High-Resolution Spectroscopy of Ursa Major Moving Group Stars

We use new and extant literature spectroscopy to address abundances and membership for UMa moving group stars. We first compare the UMa, Coma, and Hyades H-R diagrams via a homogeneous set of isochrones, and find that these three aggregates are essentially coeval. Our spectroscopy of cool UMa dwarfs reveals striking abundance anomalies--trends with Teff, ionization state, and excitation potential--like those recently seen in young cool M34, Pleaides, and Hyades dwarfs. In particular, the trend of rising 7774 Ang-based OI abundance with declining Teff is markedly subdued in UMa compared to the Pleiades, suggesting a dependence on age or metallicity. Despite disparate sources of Li data,our homogeneous analysis indicates that UMa members evince remarkably small scatter in the Li-Teff plane for Teff>5200 K. Significant star-to-star scatter suggested by previous studies is seen for cooler stars. Comparison with the consistently determined Hyades Li-Teff trend reveals differences qualitatively consistent with this cluster's larger [Fe/H] (and perhaps slightly larger age). However, quantitative comparison with standard stellar models indicates the differences are smaller than expected, suggesting the action of a fourth parameter beyond age, mass, and [Fe/H] controlling Li depletion.Comment: To appear in Publ. Astron. Soc. Pacif. (September 2005

Hybrid propulsion technology program: Phase 1, volume 1

A number of booster propulsion system concepts are being considered for the next generation of manned and unmanned space launch vehicles. The one propulsion system concept that has potential for reducing costs with increased safety, reliability, and performance is hybrid propulsion (HP). A HP system may be thought of as a liquid propulsion system with solid fuel or a solid propulsion system with a liquid oxidizer. The liquid propulsion features that are most attractive are the higher specific impulse, clean exhaust, separated propellants, and oxidizer loading just prior to launch. The most attractive solid propulsion features includes low life cycle costs, no rotating machinery, compact size, and a robust case. In addition, a HP system has a robust LO2 tank; provides thrust control for ignition, to alleviate flight loads, and for thrust termination; and uses an inert grain that is not sensitive to anomalies such as cracks, voids, and separations. The object is to develop the technology to enable the application of HP to manned and unmanned space launch vehicles. This program will identify the necessary technology, acquire that technology, and demonstrate that technology. This volume is the executive summary

Hybrid propulsion technology program: Phase 1. Volume 3: Thiokol Corporation Space Operations

Three candidate hybrid propulsion (HP) concepts were identified, optimized, evaluated, and refined through an iterative process that continually forced improvement to the systems with respect to safety, reliability, cost, and performance criteria. A full scale booster meeting Advanced Solid Rocket Motor (ASRM) thrust-time constraints and a booster application for 1/4 ASRM thrust were evaluated. Trade studies and analyses were performed for each of the motor elements related to SRM technology. Based on trade study results, the optimum HP concept for both full and quarter sized systems was defined. The three candidate hybrid concepts evaluated are illustrated

Atmospheric nitric oxide measurement techniques Final report

Optical radar technique for measuring vertical density distribution of neutral nitric oxide in earth atmospher

Lithium in the Upper Centaurus Lupus and Lower Centaurus Crux Subgroups of Scorpius-Centaurus

We utilize spectroscopically derived model atmosphere parameters and the \ion{Li}{1} $\lambda6104$ subordinate line and the $\lambda6708$ doublet to derive lithium abundances for 12 members of the Upper-Centaurus Lupus (UCL) and Lower-Centaurus Crux (LCC) subgroups of the Scorpius Centaurus OB Association. The results indicate any intrinsic Li scatter in our 0.9-1.4 $M_{\odot}$ stars is limited to ${\sim}0.15$ dex, consistent with the lack of dispersion in ${\ge}1.0$ $M_{\odot}$ stars in the 100 Myr Pleiades and 30-50 Myr IC 2391 and 2602 clusters. Both ab initio uncertainty estimates and the derived abundances themselves indicate that the $\lambda$6104 line yields abundances with equivalent or less scatter than is found from the $\lambda$6708 doublet as a result of lower uncertainties for the subordinate feature, a result of low sensitivity to broadening in the subordinate feature. Because NLTE corrections are less susceptible to changes in surface gravity and/or metallicity for the 6104 {\AA} line, the subordinate Li feature is preferred for deriving lithium abundances in young Li-rich stellar association stars with $T_{\rm eff}{\ge}5200$ K.Comment: Accepted for publication in Astronomical Journal (abstract shortened for astro-ph submission

Fe I and Fe II Abundances of Solar-Type Dwarfs in the Pleiades Open Cluster

We have derived Fe abundances of 16 solar-type Pleiades dwarfs by means of an equivalent width analysis of Fe I and Fe II lines in high-resolution spectra obtained with the Hobby - Eberly Telescope and High Resolution Spectrograph. Abundances derived from Fe II lines are larger than those derived from Fe I lines (herein referred to as over-ionization) for stars with Teff < 5400 K, and the discrepancy (deltaFe = [Fe II/H] - [Fe I/H]) increases dramatically with decreasing Teff, reaching over 0.8 dex for the coolest stars of our sample. The Pleiades joins the open clusters M 34, the Hyades, IC 2602, and IC 2391, and the Ursa Major moving group, demonstrating ostensible over-ionization trends. The Pleiades deltaFe abundances are correlated with Ca II infrared triplet and Halpha chromospheric emission indicators and relative differences therein. Oxygen abundances of our Pleiades sample derived from the high-excitation O I triplet have been previously shown to increase with decreasing Teff, and a comparison with the deltaFe abundances suggests that the over-excitation (larger abundances derived from high excitation lines relative to low excitation lines) and over-ionization effects that have been observed in cool open cluster and disk field main sequence (MS) dwarfs share a common origin. Star-to-star Fe I abundances have low internal scatter, but the abundances of stars with Teff < 5400 K are systematically higher compared to the warmer stars. The cool star [Fe I/H] abundances cannot be connected directly to over-excitation effects, but similarities with the deltaFe and O I triplet trends suggest the abundances are dubious. Using the [Fe I/H] abundances of five stars with Teff > 5400 K, we derive a mean Pleiades cluster metallicity of [Fe/H] = +0.01 +/- 0.02.Comment: 32 pages, 7 figures, 7 tables; accepted by PAS

Two-photon mediated resonance production in e+e- collisions: cross sections and density matrices

Earlier described model amplitudes are used in this paper to evaluate both cross sections and density matrices for two-photon mediated resonance production in e^+e^- collisions. All 25 q\bar{q} low-lying ^1S_0, ^3P_J and ^1D_2 resonances can thus be treated. Two independent methods are described to obtain the resonance production density matrices and cross sections. These density matrices combined with a resonance decay density matrix give the detailed angular distributions of the resonance decay products. For two particular decays, \chi_{c2},\chi_{c1}\to\gamma J/\psi the details are given. Several numerical results are presented as well.Comment: 27 pages, 4 figure

Red Bonnet : Three Step

https://digitalcommons.library.umaine.edu/mmb-ps/1034/thumbnail.jp

A Critical and Comparative Analysis of John Calvin\u27s and the Early Friends\u27 Doctrine of the Word of God

The question has been raised since the inception of the Friends or Quaker movement, What position do the Friends hold in reference to a basis of authority for their proposed and propounded doctrines? This basis of authority was first questioned by various religious leaders of the day when George Fox went about preaching against the cold, dead, formalism of the churches in England, and remains a matter of some debate today. Since the beginning of the Friends movement, it has held the Bible in great reverence and has used it as a basis of their teaching. Other groups, too, considered the Bible their source of authority -- groups such as John Calvin brought into being. We find that Calvin\u27s approach to Christianity was logical and systematic, whereas George Fox preached a purely experiential religion. They both used the Bible as their authority, yet they arrived at the widely divergent conceptions of Christina rules and faith. Every theological system has some thing or some one as a basis of its authority. For the Christian religion this source is called the Word of God. But in the consideration of defining the Word of God, it would seem every separate group in Christianity has a different view of what the term consists. When there are divergent views on what the Word of God consists there will be different views of Christina doctrine and faith. It is proposed to state as concisely as possible the views of John Calvin and the early Friends in an attempt to discover where and for what reasons there is this divergence of views between them. Some theologians feel that within the scope of the term Word of God are involved more than merely the written Scriptures. It is essential that three phases of study be undertaken here for all are directly related to such a study in any group. These phases or areas are 1) Revelation in general 2) Revelation in regard to the Word of God, and 3) Revelation in regard to the Sacraments. Some of the specific problems to be considered are: 1) How has God revealed Himself to man and does He still reveal Himself: Is revelation finished? 2) Of what does the Word of God consist -- i.e. is it limited to the written Word, and if so, to what extent? If not, what are the other phases of the Word of God? 3) Of what do the sacraments consist and what part do they play in the salvation of man? Are they essential to salvation? If there any real merit or value between the spiritual and physical or corporeal elements

Voice Of The Lilies : Reverie

https://digitalcommons.library.umaine.edu/mmb-ps/2941/thumbnail.jp