Lithium-containing cement admixtures including a calcium aluminate phosphate cement; a lithium-ion-containing compound; and an aqueous base fluid and methods of introducing the lithium-containing cement admixtures into a subterranean formation. The lithium-containing cement admixtures may further comprise an aluminosilicate or an additive including a set retarder, a set accelerator, a suspension aid, a density reducing agent, a fluid loss control agent, a defoamer, and any combination thereof.

Lithium-containing cement admixtures including a calcium aluminate phosphate cement; a lithium-ion-containing compound; and an aqueous base fluid and methods of introducing the lithium-containing cement admixtures into a subterranean formation. The lithium-containing cement admixtures may further comprise an aluminosilicate or an additive including a set retarder, a set accelerator, a suspension aid, a density reducing agent, a fluid loss control agent, a defoamer, and any combination thereof.

A system and method for applying a cement composition, including storing a slurry, adding magnesium oxide to the slurry to give a magnesium-oxychloride cement slurry, pumping the magnesium-oxychloride cement slurry into a wellbore, and sealing a loss circulation zone in the wellbore.

A system and method for applying a cement composition, including storing a slurry, adding magnesium oxide to the slurry to give a magnesium-oxychloride cement slurry, pumping the magnesium-oxychloride cement slurry into a wellbore, and sealing a loss circulation zone in the wellbore.

A method of producing a carbonated composite material is described that includes: providing a carbonatable cementitious material in particulate form; mixing the carbonatable cementitious material with water to produce a mix; forming a predetermined shape with the mix, wherein the predetermined shape has an initial pore structure containing an initial pore solution having a first pH; pre-conditioning the predetermined shape to remove a predetermined amount of the water from the predetermined shape to produce a pre-conditioned shape; carbonating the pre-conditioned shape in an environment comprising carbon dioxide to produce a modified pore structure containing a modified pore solution having and a second pH, wherein the difference between the first pH and the second pH is represented by a ΔpH, and the ΔpH is 1.0 or less, 0.75 or less, 0.5 or less, 0.25 or less, or about 0.0. A calcium silicate composition including solid components and liquid components having improved pore solution pH stability is also disclosed.

A method including entraining carbon dioxide (CO.sub.2) in a cement slurry composition and subjecting the cement slurry composition to conditions under which the CO.sub.2 achieves and maintains a supercritical state; and allowing the cement slurry composition to harden to form a hardened cement having CO.sub.2 sequestered therein.

In one aspect, the disclosure relates to processes for preparation of a carbon foam material, the process comprising devolatization of coal-derived pitches or extracts at atmospheric pressure near green coke temperatures, thereby forming a solid coke-like material. In a further aspect, the process can further comprise grinding the solid coke-like material to a powder, providing the ground powder to a mold, and then reheating above green coking temperature (e.g., >600 C.) to further devolatize the material and form a porous solid foam material. The process further provides carbon materials such as carbon composite materials and sp2-hybridized carbon in the form of graphene oxide or graphene. In various aspects, the disclosure relates to the carbon foam and other materials prepared using the disclosed processes. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

This disclosure involves a method of controlling a safety critical control device, the method comprising: sending user inputs to a first state machine, identifying user inputs by the first state machine, determining the correct state to communicate to a second state machine, the correct state being determined by selecting one state of a plurality of states depending on the user inputs, communicating the correct state to a second state machine through a control bus, and determining the correct state for the second state machine based on communication from the control bus.

This disclosure involves a method of controlling a safety critical control device, the method comprising: sending user inputs to a first state machine, identifying user inputs by the first state machine, determining the correct state to communicate to a second state machine, the correct state being determined by selecting one state of a plurality of states depending on the user inputs, communicating the correct state to a second state machine through a control bus, and determining the correct state for the second state machine based on communication from the control bus.

A method including entraining carbon dioxide (CO.sub.2) in a cement slurry composition and subjecting the cement slurry composition to conditions under which the CO.sub.2 achieves and maintains a supercritical state; and allowing the cement slurry composition to harden to form a hardened cement having CO.sub.2 sequestered therein.