Abstract: The invention relates to a method for liquefying methane-rich feed gas (12), the method comprising: mixing the feed gas with recycled gas (18), compressing the gas to a pressure of between 19 and 70 bar absolute, and purifying the gas, a first pre-cooling of the gas to a temperature of between ?40° C. and ?15° C., and second pre-cooling of the gas by heat exchange with the recycled gas, liquefying the gas by heat exchange only with a liquefaction refrigeration cycle (46), sub-cooling the gas by heat exchange with at least the recycled gas, and expanding the sub-cooled liquid (52) to obtain a liquefied gas (14) and the recycled gas representing a mole fraction of less than 35%.

Abstract: Some embodiments of the presently disclosed subject matter relate to a method and system for the real-time calculation of the amount of residual chemical energy in a non-refrigerated, pressurised tank containing liquefied natural gas, without a composition of the liquefied natural gas having to be determined.

Abstract: Some embodiments of the presently disclosed subject matter relate to a method and system for the real-time calculation of the amount of residual chemical energy in a non-refrigerated, pressurised tank containing liquefied natural gas, without a composition of the liquefied natural gas having to be determined.

Abstract: Noise reduction for a switching amplifier system having a differential output stage and demodulator filter responsive to complementary PWM signals includes generating in-phase PWM signals and gradually adjusting their duty cycle between a low duty cycle and the full duty cycle of the complementary PWM signals, generating full duty cycle PWM signals and gradually shifting their relative phase between in-phase and out-of-phase; and in response to a turn-on signal, adjusting the in-phase PWM signals from low to full duty cycle and shifting the relative phase from in-phase to out-of-phase, and in response to a turn-off signal shifting the relative phase from out-of-phase to in-phase and adjusting the in-phase PWM signals from full to low duty cycle for maintaining balanced charge on the demodulation filter to reduce audible noise.

Abstract: Noise reduction for a switching amplifier system having a differential output stage and demodulator filter responsive to complementary PWM signals includes generating in-phase PWM signals and gradually adjusting their duty cycle between a low duty cycle and the full duty cycle of the complementary PWM signals, generating full duty cycle PWM signals and gradually shifting their relative phase between in-phase and out-of-phase; and in response to a turn-on signal, adjusting the in-phase PWM signals from low to full duty cycle and shifting the relative phase from in-phase to out-of-phase, and in response to a turn-off signal shifting the relative phase from out-of-phase to in-phase and adjusting the in-phase PWM signals from full to low duty cycle for maintaining balanced charge on the demodulation filter to reduce audible noise.