Abstract: An acoustic attenuation device includes resonator panels stacked in a thickness direction of the device. Each resonator panel is tuned to a different frequency range and includes a plurality of openings through which excited air resonates. The resonator panels are placed adjacent to other resonator panels such that all openings are accessible to the environment.

Abstract: An acoustic attenuation assembly includes a low frequency sound attenuation device having at least one sound attenuation chamber containing a volume and mass of air. First and second openings are associated with each low frequency chamber through which excited air resonates. The first and second openings extend through the first sheet into each low frequency chamber. Each chamber has an open side. A high frequency sound attenuation device is secured to the low frequency attenuation device and closes the open side of each chamber. The high frequency sound attenuation device includes a plurality of projections formed from a sound absorbing material that absorbs excited air.

Abstract: An acoustic attenuation device extends from a first end to a second end and includes first and second sheets. A plurality of webs positioned between the first and second sheets cooperates with the first and second sheets to form a series of sound attenuation chambers containing a volume and mass of fluid. A first panel secured to the sheets closes the chambers at the first end of the device. A second panel secured to the sheets closes the chambers at the second end of the device. The device further includes first and second openings associated with each chamber and through which excited fluid resonates. The first and second openings extend through the first sheet into each chamber. The first openings have an invariable cross-section. At least one of the second openings has an adjustable cross-section for varying a resonant frequency of the chamber.

Abstract: A method for additive manufacturing a multilayered part includes optimizing a powder material based on at least one parameter characterizing the powder material. Each layer of the multilayered part formed from the optimized powder material is optimized based on at least one parameter characterizing the layer. The multilayered part is formed using additive manufacturing based on the optimized powder material and optimized layers constituting the multilayered part. The multilayered part is optimized based on at least one parameter characterizing the multilayered part.

Abstract: A method of manufacturing an acoustic attenuation device includes three-dimensionally printing a pair of sheets and webs that cooperate with the sheets to define attenuation chambers. Each chamber has at least one opening through which excited air resonates.

Abstract: A modular apparatus for acquiring biometric data may include circuitry operative to receive an input signal indicative of a biometric condition, the circuitry being configured to process the input signal according to a transfer function thereof and to provide a corresponding processed input signal. A controller is configured to provide at least one control signal to the circuitry to programmatically modify the transfer function of the modular system to facilitate acquisition of the biometric data.

Abstract: A modular system for acquiring biometric data includes a plurality of data acquisition modules configured to sample biometric data from at least one respective input channel at a data acquisition rate. A representation of the sampled biometric data is stored in memory of each of the plurality of data acquisition modules. A central control system is in communication with each of the plurality of data acquisition modules through a bus. The central control system is configured to collect data asynchronously, via the bus, from the memory of the plurality of data acquisition modules according to a relative fullness of the memory of the plurality of data acquisition modules.

Abstract: A method of forming a composite structure can include providing a plurality of composite panels of material, each composite panel having a plurality of holes extending through the panel. An adhesive layer is applied to each composite panel and a adjoining layer is applied over the adhesive layer. The method also includes stitching the composite panels, adhesive layer, and adjoining layer together by passing a length of a flexible connecting element into the plurality of holes in the composite panels of material. At least the adhesive layer is cured to bond the composite panels together and thereby form the composite structure.