A general review of concepts for reducing skin friction, including recommendations for future studies

Four main concepts which have significantly reduced skin friction in experimental studies are discussed; suction, gaseous injection, particle additives, and compliant wall. It is considered possible that each of these concepts could be developed and applied in viable skin friction reduction systems for aircraft application. Problem areas with each concept are discussed, and recommendations for future studies are made

Numerical methods for incompressible viscous flows with engineering applications

A numerical scheme has been developed to solve the incompressible, 3-D Navier-Stokes equations using velocity-vorticity variables. This report summarizes the development of the numerical approximation schemes for the divergence and curl of the velocity vector fields and the development of compact schemes for handling boundary and initial boundary value problems

Particle distributions in approximately 10(14) 10(16) eV air shower cores at sea level

Experimental evidence is reported for fixed distances (0, 1.0, 2.5 and 4.0 m) from the shower centers and for core flattening. The cores become flatter, on average, as the shower size (primary energy) increases. With improved statistics on 4192 cores, the previous results are exactly confirmed

Stability of streamwise vortices

A brief overview of some theoretical and computational studies of the stability of streamwise vortices is given. The local induction model and classical hydrodynamic vortex stability theories are discussed in some detail. The importance of the three-dimensionality of the mean velocity profile to the results of stability calculations is discussed briefly. The mean velocity profile is provided by employing the similarity solution of Donaldson and Sullivan. The global method of Bridges and Morris was chosen for the spatial stability calculations for the nonlinear eigenvalue problem. In order to test the numerical method, a second order accurate central difference scheme was used to obtain the coefficient matrices. It was shown that a second order finite difference method lacks the required accuracy for global eigenvalue calculations. Finally the problem was formulated using spectral methods and a truncated Chebyshev series

A Review of the Problems and Results of Studies on Manual and Power Toothbrushes

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141464/1/jper0202.pd

Occlusion, TMDs, and dental education

The paradigmatic shift to evidence-based dentistry (EBD) that relates to occlusal therapy, selective occlusal adjustment (OA) and stabilization splints therapy (SS) for TMDs has had an unfavourable impact on the teaching of many of the important aspects of occlusion needed in dental practice. The teaching of OA systematically in dental schools has been nearly abandoned because of the belief that OA is an irreversible procedure and gives the impression that it is without merit elsewhere in the management of occlusion. However, a particular dose of knowledge and practice of occlusion that is necessary for all aspects of dental care should be taught systematically in dental schools. The uses and misuses of OA and SS and their limitations should be emphasized because of their importance to bring clinical reality into the dental curriculum. Thus, and irrespective of EBD induced contradictions, OA and SS should still have a significant place in systematically teaching of occlusal therapy. However, there are many more aspects of the management of occlusion that should to be considered. Hopefully, because of their importance, other aspects of the management of occlusion will once again become a significant part of the dental curriculum

Public School Choice and Desegregation in Arkansas

Public school choice is an umbrella term for policies that allow students to enroll in a public school other than their residentially-assigned school. Public school choice, also called openenrollment, is typically divided into two categories: intra-district choice, transfers to schools in the same district, and inter-district choice, transfers to schools in other districts