A golf ball including a thermoplastic inner core layer that has a geometric center hardness greater than its surface hardness to define a negative hardness gradient. An outer core layer is disposed about the inner core and is formed from a thermoplastic material and has an inner surface hardness substantially less than its outer surface hardness to define a positive hardness gradient. An inner cover layer is disposed about the outer core layer and an outer cover layer is disposed about the inner cover layer.

A golf ball including a thermoplastic inner core layer that has a geometric center hardness greater than its surface hardness to define a negative hardness gradient. An outer core layer is disposed about the inner core and is formed from a thermoplastic material and has an inner surface hardness substantially less than its outer surface hardness to define a positive hardness gradient. An inner cover layer is disposed about the outer core layer and an outer cover layer is disposed about the inner cover layer.

A method of manufacturing a heat exchanger array that includes stacking a plurality of heat exchanger units in an aligned configuration with respective first ports of the plurality of heat exchanger units aligned. The method can further include generating heat in the first coupling elements at the same time and at a temperature sufficient to generate a first plurality of respective couplings between adjacent sheets of adjacent heat exchanger units about adjacent first ports and without a coupling being generated between the first and second sheets of a given heat exchanger unit.

A method of manufacturing a heat exchanger array that includes stacking a plurality of heat exchanger units in an aligned configuration with respective first ports of the plurality of heat exchanger units aligned. The method can further include generating heat in the first coupling elements at the same time and at a temperature sufficient to generate a first plurality of respective couplings between adjacent sheets of adjacent heat exchanger units about adjacent first ports and without a coupling being generated between the first and second sheets of a given heat exchanger unit.

According to one aspect of the present invention, there is provided a hollow structure body having a hollow structure, in which a first shaped product constituted by a first fiber-reinforced resin material containing first reinforcing fibers and a first matrix resin and a second shaped product constituted by a second fiber-reinforced resin material containing second reinforcing fibers and a second matrix resin are combined, wherein in an arbitrary cross section in a direction perpendicular to an axial direction of the hollow structure, a ratio Sc/St between compressive strength Sc of a structure in the first shaped product and tensile strength St of a structure in the second shaped product satisfies formula (1):
(σc/σt)*(Hc/Ht)<(Sc/St)<(σt/σc)*(Hc/Ht)  formula (1).

According to one aspect of the present invention, there is provided a hollow structure body having a hollow structure, in which a first shaped product constituted by a first fiber-reinforced resin material containing first reinforcing fibers and a first matrix resin and a second shaped product constituted by a second fiber-reinforced resin material containing second reinforcing fibers and a second matrix resin are combined, wherein in an arbitrary cross section in a direction perpendicular to an axial direction of the hollow structure, a ratio Sc/St between compressive strength Sc of a structure in the first shaped product and tensile strength St of a structure in the second shaped product satisfies formula (1):
(σc/σt)*(Hc/Ht)<(Sc/St)<(σt/σc)*(Hc/Ht)  formula (1).

A vessel includes a vessel wall and an insulation assembly coupled to the vessel wall. The insulation assembly includes a stochastic foam material and a microtruss structure encased within the foam material. The microtruss structure includes a plurality of truss members interconnected at a plurality of nodes. Each truss member is in contact with the foam material such that the microtruss structure provides a structural core for the foam material.

A method for increasing the adhesion between the first surface of a first web-type material and a first surface of a second web-type material, the first web-type material and the second web-type material being supplied to a lamination nip continuously and with the same direction of the web. In said nip, the first surface of the first web-type material and of the second web-type material are laminated together and both first surfaces are treated with a plasma over the whole surface. The lamination nip is formed by a pressure roller and a counter-pressure roller and at least one of the surfaces of the rollers or both are equipped with a dielectric. The plasma or the corona is produced by a nozzle. The first web-type material comprises an adhesive compound layer arranged in the first web-type material such as to form the first surface of the first web-type material.

A method for increasing the adhesion between the first surface of a first web-type material and a first surface of a second web-type material, the first web-type material and the second web-type material being supplied to a lamination nip continuously and with the same direction of the web. In said nip, the first surface of the first web-type material and of the second web-type material are laminated together and both first surfaces are treated with a plasma over the whole surface. The lamination nip is formed by a pressure roller and a counter-pressure roller and at least one of the surfaces of the rollers or both are equipped with a dielectric. The plasma or the corona is produced by a nozzle. The first web-type material comprises an adhesive compound layer arranged in the first web-type material such as to form the first surface of the first web-type material.

The method for producing a polyimide fiber includes a coagulation step of forming a polyimide precursor fiber by extruding a polyimide precursor solution containing a polyimide precursor and a compound having an acid dissociation constant (pKa) of a conjugate acid in water at 25° C. of 6.0 to 10 inclusive and an octanol-water partition coefficient (Log P) at 25° C. of −0.75 to 0.75 inclusive into a poor solvent or nonsolvent for the polyimide precursor; and a heat drawing step of forming the polyimide fiber by drawing the polyimide precursor fiber while heating same. The polyimide fiber of the present disclosure has a physical property such that the coefficient of thermal expansion thereof is in the range of −15 ppm/K to 0 ppm/K inclusive.