Semicrompressible Ocean Thermodynamics and Boussinesq Energy Conservation

Equations more accurate than the Boussinesq set that still filter out sound were recently introduced. While these equations were shown to have a consistent potential energy, their thermodynamical behavior and associated implications were not fully analyzed. These shortcomings are remedied in the present note that argues both sets are fully consistent from a thermodynamic perspective. It is further argued that both sets remain computationally competitive with the Boussinesq set

Collaboration Engineering for Incident Response Planning: Process Development and Validation

Contains fulltext : 34998.pdf (publisher's version ) (Open Access)HICS

Overview of the Langley subsonic research effort on SCR configuration

Recent advances achieved in the subsonic aerodynamics of low aspect ratio, highly swept wing designs are summarized. The most significant of these advances was the development of leading edge deflection concepts which effectively reduce leading edge flow separation. The improved flow attachment results in substantial improvements in low speed performance, significant delay of longitudinal pitch up, increased trailing edge flap effectiveness, and increased lateral control capability. Various additional theoretical and/or experimental studies are considered which, in conjunction with the leading edge deflection studies, form the basis for future subsonic research effort

Infrared spectroscopy of a polyurethane elastomer under thermal stress

FTIR spectroscopy was used to study changes in hydrogen bonding in estane, a polyurethane elastomer used as a binding agent in high explosive systems, as a function of temperature. Hydrogen bonding in estane has been observed to decrease with an increase in temperature

Ohio Northern Alumnus - July, 1927

https://digitalcommons.onu.edu/alumni_mag/1001/thumbnail.jp

Characterizing mechanical effects of aging damage

This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal was to develop and apply several different experimental and theoretical/computational tools to better understand physical and chemical aging phenomena in plastic-bonded high explosives, and to develop a methodology for predicting the likely effects of aging on the mechanical properties of the composite based on input from these fundamental studies. Initial comparisons were done for spectra of fresh and aged Esane, as well as PBX-9501, and the authors found differences in the carbonyl region of the spectrum, which possibly reflect differences in hydrogen bonding due to aging phenomena. The micromechanical model of composites was extended to study various volume fractions of HMX with binders. The results showed that, as the binder fraction increases, there is a decrease in the maximum stress that can be supported but an increase in the percent strain at final fracture. A more realistic microstructural model was obtained through the use of a phase field model. Using this model, the authors have studied the microstructural evolution as a function of the grain boundary energy vs. misorientation relationship. The initial results indicate that there are some changes in the grain growth rate when the grain-boundary energy dependence on the angle is not constant. They also find that solute tends to segregate at the grain boundary and slows the grain growth kinetics

Resonance Raman studies of Rieske-type proteins

Resonance Raman (RR) spectra are reported for the [2Fe-2S] Rieske protein from Thermus thermophilus (TRP) and phthalate dioxygenase from Pseudomonas cepacia (PDO) as a function of pH and excitation wavelength. Depolarization ratio measurements are presented for the RR spectra of spinach ferredoxin (SFD), TRP, and PDO at 74 K. By comparison with previously published RR spectra of SFD, we suggest reasonable assignments for the spectra of TRP and PDO. The spectra of PDO exhibit virtually no pH dependence, while significant changes are observed in TRP spectra upon raising the pH from 7.3 to 10.1. One band near 270 cm-1, which consists of components at 266 cm-1 and 274 cm-1, is attributed to Fe(III)-N(His) stretching motions. We suggest that these two components arise from conformers having a protonated-hydrogen-bonded imidazole (266 cm-1) and deprotonated-hydrogen-bonded imidazolate (274 cm-1) coordinated to the Fe/S cluster and that the relative populations of the two species are pH-dependent; a simple structural model is proposed to account for this behavior in the respiratory-type Rieske proteins. In addition, we have identified RR peaks associated with the bridging and terminal sulfur atoms of the Fe-S-N cluster. The RR excitation profiles of peaks associated with these atoms are indistinguishable from each other in TRP (pH 7.3) and PDO and differ greatly from those of [2Fe-2S] ferredoxins. The profiles are bimodal with maxima near 490 nm and > approx. 550 nm. By contrast, bands associated with the Fe-N stretch show a somewhat different enhancement profile. Upon reduction, RR peaks assigned to Fe-N vibrations are no longer observed, with the resulting spectrum being remarkably similar to that reported for reduced adrenodoxin. This indicates that only modes associated with Fe-S bonds are observed and supports the idea that the reducing electron resides on the iron atom coordinated to the two histidine residues. Taken as a whole, the data are consistent with an St2FeSb2Fe[N(His)]t2 structure for the Rieske-type cluster.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29687/1/0000014.pd

Fourier Transform Infrared Spectroscopic Analysis Of Plastic Capsule Materials Exposed To Deuterium-Tritium (DT) Gas

Planar samples of varying thicknesses of both CH and CD glow discharge polymer have been measured with Fourier transform infrared (FTIR) spectroscopy before and after exposure to deuterium-tritium (DT) gas at elevated temperature and pressure. Planar samples of polyimide films made from both hydrogenated and deuterated precursors have also been examined by FTIR before and after DT exposure. The post-exposure FTIR spectra demonstrated no measurable exchange of hydrogen with deuterium or tritium for either polymer. Evidence for oxidation of the glow discharge polymer due to atmospheric oxygen was the only chemical change indicated by the FTIR data