Abstract: A high efficiency solar cell for creating current from incident radiant energy, comprising a concentrator for concentrating the incident radiant energy into concentrated radiant energy, a refraction element for receiving the concentrated radiant energy and splitting the radiant energy into a plurality of bands of radiant energy, each band of the plurality of bands having a frequency range and impinging on an area, and a plurality of band solar cells, each band solar cell disposed to receive one of the plurality of bands impinging on an area and also tuned to absorb the frequency range of the one of the plurality bands.

Abstract: A simulation system [200] models and optimizes parameters for a pulsed liquid slug boring system employing an energetic fluid [7]. The simulation system [200] employs a fluid flow energy unit [251], an exhaust and retention energy unit [253] and a comminuting energy unit [255] to calculate energies of the system. Total energy unit [257] combines these energies. Fluid flow energy unit 251 receives fluid volume and calculates the fluid flow energy. Exhaust and retention energy unit 253 receives input from the exhaust energy volume unit [243] and mission duration unit [211] to determine the exhaust and retention energy. Comminuting energy unit 255 receives hole depth and hole diameter and specific energy of rock to determine the require comminuting energy. The simulation system [200] operates to determine optimum values of design parameters by searching for the minimum energy solution.

Abstract: A system having a number of land units [100, 4000, 5000] is disclosed which operates to efficiently find and create boreholes [5] to one or more underground targets [1]. Each of the land units [100, 4000, 5000] may be remotely controlled from a central command unit [6000]. The land unit also may be self-controlled, or partially controlled by the central command unit [6000]. The system [10] is reconfigurable to reallocate tasks to functional land units [100, 4000, 5000] which were originally allocated to land units which have been destroyed and are now non-functional.

Abstract: The present invention is a self-contained, high-energy liquid rock-boring system that will bore a small-diameter access hole [5] several hundred meters through hard granite and other obstacles within minutes of deployment. It employs a land unit [100] platform subsystem [1000] with an energetic fluid fuel reservoir [1300] and a boring subsystem [3000] having a plurality of pulsejets [3100]. Each pulsejet [3100] repeatedly ignites the energetic fluid [7] causing a plurality of rapidly-expanding gas bubbles [3250] which create and force a plurality liquid slugs [10] ahead of them rapidly out through a nozzle [3260] causing the slugs [10] to impact against materials ahead of the nozzles [3260], boring an access hole [5]. The system also employs an umbilical subsystem [2000] connecting the boring [3000] and the platform subsystems [1000]. The system can be used to rapidly bore an access hole [5] to provide air and resources to trapped miners.

Abstract: A cryogenic system is described for boring a small-diameter hole through various materials including rock, soil and stone. It employs a valveless technique in a borehead [3000] where cryogenic fluid [7] fills at least one pulsejet [3100] which has proximal [3001] and distal [3003] ends. The cryogenic fluid [7] is frozen into a plug [8] near the distal end [3003], acting as a valve. Cryogenic fluid [7] just distal to the frozen plug [8] is rapidly heated by thermal units [3510, 3530] causing it to become a rapidly-expanding gas bubble. The rapidly-expanding gas bubble forces any liquid [7] distal to the expanding gas out of the distal end [3003] of each pulsejet [3100] causing it to impact the material [I]. Rapidly repeating this process causes the system to bore a hole through the material [I].

Abstract: The present invention is a high-efficiency solar cell having a top cell [1300] optimized to absorb incident radiant energy in a first absorption band and a bottom cell [1500] attached to the top cell optimized to absorb incident energy in a second absorption band which preferably does not substantially overlap the first absorption band. The top cell [1300] employs a first layer [1310] being a highly doped n-type material, a second layer [1330] being a lightly doped n-type material in contact with the first layer [1310], and a p-type material [1350] in contact with the second layer [1330] optimized to pass the lower frequencies of incident radiation to the bottom cell [1500]. The bottom cell [1500] has a quantum cell region [1550] comprised of a plurality of quantum wells. The quantum wells are designed to absorb near 1 eV. Alternatively, the incident radiant energy may be diffracted into frequency bands with each solar cell tuned to absorb one specific band.

Abstract: A method and device for boring a hole [5] through a material along a desired path includes an umbilical subsystem [2000] connected to a boring subsystem [3000] having a plurality of pulsejets [3100]. These pulsejets [3100] repeatedly receive and ignite a combustible fluid [7] in a combustion chamber [3230] causing a portion of the fluid [7] to be forced out of a nozzle [3260] at high speeds as a fluid slug [10] that impacts materials ahead of the pulsejet [3100]. A controller [3310] controls the amount of fluid provided to each pulsejet [3100], and the firing timing, thereby controlling the intensity in which each slug [10] impacts the material. By modulating the intensity and firing sequence of each of the pulsejets [3100], material ahead of the boring subsystem [3000] is differentially bored thereby allowing steering of the boring subsystem [3000].

Abstract: A system having a number of land units [100, 4000, 5000] is disclosed which operates to efficiently find and create boreholes [5] to one or more underground targets [1]. Each of the land units [100, 4000, 5000] may be remotely controlled from a central command unit [6000]. The land unit also may be self-controlled, or partially controlled by the central command unit [6000]. The system [10] is reconfigurable to reallocate tasks to functional land units [100, 4000, 5000] which were originally allocated to land units which have been destroyed and are now non-functional.

Abstract: The present invention is a self-contained, high-energy liquid rock-boring system that will bore a small-diameter access hole [5] several hundred meters through hard granite and other obstacles within minutes of deployment. It employs a land unit [100] platform subsystem [1000] with an energetic fluid fuel reservoir [1300] and a boring subsystem [3000] having a plurality of pulsejets [3100]. Each pulsejet [3100] repeatedly ignites the energetic fluid [7] causing a plurality of rapidly-expanding gas bubbles [3250] which create and force a plurality liquid slugs [10] ahead of them rapidly out through a nozzle [3260] causing the slugs [10] to impact against materials ahead of the nozzles [3260], boring an access hole [5]. The system also employs an umbilical subsystem [2000] connecting the boring [3000] and the platform subsystems [1000]. The system can be used to rapidly bore an access hole [5] to provide air and resources to trapped miners.

Abstract: A method and device for boring a hole [5] through a material along a desired path includes an umbilical subsystem [2000] connected to a boring subsystem [3000] having a plurality of pulsejets [3100]. These pulsejets [3100] repeatedly receive and ignite a combustible fluid [7] in a combustion chamber [3230] causing a portion of the fluid [7] to be forced out of a nozzle [3260] at high speeds as a fluid slug [10] that impacts materials ahead of the pulsejet [3100]. A controller [3310] controls the amount of fluid provided to each pulsejet [3100], and the firing timing, thereby controlling the intensity in which each slug [10] impacts the material. By modulating the intensity and firing sequence of each of the pulsejets [3100], material ahead of the boring subsystem [3000] is differentially bored thereby allowing steering of the boring subsystem [3000].

Abstract: A cryogenic system is described for boring a small-diameter hole through various materials including rock, soil and stone. It employs a valveless technique in a borehead [3000] where cryogenic fluid [7] fills at least one pulsejet [3100] which has proximal [3001] and distal [3003] ends. The cryogenic fluid [7] is frozen into a plug [8] near the distal end [3003], acting as a valve. Cryogenic fluid [7] just distal to the frozen plug [8] is rapidly heated by thermal units [3510, 3530] causing it to become a rapidly-expanding gas bubble. The rapidly-expanding gas bubble forces any liquid [7] distal to the expanding gas out of the distal end [3003] of each pulsejet [3100] causing it to impact the material [I]. Rapidly repeating this process causes the system to bore a hole through the material [I].

Abstract: A simulation system [200] models and optimizes parameters for a pulsed liquid slug boring system employ an energetic fluid [7]. The simulation system [200] employs a fluid flow energy unit [251], an exhaust and retention energy unit [253] and a comminuting energy unit [255] to calculate energies of the system. Total energy unit [257] combines these energies. Fluid flow energy unit 251 receives fluid volume and calculates the fluid flow energy. Exhaust and retention energy unit 253 receives input from the exhaust energy volume unit [243] and mission duration unit [211] to determine the exhaust and retention energy. Comminuting energy unit 255 receives hole depth and hole diameter and specific energy of rock to determine the require comminuting energy. The simulation system [200] operates to determine optimum values of design parameters by searching for the minimum energy solution.