69,432 research outputs found
Old Licenses and New Uses: Motion Picture and Television Rights
There are many possible ways to perform the attitude control of a quadcopter and, recently, the subject of event-triggered control has become relevant in the scientic community. This thesis deals with the analysis and implementation of a saturating attitude controller for a quadcopter system, together with the derivation of an event-triggering rule to work with it. Two distinct rules are presented, one that ensures the stability of the closed loop system, the other, a linearised version that does not. The way those were derived consists in the use of a Lyapunov based approach. The stability of the system when under these rules was veried experimentally
Analysis of filament reinforced metal-shell pressure vessels
Computer program analyzes design requirements and computes designs for metal-lined filament-wound pressure vessels with either geodesic /helical/ or in-plane filament winding patterns on the cylindrical portion and over the ends, reinforced by circumferential windings on the cylindrical portion
Procedures for experimental measurement and theoretical analysis of large plastic deformations
Theoretical equations are derived and analytical procedures are presented for the interpretation of experimental measurements of large plastic strains in the surface of a plate. Orthogonal gage lengths established on the metal surface are measured before and after deformation. The change in orthogonality after deformation is also measured. Equations yield the principal strains, deviatoric stresses in the absence of surface friction forces, true stresses if the stress normal to the surface is known, and the orientation angle between the deformed gage line and the principal stress-strain axes. Errors in the measurement of nominal strains greater than 3 percent are within engineering accuracy. Applications suggested for this strain measurement system include the large-strain-stress analysis of impact test models, burst tests of spherical or cylindrical pressure vessels, and to augment small-strain instrumentation tests where large strains are anticipated
Development of low viscosity alkane-based urethane for connector potting applications
Two series of saturated hydrocarbon-based urethanes were prepared with isophorone diisocyanate and one series with methyl bis (4-cyclohexyl isocyanate). The urethanes with molecular weights as great as 2500 had viscosities low enough and a working life long enough to be used in potting, molding, and coating applications. Specimens were prepared and mechanical properties such as hardness, tensile strength elongation, and tear strength were determined. Thermomechanical properties (glass transition and expansion coefficient) and thermogravimetric properties were determined
Analysis of filament-wound dome and polar boss of metal-lined glass-filament-wound pressure vessels
Structural analysis of glass filament wound, aluminum lined pressure vessel design
Gas flowmeter
Mass flowmeter measures rates of flow of all common gases from purges and collected leaks at leak ports. Without dependence on gravity, it measures rates between 5 and 650 cc/min with pressures ranging from 0.001 to 10 to the minus thirteenth torr at temperatures between 70 and 500 degrees K
Description of a new Crossidius LeConte (Coleoptera: Cerambycidae: Cerambycinae: Trachyderini) from southern Georgia with comments on its biology and unusual distribution
Crossidius grahami Morris and Wappes new species (Coleoptera: Cerambycidae) is described from the Ohoopee Dunes of southern Georgia. Comments are included on the new species’ biology and disjunct distribution compared to other species of Crossidius LeConte. Illustrations include: dorsal and lateral views of the primary types of C. grahami, its natural habitat, the known host plant (Chrysoma pauciflosculosa (Michx.) Greene (Asteraceae)), pupal chamber, and dorsal views of both sexes of Crossidius humeralis quadrivittata Penrose, 1974, considered its closest anatomical counterpart and nearest geographical relative
Polymerizable disilanols having in-chain perfluoroalkyl groups
Disilanols containing in-chain perfluoroalkyl and aromatic groups and the process by which they were prepared are discussed. The disilanols, when reacted with a diaminosilane and cured, produce polymeric material resistant to hydrocarbon fuels and stable at elevated temperatures
- …