A block copolymer including a polymer block (A) containing more than 70 mol % of a unit derived from an aromatic vinyl compound, and a polymer block (B) containing 30 mol % or more of a unit derived from a conjugated diene compound is provided. The block copolymer satisfies the conditions: (1): a content of the polymer block (A) in the block copolymer is 1 to 70% by mass; (2): a maximum width of a series of temperature regions where tan δ measured in accordance with JIS K7244-10 (2005), under conditions including a strain amount of 0.1%, a frequency of 1 a measurement temperature of −70 to 100° C., and a temperature rise rate of 3° C./min, is 1.0 or more is less than 16° C.; (3): a temperature at a peak position of tan δ in the condition (2) is 0° C. to +50° C.; and (4): a mobility parameter M indicating a mobility of the polymer block (B) is 0.01 to 0.25 sec.

A single-step method of generating a three dimensional (3D) printed article includes: selecting a first metastructure and a second metastructure; designing and constructing a first transitional metastructure that transitions from the first metastructure to the second metastructure; depositing a first layer comprising the first metastructure; seamlessly connecting the first and first transitional metastructures by depositing a first transitional layer comprising the first transitional metastructure on the first layer; and seamlessly connecting the first transitional and second metastructures by depositing a second layer comprising the second metastructure on the first transitional layer.

A single-step method of generating a three dimensional (3D) printed article includes: selecting a first metastructure and a second metastructure; designing and constructing a first transitional metastructure that transitions from the first metastructure to the second metastructure; depositing a first layer comprising the first metastructure; seamlessly connecting the first and first transitional metastructures by depositing a first transitional layer comprising the first transitional metastructure on the first layer; and seamlessly connecting the first transitional and second metastructures by depositing a second layer comprising the second metastructure on the first transitional layer.

A sound damping wallboard and methods of forming a sound damping wallboard are disclosed. The sound damping wallboard comprises a gypsum layer with a gypsum surface having an encasing layer. The encasing layer is partially removed to expose the gypsum surface and form a gypsum surface portion and a first encasing layer portion on the gypsum layer. A sound damping layer is applied to the gypsum layer to cover at least part of the gypsum surface portion and the encasing layer portion.

A sound damping wallboard and methods of forming a sound damping wallboard are disclosed. The sound damping wallboard comprises a gypsum layer with a gypsum surface having an encasing layer. The encasing layer is partially removed to expose the gypsum surface and form a gypsum surface portion and a first encasing layer portion on the gypsum layer. A sound damping layer is applied to the gypsum layer to cover at least part of the gypsum surface portion and the encasing layer portion.

An acoustic absorption structure comprising a plurality of resonators. Each resonator comprises a first chamber which has a first mouthpiece delimited by an edge pressed against an inner surface of a porous zone of a skin so that the first chamber and the skin delimit a first cavity, a second chamber, in which is positioned the first chamber, which delimits, with the first chamber, a second cavity, at least one acoustic orifice passing through the first chamber, at least one drainage orifice passing through the first chamber and at least one drainage hole passing the second chamber, each drainage orifice and each drainage hole being configured to limit an accumulation of fluid in the resonator. Also, an aircraft propulsive assembly or an aircraft comprising the acoustic absorption structure are provided.

A method for building a soundproof enclosure (10) in the form of an independent structure with acoustic properties for isolating noise and vibration is disclosed. The soundproof enclosure (10) comprised a plurality of acoustical wall panels (12) interconnectable each to another at opposing sides for enclosing an interior space (41) of various sizes. The soundproof enclosure (10) further comprised one or more modular multilayer ceiling unit(s) (13) assembled onto the top edges of the acoustical wall panels (12) to form the enclosure. The ceiling unit (13) comprised a plurality of ceiling layers (17), each ceiling layer (17) being vertically spaced apart with one another by brackets to topographically form the multiple guided spaces necessary for air flow circulation within the enclosure (10). These guided spaces can also house multiple implements such as circulation fan, air filter and sound silencer. Sound insulating material layer(s) are interposed between the contacting surfaces of the ceiling unit (13) and the acoustical wall panels (12) and/or all around the surfaces to isolate and decouple the ceiling unit (13) from the acoustical wall panels (12) from vibrations. A sound barrier cover (16a or 79) is interposed at the openings (25) of the air passages (24) to further reduce the sound level emitted into and exiting from the enclosure. In addition, a construction method by elevating the heavy acoustical wall panels (12) and the ceiling units (13) until they fall into precise assembly location for ease of assembly of the components of the enclosure (10) and a floor base unit 11 that enabled the enclosure (10) to about easily in whole is also disclosed. Furthermore, a method to ease assembly of the enclosure (10) by use of removable heavy-duty handles (87) is disclosed.

A method for building a soundproof enclosure (10) in the form of an independent structure with acoustic properties for isolating noise and vibration is disclosed. The soundproof enclosure (10) comprised a plurality of acoustical wall panels (12) interconnectable each to another at opposing sides for enclosing an interior space (41) of various sizes. The soundproof enclosure (10) further comprised one or more modular multilayer ceiling unit(s) (13) assembled onto the top edges of the acoustical wall panels (12) to form the enclosure. The ceiling unit (13) comprised a plurality of ceiling layers (17), each ceiling layer (17) being vertically spaced apart with one another by brackets to topographically form the multiple guided spaces necessary for air flow circulation within the enclosure (10). These guided spaces can also house multiple implements such as circulation fan, air filter and sound silencer. Sound insulating material layer(s) are interposed between the contacting surfaces of the ceiling unit (13) and the acoustical wall panels (12) and/or all around the surfaces to isolate and decouple the ceiling unit (13) from the acoustical wall panels (12) from vibrations. A sound barrier cover (16a or 79) is interposed at the openings (25) of the air passages (24) to further reduce the sound level emitted into and exiting from the enclosure. In addition, a construction method by elevating the heavy acoustical wall panels (12) and the ceiling units (13) until they fall into precise assembly location for ease of assembly of the components of the enclosure (10) and a floor base unit 11 that enabled the enclosure (10) to about easily in whole is also disclosed. Furthermore, a method to ease assembly of the enclosure (10) by use of removable heavy-duty handles (87) is disclosed.

A sound-absorbing cover comprises a first sound-absorbing layer and a second sound-absorbing layer made of foam, a first skin layer of the first sound-absorbing layer and a second skin layer of the second sound-absorbing layer are layered in a state of being made to face each other, and an air layer is provided between the facing surfaces of the first skin layer and the second skin layer. The rigidity of the first skin layer of the first sound-absorbing layer is different from the rigidity of the second skin layer of the second sound-absorbing layer.

A sound-absorbing cover comprises a first sound-absorbing layer and a second sound-absorbing layer made of foam, a first skin layer of the first sound-absorbing layer and a second skin layer of the second sound-absorbing layer are layered in a state of being made to face each other, and an air layer is provided between the facing surfaces of the first skin layer and the second skin layer. The rigidity of the first skin layer of the first sound-absorbing layer is different from the rigidity of the second skin layer of the second sound-absorbing layer.