A fuel-air mixture control apparatus for adjusting the mixture of fuel and air that a carburetor provides to an internal combustion engine. A processor of the transactional memory system executes a first salvage checkpoint instruction in a code region during transactional execution of the code region, and based on the executing the first salvage checkpoint instruction, the processor records transaction state information comprising an address of the first salvage checkpoint instruction within the code region. A member in the apparatus prevents an element from being popped upwardly in a first positioning of the member and provides for the element pop-up in a second positioning of the member. keeping addition of said active silicic acid to said solution obtained from step b) continuously until the concentration of SiO2 reaches 6 to 50% by weight. Also included is a method providing for a uniform fluid distribution within a vessel.