Abstract: The invention relates to vibrating micro-systems, and notably but not exclusively to pressure, acceleration, or angular speed micro-sensors with a resonator in an evacuated cavity. The resonator (10) with a vibrating element is placed in an oscillating circuit controlled by a closed-loop control, the oscillating circuit supplying an oscillating signal y(t) at a resonance frequency Fp representing the measurement of a physical quantity. The resonance frequency is calculated by counting pulses over a time window. The sensor furthermore comprises means for calculating a continuity parameter Pc representing the variations in the result of the calculation of the resonance frequency over the course of the successive time windows, and means for comparing the parameter Pc with a threshold in order to deduce from this information on the degradation of the precision of the sensor.

Abstract: The invention relates to vibrating micro-systems, and notably but not exclusively to pressure, acceleration, or angular speed micro-sensors with a resonator in an evacuated cavity. The resonator (10) with a vibrating element is placed in an oscillating circuit controlled by a closed-loop control, the oscillating circuit supplying an oscillating signal y(t) at a resonance frequency Fp representing the measurement of a physical quantity. The resonance frequency is calculated by counting pulses over a time window. The sensor furthermore comprises means for calculating a continuity parameter Pc representing the variations in the result of the calculation of the resonance frequency over the course of the successive time windows, and means for comparing the parameter Pc with a threshold in order to deduce from this information on the degradation of the precision of the sensor.

Abstract: The invention relates to a device for neutralizing a signal obtained by modulating, on to a high frequency carrier, a useful signal delivered by a system comprising a parasitic capacitance Cp that varies over time, the device comprising a neutralizing capacitance Cn, means for providing an adjustable gain G, said means being equipped with a JFET field-effect transistor (J1) equipped with a gate first electrode and drain and source second electrodes, and a control loop for providing gain G so that G×Cn permanently equals Cp by controlling the voltage on the gate first electrode of the transistor (J1). The neutralizing capacitance Cn comprises a first capacitor Cneutro1 and a second capacitor Cneutro2 placed in parallel at the output of said means for providing gain G.

Abstract: The invention relates to a device for neutralizing a signal obtained by modulating, on to a high frequency carrier, a useful signal delivered by a system comprising a parasitic capacitance Cp that varies over time, the device comprising a neutralizing capacitance Cn, means for providing an adjustable gain G, said means being equipped with a JFET field-effect transistor (J1) equipped with a gate first electrode and drain and source second electrodes, and a control loop for providing gain G so that G×Cn permanently equals Cp by controlling the voltage on the gate first electrode of the transistor (J1). The neutralizing capacitance Cn comprises a first capacitor Cneutro1 and a second capacitor Cneutro2 placed in parallel at the output of said means for providing gain G.

Abstract: Methods for oxidizing a liquid with an oxidization gas in a closed volume reactor. A feed liquid which contains compounds to be oxidized is fed into the closed volume reactor, and a feed gas containing oxygen is fed into the reactor so as to form a gas overhead above the feed liquid. The overhead is later purged at a specific rate so as to ensure a predetermined oxygen partial pressure is maintained in the gas overhead. The value of this partial pressure corresponds to a predetermined, desired rate of oxidation of the compounds contained in the feed liquid.

Abstract: The subject of the present invention is a process for the oxidation of a liquid contained in a reactor having a closed volume by means of an oxidation gas. The reactor comprises at least one means for feeding the gas into the reactor and at least one means for feeding the liquid into the reactor, at least one means for withdrawing the liquid and at least one means for withdrawing the gas. In the said process, the liquid contains compounds to be oxidized and the oxidation gas contains oxygen, the liquid and the oxygen gas are fed into the reactor in amounts such that a gas overhead is formed above the liquid contained in the reactor and a purge of the gas overhead is carried out. Characteristically, the said purge ensures that there is a predetermined oxygen partial pressure in the gas overhead, the value of this partial pressure corresponding to the desired rate of oxidation of the said compounds.

Abstract: A method of bleaching recycled paper containing pulp wherein said pulp is contacted with ozone in an ozone stage (Z) treatment with a brightness stabilizing step during or at the end of said ozone stage (Z), said stabilizing step consisting of contacting a small amount of hydrogen peroxide with said pulp, the amount of hydrogen peroxide contacted with said pulp being small compared to the amount of hydrogen peroxide usually in an hydrogen peroxide stage, no washing step of the pulp being provided between the ozone contacting step with said pulp and the hydrogen peroxide contacting step. The pulp is first submitted to a test procedure to determine whether the pulp is more reactive to ozone in acidic or alkaline conditions, and if necessary the pH is accordingly adjusted.

Abstract: The invention relates to a method of bleaching waste paper pulp. The pulp is first treated to a reductive chemical followed by acidification and washing or dewatering. The pulp is then subjected to ozone and then to hydrogen peroxide. The reductive chemical used is either formamidine sulphinic acid or sodium hydrosulfite.