Fluid friction reduction by water soluble linear high polymers

The effects of various dilute aqueous linear high polymer solutions on turbulent pipe flow were studied to determine the polymer most suitable for testing as the drag reducing component in the proposed coating. Results of this study are presented for commercial schedule 40 1/4 inch NPS black iron pipe. Tests were conducted at Reynolds numbers of 6.2x104,8.3x104 and 9.8x104. Attempts were made to prepare a coating containing a friction drag reducing polymer - Polyhall 295 polyacrylamide - utilizing various techniques of polymer incorporation into the paint including several grinding and dispersion methods, adding the polymer in a water in oil emulsion to a finished paint and adding the polymer in solution to a finished paint. Pipes were flow coated to a dry film thickness of two to three mils with coatings representative of each type of incorporation method. The unmodified Paints were composed of resins and pigmentations of which some components had a certain degree of water solubility to aid the leaching of the Polyhall 295 into the water. Results of these tests showed negative results insofar as the dispersions produced were very coarse and the resultant films increased the friction loss in the pipes while the solution and emulsion techniques allowed only a very small amount of the polymer to be added to the coating and resulted in no effect on the frictional resistance at all.One apparently successful trial of a coating containing ten percent Polyhall 295 could not be duplicated

Differentiability and continuity properties of solutions of certain partial differential equations of applied mathematics

Solutions, in the form H/r, of the homogeneous linear partial differential equation of the second order with constant coefficients are used as generalized potential functions. With the aid of generalized Green\u27s theorems and the methods developed by Erhardt Schmidt, it is possible to obtain the breaks in the derivatives of the generalized potentials due to a volume, simple surface and double surface distribution;When the functions involved satisfy certain differetiability and continuity conditions, it is shown that the breaks in the (n + 1)st order derivatives of these generalized potentials are given by recursion. For example, the breaks in the (n + 1)st order derivatives of the generalized volume potential are obtained from the breaks in the nth order derivatives of potential due to a volume and simple surface distribution. Similar relations are shown to exist for the breaks in the (n + 1)st order derivatives of the generalized potential due to simple surface and double surface distribution;In chapter IV the theory has been applied to two problems and the breaks in the potentials and their first and second order derivatives have been found for the case of the x3 axis parallel to the normal at the point

A systems approach to synchronization and naming in a distributed computing environment

This thesis describes the development of a distributed computer architecture that supports the interconnection of loosely-coupled computing resources (sites) by heterogeneous communication networks. The internetwork system, named the intelligent message transport system, provides for reliable delivery of intersite messages even though the interconnecting networks may use a probabilistic ( best-effort ) delivery scheme. Processors are interfaced to each other by a network gateway processor. The gateway processors are autonomous network controllers that provide a simple and consistent site interface to the internetwork system. The gateway processors also provide for high level functions at the Transport Layer of the system rather than burdening the user with networking details at the Application Layer. These high-level functions include the synchronization of concurrent updates to replicated data objects, and the management of the system-wide name space for shared data