A refrigeration system for multi-temperature and single-temperature applications combines a refrigeration circuit and a single-phase fluid heat-transfer circuit in heat-conducting contact through a thermoelectric device. A vapor compression cycle provides a first stage of cooling and the thermoelectric device in conjunction with the heat-transfer circuit provides the second stage of cooling. Polarity of the thermoelectric device can be reversed to provide a defrost function for the refrigeration system.

Refrigeration system including thermoelectric module

A fluid compression circuit may include a compression mechanism, a volume, a heat exchanger, a fluid conduit, a thermoelectric device, and a heat-transfer device. The compression mechanism includes first and second members cooperating to form a fluid pocket. The volume receives discharge fluid from the fluid pocket. The heat exchanger is in communication with the volume. The fluid conduit is connected to at least one of the volume and the heat exchanger. The thermoelectric device may include a first side in heat-transfer relation with a member at least partially defining the volume and a second side in heat-transfer relation with ambient air and cooperating with the first side to define a temperature gradient generating electrical current in the thermoelectric device. The heat-transfer device may receive electrical current generated by the thermoelectric device and may be in heat-transfer relation with at least one of the heat exchanger and the fluid conduit.

Vapor compression circuit and method including a thermoelectric device

Novel colorant/pigment compositions, prepared via precipitation technique and well suited for the coloration of a wide variety of materials and substrates, e.g., plastics, paints and inks, ceramics, cosmetics, etc., comprise composite core/sheath particulates, the cores of which comprising particles of at least one crystalline rare earth metal sesquisulfide having the formula M 2 S 3 in which M is at least one lanthanide element having an atomic number of from 57 to 71, or yttrium, and such core particles having at least one alkali and/or alkaline earth metal dopant at least in part incorporated within the crystal lattice of the at least one crystalline rare earth metal sesquisulfide, and each sheath comprising a coating layer of at least one transparent oxide deposited onto the external face surfaces of the doped core particles.

Rare earth metal sulfide pigment compositions

The invention relates to new compositions based on rare-earth metal sesquisulphides M2S3, which can be used especially as colouration pigments, these compositions being characterized by the fact that they contain alkali metal and/or alkaline-earth metal elements for part at least included in the crystalline network of the said sesquisulphides. The process for their preparation consists in heating at a suitable temperature, under a non-oxidizing and preferably reducing atmosphere, an initial mixture containing a rare-earth compound, sulphur and a compound of an alkali metal and/or alkaline-earth metal element.

Compositions based on rare earth sulfides, preparation and use thereof

The invention relates to a process for the treatment of pigments based on rare-earth sesquisulphides, aimed more particularly at improving the colour of the latter, the said process being characterised in that it consists in subjecting the said pigments to a fluoridation treatment allowing fluorine atoms to be incorporated, preferably at the surface, within the said pigments. The invention also relates to new pigments based on rare-earth sesquisulphides with improved chromatic properties and characterised essentially in that they contain fluorine atoms, preferably at the surface. These fluoridised pigments may furthermore take an encapsulated form, preferably in silica. The invention finally relates to the use of the said pigments for colouring various materials, in particular plastics.

Process for treating rare earth sulfide pigments, thus obtained pigments and their use

Lanthanum sulfide is maintained in the stable cubic phase form over a temperature range of from 500° C. to 1500° C. by adding to it small amounts of calcium, barium, or strontium. This novel compound is an excellent thermoelectric material.

/pdf/stabilized-lanthanum-sulphur-compounds-3lji8znxpj.pdf

George H. Reynolds

Papers

Stabilized lanthanum sulphur compounds