Abstract: The prevention or substantial reversal of octane requirement increase in a spark-ignited, internal combustion engine is achieved by introducing, with the combustion intake charge, a fuel and/or lubricant composition containing an octane requirement increase-inhibiting amount of a high surface area, solid acid catalyst having an average particle size in the range of about 0.01 to 10 microns and an average non-volatile surface acidity of about 1 or less, expressed as pKa value, said solid acid catalyst being essentially nonreactive with the fuel or lubricant prior to combustion and chemically and thermally stable under combustion conditions in the engine.

Abstract: The prevention or substantial reversal of octane requirement increase in a spark-ignited, internal combustion engine is achieved by introducing, with the combustion intake charge, a fuel and/or lubricant composition containing an octane requirement increase-inhibiting amount of a high surface area, solid acid catalyst having an average particle size in the range of about 0.01 to 10 microns and an average non-volatile surface acidity of about 1 or less, expressed as pKa value, said solid acid catalyst being essentially nonreactive with the fuel or lubricant prior to combustion and chemically and thermally stable under combustion conditions in the engine.

Abstract: A tubular connected series of biofilm samplers is provided for monitoring biofouling by microorganisms in a continuous flow stream. Tubular bypasses are provided around each sampler, so that each sampler is removable for inspection of biofouling without interruption of the continuous flow stream. In addition, each sampler has a contoured surface which is in contact with the continuous flow stream and which is flush with the inner surface of the tubulars connecting the samplers.