Abstract: Control of a heliostat field (1) in a solar energy plant is provided with a system (6) which controls the alignment of heliostat mirrors (2) in a controlled area of the heliostat field (1) with respect to a selected zone in a target plane (P). The control system (6) comprises a detection device (7) removed from the target plane (P) in the direction of propagation of radiation (R') directed by the heliostat mirrors towards the target plane (P). The detection device (7) has a detection surface (8) facing the radiation (R').

Abstract: A method of delivering guided radiation arriving via a first transparent medium having a first refractive index into a second transparent medium having a second refractive index that is smaller than the first refractive index, comprising: providing a transparent radiation delivery waveguide capable of admitting concentrated radiation and having a longitudinal axis and a third refractive index substantially equal to or greater than the first refractive index and adapted to guide the radiation along the longitudinal axis. The waveguide having a tapered radiation delivery portion of non-circular cross-sectional shape. Mounting the waveguide in optical contact with the first transparent medium so that the radiation delivery portion projects inside the second transparent medium.

Abstract: A two layer system for heat energy capture and storage with an upper or lower layer for heat extracting and the other layer for heat transfer. Either layer can function as a phase change material. Heat stored is conducted externally of the system and can be used directly in a converting system, i.e., heat to mechanical or electrical energy or transferred as heat for further applications.

Abstract: A laser apparatus of the end pumping kind in which an elongated transparent laser element is mounted in spaced relationship within a tubular waveguide which has a highly reflective inner surface. The arrangement is such that, at least along part of the laser element, the optical distances between different points on the surface of the laser element and the inner contour of the waveguide vary.

Abstract: The disclosure concerns various improvements in a solar energy plant of the kind in which incoming solar radiation is concentrated by a Fresnel reflector, i.e. a field of concentrating mirrors, and the concentrated radiation is focused into a solar receiver. By one improvement a dielectric mirror is provided at a suitable level above the solar collector, to reflect the concentrated solar radiation into the collector. By another disclosed improvement a plurality of non-imaging secondary concentrators arranged in concentric zones is provided intermediary between the dielectric mirror and receiver. By yet another improvement the solar receiver is directly attached to a heat storage system.

Abstract: Modifications are made to the standard process for the manufacture of ammonia and related compounds, resulting in lower operating costs through reduced total energy consumption. In one aspect of the invention, this is achieved by directing ammonia gas through one feed line, and carbon dioxide gas and steam through another feed line, into a closed reaction chamber to form ammonium carbonate. The formation of this solid compound results in a reduced pressure in the chamber. This reduced pressure can be used to drive heat engines in the reactant feed lines. In another aspect of the invention, the cost of running the potassium carbonate loop while the rest of the system is down is reduced by constructing an alternate pathway along part of the loop. The carbon dioxide gas and water vapor formed by the heating of the potassium bicarbonate flow through a heat engine and are cooled. The cooled water vapor and carbon dioxide gas are then recycled.

Abstract: A composite working fluid for a Rankine cycle power plant operating between a boiler temperature and a condenser temperature comprises a mixture of immiscible fluids selected such that the saturated vapor line of the composite fluid in the vicinity of the boiler temperature is generally along a line of substantially constant entropy. As a result, the vapor of the composite working fluid expands from boiler to condenser temperature generally along the saturated vapor line of the composite working fluid. One of the immiscible fluids of the composite working fluid is a "wet" fluid, and one of the immiscible fluids is a "dry" fluid. The "wet" fluid is a polar compound with a molecular weight smaller than the molecular weight of the "dry" fluid, which is a non-polar compound. Preferably, the "wet" fluid is water, and the "dry" fluid is selected from a class comprising hydrocarbons and their halogenated derivatives.

Abstract: A Rankine cycle power plant utilizes as a working fluid and compounds selected from the group consisting of bicyclic hydrocarbons, substituted bicyclic aromatic hydrocarbons, heterocyclic bicyclic aromatic hydrocarbons, substituted heterocyclic bicyclic aromatic hydrocarbons, bicyclic compounds where one ring is aromatic and the other condensed ring is non-aromatic, and their mixtures.

Abstract: A gel is formed by copolymerizing an acrylic monofunctional monomer and an acrylic bifunctional monomer in an aqueous solution exposed to an oxygen containing atmosphere. Spontaneous polymerization takes place in an atmosphere containing oxygen after the solution is placed in sunlight, or in the dark if the solution also contains a dissolved inorganic salt. The gel so formed is transparent to solar radiation, and is stable in the presence of such radiation and of temperatures in the vicinity of the boiling point of water. As a consequence, the gel is suitable for covering a heat storage liquid and thermally insulates the liquid against significant conductive heat loss to an ambient medium above the gel. By providing a myriad of small bubbles trapped in the gel, the insulating efficiency of the gel is increased without significantly interferring with the transmission of solar radiation to the heat storage layer below the gel.

Abstract: A heat storage pond comprises a heat storage liquid covered by a non-liquid insulating layer that floats on the liquid and is thick enough to thermally insulate the latter against significant conductive heat loss to an ambient medium above the insulating layer which may be an aqueous or a non-aqueous gel. The medium above the gel may be a layer of water which operates as a heat sink for a power plant whose heat source is the heat storage layer. The power plant may include a heat engine, such as an organic working fluid turbine, which extracts heat from the heat storage liquid, the layer of water above the gel serving as a condenser for the turbine.