A unique formulation of elastic airplane longitudinal equations of motion

Control-configured vehicle technology has increased the demand for detailed analysis of dynamic stability and control, handling and ride qualities, and control system dynamics at early stages of preliminary design. An approximate, but reasonably accurate, set of equations of motion are needed for these early analyses. Such a formulation is developed for the longitudinal dynamics of elastic airplanes. It makes use of only rigid-body aerodynamic stability derivatives in formulating the forces and moments due to elastic motion. Verification of accuracy using data for the B-1 airplane shows very good agreement. Frequencies and damping ratios of the coupled modes corresponding to complex roots of the characteristic equations agree closely with four symmetric elastic modes included

One-step dual purpose joining technique

This fastener used in induction heating is a wire screen basically of an eddy current carrying material such as carbon steel. Selected wires in the screen are copper, sheathed in an insulating material. The screen is placed between two sheets of thermoplastics. When inductively heated, the composite softens and flows around the apertures of the screen. After this heating and joining, the copper wires may be used to conduct electricity

Edward Taylor: Toward Union With God; Studies in the Preparatory Meditations

Persistent critical attention has been directed to the poetry of Edward Taylor since Thomas H. Johnson\u27s publication of The Poetical Works of Edward Taylor in 1939. However, even after scrupulous efforts by literary scholars, the life and works of Taylor continue to provoke questions. The same, obviously, can be said for the lives and literary achievements of numerous figures; after all, the work of the biographer and literary critic is theoretically never done. But Edward Taylor, owing to scant biographical data and perhaps the shortness of time since the publication of his work, poses confounding questions (e.g., the reason for Taylor\u27s leaving England as a young man and the reason for his injunction against the publication of his writings). Central to this study, however, is a more intriguing question. Given the narrow religious setting of Colonial New England, a milieu which Willie T. Weathers correctly characterizes as not a very good school for poets, how does one account for poetry of the nature of the Preparatory Meditations, poetry celebrating man while taking note of his limitations and poetry focusing on a loving Christ rather than a militant Christ? The question appears to have gone largely unanswered

Ride quality sensitivity to SAS control law and to handling quality variations

The RQ trends which large flexible aircraft exhibit under various parameterizations of control laws and handling qualities are discussed. A summary of the assumptions and solution technique, a control law parameterization review, a discussion of ride sensitivity to handling qualities, and the RQ effects generated by implementing relaxed static stability configurations are included

Effects of control laws and relaxed static stability on vertical ride quality of flexible aircraft

State variable techniques are utilized to generate the RMS vertical load factors for the B-52H and B-1 bombers at low level, mission critical, cruise conditions. A ride quality index is proposed to provide meaningful comparisons between different controls or conditions. Ride quality is shown to be relatively invariant under various popular control laws. Handling quality variations are shown to be major contributors to ride quality variations on both vehicles. Relaxed static stability is artificially implemented on the study vehicles to investigate its effects on ride quality. The B-52H ride quality is generally degraded when handling characteristics are automatically restored by a feedback control to the original values from relaxed stability conditions. The B-1 airplane shows little ride quality sensitivity to the same analysis due to the small rigid body contribution to load factors at the flight condition investigated

Cavity Optomechanical Magnetometer

A cavity optomechanical magnetometer is demonstrated where the magnetic field induced expansion of a magnetostrictive material is transduced onto the physical structure of a highly compliant optical microresonator. The resulting motion is read out optically with ultra-high sensitivity. Detecting the magnetostrictive deformation of Terfenol-D with a toroidal whispering gallery mode (TWGM) resonator a peak sensitivity of 400 nT/Hz^.5 was achieved with theoretical modelling predicting that sensitivities of up to 500 fT/Hz^.5 may be possible. This chip-based magnetometer combines high-sensitivity and large dynamic range with small size and room temperature operation

Past Facts and the Nature of History

This is the final version. Available on open access from Brill via the DOI in this recordWe defend a realist account of history: past facts are discoveries not creations. We show how ‘moderate’ realists, who admit the critical role of perspective, while insisting on history’s metaphysical independence from historians, can accommodate Paul Roth’s arguments in favor of irrealism. Moreover, our position is consistent with a dynamic past: as history unfurls past events gain new properties. Realism is necessary, we argue, to capture substantive disputes within history. It also grounds history’s reflexivity: the point of the continual re-examination of history (and history’s history!) turns in part on there being mind-independent past facts to be had