Jettisoning system for a parachute's canister

Three-point automatically released suspension and jettisoning system operates independently of lander's power system and releases parachute on touchdown. The system is based on a ball-lock device operated by the shock of the parachute's opening and by the subsequent decay in the load on the main cord

1.4-GHz observations of extended giant radio galaxies

This paper presents 1.4-GHz radio continuum observations of 15 very extended radio galaxies. These sources are so large that most interferometers lose partly their structure and total flux density. Therefore, single-dish detections are required to fill in the central (u,v) gap of interferometric data and obtain reliable spectral index patterns across the structures, and thus also an integrated radio continuum spectrum. We have obtained such 1.4-GHz maps with the 100-m Effelsberg telescope and combined them with the corresponding maps available from the NVSS. The aggregated data allow us to produce high-quality images, which can be used to obtain physical parameters of the mapped sources. The combined images reveal in many cases extended low surface-brightness cocoons.Comment: 39 pages, 19 figures, 3 tables. Published in Ac

A study of the sonic-boom characteristics of a blunt body at a Mach number of 4.14

An experimental and theoretical study has shown that the applicability of far-field sonic-boom theory previously demonstrated for more slender shapes may now be extended to bodies with ratios of diameter to length as great as 2 and to Mach numbers at least as high as 4.14. This finding is of special significance in view of the limitations to the use of existing methods for the extrapolation of close-in experimental data

Estimation of wing nonlinear aerodynamic characteristics at supersonic speeds

A computational system for estimation of nonlinear aerodynamic characteristics of wings at supersonic speeds was developed and was incorporated in a computer program. This corrected linearized theory method accounts for nonlinearities in the variation of basic pressure loadings with local surface slopes, predicts the degree of attainment of theoretical leading edge thrust, and provides an estimate of detached leading edge vortex loadings that result when the theoretical thrust forces are not fully realized

Separation of two bodies in space. A machine programmed analysis using the Lagrange equations and Eulerian angles

Fortran computer program and Lagrangian motion equations for separation analysis of two bodies in spac

The Importance of Broadband Provision to Knowledge Intensive Firm Location

Despite the volume of literature afforded knowledge work and innovations in information and communications technologies (ICTs), few studies have examined the importance of ICTs to knowledge industries and the impact of their availability on firm location decisions. This study will evaluate the relative importance of ICTs to knowledge intensive firm location for select US metropolitan statistical areas (MSAs). Spatial econometric estimation techniques are used to construct models from ZIP code level data that describe the relative importance of broadband to knowledge intensive industries, as defined in this study. A global model is constructed for all relevant ZIP code areas across the continental U.S and the results are compared to metropolitan specific models. In addition to demonstrating variations by metropolitan area in the relative importance of broadband provision, the results suggest that broadband deployment initiatives will have varied outcomes on knowledge intensive firm growth and the subsequent change in the industrial composition of regional economies in future years.

Numerical Investigation of Second Mode Attenuation over Carbon/Carbon Surfaces on a Sharp Slender Cone

We have carried out axisymmetric numerical simulations of a spatially developing hypersonic boundary layer over a sharp 7$^{\circ{}}$-half-angle cone at $M_\infty=7.5$ inspired by the experimental investigations by Wagner (2015). Simulations are first performed with impermeable (or solid) walls with a one-time broadband pulse excitation applied upstream to determine the most convectively-amplified frequencies resulting in the range 260kHz -- 400kHz, consistent with experimental observations of second-mode instability waves. Subsequently, we introduce harmonic disturbances via continuous periodic suction and blowing at 270kHz and 350kHz. For each of these forcing frequencies complex impedance boundary conditions (IBC), modeling the acoustic response of two different carbon/carbon (C/C) ultrasonically absorptive porous surfaces, are applied at the wall. The IBCs are derived as an output of a pore-scale aeroacoustic analysis -- the inverse Helmholtz Solver (iHS) -- which is able to return the broadband real and imaginary components of the surface-averaged impedance. The introduction of the IBCs in all cases leads to a significant attenuation of the harmonically-forced second-mode wave. In particular, we observe a higher attenuation rate of the introduced waves with frequency of 350kHz in comparison with 270kHz, and, along with the iHS impedance results, we establish that the C/C surfaces absorb acoustic energy more effectively at higher frequencies.Comment: AIAA-SciTech 201

Separation of two bodies in space

Computer program analyzes the motion of two rigid bodies in space, separating as a result of any one, or a combination of, the following mechanisms - springs with ball ends, springs with one end guided, pyrotechnics, rockets, cold-gas jets, air pistons, and Coulomb drag

Factorizing Numbers with the Gauss Sum Technique: NMR Implementations

Several physics-based algorithms for factorizing large number were recently published. A notable recent one by Schleich et al. uses Gauss sums for distinguishing between factors and non-factors. We demonstrate two NMR techniques that evaluate Gauss sums and thus implement their algorithm. The first one is based on differential excitation of a single spin magnetization by a cascade of RF pulses. The second method is based on spatial averaging and selective refocusing of magnetization for Gauss sums corresponding to factors. All factors of 16637 and 52882363 are successfully obtained.Comment: 4 pages, 4 figures; Abstract and Conclusion are slightly modified. References added and formatted with Bibte

Evaluation of copper slag blast media for railcar maintenance

Copper slag was tested as a blasting substitute for zirconium silicate which is used to remove paint from railroad cars. The copper slag tested is less costly, strips paint faster, is produced near the point of need, provides a good bonding surface for paint, and permits the operator to work in a more comfortable position, i.e., standing nearly erect instead of having to crouch. Outdoor blasting with the tested Blackhawk (20 to 40 mesh) copper slag is also environmentally acceptable to the State of Utah. Results of tests for the surface erosion rate with copper slag blasting are included