Using the GPS to Improve Trajectory Position and Velocity Determination during Real-Time Ejection Seat Design, Test and Evaluation

Test and evaluation of the United States Air Force’s latest aircraft escape system technology requires accurate position and velocity profiles during each test to determine the relative positions between the aircraft, ejection seat, manikin and the ground. Current rocket sled testing relies on expensive ground based multiple camera systems to determine the position and velocity profiles. While these systems are satisfactory at determining seat and manikin trajectories for sled testing, their accuracy decreases when they are used for in-flight testing, especially at high altitudes. This research presents the design and test results from a new GPS-based system capable of monitoring all major ejection test components (including multiple ejection seat systems) during an entire escape system test run. This portable system can easily be integrated into the test manikin, within the flight equipment, or in the ejection seat. Small, low-power, lightweight Global Positioning System (GPS) GPS receivers, capable of handling high-accelerations, are mounted on the desired escape system component to maintain track during the escape system test sequence from initiation until the final landing. The GPS-based system will be used to augment the telemetry and photography systems currently being used at the Air Force (AF) and other Department of Defense’s (DoD) sled track test facilities to improve tracking accuracy and reduce testing costs

Laboratory and observational study of the interrelation of the carbonaceous component of interstellar dust and solar system materials

By studying the chemical and isotopic composition of interstellar ice and dust, one gains insight into the composition and chemical evolution of the solid bodies in the solar nebula and the nature of the material subsequently brought into the inner part of the solar system by comets and meteorites. It is now possible to spectroscopically probe the composition of interstellar ice and dust in the mid-infrared, the spectral range which is most diagnostic of fundamental molecular vibrations. We can compare these spectra of various astronomical objects (including the diffuse and dense interstellar medium, comets, and the icy outer planets and their satellites) with the spectra of analogs we produce in the laboratory under conditions which mimic those in these different objects. In this way one can determine the composition and abundances of the major constituents of the various ices and place general constraints on the types of organics coating the grains in the diffuse interstellar medium. In particular we have shown the ices in the dense clouds contain H2O, CH3OH, CO, perhaps some NH3 and H2CO, we well as nitriles and ketones or esters. Furthermore, by studying the photochemistry of these ice analogs in the laboratory, one gains insight into the chemistry which takes place in interstellar/precometary ices. Chemical and spectroscopic studies of photolyzed analogs (including deuterated species) are now underway. The results of some of these studies will be presented and implications for the evolution of the biogenic elements in interstellar dust and comets will be discussed

Aqua­tricarbon­yl(4-carboxy­pyridine-2-carboxyl­ato-κ2 N,O 2)rhenium(I)

There are two mol­ecules with similar bond dimensions in the asymmetric unit of the title complex, [Re(C7H4NO4)(CO)3(H2O)]. The metal centre is coordinated facially by three carbonyl groups, is chelated by a 4-carboxy­pyridine-2-carboxyl­ate ligand and is also coordinated by a water mol­ecule. O—H⋯O hydrogen bonds give rise to a three-dimensional network

2-(Ammonio­meth­yl)pyridinium sulfate monohydrate

In the crystal of the title hydrated molecular salt, C6H10N2 2+·SO4 2−·H2O, N—H⋯O and O—H⋯O hydrogen bonds link the mol­ecules into layers parallel to the ab plane. C—H⋯O hydrogen bonds are observed both within these layers and between mol­ecules and ions in adjacent layers

[N,N-Bis(diphenyl­phosphino)propyl­amine-κ2 P,P]bromidotricarbonyl­rhenium(I)

In the title compound, [ReBr(C27H27NP2)(CO)3], the ReI atom is octa­hedrally surrounded by three carbonyl ligands in a facial arrangement, a bromide ligand and the P,P′-bidentate ligand Bis(diphenyl­phosphino)propyl­amine. The compound exhibits substitutional disorder of the bromide ligand and the axial carbonyl ligand, with almost 50% occupancy for both Br amd CO [0.538 (4) and 0.462 (4), respectively]. In addition, the propyl chain on the N atom of the bidentate ligand exhibits a 0.648 (9):0.352 (9) disorder. C—H⋯O and C—H⋯Br hydrogen bonding consolidates the crystal packing

Notations and conventions in molecular spectroscopy: part 1. General spectroscopic notation

The field of Molecular Spectroscopy was surveyed in order to determine a set of conventions and symbols which are in common use in the spectroscopic literature. This document, which is Part I in a series, establishes the notations and conventions used for general spectroscopic notations and deals with quantum mechanics, quantum numbers (vibrational states, angular momentum and energy levels), spectroscopic transitions, and miscellaneous notations (e.g. spectroscopic terms). Further parts will follow, dealing inter alia with symmetry notation, permutation and permutation-inversion symmetry notation, vibration-rotation spectroscopy and electronic spectroscopy

6,6′-(Pyridine-2,6-di­yl)bis­(pyrrolo­[3,4-b]pyridine-5,7-dione)

The title compound, C19H9N5O4, has crystallographically imposed twofold rotational symmetry. The asymmetric unit contains one half-mol­ecule. The crystal structure is stabilized by π–π stacking of inversion-related pyrrolo­[3,4-b]pyridine rings, with a centroid–centroid distance between stacked pyridines of 3.6960 (8) Å. The dihedral angle between the central pyridine ring and the pyrrolo-pyridine side rings is 77.86 (2)° while the angle between the two side chains is 60.87 (2)°

Tetra­ethyl­ammonium dibromido­tricarbon­yl(o-toluidine)rhenate(I)

In the title compound, (C8H20N)[ReBr2(C7H9N)(CO)3], the ReI atom is octa­hedrally surrounded by three carbonyl ligands orientated in a facial arrangement, two bromide ligands and an o-toluidine ligand. The amine lies trans to the carbonyl ligand and is substitutionally disordered over two positions in a 0.66 (1):0.34 (1) ratio. An array of C—H⋯O, C—H⋯Br and N—H⋯Br hydrogen-bonding inter­actions between the cations and the surrounding rhenate anions stabilize the crystal structure

Notations and conventions in molecular spectroscopy: part 2. Symmetry notation

The field of Molecular Spectroscopy was surveyed in order to determine a set of conventions and symbols which are in common use in the spectroscopic literature. This document, which is Part 2 in a series, establishes the notations and conventions used for the description of symmetry in rigid molecules, using the Schoenflies notation. It deals firstly with the symmetry operators of the molecular point groups (also drawing attention to the difference between symmetry operators and elements). The conventions and notations of the molecular point groups are then established, followed by those of the representations of these groups as used in molecular spectroscopy. Further parts will follow, dealing inter alia with permutation and permutation-inversion symmetry notation, vibration-rotation spectroscopy and electronic spectroscopy