Abstract: A system is provided to change a temperature of an environment. A first plurality of containers store metal hydride, while a second plurality of containers store metal alloy capable of absorbing hydrogen atoms at a pressure less than a storage pressure of the metal hydride. Valved conduits link container pairs of metal hydride and metal alloy. When the valves are opened, hydrogen atoms desorbed from the metal hydride are transported through the conduit and are absorbed by the metal alloy. Desorption of the hydrogen cools the metal hydride containing container and heats the metal alloy containing container, which are each in thermal communication with the environment to cool or heat the environment via fluid circulation means. One or more container pairs may be operated to cool/heat the environment, while one or more other container pairs may be regenerated using a renewable power source.

Abstract: The invention is a submersible hand warmer apparatus for warming a diver's gloved hands. The apparatus includes a sleeve having a center portion with an elongate chamber with a right access port and a left access port; and right and left sleeve portions with elastic cuffs. The cuffs can be stretched allowing the diver's gloved hands access to the chamber, and then retract, forming a seal against the diver's arms. The chamber is sized for enough heat transfer fluid, such as water, so that the temperature of the diver's hands is raised to at least 54° F. upon immersion of his hands in the water. The apparatus also includes a heating component; an energy source, such as a battery; a housing which provides structural support; an insulation that slows the loss of heat to the cold ambient water; and a controller that controls the rate that energy is consumed.

Abstract: The disclosed invention provides a composition that possesses insulation values approaching that of uncompressed foam neoprene. The liquid composition is incompressible and may be formulated to be neutrally buoyant in water. The composition is suitable for a use in a number of applications where insulation is required, including divers' suits and underwater cabins, such as chambers, submersible hulls, and waterproof housings.

Abstract: The disclosed invention provides a composition that possesses insulation values approaching that of uncompressed foam neoprene. The liquid composition is incompressible and may be formulated to be neutrally buoyant in water. The composition is suitable for a use in a number of applications where insulation is required, including divers' suits and underwater cabins, such as chambers, submersible hulls, and waterproof housings.

Abstract: A reconfigurable system is provided for effecting temperature changes. A first thermally-conductive container stores a metal hydride while a second thermally-conductive container stores a metal alloy that is capable of absorbing hydrogen atoms at a pressure that is less than the storage pressure of the metal hydride. A valved conduit links the metal hydride and the metal alloy. A thermal insulator is disposed about one of the containers depending on whether the system is to be used for cooling or heating. A circulating fluid is placed in thermal communication with the insulated container and with an environment requiring temperature changes. When the conduit's valve is opened, hydrogen atoms desorbed from the metal hydride are transported through the conduit and are absorbed by the metal alloy. Desorption of the hydrogen generates a cooling effect while absorption of the hydrogen generates heat.

Abstract: The present invention reduces the amount of oxygen in an oxygen-containing gas within a closed environment. A selected amount of hydrogen gas is mixed with a portion of the oxygen-containing gas from the closed environment to form a first gas mixture. A catalyst exposed to the first gas mixture causes a reaction between the hydrogen and at least a portion of the oxygen therein. The resulting second gas mixture, which is returned to the closed environment, has a lower percentage of oxygen. At least one oxygen sensor is positioned in the closed environment to determine when oxygen levels in the closed environment reach a threshold level. The output signal from the sensor is used to control when and/or how much hydrogen is mixed in the first gas mixture.

Abstract: A method and system are provided for simulating the metabolic consumption of oxygen contained in a breathable gas. A variable volume chamber cyclically increases/decreases in volume to receive the breathable gas/expel an exhaust gas. Hydrogen and carbon dioxide are introduced into the chamber to mix with the breathable gas to form the exhaust gas. Hydrogen is introduced in an amount sufficient to react with an amount of the oxygen in the exhaust gas equivalent to that used by a human during a selected level of activity. Carbon dioxide is introduced in an amount equivalent to that provided by a metabolic respiratory quotient associated with the same level of activity. A catalyst, exposed to the exhaust gas, causes a reaction between the hydrogen and oxygen in the exhaust gas to generate simulated human exhalation.

Abstract: A method and system are provided for simulating the metabolic consumption of oxygen contained in a breathable gas. A variable volume chamber cyclically increases/decreases in volume to receive the breathable gas/expel an exhaust gas. Hydrogen and carbon dioxide are introduced into the chamber to mix with the breathable gas to form the exhaust gas. Hydrogen is introduced in an amount sufficient to react with an amount of the oxygen in the exhaust gas equivalent to that used by a human during a selected level of activity. Carbon dioxide is introduced in an amount equivalent to that provided by a metabolic respiratory quotient associated with the same level of activity. A catalyst, exposed to the exhaust gas, causes a reaction between the hydrogen and oxygen in the exhaust gas to generate simulated human exhalation.

Abstract: The present invention reduces the amount of oxygen in an oxygen-containing gas within a closed environment. A selected amount of hydrogen gas is mixed with a portion of the oxygen-containing gas from the closed environment to form a first gas mixture. A catalyst exposed to the first gas mixture causes a reaction between the hydrogen and at least a portion of the oxygen therein. The resulting second gas mixture, which is returned to the closed environment, has a lower percentage of oxygen. At least one oxygen sensor is positioned in the closed environment to determine when oxygen levels in the closed environment reach a threshold level. The output signal from the sensor is used to control when and/or how much hydrogen is mixed in the first gas mixture.

Abstract: A catalytic heater supplies heated water that circulates to heat a diver's suit. An insulating housing closed at opposite ends by cap members defines a chamber containing a catalyst inside of a multi-tube heat exchanger. Fittings in the cap members pass water through the multi-tube heat exchanger to and from the suit, and a gas circuit flows mixed hydrogen and oxygen to the catalyst that reacts with the mixed hydrogen and oxygen to produce heat that heats the water in the multi-tube heat exchanger for the diving suit. Optionally, hydrogen may be mixed with oxygen from a breathing gas mixture so that after heating the water, the gases remaining may be breathed by the diver. The catalytic heater provides a safe, reliable source of warm water for active thermal protection of divers over a wide range of diving applications.

Abstract: A semi-closed circuit rebreather system that adapts to a user's activity level is provided. A vacuum pressure develops in a chamber coupled to a mouthbit as a breathing gas is drawn by the user from the chamber. A positive pressure develops in the chamber as an exhalation gas is expelled by the user into the chamber. An open circuit is coupled to the chamber to supply an increasing mass of fresh make-up gas to the chamber as vacuum pressure in the chamber develops and increases. A closed circuit coupled to the chamber receives and processes the exhalation gas to produce a recycled gas suitable for breathing. No recycled gas is supplied to the chamber until a threshold vacuum pressure is reached therein. The threshold vacuum pressure is indicative of a higher level of respiratory minute volume (RMV). At that point, a volume of recycled gas is supplied to the chamber proportionally with respect to increases in the mass of fresh make-up gas as vacuum pressure increases beyond the threshold vacuum pressure.

Abstract: A system and method are provided for supplying breathable gas to an underwater habitat submerged in water. A flow of respired gas that includes metabolically-produced carbon dioxide is extracted from the underwater habitat and mixed with water from the surrounding environment. As a result of such mixing, carbon dioxide in the respired gas is substantially absorbed by the water while a first gas is produced. Moisture in the first gas is filtered out to produce a breathable gas which is then introduced back into the underwater habitat.

Abstract: A catalytic heater supplies heated water that circulates to heat a diver's suit. An insulating housing closed at opposite ends by cap members defines a chamber containing a catalyst inside of a multi-tube heat exchanger. Fittings in the cap members pass water through the multi-tube heat exchanger to and from the suit, and a gas circuit flows mixed hydrogen and oxygen to the catalyst that reacts with the mixed hydrogen and oxygen to produce heat that heats the water in the multi-tube heat exchanger for the diving suit. Optionally, hydrogen may be mixed with oxygen from a breathing gas mixture so that after heating the water, the gases remaining may be breathed by the diver. The catalytic heater provides a safe, reliable source of warm water for active thermal protection of divers over a wide range of diving applications.

Abstract: A thermal liner in a diving suit has a layer of incompressible phase change materials for storing latent heat energy and for later releasing the std energy while changing phase. This thermal liner provides thermal protection for divers' wetsuits, drysuits, and hot-water suits using stored energy from phase change materials, for extreme cold water diving. The thermal liner can function as an emergency backup heat source upon power failure when electrically-heated drysuits are used, or as an emergency backup heat source in case of interruption of warm water supply when hot-water diving suits are used. It can also be used as a supplemental source of heat for divers wearing passively-insulated wetsuits or drysuits to prolong acceptable durations in cold water missions. The thermal liner gives divers an emergency "come home" capability in case of power failure within drysuits supplied with an electrically-heated undergarment, or of an interruption of the warm water supply to a hot-water suit.

Abstract: A liquid-insulated garment supplements the inherent thermal protection va of traditional suit insulations in conventional passive diving suits with bladders containing insulating liquids having substantially the same densities as water and thermal conductivities of less than 0.070 Btu/ft-hr.degree. F. to provide insulation from ambient cold. The additional thermal protection created by the liquid-insulated garment helps the diver surpass the performance and acceptable duration constraints imposed by conventional drysuits or wetsuits and allows easy adjustments to the level of thermal comfort required by the diver. It additionally reduces the inherent buoyant forces associated with conventional drysuits and wetsuits, and provides uniform thermal protection over the entire surface of the diver's body since it is tailored to fit the diver.

Abstract: A water excluding vent valve for insulated gloves or other portions of a er's dry suit utilizes a vent control element including a microporous membrane disposed in obturating relation to an opening in the shell of the glove or other article. The membrane is laminated between protective layers of woven synthetic fabric, and a retaining means permitting replacement of the control element is described.