A method for controlling an internal combustion engine system, the engine system including a combustor arranged to receive air and fuel, and combust the received air and fuel, an expander arranged to expand exhaust gases from the combustion in the combustor and to extract energy from the expanded exhaust gases, and a communication valve arranged to control a communication between the combustor and the expander, including determining during operation of the engine system whether there is a pressure difference across said communication valve.

Passage-separated intake of the present invention refers to that a separate supercharged intake passage and a separate supercharged intake supply apparatus are provided such that natural intake is separated from supercharged intake to implement respective intake without mutual interference. Time-separated intake refers to that in order to avoid a cylinder C from becoming a passage between natural intake and supercharged intake, natural intake is performed first in an intake stroke, and supercharged intake is performed after a bottom dead center of the intake stroke at the end of the natural intake.

In various aspects, internal combustion engines, engine controllers and methods of controlling engines are described. The engine includes a camshaft and a two cylinder sets. Cylinders in the first are deactivatable and cylinders in the second set may be fired at high or low output levels. The air charge for each fired working cycle is set based on whether a high or low torque output is selected. In some implementations, the camshaft is axially shiftable between first and second positions. First cam lobes are configured to cause their associated cylinders to intake a large air charge during intake strokes that occur when the camshaft is in the first position. Second cam lobes for cylinders in the second set cause their associated cylinders to intake a smaller air charge when the camshaft is in the second position. Second cam lobes for cylinders in the first set deactivate their associated cylinders.

A method and apparatus, for treating plaque and calculus in the mouth cavity—particularly on teeth—are disclosed. The apparatus—and accordingly the method—is comprised of introducing at least one first-component comprising a material with a redox potential for preventing anions precipitation; and introducing at least one second-component comprising a material with a redox potential for preventing cations precipitation.

A method of controlling vacuum pressure for vehicle braking may include checking whether a vehicle is idle or enters a deceleration state, comparing an engine vacuum pressure and a booster vacuum pressure of the vehicle with a preset reference value, checking whether a valve control system of the vehicle is operable when the engine vacuum pressure and the booster vacuum pressure are lower less than the preset reference value, controlling the valve control system when the valve control system is operable; and controlling an air conditioner (A/C) or an alternator of the vehicle when the valve control system is inoperable.

The present disclosure relates to piston engine systems which are no longer restricted by their compression ratios. Rather, a mixture of fuel and pre-compressed air is used to complete the combustion. The pressure of the compressed air is independently controlled. As a result, the clearance volume can be reduced to less than 1/50 or to zero, and the piston engine systems can be used with different types of fuels, for example, gasoline, diesel, ethanol, or vegetable oils.

A method and apparatus, for treating plaque and calculus in the mouth cavity—particularly on teeth are disclosed. The apparatus—and accordingly the method—is comprised of introducing at least one first-component comprising a material with a redox potential for preventing anions precipitation; and introducing at least one second-component comprising a material with a redox potential for preventing cations precipitation.

The present disclosure relates to a method for operating an internal combustion engine (IO). The method includes generating a pressure pulse in an exhaust gas system of the internal combustion engine (IO). The method also includes supplying exhaust gas from a combustion chamber of a cylinder during an exhaust outlet stroke of the cylinder into an inlet channel of the cylinder by propagating the pressure pulse from the exhaust gas system into the combustion chamber of the cylinder. The method further includes supplying the exhaust gas from the inlet channel of the cylinder into the combustion chamber of the cylinder during an intake stroke of the cylinder. By means of internal residual gas control (residual exhaust gas control), the method permits the exhaust gas temperature to be raised in at low load without negatively influencing the full load performance of the internal combustion engine (IO).

A misfire detection device for an internal combustion engine includes a storage device and processing circuitry, the storage device stores first mapping data corresponding to a case where a warm-up process of a catalyst provided in an exhaust passage of an internal combustion engine is being executed, and second mapping data corresponding to a case where the warm-up process is not being executed, and each of the first mapping data and the second mapping data uses a rotation waveform variable as an input and defines a mapping that outputs a misfire variable that is a variable related to a probability misfire has occurred. The rotation waveform variable is a variable indicating a difference between a plurality of values of an instantaneous speed variable respectively corresponding to a plurality of different minute angular intervals.

Methods and systems are provided for improving fuel vapor storage canister purging operations for vehicles with dual-path purge systems. In one example, a method may include purging fuel vapors from a fuel vapor storage canister to an engine of a vehicle via a single path, and in response to an unmetered increase in a concentration of the fuel vapors being purged to the engine via the single path, switching the fuel vapors to be purged to the engine via two paths simultaneously. In this way, fuel vapors may be distributed in time along the two paths, which may lower an effective concentration of fuel vapors entering the engine and may thereby avoid degradation of engine operating conditions.