222 research outputs found
Design concepts for low-cost composite turbofan engine frame
Design concepts for low cost, lightweight composite engine frames were applied to the design requirements for the frame of a commercial, high bypass engine. Four alternative composite frame design concepts identified which consisted of generic type components and subcomponents that could be adapted to use in different locations in the engine and the different engine sizes. A variety of materials and manufacturing methods were projected with a goal for the lowest number of parts at the lowest possible cost. After a preliminary evaluation of all four frame concepts, two designs were selected for an extended design and evaluation which narrowed the final selection down to one frame that was significantly lower in cost and slighty lighter than the other frame. An implementation plan for this lowest cost frame is projected for future development and includes prospects for reducing its weight with proposed unproven, innovative fabrication techniques
Widely wavelength-selective Al2O3:Er3+ ring laser
Integrated Al2O3:Er3+ channel waveguide ring lasers were realized on thermally oxidized silicon substrates. High pump power coupling into- and low output power coupling from the ring is achieved in a straightforward design. Wavelength\ud
selection in the range 1532 to 1557 nm was demonstrated by\ud
varying the length of the output coupler from the ring
Analytical approach to dielectric optical bent slab waveguides
A rigorous classical analytic frequency domain model of con?ned optical wave propagation along 2D bent slab waveguides and curved dielectric interfaces is investigated, based on a piecewise ansatz for bend mode profiles in terms of Bessel and Hankel functions. This approach provides a clear picture of the behaviour of bend modes, concerning their decay for large radial arguments or effects of varying bend radius. Fast and accurate routines are required to evaluate Bessel functions with large complex orders and large arguments. Our implementation enabled detailed studies of bent waveguide properties, including higher order bend modes and whispering gallery modes, their interference patterns, and issues related to bend mode normalization and orthogonality properties
Al<sub>2</sub>O<sub>3</sub>:Er<sup>3+</sup> as a broad gain medium for 1.53-µm integrated optical applications
One-loop matching of the CP-odd three-gluon operator to the gradient flow
The calculation of the neutron electric dipole moment within effective field theories for physics beyond the Standard Model requires non-perturbative hadronic matrix elements of effective operators composed of quark and gluon fields. In order to use input from lattice computations, these matrix elements must be translated from a scheme suitable for lattice QCD to the minimal-subtraction scheme used in the effective-field-theory framework. The accuracy goal in the context of the neutron electric dipole moment necessitates at least a one-loop matching calculation. Here, we provide the one-loop matching coefficients for the CP-odd three-gluon operator between two different minimally subtracted 't Hooft–Veltman schemes and the gradient flow. This completes our program to obtain the one-loop gradient-flow matching coefficients for all CP-violating and flavor-conserving operators in the low-energy effective field theory up to dimension six
Additive-Assisted, Cerium-Based, Corrosion-Resistant e-coating
Corrosion resistance of metallic components such as stainless steel components of vehicles, and especially aluminum- based components of aircraft, is enhanced by application of an e-coat paint or primer which is enhanced by incorporation of cerium ions into the e-coat electrolytic bath. The resulting overall coating includes a cerium-based layer under a cerium-enhanced e-coat paint or primer layer
Additive-Assisted Cerium-Based Electrolytic Coating Process for Corrosion Protection of Aluminum Alloys
The corrosion resistance of an aluminum or aluminum alloy component is enhanced by immersing an aluminum alloy to act as a cathode and an oxygen-evolving anode in an electrolyte comprising water, cerium ions, and an additive selected from among animal gelatin, derivatives of animal gelatin, and amino acids, then passing an electrical current through the electrolyte to deposit a cerium-based coating onto the aluminum-based component
Cerium-Based Spontaneous Coating Process for Corrosion Protection of Aluminum Alloys
A cerium-based coating for corrosion resistance is applied by exposing a cleaned aluminum-based component to a corrosion-inhibiting cerium solution containing cerium ions in the presence of an oxidizing agent. The coating deposits spontaneously without an external source of electrons
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