a theory for debriefing, and show proof of current simulation education for the educators. The Simulation Design project implemented the National League for Nursing (NLN) Jeffries Simulation Theory, the INACSL Standards of Best Practice: Simulation Design, and Debriefing with Good Judgment to a cohort of 43 pre-licensure nursing students in a medical-surgical laboratory course. The project was implemented in a private university in the southeastern part of the United States. The Simulation Design project consisted of educational sessions for the facilitators, three pilot sessions, and three new and revised simulation-based experiences. The NLN Simulation Design Scale was a five point Likert-type design scale with one being strongly disagree with statement and five strongly agree with statement. The participants completed the survey after each simulation-based experience. The analysis revealed there were no significant differences between the simulations except in the category of fidelity (realism). The project administrator believed this was due to using participants as the client\u27s parent, spouse or as a lab technician. The Simulation Design project will continue to be implemented throughout all courses in the pre-licensure School of Nursing program in order to meet State Board of Nursing requirements and INACSL standards

Interview with Alva and Mary Hall & Jim and Sharon Lang

Alva and Mary Hall talk about the history of the farm, and farm real estate. They are joined by their great grandchildren and the children\u27s parents, Jim and Sharon Lang.https://digital.kenyon.edu/ffp_interviews/1004/thumbnail.jp

Barking Up the Wrong Tree: A Qualitative Study of the Potential for Dog-Owner Technology

Current approaches to dog technology are predominantly aimed at owners monitoring and remotely engaging their dogs to prevent boredom when they are left home alone. The potential of technology to enhance the collocated dog-human experience has received little attention. This paper discusses a qualitative study with 10 owners and their dogs, exploring how technology could be used to enhance dog-human interaction in the home. Results highlight that dog toys are actually targeted at play involving both dog and owner; that playful interactions between dogs and owners focus on increasing bonding and affective symbiosis; and that the play isn’t the point for neither dog nor human, the relationship is. The study concludes that dog-human technology for collocated enjoyable interaction will be significantly different than that used in remote human-dog interaction and requires further work

Best Management Practices for Corn Production in South Dakota: Corn Growth and Development

Corn growth is influenced by cultural practices and available natural resources. The rate of growth and development changes during the season (fig. 1.1). In South Dakota, water and nitrogen (N) are important resources that limit yield. Other factors that reduce yield include disease, insects, weeds, and deficiency of other plant nutrients. For example, disease and insect infestations can reduce water and nutrient uptake or severely damage the plant to the point of yield loss. Weeds compete with the crop for water, nutrients, and light. Stress from temperature and water extremes affects nutrient availability, often increasing pest population and occurrence and ultimately reducing plant growth

Digitally restoring artefacts using 3D modelling techniques for immersive learning opportunities

Digital heritage projects are an important tool in safeguarding cultural heritage and making it available to future generations. The work presented here synthesises 3D modelling techniques with the process of digitising artefacts. New digital reconstructions can be created based on authentic data. These are then implemented in various immersive learning opportunities, such as interactive activities and engaging virtual worlds. This is applied to the restoration of two Pictish symbol stones used in an online colour configurator tool and a virtual environment

Digitally restoring artefacts using 3D modelling techniques for immersive learning opportunities

Digital heritage projects are an important tool in safeguarding cultural heritage and making it available to future generations. The work presented here synthesises 3D modelling techniques with the process of digitising artefacts. New digital reconstructions can be created based on authentic data. These are then implemented in various immersive learning opportunities, such as interactive activities and engaging virtual worlds. This is applied to the restoration of two Pictish symbol stones used in an online colour configurator tool and a virtual environment.Publisher PD

Digital modes of interpretation of Pictish sculpture

Funding: Scottish Funding Council.Cultural heritage is no longer something that can only be experienced in a museum exhibition. Digital tools have facilitated the distribution of material relating to artefacts, both in its representation and in presenting its context. This paper describes how digital modelling techniques can be synthesised with 3D scanning to digitally restore artefacts and create authentic replicas of their original states. The digital artefacts can then be used to assist the process of interpreting these artefacts in diverse forms, both in the museum and outside the museum. The study looks at Pictish sculpture as a case-study, restoring 3D models of two stones, and creating varying opportunities for their interpretation. As part of this study, new interactive tools, a virtual reality environment, and a virtual tour are built to assist immersive interpretation of the Pictish sculpture. The application of these digitised objects serves as an opportunity for informal learning. These applications were evaluated during a drop-in session. Findings show that all participants enjoyed the immersive mode of learning with 89% also showing a willingness to learn more about the topic.Publisher PDFPeer reviewe