Three-dimensional coating and rimming flow: a ring of fluid on a rotating horizontal cylinder

The steady three-dimensional flow of a thin, slowly varying ring of Newtonian fluid on either the outside or the inside of a uniformly rotating large horizontal cylinder is investigated. Specifically, we study “full-ring” solutions, corresponding to a ring of continuous, finite and non-zero thickness that extends all the way around the cylinder. In particular, it is found that there is a critical solution corresponding to either a critical load above which no full-ring solution exists (if the rotation speed is prescribed) or a critical rotation speed below which no full-ring solution exists (if the load is prescribed). We describe the behaviour of the critical solution and, in particular, show that the critical flux, the critical load, the critical semi-width and the critical ring profile are all increasing functions of the rotation speed. In the limit of small rotation speed, the critical flux is small and the critical ring is narrow and thin, leading to a small critical load. In the limit of large rotation speed, the critical flux is large and the critical ring is wide on the upper half of the cylinder and thick on the lower half of the cylinder, leading to a large critical load.\ud \ud We also describe the behaviour of the non-critical full-ring solution, and, in particular, show that the semi-width and the ring profile are increasing functions of the load but, in general, non-monotonic functions of the rotation speed. In the limit of large rotation speed, the ring approaches a limiting non-uniform shape, whereas in the limit of small load, the ring is narrow and thin with a uniform parabolic profile. Finally, we show that, while for most values of the rotation speed and the load the azimuthal velocity is in the same direction as the rotation of the cylinder, there is a region of parameter space close to the critical solution for sufficiently small rotation speed in which backflow occurs in a small region on the right-hand side of the cylinder

Thermoviscous Coating and Rimming Flow

A comprehensive description is obtained of steady thermoviscous (i.e. with temperature-dependent viscosity) coating and rimming flow on a uniformly rotating horizontal cylinder that is uniformly hotter or colder than the surrounding atmosphere. It is found that, as in the corresponding isothermal problem, there is a critical solution with a corresponding critical load (which depends, in general, on both the Biot number and the thermoviscosity number) above which no ``full-film'' solutions corresponding to a continuous film of fluid covering the entire outside or inside of the cylinder exist. The effect of thermoviscosity on both the critical solution and the full-film solution with a prescribed load is described. In particular, there are no full-film solutions with a prescribed load M for any value of the Biot number when M is greater than or equal to M_{c0} divided by the square root of f for positive thermoviscosity number and when M is greater than M_{c0} for negative thermoviscosity number, where f is a monotonically decreasing function of the thermoviscosity number and M_{c0} = 4.44272 is the critical load in the constant-viscosity case. It is also found that when the prescribed load M is less than 1.50315 there is a narrow region of the Biot number - thermoviscosity number parameter plane in which backflow occurs

Studies of discharge mechanisms in high pressure gases-applications to high efficiency high power lasers

By measuring the absorption and emission cantinua of various states in the cesium/xenon molecule, the collisional rates critical in populating the alkali/rare gas excimer levels have been estimated. Cs atomic states that are weakly optically connected to ground have been shown to form excimer levels that are attractive as potential dissociation lasers. In particular, the (Cs/7 2S/Xe) excited molecule appears promising as a source of high energy laser radiation due to its large dissociation energy, stimulated emission cross section, and small population inversion densities. Monitoring of the optically pumped Cs2 molecular absorption profile in the presence of xenon shows a drastic change with increasing xenon pressure for the Cs2C band. Dominant absorption at large xenon densities is centered around approximately 6380 A as opposed to 6300 A for lower perturber pressure

Helping the Me Generation Decenter: Service Learning with Refugees

Recent research has empirically demonstrated that young adults today are different from prior generations in their decreased empathy, increased narcissism, and decreased civic engagement. The formative years of young adulthood are a critical period for the development of civic values and civil ideologies, a time when college-age adults need to acquire the experiences and skills to decenter and develop into civic-minded stewards of their communities. Engagement in service learning with individuals unlike themselves, i.e., outgroup members, is the approach we have taken at the University of North Florida to encourage this decentering through service learning engagement with refugees embedded in an honors colloquium during students’ first term in college. We took a three-pronged approach to the assessment of the impact of this service learning engagement. In the first approach, evaluations of student responses to open-ended questions provided evidence of a reduction in their self-centeredness and increases in social empathy and multicultural competence. The second approach confirmed these changes in decentering by showing that honors students who were engaged in more interactive service projects with refugees scored higher on two measures of empathy—i.e., the Basic Empathy Scale Basic Empathy Scale ( Jolliffe & Farrington) and the Toronto Empathy Questionnaire (Spreng et al.)—than did students engaged in less interactive service projects with refugees. In the final approach, evaluations of artifacts from the course suggested that levels of decentering, empathy, and civic action differed for students who had intensive versus superficial interactions with refugees

Helping the Me Generation Decenter: Service Learning with Refugees

Recent research has empirically demonstrated that young adults today are different from prior generations in their decreased empathy, increased narcissism, and decreased civic engagement. The formative years of young adulthood are a critical period for the development of civic values and civil ideologies, a time when college-age adults need to acquire the experiences and skills to decenter and develop into civic-minded stewards of their communities. Engagement in service learning with individuals unlike themselves, i.e., outgroup members, is the approach we have taken at the University of North Florida to encourage this decentering through service learning engagement with refugees embedded in an honors colloquium during students’ first term in college. We took a three-pronged approach to the assessment of the impact of this service learning engagement. In the first approach, evaluations of student responses to open-ended questions provided evidence of a reduction in their self-centeredness and increases in social empathy and multicultural competence. The second approach confirmed these changes in decentering by showing that honors students who were engaged in more interactive service projects with refugees scored higher on two measures of empathy—i.e., the Basic Empathy Scale Basic Empathy Scale ( Jolliffe & Farrington) and the Toronto Empathy Questionnaire (Spreng et al.)—than did students engaged in less interactive service projects with refugees. In the final approach, evaluations of artifacts from the course suggested that levels of decentering, empathy, and civic action differed for students who had intensive versus superficial interactions with refugees

Assessment of Oral Presentations in an Undergraduate Accounting Program: An Application of Videotapes, Role Plays and Student Involvement

The subject School of Accountancy assesses oral presentations at the undergraduate (Bachelor of Business Administration in Accounting) level to accomplish program improvement and accreditation maintenance. Historically, accounting students were assessed on their oral presentation skills by giving a 3-4 minute presentation of a completed research paper and used presentation software. Accounting faculty members assessed the presentation using a six-factor four-level rubric. This work was motivated by feedback received from the School’s Accounting Advisory Board; the members were dissatisfied with new accounting staff hires’ inability to communicate with their clients face-to-face. While they appreciated the favorable results achieved in the oral presentation assessments, the members questioned if the School was measuring the right approach to presentations. Would it be possible to assess one-on-one communication of technical material? The authors present a pilot test created to investigate the use of one-on-one roleplays using undergraduate tax and advanced marketing sales students. Undergraduate tax students role-played an individual tax return prepared as a class project to the advanced sales students. The presentations were video taped. Graduate tax students assessed the videotapes and reported results to the authors. Results were again favorable. In addition, results suggest that using students who are naive to each others’ situation gives a more realistic feel to the role-play presentations

eBank UK: linking research data, scholarly communication and learning

This paper includes an overview of the changing landscape of scholarly communication and describes outcomes from the innovative eBank UK project, which seeks to build links from e-research through to e-learning. As introduction, the scholarly knowledge cycle is described and the role of digital repositories and aggregator services in linking data-sets from Grid-enabled projects to e-prints through to peer-reviewed articles as resources in portals and Learning Management Systems, are assessed. The development outcomes from the eBank UK project are presented including the distributed information architecture, requirements for common ontologies, data models, metadata schema, open linking technologies, provenance and workflows. Some emerging challenges for the future are presented in conclusion