Underwater visual inspection and measurement using optical holography

In offshore oil and gas exploration, visual inspection and measurement often has to be carried out under conditions of poor visibility and at great depths. Recording a hologram of an underwater scene with its subsequent replay in the laboratory could provide enormous benefits to the inspection engineer. When replayed in the real image mode, dimensional measurement may be performed directly on the image formed in real space using, for example, measuring microscopy or TV cameras. Potential applications include general archiving, measurement of corrosion pitting and cracking, examination and measurement of damage sites, structural profiling and examination of marine growth. In this paper, we outline the general concepts of underwater holography. A résumé is given of the work undertaken in the past, the problems experienced and their solution and an indication of our general direction leading to the establishment of holography as a unique method of subsea inspection.     

OPPORTUNITY COSTS OF FEDERAL LAND-USE RESTRICTIONS FOR U.S. COAL MARKETS

U.S. federal government land-use restrictions limit access to high-quality, low-cost coal on federal lands in the western U.S. The main purpose of these limits is to protect the environment. A substantial amount of U.S. coal resources has been set aside, about 67 billion tons, which represents 27% of total U.S. surface-minable coal. Debate has focused on the environmental benefits attained by the land-use restrictions; little effort has gone into the explicit quantification of opportunity costs. To help fill that gap, this analysis examines the long-term effects that these restrictions could have on the national cost of meeting future coal demands, including impacts on regional patterns of coal availability and production.     

On Flame-Edge Propagation

Contemporary interest exists for understanding how reaction zones stabilize and counter-propagate against incoming reactants. Images of flame position, morphology and dynamics are presented primarily from CH planar laser-induced fluorescence (CH-PLIF) measurements. Observations of the leading-edge flame behavior with respect to upstream propagation and recession downstream are made with sequential CH-PLIF imaging, and data have been revisited in light of the recent research of McCraw et al. (Flow Turbul Combust 70(1):83–97, 2007). It is found that in cases where a distinct branch of the outer (fuel-lean) edge of the reaction zone is present, the edge of the flame is either witnessed to propagate upstream or locally disappear. In cases where no distinct branch other than the main branch is observed, the flame is witnessed to either remain stationary or drop back downstream. These observations support the notion that structures in the low speed, outer edge of the reaction zone are involved in the upstream phase of the flame propagation.     

On Nonlinear Coapproximation in Banach Spaces

The problem of nonlinear coapproximation in Banach spaces is considered, and characterization results and strong coapproximation results are presented.     

The reaction π−p→K0Λ0 up to 2375 MeV/c: New results and analysis

New data are presented on the reaction π^?p→K⁰Λ⁰ at 13 incident momenta between 1395 and 2375 MeV/c. A partial-wave analysis has been performed using these data and previous data at lower momenta. The resulting resonance parameters are in broad agreement with recent πN analyses and with the predictions of SU(6)_W × O(3) for the couplings.