Gravitomagnetic Resonance Shift due to a Slowly Rotating Compact Star

The effect of a slowly rotating mass on a forced harmonic oscillator with two degrees of freedom is studied in the weak field approximation. It is found that according to the general theory of relativity there is a shift in the resonat frequency of the oscillator which depends on the density and rotational frequency of the gravitational source. The proposed shift is quite small under normal physical situations however it is estimated that for compact x-ray sources such as white dwarfs, pulsars, and neutron stars the shift is quite appreciable.Comment: 8 pages, 2 figures, Accepted for Publication in Inter. Journal of Modern Physics

Exposure damage mechanisms for KCl windows in high power laser systems

An experimental study of the 10.6 micrometer and 0.6328 micrometer optical properties of single crystal and europium doped polycrystal is described. Significant variations in the optical properties are observed over periods of exposure up to 100 hours. Models are proposed to predict the 10.6 micrometer absorptivity for long exposure periods. Mechanical creep has been detected in both materials at high temperature

Methods to Isolate Possible Bacteriophage for Micrococcus Luteus and Acinetobacter Baumannii

The increasing prevalence of antibiotic-resistant strains of bacteria has led to a crisis in treatment options. Acinetobacter baumannii is an example of a bacterium that has developed a dangerous level of multidrug resistance. Not only does it have genes allowing for the resistance to antibiotics, but it also produces a biofilm that protects it. In recent years, A. baumannii has become a major contributor to nosocomial infections making it critical to develop new treatment methods. Micrococcus luteus, while typically not thought of as a pathogen, is also developing a resistance to antibiotics. M. luteus is capable of forming a biofilm on its own making it worrisome as it has increasingly been noted as an opportunistic pathogen. One potential new treatment of antibiotic resistance is the development of bacteriophage therapy, using bacterial viruses to target the infection and treat it. This study examines methods for isolating novel bacteriophage from dairy cattle feces, specifically for the biofilm producers A. baumannii and M. luteus

Chaos in the Kepler System

The long-term dynamical evolution of a Keplerian binary orbit due to the emission and absorption of gravitational radiation is investigated. This work extends our previous results on transient chaos in the planar case to the three dimensional Kepler system. Specifically, we consider the nonlinear evolution of the relative orbit due to gravitational radiation damping as well as external gravitational radiation that is obliquely incident on the initial orbital plane. The variation of orbital inclination, especially during resonance capture, turns out to be very sensitive to the initial conditions. Moreover, we discuss the novel phenomenon of chaotic transition.Comment: RevTeX, 22 pages, 6 figure

Advanced high temperature static strain sensor development

An examination was made into various techniques to be used to measure static strain in gas turbine liners at temperatures up to 1150 K (1600 F). The methods evaluated included thin film and wire resistive devices, optical fibers, surface acoustic waves, the laser speckle technique with a heterodyne readout, optical surface image and reflective approaches and capacitive devices. A preliminary experimental program to develop a thin film capacitive device was dropped because calculations showed that it would be too sensitive to thermal gradients. In a final evaluation program, the laser speckle technique appeared to work well up to 1150 K when it was used through a relatively stagnant air path. The surface guided acoustic wave approach appeared to be interesting but to require too much development effort for the funds available. Efforts to develop a FeCrAl resistive strain gage system were only partially successful and this part of the effort was finally reduced to a characterization study of the properties of the 25 micron diameter FeCrAl (Kanthal A-1) wire. It was concluded that this particular alloy was not suitable for use as the resistive element in a strain gage above about 1000 K

Arecibo timing and single-pulse observations of 17 pulsars

We report on timing and single-pulse observations of 17 pulsars discovered at the Arecibo observatory. The highlights of our sample are the recycled pulsars J1829+2456, J1944+0907 and the drifting subpulses observed in PSR J0815+0939. For the double neutron star binary J1829+2456, in addition to improving upon our existing measurement of relativistic periastron advance, we have now measured the pulsar's spin period derivative. This new result sets an upper limit on the transverse speed of 120 km/s and a lower limit on the characteristic age of 12.4 Gyr. From our measurement of proper motion of the isolated 5.2-ms pulsar J1944+0907, we infer a transverse speed of 188 +/- 65 km/s. This is higher than that of any other isolated millisecond pulsar. An estimate of the speed, using interstellar scintillation, of 235 +/- 45 km/s indicates that the scattering medium along the line of sight is non-uniform. We discuss the drifting subpulses detected from three pulsars in the sample, in particular the remarkable drifting subpulse properties of the 645-ms pulsar J0815+0939. Drifting is observed in all four components of the pulse profile, with the sense of drift varying among the different components. This unusual `bi-drifting'' behaviour challenges standard explanations of the drifting subpulse phenomenon.Comment: 9 pages, 6 figures. Accepted for publication in MNRA

Exploring and Testing Wildfire Risk Decision-Making in the Face of Deep Uncertainty

We integrated a mechanistic wildfire simulation system with an agent-based landscape change model to investigate the feedbacks among climate change, population growth, development, landowner decision-making, vegetative succession, and wildfire. Our goal was to develop an adaptable simulation platform for anticipating risk-mitigation tradeoffs in a fire-prone wildland– urban interface (WUI) facing conditions outside the bounds of experience. We describe how five social and ecological system (SES) submodels interact over time and space to generate highly variable alternative futures even within the same scenario as stochastic elements in simulated wildfire, succession, and landowner decisions create large sets of unique, path-dependent futures for analysis. We applied the modeling system to an 815 km2 study area in western Oregon at a sub-taxlot parcel grain and annual timestep, generating hundreds of alternative futures for 2007–2056 (50 years) to explore how WUI communities facing compound risks from increasing wildfire and expanding periurban development can situate and assess alternative risk management approaches in their localized SES context. The ability to link trends and uncertainties across many futures to processes and events that unfold in individual futures is central to the modeling system. By contrasting selected alternative futures, we illustrate how assessing simulated feedbacks between wildfire and other SES processes can identify tradeoffs and leverage points in fire-prone WUI landscapes. Assessments include a detailed “post-mortem” of a rare, extreme wildfire event, and uncovered, unexpected stabilizing feedbacks from treatment costs that reduced the effectiveness of agent responses to signs of increasing risk

Spin dependent fragmentation functions at Belle

The Belle detector at the KEKB e+e− collider provides large amounts of statistics to study the fragmentation of light quarks into final state hadrons. In addition to unpolarized fragmentation functions also spin dependent fragmentation can be studied. Belle has successfully extracted asymmetries related to the Collins and interference fagmentation functions for charged pions

Gravitational Ionization: A Chaotic Net in the Kepler System

The long term nonlinear dynamics of a Keplerian binary system under the combined influences of gravitational radiation damping and external tidal perturbations is analyzed. Gravitational radiation reaction leads the binary system towards eventual collapse, while the external periodic perturbations could lead to the ionization of the system via Arnold diffusion. When these two opposing tendencies nearly balance each other, interesting chaotic behavior occurs that is briefly studied in this paper. It is possible to show that periodic orbits can exist in this system for sufficiently small damping. Moreover, we employ the method of averaging to investigate the phenomenon of capture into resonance.Comment: REVTEX Style, Submitte