A hydrogen gas producing apparatus includes a porous body (100) and a mixed gas source (300). The porous body (100) is permeable to hydrogen gas and carbon dioxide gas, and has a property of being more permeable to hydrogen gas than carbon dioxide gas. The mixed gas source (300) causes a mixed gas including carbon dioxide gas and hydrogen gas to flow into the porous body (100) under a condition that a pressure gradient represented by (P.sub.1P.sub.2)/L is below 50 MPa/m, where L represents the length of the porous body (100) in a direction in which the mixed gas permeates; P.sub.1 represents an inflow pressure of the mixed gas into the porous body (100); and P.sub.2 represents an outflow pressure thereof from the porous body (100).

A hydrogen gas producing apparatus includes a porous body (100) and a mixed gas source (300). The porous body (100) is permeable to hydrogen gas and carbon dioxide gas, and has a property of being more permeable to hydrogen gas than carbon dioxide gas. The mixed gas source (300) causes a mixed gas including carbon dioxide gas and hydrogen gas to flow into the porous body (100) under a condition that a pressure gradient represented by (P.sub.1P.sub.2)/L is below 50 MPa/m, where L represents the length of the porous body (100) in a direction in which the mixed gas permeates; P.sub.1 represents an inflow pressure of the mixed gas into the porous body (100); and P.sub.2 represents an outflow pressure thereof from the porous body (100).

A method for producing microencapsulated fuel pebble fuel more rapidly and with a matrix that engenders added safety attributes. The method includes coating fuel particles with ceramic powder; placing the coated fuel particles in a first die; applying a first current and a first pressure to the first die so as to form a fuel pebble by direct current sintering. The method may further include removing the fuel pebble from the first die and placing the fuel pebble within a bed of non-fueled matrix ceramic in a second die; and applying a second current and a second pressure to the second die so as to form a composite fuel pebble.

A method for producing microencapsulated fuel pebble fuel more rapidly and with a matrix that engenders added safety attributes. The method includes coating fuel particles with ceramic powder; placing the coated fuel particles in a first die; applying a first current and a first pressure to the first die so as to form a fuel pebble by direct current sintering. The method may further include removing the fuel pebble from the first die and placing the fuel pebble within a bed of non-fueled matrix ceramic in a second die; and applying a second current and a second pressure to the second die so as to form a composite fuel pebble.

Body armor composite material that includes a substrate, a tempered aluminum binder, and ceramic spheres embedded in the binder. The ceramic spheres have interstitial space that are filled by the aluminum binder.

A densified ceramic matrix composite (CMC) material densified CMC exhibits superior strength and toughness, relative to prior CMCs The material can be made by a process that includes impregnating a set of ceramic fibers with a non-fibrous ceramic material, resulting in a precursor matrix, stabilizing the precursor matrix, resulting in a stabilized matrix, and densifying the stabilized matrix using a frequency assisted sintering technology (FAST) process, resulting in the densified CMC material.

A densified ceramic matrix composite (CMC) material densified CMC exhibits superior strength and toughness, relative to prior CMCs The material can be made by a process that includes impregnating a set of ceramic fibers with a non-fibrous ceramic material, resulting in a precursor matrix, stabilizing the precursor matrix, resulting in a stabilized matrix, and densifying the stabilized matrix using a frequency assisted sintering technology (FAST) process, resulting in the densified CMC material.

A method of making a ceramic matrix composite (CMC) brake component may include the steps of applying a pressure to a mixture comprising ceramic powder and chopped fibers, pulsing an electrical discharge across the mixture to generate a pulsed plasma between particles of the ceramic powder, increasing a temperature applied to the mixture using direct heating to generate the CMC brake component, and reducing the temperature and the pressure applied to the CMC brake component. The ceramic powder may have a micrometer powder size or a nanometer powder size, and the chopped fibers may have an interphase coating.

A method of making a ceramic matrix composite (CMC) brake component may include the steps of applying a pressure to a mixture comprising ceramic powder and chopped fibers, pulsing an electrical discharge across the mixture to generate a pulsed plasma between particles of the ceramic powder, increasing a temperature applied to the mixture using direct heating to generate the CMC brake component, and reducing the temperature and the pressure applied to the CMC brake component. The ceramic powder may have a micrometer powder size or a nanometer powder size, and the chopped fibers may have an interphase coating.

Provided is a SiC sintered body which contains nitrogen atoms, wherein a ratio R.sub.max/R.sub.ave of a maximum volume resistivity R.sub.max of the sintered body to an average volume resistivity R.sub.ave of the sintered body is 1.5 or lower; a ratio R.sub.min/R.sub.ave of a minimum volume resistivity R.sub.min of the sintered body to the average volume resistivity R.sub.ave is 0.7 or higher; and a relative density of the sintered body is 98% or higher.