Abstract: A one-piece diaphragm and ring for a stethoscope chestpiece is disclosed herein. The one-piece diaphragm and ring includes a diaphragm portion having a flat disk shape; and a ring portion connected to an outer periphery of the diaphragm portion, the ring portion being integrally formed with the diaphragm portion, and the ring portion configured to be attached to a rim of a chestpiece body portion. A chestpiece of a stethoscope that includes the one-piece diaphragm and ring is also disclosed herein.

Abstract: An acoustical building panel is disclosed that comprises a fibrous panel comprising: a central portion having a first major surface; a perimeter portion surrounding the central portion; a recess press-formed into the perimeter portion, the recess circumscribing the first major surface and comprising a recess floor surface; a second major surface opposite the first major surface; and side edge surfaces that define a perimeter of the fibrous panel and extend from the second major surface to the recess floor surface.

Abstract: A muffler for an engine includes a muffler body, at least one partition wall, and at least one reinforcing plate. The muffler body has an inner space formed by a shell. The partition wall includes a flange portion which is in tight contact with an inner surface of the shell, and the partition wall divides the inner space of the muffler body into a plurality of chambers. The reinforcing plate is welded on an outer surface of the shell at a position facing the flange portion of the partition wall.

Abstract: An apparatus and method are provided for a drone elimination muffler to attenuate drone exhibited by engine exhaust systems. The drone elimination muffler comprises a hollow canister having a length and a diameter, and a tuned port comprising a first end connected to the canister and a second end connected to the exhaust system. The canister operates in concert with the tuned port as a dampener configured to substantially attenuate exhaust drone, or resonance, at one or more frequencies of engine operation. A valve is configured to switch the drone elimination muffler between a closed state in which the exhaust system operates without acoustic influence due to the drone elimination muffler, and an open state in which the drone elimination muffler directly influences the acoustic properties of the exhaust system.

Abstract: An acoustic absorber includes a chamber formed from walls with a resistive portion providing the only communication between the chamber volume and ambient air. In some examples chamber walls enable selection or adjustment of chamber volume or resistive area, thereby altering the acoustic absorption spectrum below 250 Hz. In some examples the chamber volume contains fibrous filler material exhibiting no airflow resistance or acoustic absorption. Density and heat capacity of the fibrous filler material results in the chamber volume exhibiting compressibility of air within the chamber, for at least acoustic frequencies up to about 50 Hz, that is larger than adiabatic compressibility of air. That larger compressibility results in an increased acoustic absorption coefficient, for at least acoustic frequencies up to about 50 Hz, 50% to 100% larger than that of an identical chamber entirely characterized by the adiabatic compressibility of air.

Abstract: Ultrasonic transducers that include membrane films and perforated baseplates. An ultrasonic transducer includes a baseplate having a conductive surface with a plurality of apertures, openings, or perforations formed thereon or therethrough, and a membrane film having a conductive surface. The membrane film is positioned adjacent to the apertures, openings, or perforations formed on or through the baseplate. By applying a voltage between the conductive surface of the membrane film and the conductive surface of the baseplate, an electrical force of attraction can be created between the membrane film and the baseplate. Varying this applied voltage can cause the membrane film to undergo vibrational motion. The dimensions corresponding to the size and/or shape of the apertures, openings, or perforations formed on or through the baseplate can be varied so that different regions of the baseplate produce different frequency responses, allowing the net bandwidth of the ultrasonic transducer to be increased.

Abstract: Methods and systems are provided for an exhaust muffler system with multiple inlets of different diameters. In one example, the muffler system may include multiple sets of inlet pipes to a muffler with each set of inlet pipes including pipes of different diameters with valves controlling exhaust flow into the inlet pipes. Exhaust from an engine bank may flow to a distinct set of inlet pipes and a distinct outlet pipe of the muffler via a separate exhaust passage.

Abstract: An electrical power system is provided. The electrical power system involves a battery powered motor which in turn generates electricity using a primary generator and a secondary generator. The secondary generator provides a recycle electricity to the battery, while the primary generator provides an electrical output for powering electrical devices.

Abstract: A vehicle exhaust system includes a tubular component having an inner surface and an outer surface. The vehicle exhaust system also includes at least one opening defined by the tubular component. The at least one opening extends through each of the inner surface and the outer surface. The vehicle exhaust system further includes a patch adapted to cover the at least one opening. The patch includes a first portion extending parallel to the central axis. The first portion defines a plurality of pores. The first portion covers the at least one opening. The patch also includes a second portion extending away from the first portion. The first portion has a first thickness and the second portion has a second thickness.

Abstract: Described herein is an stain and sag resistant acoustic building panel comprising a porous body formed from building material and latex binder, wherein the building material may include fibers and filler and at one of the building materials has been pre-treated with a charge-modifying component, thereby enhancing the sag-resistance of the building panel.

Abstract: One aspect of the present disclosure provides a muffler including an exhaust pipe and a space forming member. The exhaust pipe has a cylindrical shape having a flow passage inside through which exhaust gas passes. The space forming member forms closed spaces between itself and the exhaust pipe, the closed spaces being branched from the flow passage and adjacent to the flow passage. Each of the closed spaces and the flow passage communicate with one another via a single communication hole.

Abstract: A vehicle exhaust system includes a tubular component defining a primary exhaust gas flow path. At least one opening defined by the tubular component extends through an inner surface and an outer surface of the tubular component. A patch covers the at least one opening. The patch includes a plate disposed on the tubular component. The plate defines at least one flow channel to receive exhaust gases from the at least one opening and impart at least one directional change to the received exhaust gases. The plate further defines at least one outlet opening adapted to receive exhaust gases from the flow channel. A secondary exhaust gas flow path is defined through the at least one opening in the tubular component, the flow channel defined by the plate, and the outlet opening defined by the plate.

Abstract: A noise abatement system for internal combustion engines comprising: a containment body (12) equipped with an inlet hole (6) for the entry of exhaust gases from an internal combustion engine, a plurality of expansion chambers (10) placed in sequence and separated by parallel dividing partitions (13), each equipped with a through-hole (4) for the passage of gases placing in fluid communication two neighboring expansion chambers (10); said expansion chambers (10) having two opposing through-holes (4), one as gas inlet and one as gas outlet. A rotating shaft (9) is integrated in a rotating turbine (1), along an axis comprising the center of gravity of the expansion chambers (10) up to an opposite end of the containment body (12), said rotating shaft (9) having placed around said axis and on said shaft (9) rotary fins (3) which open and close the through-holes (4) between expansion chambers (10) alternately and generating a swirling movement of the flow of gas entering each expansion chamber (10).

Abstract: This disclosure is related generally to marine surveying. An apparatus for generation of seismic waves in a body of water may include a wave generator. The apparatus may further include a housing defining an internal chamber having an open end. The housing may include baffles positioned between the open end and the wave generator. The housing may further include a vent positioned on an opposite end of the housing from the baffles.

Abstract: A suppressor for a multi-barrel weapon system includes a barrel clamp about which the barrels rotate during discharge of the weapon, an adapter baffle engaging the barrel clamp and configured to receive the muzzles of the barrels, a plurality of extension baffles aligned with and arranged in a stack against the adaptor baffle, and an endcap baffle aligned with the extension baffles and engaging the final extension baffle in the stack. A plurality of projectile apertures in each baffle aligns with the muzzles to define a plurality of parallel bullet paths. The stacked baffles define a single continuous interior chamber in which the muzzles are enclosed and through which propellant gases comingle before venting out of the endcap baffle. A connecting rod extends through the barrel clamp and the baffle stack to compressively secure the baffle stack to the barrel clamp.

Abstract: A dynamic acoustic locking ceiling baffle and a dynamic acoustic locking ceiling system, that includes a single piece of material folded into acoustic locking ceiling baffles, using locking pieces and locking mechanisms, to quickly and easily install the acoustic locking ceiling baffle onto construction ceiling hangers to provide an aesthetically pleasing image, along with a reduction in unwanted noise or room acoustics.

Abstract: Exhaust systems for a vehicle are provided. In one example, an exhaust system includes a muffler, a first exhaust outlet pipe fluidly coupled to a first outlet of the muffler, a second exhaust outlet pipe fluidly coupled to a second outlet of the muffler, a bypass duct fluidly coupled to a third outlet of the muffler, and a combined X-Y shaped intersection at which the first exhaust outlet pipe, the second exhaust outlet pipe, and the bypass duct are fluidly coupled to each other.

Abstract: A sound damping wallboard for installation on an installed wallboard, a sound damping wallboard system, and a method of constructing a sound damping wallboard on a building structure are disclosed. The sound damping wallboard includes a gypsum layer having a gypsum layer inner surface and a gypsum layer outer surface, a first sound damping layer disposed at the gypsum layer inner surface and having a first sound damping layer inner surface opposite the gypsum layer inner surface, a first encasing layer disposed at the gypsum layer outer surface, a second encasing layer disposed at the first sound damping layer inner surface, and a second sound damping layer disposed at the second encasing layer opposite the first sound damping layer inner surface.

Abstract: An acoustic panel is provided that includes a perforated first skin, a second skin and a corrugated structure. The corrugated structure is between and is connected to the perforated first skin and the second skin. The corrugated structure includes a first baffle, a first septum, first material and second material that is configured with the first material. The first baffle is formed by an uninterrupted portion of the first material. The first septum is formed by a portion of the second material that is exposed through an interruption in the first material.

Abstract: A device for controlling an exhaust sound of a vehicle includes a sound tunnel mounted near a muffler and an exhaust pipe so as to transmit exhaust sound to an interior of a vehicle, a sound introduction hole formed in the sound tunnel, and a catalytic assembly mounted in the sound tunnel so as to clog the sound introduction hole, the catalytic assembly functioning to reduce high-frequency noise and to filter exhaust gas, thereby reducing high-frequency noise included in the exhaust sound transmitted to the interior of the vehicle and thereby filtering the exhaust gas so as to prevent introduction of the exhaust gas into the interior of the vehicle.