A method of improving rheological properties of a divalent brine based downhole treatment fluid at an elevated temperature comprises adding to the divalent brine based downhole treatment fluid a rheological modifier, which comprises a carboxylic acid ester, or a phosphate ester blended with an ethoxylated glycol, or a combination comprising at least one of the foregoing in an amount effective to improve the rheological properties of the divalent brine based downhole treatment fluid at a temperature of greater than about 200 F. The divalent brine based downhole treatment fluid comprises calcium bromide, calcium chloride, zinc bromide, zinc chloride, or a combination comprising at least one of the foregoing.

A method of improving rheological properties of a divalent brine based downhole treatment fluid at an elevated temperature comprises adding to the divalent brine based downhole treatment fluid a rheological modifier, which comprises a carboxylic acid ester, or a phosphate ester blended with an ethoxylated glycol, or a combination comprising at least one of the foregoing in an amount effective to improve the rheological properties of the divalent brine based downhole treatment fluid at a temperature of greater than about 200 F. The divalent brine based downhole treatment fluid comprises calcium bromide, calcium chloride, zinc bromide, zinc chloride, or a combination comprising at least one of the foregoing.

The present disclosure relates to a preparation method of a methionine-metal chelate, and the methionine-metal chelate, which is prepared by first reacting Ca(OH).sub.2 and methionine and adding metal chloride salts, can be used as feeds and feed additives.

The present disclosure relates to a preparation method of a methionine-metal chelate, and the methionine-metal chelate, which is prepared by first reacting Ca(OH).sub.2 and methionine and adding metal chloride salts, can be used as feeds and feed additives.

A method for separating a particulate stream of an evaporite mineral feedstock, the method comprising passing the stream to an air classifier configured to separate the particulate stream into a fine component and a coarse component.

Provided are a method of preparing a metal oxide-silica composite aerogel, which includes preparing metal oxide-silica composite precipitates by adding a metal salt solution to a silicate solution and performing a reaction, and drying the metal oxide-silica composite precipitates by irradiation with infrared rays in a wavelength range of 2 m to 8 m, and a metal oxide-silica composite aerogel having excellent physical properties, such as low tap density and high specific surface area, as well as excellent pore properties prepared by the method.

Provided are a method of preparing a metal oxide-silica composite aerogel, which includes preparing metal oxide-silica composite precipitates by adding a metal salt solution to a silicate solution and performing a reaction, and drying the metal oxide-silica composite precipitates by irradiation with infrared rays in a wavelength range of 2 m to 8 m, and a metal oxide-silica composite aerogel having excellent physical properties, such as low tap density and high specific surface area, as well as excellent pore properties prepared by the method.

Provided herein are methods comprising a) calcining limestone in a cement plant to form carbon dioxide and calcium compound selected from calcium oxide, calcium hydroxide, or combination thereof; b) treating the calcium compound with N-containing salt in water to produce an aqueous solution comprising calcium salt and N-containing salt; and c) contacting the aqueous solution with the carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant aqueous solution wherein the calcium carbonate comprises vaterite.

Provided herein are methods comprising a) calcining limestone in a cement plant to form carbon dioxide and calcium compound selected from calcium oxide, calcium hydroxide, or combination thereof; b) treating the calcium compound with N-containing salt in water to produce an aqueous solution comprising calcium salt and N-containing salt; and c) contacting the aqueous solution with the carbon dioxide under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant aqueous solution wherein the calcium carbonate comprises vaterite.

Strontium oxide (SrO) nanoparticle and various concentrations of chitosan (CS)-doped SrO nanocomposite were synthesized via co-precipitation method. A variety of characterization techniques including were done for characterizing and qualifying the nanocomposite. X ray powder diffraction affirmed cubic and tetragonal structure of SrO nanoparticle and CS-doped SrO nanocomposite with a decrease in crystallinity upon doping. Fourier transform infrared spectrum endorsed existing functional groups on CS/SrO surfaces while d-spacing was estimated using high resolution Transmission electron microscopes images. UV-Visible and Photoluminescence spectroscopy spectra showed an increase in band gap energies with an increase in doping concentration. Elemental composition of CS-doped SrO nanocomposite deposited with different doping concentrations was studied using Energy dispersive Spectroscopy. Addition of chitosan resulted in the formation of nanocomposite and rod-like structures that led to enhanced catalytic activity during methylene blue ciprofloxacin degradation in the presence of reducing agent sodium borohydrate at various pH conditions.