A method for improving the heating efficiency of steam wherein a polyamine represented by the following general formula (1) is caused to be present in a steam system to be used for heating. R.sup.1—[NH—(CH.sub.2).sub.m].sub.n—NH.sub.2 . . . (1) wherein R.sup.1 represents a saturated or unsaturated hydrocarbon group having 10 to 22 carbon atoms; m is an integer of 1 to 8, and n is an integer of 1 to 7; and when n is 2 or more, a plurality of NH—(CH.sub.2).sub.m may be identical or different.

A method for improving the heating efficiency of steam wherein a polyamine represented by the following general formula (1) is caused to be present in a steam system to be used for heating. R.sup.1—[NH—(CH.sub.2).sub.m].sub.n—NH.sub.2 . . . (1) wherein R.sup.1 represents a saturated or unsaturated hydrocarbon group having 10 to 22 carbon atoms; m is an integer of 1 to 8, and n is an integer of 1 to 7; and when n is 2 or more, a plurality of NH—(CH.sub.2).sub.m may be identical or different.

Coolants with increased activity against corrosion of aluminium and aluminium alloys and with improved storage stability, and corresponding coolant concentrates, are useful.

The present disclosure relates to agents, compositions, and methods for inhibiting corrosion in various substrates, for example in metal substrates. The present disclosure also relates to compositions for inhibiting corrosion comprising at least one organic heterocyclic compound and at least one metal salt or mixed metal salt selected from rare earth, alkali earth and transition metals.

The present disclosure relates to agents, compositions, and methods for inhibiting corrosion in various substrates, for example in metal substrates. The present disclosure also relates to compositions for inhibiting corrosion comprising at least one organic heterocyclic compound and at least one metal salt or mixed metal salt selected from rare earth, alkali earth and transition metals.

Corrosion inhibitor formulations for use in heat transfer fluids include: (a) an optionally substituted benzoic acid or a salt thereof; (b) at least a first n-alkyl monocarboxylic acid or a salt thereof and a second n-alkyl monocarboxylic acid or a salt thereof, the first n-alkyl monocarboxylic acid and the second n-alkyl monocarboxylic acid being different; and (c) an azole compound. A ratio of weight percent of the first n-alkyl monocarboxylic acid or the salt thereof to weight percent of the second n-alkyl monocarboxylic acid or the salt thereof ranges from about 1:0.75 to about 1:2.00. A ratio of weight percent of the benzoic acid or the salt thereof to combined weight percent of the first n-alkyl monocarboxylic acid or the salt thereof and the second n-alkyl monocarboxylic acid or the salt thereof ranges from about 1:0.30 to about 1:2.25.

Graphene quantum dots are functionalized by covalently bonding a corrosion inhibitor molecule thereto. In a useful method, a corrosion inhibitor compound is blended with a graphene quantum dot-tagged corrosion inhibitor compound, and the blend is applied to a metal surface, such as the interior of a carbon steel pipe. The blend inhibits corrosion arising from contact with produced water generated by hydrocarbon recovery from one or more subterranean reservoirs. The produced water having the blend dispersed therein is irradiated with a source of light having a selected first range of wavelengths, and the luminescent emission of the graphene quantum dot-tagged corrosion inhibitor is measured at a selected second range of wavelengths, thereby providing for real-time measurement of corrosion inhibitor concentration within the pipe.

Graphene quantum dots are functionalized by covalently bonding a corrosion inhibitor molecule thereto. In a useful method, a corrosion inhibitor compound is blended with a graphene quantum dot-tagged corrosion inhibitor compound, and the blend is applied to a metal surface, such as the interior of a carbon steel pipe. The blend inhibits corrosion arising from contact with produced water generated by hydrocarbon recovery from one or more subterranean reservoirs. The produced water having the blend dispersed therein is irradiated with a source of light having a selected first range of wavelengths, and the luminescent emission of the graphene quantum dot-tagged corrosion inhibitor is measured at a selected second range of wavelengths, thereby providing for real-time measurement of corrosion inhibitor concentration within the pipe.

Please replace the Abstract of the application as filed with the following replacement A coolant composition containing the following substances: a) an alcohol; b) water; c1) a triazole compound; c2) an imidazole compound; d) a phosphate ion; and e) a metasilicate.

Disclosed is an antifreezing coolant composition, which does not include glycol but includes environmentally friendly materials, such as a carboxylic acid salt, an anthranilamide compound, a corrosion inhibitor and a triazole compound. The antifreezing coolant composition may form a thin film on the metal surface in cooling systems for vehicles to thereby exhibit high corrosion resistance at low and high temperatures, superior antifreezing performance at low temperatures, and superior cooling performance at high temperatures.