Abstract: A hair fiber strengthening composition includes an aqueous vehicle containing as a hair strengthening additive a source of metal cations having a valence of 2 or 3 and anions derived from an oxidized carbohydrate, an inorganic acid and/or an organic acid, the composition having a pH of less than about 6. These compositions have the advantage of strengthening the hair fibers without the undesirable effect of darkening or spotting the hair, particularly light-colored or bleached hair. These compositions are particularly useful for strengthening hair that has been subjected to potentially damaging chemical treatments such as bleaching, coloring, or relaxing, or to provide a strengthening effect prior to and in anticipation of such chemical treatments.

Abstract: A system for the dissolution of gas in a large body of liquid comprising an impeller positioned below the surface of the large body of liquid; a floating hood positioned over the impeller and of sufficient size to capture undissolved gas; a conduit for introducing a feed gas stream beneath the floating hood and directly into the large body of liquid; at least one segregation ring positioned under the floating hood and extending below the surface of the large body of liquid such that a first inner region between the ring and the impeller, and a second outer region between the ring and an outer diameter of the floating hood are created, and a back pressure regulator located in the floating hood adjacent to the outer diameter of the floating hood.

Abstract: Oxygen or other gases are dissolved in large bodies of liquid by injection under a baffle for passage into a submerged hollow draft-tube-impeller means assembly for downward passage therein. Liquid containing dissolved gas is dispersed throughout the body of liquid, while any undissolved gas is effectively recovered and recycled.

Abstract: A shell and tube heat exchanger reactor with forced circulation is used to improve heat and mass transfer for exothermic liquid--liquid, gas-liquid and gas-liquid-solid reactions. Enhanced productivity and selectivity are obtained.

Abstract: A high efficiency gas dissolution system is used to dissolve gas in a portion of a body of liquid, improving gas utilization and reducing associated energy requirements. A portion of the body of liquid is recirculated through a mechanical, in-line gas dissolution device wherein a secondary feed gas is dissolved in the liquid.

Abstract: A feed gas stream is introduced directly into a recirculating liquid stream so as to facilitate formation and maintenance of gas bubbles in a dispersed form in a recirculating gas bubble-liquid mixture. By the maintaining of a gas-liquid interface and overhead gas phase in conjunction with a quiescent zone of liquid apart from the portion of liquid in which said mixture is maintained in a recirculating flow condition, the loss of appreciable amounts of gas to the overhead gas phase is avoided.