Hydrodynamic pressures on sloping dams during earthquakes. Part 2. Exact theory

The equations for the earthquake forces on a rigid dam with an inclined upstream face of constant slope are solved exactly by two-dimensional potential-flow theory. The distribution of the hydrodynamic pressure along the upstream face and the total horizontal, vertical and normal loads on the dam are computed from the integral solutions. The results obtained from the exact theory are compared with those derived from the momentum-balance method and there is reasonable agreement

Hydromechanics of low-Reynolds-number flow. Part 2. Singularity method for Stokes flows

The present study furthcr explores the fundamental singular solutions for Stokes flow that can be useful for constructing solutions over a wide range of free-stream profiles and body shapes. The primary singularity is the Stokeslet, which is associated with a singular point force embedded in a Stokes flow. From its derivatives other fundamental singularities can be obtained, including rotlets, stresslets, potential doublets and higher-order poles derived from them. For treating interior Stokes-flow problems new fundamental solutions are introduced; they include the Stokeson and its derivatives, called the roton and stresson. These fundamental singularities are employed here to construct exact solutions to a number of exterior and interior Stokes-flow problems for several specific body shapes translating and rotating in a viscous fluid which may itself be providing a primary flow. The different primary flows considered here include the uniform stream, shear flows, parabolic profiles and extensional flows (hyperbolic profiles), while the body shapcs cover prolate spheroids, spheres and circular cylinders. The salient features of these exact solutions (all obtained in closed form) regarding the types of singularities required for the construction of a solution in each specific case, their distribution densities and the range of validity of the solution, which may depend on the characteristic Reynolds numbers and governing geometrical parameters, are discussed

Hydromechanics of low-Reynolds-number flow. Part 4. Translation of spheroids

The problem of a uniform transverse flow past a prolate spheroid of arbitrary aspect ratio at low Reynolds numbers has been analysed by the method of matched asymptotic expansions. The solution is found to depend on two Reynolds numbers, one based on the semi-minor axis b, R[sub]b = Ub/v, and the other on the semi-major axis a, R[sub]a = Ua/v (U being the free-stream velocity at infinity, which is perpendicular to the major axis of the spheroid, and v the kinematic viscosity of the fluid). A drag formula is obtained for small values of R[sub]b and arbitrary values of R[sub]a. When R[sub]a is also small, the present drag formula reduces to the Oberbeck (1876) result for Stokes flow past a spheroid, and it gives the Oseen (1910) drag for an infinitely long cylinder when R[sub]a tends to infinity. This result thus provides a clear physical picture and explanation of the 'Stokes paradox' known in viscous flow theory

Nonlinear Impulsive Force on an Accelerating Container

The nonlinear theory developed by Chwang [1

Live from the battlefield: an examination of embedded war correspondents' reporting during Operation Iraqi Freedom (21 March-14 April 2003)

During Operation Iraqi Freedom (OIF), the U.S. Department of Defense instituted a program to attach civilian journalists to coalition military units. Their purpose was to report firsthand on the military campaign to topple Saddam Hussein. These "embedded journalists," as they were called, would travel, eat, sleep, and endure the same hardships and dangers of the soldiers and Marines they were accompanying. While their immediate and highly dramatic accounts offered a perspective not before seen by the news-hungry U.S. public, they also raised questions if the "embedding" process resulted in a more thematically narrow coverage of the war. This study addresses the newspaper coverage of OIF by examining the content of the embedded and non-embedded war reporting of various highly circulating U.S. newspapers. It is posited that being attached or embedded within U.S. military units resulted in the journalists producing a body of stories concerning military operations and personnel markedly different than nonembedded reporters during OIF.http://archive.org/details/livefrombattlefi109451541Major, United States Marine CorpsApproved for public release; distribution is unlimited