A description of QUALCOMM Automatic Satellite Position Reporting (QASPR(R)) for mobile communications

Two satellite position reporting has been introduced into the OmniTRACS mobile satellite communication system. This system significantly improves position reporting reliability and accuracy while simplifying the terminal's hardware. The positioning technique uses the original OmniTRACS TDMA timing signal formats in the forward and return link directions plus an auxiliary, low power forward link signal through a second satellite to derive distance values. The distances are then converted into the mobile terminal's latitude and longitude in real time. A minor augmentation of the spread spectrum profile of the return link allowed the resolution of periodic ambiguities. The system also locates the two satellites in real time with fixed platforms in known locations using identical mobile terminal hardware. Initial accuracies of 1/4 mile have been realized uniformly throughout the USA using a satellite separation of 22 degrees and there are no dead zones, skywaves, or cycle slips as found in terrestrial systems like LORAN-C

Dry sliding wear of aluminum-silicon (A356) matrix composites with carbon fibre or graphite/silicon carbide reinforcement.

The unlubricated sliding wear of two reinforced A356 (Al-7%Si-0.3%Mg) metal matrix composites was studied using a block on ring wear machine with an AISI 52100 steel counterface (63 HRC). One composite was discontinuously reinforced with 4 $\pm$ 1 vol% non-graphitic carbon fibres coated with nickel. The composites were tested such that the fibres were either normal or parallel to the contact surface. The second composite was a hybrid composite with 20% SiC particulate and 3 or 10 vol% graphite particles. In the wear tests, the applied normal load varied from 5 to 441 N. Sliding speed ranged from 0.1 to 1 m/s with the majority of tests performed at 0.5 m/s. The wear resistance of the A35-Carbon Fibre (CF) reinforced composites was superior to the unreinforced alloy over the entire load range tested. The improved wear resistance was related to an improvement in load carrying capability of the composites as a result of the carbon fibre addition and an interfacial reaction which produced a nickel aluminide intermetallic. These composites demonstrated regions of mild and severe wear. Mild wear was characterized by surface grooves, plastic deformation and loose debris in the form of particulates and flakes. The A356-Gr-SiC composites did not experience severe wear resulting in good wear resistance at high loads. This was due to a reduction in frictional heating and the formation of a tribolayer on the surface which consisted of iron, iron oxides, graphite, SiC and aluminum. Graphite addition resulted in a reduction in counterface wear. Higher graphite concentrations led to higher wear resistance at loads below 10 N. In the load range from 20 to 300 N the 10% graphite composite experienced wear rates 2 to 4 times that of the hybrid composite with only 3% graphite possibly due to a decrease in the load carrying ability due to higher graphite content. Source: Masters Abstracts International, Volume: 33-04, page: 1318. Adviser: A. T. Alpas. Thesis (M.Sc.A.)--University of Windsor (Canada), 1994

Linear or nonlinear wave problems with input sets

Issued as Progress reports no. [1-4], and Final report, Project no. G-37-62

Mathematical sciences research equipment

Issued as Final project report, Project no. G-37-62

Analysis of mathematical models for pollutant transport and dissipation

Issued as Final report, Project no. G-37-61

Linear or nonlinear wave problems with input sets - II

Issued as Progress reports [nos.1-4], and Final report, Project no. G-37-60

Anti-cancer Action of Metal Complexes: Electron Transfer and Oxidative Stress?

Evidence is presented in support of an electron transfer mechanism for various metal complexes possessing anti-neoplastic properties. Cyclic voltammetry was performed on several metallocenes, bis(acetato)bis(imidazole)Cu(II), and coordination compounds (Cu or Fe) of the anti-tumor agents, bipyridine, phenanthroline, hydroxyurea, diethyldithiocarbamate, and α, α1-bis(8-hydroxyquinolin-7-yl)-4-methoxytoluene. The favorable reduction potentials ranged from +0.5 to -0.5 V. Electrochemical behavior is correlated in some cases with structure and physiological activity. Relevant literature data are discussed

Spacelab Data Processing Facility (SLDPF) quality assurance expert systems development

Spacelab Data Processing Facility (SLDPF) expert system prototypes were developed to assist in the quality assurance of Spacelab and/or Attached Shuttle Payload (ASP) processed telemetry data. The SLDPF functions include the capturing, quality monitoring, processing, accounting, and forwarding of mission data to various user facilities. Prototypes for the two SLDPF functional elements, the Spacelab Output Processing System and the Spacelab Input Processing Element, are described. The prototypes have produced beneficial results including an increase in analyst productivity, a decrease in the burden of tedious analyses, the consistent evaluation of data, and the providing of concise historical records