Traditional numerical discretizations of conservative systems generically yield an artificial secular drift of any nonlinear invariants. In this work we present an explicit nontraditional algorithm that exactly conserves invariants. We illustrate the general method by applying it to the Three-Wave truncation of the Euler equations, the Volterra-Lotka predator-prey model, and the Kepler problem. We discuss our method in the context of symplectic (phase space conserving) integration methods as well as nonsymplectic conservative methods. We comment on the application of our method to general conservative systems.

The shock sensitivity of a pressed solid explosive formulation, LX-19, containing 95.2% by weight epsilon phase 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (HNIW) and 4.8% Estane binder, was determined using the wedge test and embedded manganin pressure gauge techniques. This formulation was shown to be slightly more sensitive than LX-14, which contains 95.5% HMX and 4.5% Estane binder. The measured pressure histories for LX-19 were very similar to those obtained using several HMX-inert binder formulations. An Ignition and Growth reactive model for LX-19 was developed which differed from those for HMX-inert binder formulations only by a 25% higher hot spot growth rate.

A model-based approach is developed to solve an adaptive ocean acoustic signal processing problem. Here we investigate the design of model-based identifier (MBID) for a normal-mode model developed from a shallow water ocean experiment and then apply it to a set of experimental data demonstrating the feasibility of this approach. In this problem we show how the processor can be structured to estimate the horizontal wave numbers directly from measured pressure sound speed thereby eliminating the need for synthetic aperture processing or a propagation model solution. Ocean acoustic signal processing has made great strides over the past decade necessitated by the development of quieter submarines and the recent proliferation of diesel powered vessels.

A sodium-layer laser guide star adaptive optics system has been developed at Lawrence Livermore National Laboratory (LLNL) for use on the 3-meter Shane telescope at Lick Observatory. The system is based on a 127-actuator continuous-surface deformable mirror, a Hartmann wavefront sensor equipped with a fast-framing low-noise CCD camera, and a pulsed solid-state-pumped dye laser tuned to the atomic sodium resonance line at 589 nm. The adaptive optics system has been tested on the Shane telescope using natural reference stars yielding up to a factor of 12 increase in image peak intensity and a factor of 6.5 reduction in image full width at half maximum (FWHM). The results are consistent with theoretical expectations. The laser guide star system has been installed and operated on the Shane telescope yielding a beam with 22 W average power at 589 nm. Based on experimental data, this laser should generate an 8th magnitude guide star at this site, and the integrated laser guide star adaptive optics system should produce images with Strehl ratios of 0.4 at 2.2 {mu}m in median seeing and 0.7 at 2.2 {mu}m in good seeing.

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The results of a search for W boson pair production in p{bar p} collisions at {radical}s = 1.8 TeV with subsequent decay to dilepton (e{mu}, ee, and {mu}{mu}) channels are presented. One event is observed with an expected background of 0.56 {plus_minus} 0.13 events with an integrated luminosity of approximately 14 pb{sup {minus}1}. Assuming equal strengths for the WWZ and WW{gamma} gauge boson coupling parameters {kappa} and {lambda}, limits on the CP-conserving anomalous coupling constants are {minus}2.6 < {delta}{kappa} < 2.8 and {minus}2.1 {lambda} < 2.1 at the 95% confidence level.

In 1994, the second session of the 103rd Congress saw the political pressure exerted by property rights bills ascend new heights. Members supporting property rights legislation sought to add such provisions to nearly every major environmental bill. Opponents, including several committee chairmen, therefore declined to move the bills, and gridlock resulted.

Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by {approximately}5{mu}m. A series of nine 2-D images of the object were recorded at angles between {minus}50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of {approximately}1000 {Angstrom} was observed. Artifacts in the reconstruction limited the overall depth resolution to {approximately}6000 {Angstrom}, however some features were clearly reconstructed with a depth resolution of {approximately}1000 {Angstrom}. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution bringing it down to {approximately}1200 {Angstrom} overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range.

In this paper a modern approach was developed to solve the passive localization problem in ocean acoustics using the state-space formulation. It is shown that the inherent structure of the resulting processor consists of a parameter estimator coupled to a nonlinear optimization scheme. The parameter estimator is design using an acoustic propagation model in developing the modern identifier required for localization. The detection and localization of an acoustic source has long been the motivation of early sonar systems. With the advent of quieter and quieter submarines due to new manufacturing technologies and the next proliferation of diesel powered vessels, the need for more sophisticated processing techniques has been apparent for quite some time.

The shock sensitivity of the pressed solid explosive 1,3,3-trinitroazetidine (TNAZ) was determined using the embedded manganin pressure gauge technique. At an initial pressure of 1.3 GPa, pressure buildup (exothermic reaction) was observed after ten {mu}s. At 2 GPa, TNAZ reacted rapidly and transitioned to detonation in approximately 13 mm. At 3.6 GPa, detonation occurred in less than 6 mm of shock propagation. Thus, pure TNAZ is more shock sensitive than HMX-based explosives but less shock sensitive than PETN-based explosives. The shocked TNAZ exhibited little reaction directly behind the shock front, followed by an extremely rapid reaction. This reaction caused both a detonation wave and a retonation wave in the partially decomposed TNAZ. An Ignition and Growth reactive model for TNAZ was developed to help understand this complex initiation phenomenon.

The shock sensitivity of the pressed solid explosive 2,4-dinitroimidazole (2,4-DNI) was determined using the embedded manganin pressure gauge technique. At an initial shock pressure of 2 GPa, several microseconds were required before any exothermic reaction was observed. At 4 GPa, 2,4-DNI reacted more rapidly but did not transition to detonation at the 12 mm deep gauge position. At 6 GPa, detonation occurred in less than 6 mm of shock propagation. Thus, 2,4-DNI is more shock sensitive than TATB-based explosives but is considerably less shock sensitive than HMX-based explosives. An Ignition and Growth reactive flow model for 2,4-DNI based on these gauge records showed that 2,4-DNI exhibits shock initiation characteristics similar to TATB but reacts faster. The chemical structure of 2,4-DNI suggests that it may exhibit thermal decomposition reactions similar to nitroguanine and explosives with similar ring structures, such as ANTA and NTO.

The Fernald Environmental Management Project (FEMP) is a federal facility located near Cincinnati, Ohio that is being remediated. Operable Unit 3 (OU3) of the FEMP consists of 232 buildings and other structures that formerly housed various uranium and thorium metallurgical and chemical processes. The buildings are constructed primarily of steel and concrete, with transite siding. The structures are being decontaminated and dismantled using an interim remedial action approach. The disposition of the debris and other waste materials generated by the interim action is being addressed by the final remedial action for the operable unit. The preferred alternative is disposal of most of the material in an engineered disposal cell located on the FEMP property. This is complicated by the fact that the FEMP is located in an environmentally sensitive area and by the complex nature of the materials. The principal aquifer located beneath the site, the Great Miami Aquifer, is designated as a sole-source aquifer under the Safe Drinking Water Act. Disposal of any wastes at the FEMP must be protective of the aquifer. Dismantlement of OU3 structures will result in a very heterogeneous waste stream, both in terms of types of materials and levels of contamination. Wastes to be …