Abstract: Recovery of electric power from low-grade waste heat/solar energy, comprising a closed-cycle charged refrigerant loop. Pressurized refrigerant fluid is pumped at ambient temperature through a heat exchanger connected to a waste heat/solar source to extract heat energy during conversion to a high pressure gas. Heated/pressurized refrigerant gas is inlet into an expander to power an output shaft during the expansion of the fluid to a cooled gas at approximately 0 psig. Cooled gaseous refrigerant is condensed to a liquid at low pressure and ambient temperature, and recycled under pressure to the heat exchanger. The expander is a reverse-plumbed gas compressor; the pressurized, hot refrigerant gas is inlet at what is ordinarily its outlet, and the normal inlet becomes the expander end. The refrigerant gas mass flow pressure/temperature drop spins the expander shaft for direct mechanical power take-off, or coupling to a synchronous or inductive generator to produce electricity.

Abstract: Disclosed are silicon-containing nitro dyes for dying organic polymers or organosiloxanes, which are reactive dyes for synthetic or natural fibers of vegetable or animal origin, having the formula: ##STR1## wherein the chromophore component is bonded with the Si-atom by homopolar bonds and wherein X represents the same or different hydrolyzable groups or a siloxane radical, Z is a bivalent alkylene radical with 1-10 carbon atoms which may be interrupted by NR' groups, R is a monovalent organic radical, R' is hydrogen, alkyl with 1-10 carbon atoms, aryl, aralkyl or said substituted radicals, Ar is a substituted or unsubstituted aryl radical, and a and b are integers from 1-3, and a process for making said dyes. Said dyes may be built into a large number of organic and inorganic molecules and color the same without fixation.

Abstract: Disclosed are silicon-containing nitro dyes of the formula: ##STR1## wherein the coloring component is bonded with a Si-atom by homopolar bonds and whereinX represents same or different hydrolyzable groups or a silicone radical;Z is a bivalent alkylene radical with 2 to 10 C-atoms, which may be interrupted by oxygen and may also contain cyclic radicals, and wherein .sup.1 C and .sup.2 C may be parts of a cycloalkyl ring;R is a monovalent organic radical;Ar is a substituted or unsubstituted aryl radical;a and b are integers from 1-3;and a process for making said dyes. Said dyes may be built into the polymer molecules or affixed to fibers without additional fixation.