Wellbore synthesis techniques are disclosed suitable for use in geothermal applications. Embodiments are provided where open hole drilled wellbores are sealed while drilling to form an impervious layer at the wellbore/formation interface. The techniques may be chemical, thermal, mechanical, biological and are fully intended to irreversibly damage the formation in terms of the permeability thereof. With the permeability negated, the wellbore may be used to create a closed loop surface to surface geothermal well operable in the absence of well casing for maximizing thermal transfer to a circulating working fluid. Formulations for the working and drilling fluids are disclosed.

Wellbore synthesis techniques are disclosed suitable for use in geothermal applications. Embodiments are provided where open hole drilled wellbores are sealed while drilling to form an impervious layer at the wellbore/formation interface. The techniques may be chemical, thermal, mechanical, biological and are fully intended to irreversibly damage the formation in terms of the permeability thereof. With the permeability negated, the wellbore may be used to create a closed loop surface to surface geothermal well operable in the absence of well casing for maximizing thermal transfer to a circulating working fluid. Formulations for the working and drilling fluids are disclosed.

The present invention relates to the use of an additive as well as a process to improve the adhesion of a mortar to a building substrate, wherein the mortar is mixed with said additive and is applied to a building substrate selected from the group of polystyrene-containing substrates, polyolefin-containing substrates or polyvinyl chloride-containing substrates, the additive containing (i) a plasticizer that is liquid at 50 C. or lower, has a boiling point of 100 C. or higher, and that has a solubility parameter 25 C. between 22.5 MPa.sup.1/2 and MPa.sup.1/2; (ii) optionally, a filler that has a BET surface area of at least 40 m.sup.2/g; (iii) optionally, a biopolymer, (iv) optionally, a protective colloid; and (v) optionally, a water-insoluble film-forming (co)polymer based on ethylenically unsaturated monomers. The invention also covers an additive and a kit of parts suitable for use in the above process.

The present invention relates to the use of an additive as well as a process to improve the adhesion of a mortar to a building substrate, wherein the mortar is mixed with said additive and is applied to a building substrate selected from the group of polystyrene-containing substrates, polyolefin-containing substrates or polyvinyl chloride-containing substrates, the additive containing (i) a plasticizer that is liquid at 50 C. or lower, has a boiling point of 100 C. or higher, and that has a solubility parameter 25 C. between 22.5 MPa.sup.1/2 and MPa.sup.1/2; (ii) optionally, a filler that has a BET surface area of at least 40 m.sup.2/g; (iii) optionally, a biopolymer, (iv) optionally, a protective colloid; and (v) optionally, a water-insoluble film-forming (co)polymer based on ethylenically unsaturated monomers. The invention also covers an additive and a kit of parts suitable for use in the above process.

A set control composition for cementitious systems comprises a retarder (a) selected from (a-1) polymeric polycarboxylic acids selected from homopolymers and copolymers of ,-ethylenically unsaturated carboxylic acids; and copolymers of at least one ,-ethylenically unsaturated carboxylic acid and at least one sulfo group containing monomer; and salts thereof, whose milliequivalent number of carboxyl groups is 3.0 meq/g or higher, preferably 3.0 to 17.0 meq/g, and having a molecular weight 25,000 g/mol or less, assuming all the carboxyl groups to be in unneutralized form, (a-2) phosphonic acids and salts thereof, (a-3) low molecular weight polycarboxylic acids and salts thereof, and mixtures thereof, (b) at least one of (b-1) a borate source and (b-2) a carbonate source, wherein the carbonate source is selected from inorganic carbonates having an aqueous solubility of 0.1 g.Math.L.sup.1 or more at 25 C., and organic carbonates, in a weight ratio of b) to a) in the range of 0.1 to 10, (c) a polyol having at least 3 alcoholic hydroxyl groups in its molecule, in a weight ratio of c) to a) in the range of 0.2 to 4, and (d) a dispersant. The set control composition effectively improves workability of cementitious systems for prolonged periods of time without compromising early compressive strength. The compositions show sufficient open time, i.e., the time until initial setting, good workability during said open time as characterized, for example by adequate slump flow over time, and fast setting. The invention further relates to a construction composition comprising i) a cementitious binder comprising one or more calcium silicate mineral phases and one or more calcium aluminate mineral phases, ii) optionally, an extraneous aluminate source, iii) a sulfate source, and iv) the set control composition. The construction composition contains 0.05 to 0.2 mol of total available aluminate, calculated as Al(OH).sub.4.sup., from the calcium aluminate mineral phases plus the optional extraneous aluminate source, per 100 g of cementitious binder i), and the molar ratio of total available aluminate to sulfate is 0.4 to 2.0.

A curing agent for water glass molding comprises: ester; amorphous silica; and water. The amorphous silica is formed by means of a pyrolysis method and/or by means of a precipitation method. Also disclosed is a use of the curing agent for water glass molding in preparation of a casting mold and a mold core. Respective components of the curing agent comprising ester, amorphous silica and water are mixed at a high speed to form a suspension. Next, the suspension is applied to prepare a water glass self-hardening sand. The curing agent does not cause powder contamination, and can be measured and added conveniently. Also disclosed are a manufacturing method of the curing agent for water glass molding and a water glass self-hardening sand.

A curing agent for water glass molding comprises: ester; amorphous silica; and water. The amorphous silica is formed by means of a pyrolysis method and/or by means of a precipitation method. Also disclosed is a use of the curing agent for water glass molding in preparation of a casting mold and a mold core. Respective components of the curing agent comprising ester, amorphous silica and water are mixed at a high speed to form a suspension. Next, the suspension is applied to prepare a water glass self-hardening sand. The curing agent does not cause powder contamination, and can be measured and added conveniently. Also disclosed are a manufacturing method of the curing agent for water glass molding and a water glass self-hardening sand.

The present application provides a soft magnetic alloy sheet, a preparation method therefor and a use thereof. The preparation method comprises the following steps: (1) mixing thermosetting resin, thermoplastic resin, a solvent, a curing agent, and soft magnetic alloy powder having insulating coating to obtain casting slurry; and (2) carrying out degassing and casting-drying treatment on the casting slurry in step (1) in sequence to obtain the soft magnetic alloy sheet.

The present application provides a soft magnetic alloy sheet, a preparation method therefor and a use thereof. The preparation method comprises the following steps: (1) mixing thermosetting resin, thermoplastic resin, a solvent, a curing agent, and soft magnetic alloy powder having insulating coating to obtain casting slurry; and (2) carrying out degassing and casting-drying treatment on the casting slurry in step (1) in sequence to obtain the soft magnetic alloy sheet.

A method for plugging and sealing subsurface formations using alkaline nanosilica dispersion and a delayed activation chemistry is disclosed. In accordance with one embodiment of the present disclosure, the method includes introducing a mixture with a first pH into the subsurface formation. The mixture comprises an aqueous solution, an alkaline nanosilica dispersion and a water-soluble hydrolyzable compound. The method further includes allowing the water-soluble hydrolyzable compound to hydrolyze in the subsurface formation to form an acid at 70 C. or greater, thereby acidizing the mixture to a reduced second pH and causing the alkaline nanosilica dispersion to gel into a solid and seal the subsurface formation. A composition for sealing a subsurface formation is also disclosed. The composition includes an aqueous mixture including water, an alkaline nanosilica dispersion, and a water-soluble hydrolyzable compound.