Abstract: Environmentally beneficial antimicrobial compositions are described that include a cationic surfactant and certain antimicrobial agents or preservatives. Useful cationic surfactants include lauric arginate (LAE). Advantageously, the pH of the composition may be adjusted to reduce irritancy.

Abstract: Systems and methods for accurately measuring power output of a cyclist using a bike trainer that may be operated by a user for stationary riding when coupled to a conventional bicycle. The systems utilize a power output equation that models power due to resistance of a fan of the bike trainer as well as power due to kinetic energy of the fan. The systems account for operating conditions that affect the power measurements so that more accurate measurements can be provided, thereby improving the training experience of the user. Operating conditions include mechanical drag, temperature, humidity, and atmospheric pressure and/or altitude. The power output equation is dependent on the angular velocity of the fan of the bike trainer and the measured or received operating conditions.

Abstract: Signal handling equipment, such as a high power amplifier, is implemented with feed-forward compensation circuitry that adjusts the effective operation of the equipment (e.g., linearizes the amplifier). The compensation circuitry includes (i) a nulling loop, which generates an error signal based on the output from the amplifier, and (ii) an error loop, which generates, based on the error signal, a feed-forward compensation signal that is added to the output of the amplifier. The compensation circuitry is tuned by tuning the nulling loop and then iteratively tuning the error loop based on data generated by perturbing the tuning of the nulling loop. In one implementation, data corresponding to the amplitude of the output signal is analyzed to generate metric values that are used to iteratively adjust the tuning of the error loop.

Abstract: Signal handling equipment, such as a high power amplifier, is implemented with feed-forward compensation circuitry that adjusts the effective operation of the equipment (e.g., linearizes the amplifier). The compensation circuitry includes (i) a nulling loop, which generates an error signal based on the output from the amplifier, and (ii) an error loop, which generates, based on the error signal, a feed-forward compensation signal that is added to the output of the amplifier. The compensation circuitry is tuned by tuning the nulling loop and then iteratively tuning the error loop based on data generated by perturbing the tuning of the nulling loop. In one implementation, data corresponding to the amplitude of the output signal is analyzed to generate metric values that are used to iteratively adjust the tuning of the error loop.

Abstract: A freqency selective surface for passing electromagnetic wave energy and the selected frequency band is described. The device includes a conductive apertured substrate having apertures formed therein which are sized and arranged in a predetermined patern. The apertures each form a waveguide segment for electromagnetic energy. In one embodiment dielectric loading material is moldably formed directly into the apertures. In a bipolar arrangement, conductive patches are located on opposite sides of the dielectric coaxially with each waveguide for establishing a capacitive load in accordance with the area of the patches. Dielectric matching material on opposite surfaces of the substrate is employed to match the surface with external media for efficient electromagnetic wave propagation. Other arrangements employ notched patches and air dielectrics.

Abstract: A fabricated dielectric aperture assembly includes a first layer of electrically conductive material having an opening therethrough to define a first aperture, a second layer of electrically conductive material spaced from the first electrically conductive layer and having an opening therethrough to define a second aperture and a plurality of solid dielectric layers interposed between the first and second layers of electrically conductive material. The first and second layers of electrically conductive material with the multiple layers of dielectric material interposed therebetween form a generally laminar assembly. A grid-like structure is embedded in the laminar assembly and extends between the first and second electrically conductive layers. The grid-like structure has an inner wall, an outer wall portion, an interior bounded by the inner wall and a plurality of openings extending from the inner wall to the outer wall.