Abstract: A surface acoustic wave device includes at least one transducer; two acoustic reflectors disposed on either side of the at least one transducer so as to form a cavity, each acoustic reflector comprising an array of electrodes in the form of lines parallel with each other, each array comprising a subset of electrodes connected to a reference potential denoted mass defining a first connection type, and a subset of electrodes that are not connected to any potential, i.e. that have a floating connection defining a second connection type; at least one switching circuit configured to modify the distribution of the connections of at least one part of the electrodes of each array between the different connection types.

Abstract: A surface acoustic wave device: includes at least one transducer; two acoustic reflectors disposed on either side of the at least one transducer so as to form a cavity, each acoustic reflector comprising an array of electrodes in the form of lines parallel with each other, each array comprising a subset of electrodes connected to a reference potential denoted mass defining a first connection type, and a subset of electrodes that are not connected to any potential, i.e. that have a floating connection defining a second connection type; at least one switching circuit configured to modify the distribution of the connections of at least one part of the electrodes of each array between the different connection types.

Abstract: The invention relates to a method for desulphuration of the digestate and biogas in a digester (1) of urban and/or agricultural and/or industrial effluent, by biochemical and/or thermochemical processes, the digester consisting of an enclosure (2) which is closed at the top, in which anaerobic digestion of a mass of products to be treated making up the digestate (4) takes place, the digester comprising at least one loop (10) for external recirculation of the digestate; an oxidant is injected at least at one point (13, 14) of the loop (10), the injection conditions being as follows: the speed of circulation of the digestate in the loop (10) must be high enough to prevent the deposition of sulphur on the walls of the pipes; the contact time between the injected oxidant and the recirculated digestate recirculated from the injection point (13, 14) of the oxidant until the reinjection point (11b) of the digestate must be long enough for all the oxidant to be dissolved in the liquid phase of the digestate; the amou

Abstract: The invention relates to a static decanter (D) for prethickening liquid sludge in a water treatment plant, in particular wastewater, comprising an inclined bottom (8), the decanter being provided with a liquid sludge supply pump (13), a device for injecting a polymer in the liquid sludge, an overspill discharge (23) and a pump (26) for extracting the prethickened sludge from the decanter. The decanter further includes a means for accelerating the sludge decantation, a means (M) for adjusting the concentration of suspended material in the prethickened sludge at the outlet, and capable of maintaining the concentration of the prethickened sludge extracted from the decanter at a substantially constant level despite the concentration variations at the inlet, and a means (M3) for adjusting the level of the sludge blanket (V) and capable of maintaining said level at the lowest possible level.

Abstract: The invention relates to a method for desulphuration of the digestate and biogas in a digester (1) of urban and/or agricultural and/or industrial effluent, by biochemical and/or thermochemical processes, the digester consisting of an enclosure (2) which is closed at the top, in which anaerobic digestion of a mass of products to be treated making up the digestate (4) takes place, the digester comprising at least one loop (10) for external recirculation of the digestate; an oxidant is injected at least at one point (13, 14) of the loop (10), the injection conditions being as follows: the speed of circulation of the digestate in the loop (10) must be high enough to prevent the deposition of sulphur on the walls of the pipes; the contact time between the injected oxidant and the recirculated digestate recirculated from the injection point (13, 14) of the oxidant until the reinjection point (11 b) of the digestate must be long enough for all the oxidant to be dissolved in the liquid phase of the digestate; the amo

Abstract: The invention relates to a static decanter (D) for prethickening liquid sludge in a water treatment plant, in particular wastewater, comprising an inclined bottom (8), the decanter being provided with a liquid sludge supply pump (13), a device for injecting a polymer in the liquid sludge, an overspill discharge (23) and a pump (26) for extracting the prethickened sludge from the decanter. The decanter further includes a means for accelerating the sludge decantation, a means (M) for adjusting the concentration of suspended material in the prethickened sludge at the outlet, and capable of maintaining the concentration of the prethickened sludge extracted from the decanter at a substantially constant level despite the concentration variations at the inlet, and a means (M3) for adjusting the level of the sludge blanket (V) and capable of maintaining said level at the lowest possible level.

Abstract: Method for packaging liquid muds resulting from the treatment of urban and/or industrial waste water according to which the mud is subjected to a mechanical dehydration step followed by a thermal drying step. Ferric chloride and/or quicklime or slaked lime is injected into the mud after the dehydration step and before the drying step or at the beginning of the drying step.

Abstract: The disclosure relates to the protection circuits interposed between a DC supply and a load circuit to protect the load circuit against short-circuits or reversals in polarity of the supply. The protection is obtained by means of a MOS power transistor connected between the supply and the load circuit. This transistor is turned on if it receives a voltage Vg from a bias circuit through a control circuit. The bias circuit delivers the voltage Vg only if the voltage given to it by the supply is sufficient while the control circuit turns the power transistor off if the output of the supply gets short-circuited or gives a voltage with reversed polarity.

Abstract: A mandrel for holding gradient coils in an instrument that measures nuclear magnetic resonance is fastened directly to the magnet of this instrument. It is shown that this arrangement can be used to reduce the output of noise while, at the same time, making it easy to adjust the position of the mandrel. The device comprises two sets of brackets fastened by their struts, on either side of the magnet, to the end rings of the magnet. Each bracket exerts a holding force on the mandrel.

Abstract: The object of the invention is an improved gradient coil. The improvement consists in making steps in the saddle-shaped conductors that form the coil in order to modify local distortions in the magnetic field produced. It is shown that the correction thus made has little effect on the rest of the field of distribution.

Abstract: A high frequency antenna is provided for an apparatus measuring nuclear magnetic resonance, of the type whose radiating means comprise conductors forming high frequency resonators with a metal casing. They are frequency tuned by adjustment capacitors situated at their ends. For simplifying the frequency tuning of two paired resonators through which flow currents in phase opposition, it is proposed to join together galvanically two ends of these two resonators by a high frequency line section whose length is substantially equal to half the wave length of the energization wave to be emitted. The frequency matching of the antenna may be made by adjusting simultaneously all the adjustment capacitors by means of a common control knob. Coupling of the energization energy is provided magnetically in the middle of this high frequency line section.

Abstract: A gradient coil is provided for a nuclear magnetic resonance image forming apparatus, the gradient coil being formed of four identical arrangements symmetrical with respect to the centre of a predetermined examination space. These arrangements comprise conductors formed in the shape of a saddle. In a particular embodiment for each arrangement two groups of conductors are provided. They may moreover be superimposed. In the invention, the conductors are flat conductors. Preferably their section is rectangular, the large side being greater than or equal to two and a half times the small side. The choice of flat conductors reduces the self-inductance of the system thus constructed. Finally, it is the necessary driving power which is reduced for establishing a field gradient. The temperature behavior of the whole of the apparatus is improved thereby.

Abstract: A reactor for aerobically or non-aerobically treating a fluid flowing from the bottom to the top of the reactor through a fluidized bed of granular material. The reactor includes a base having an orifice therein, through which fluid flows into the reactor and in which gas is added to the fluid. A horizontally extending plate surrounded by a supple membrane faces the base and the orifice. The plate and the membrane form a valve for preventing fluid from the reactor from entering the orifice in the event fluid flow into the reactor ceases. The gas entrains the granular material so that when the gasified fluid passes upward through the granular material a three-phase liquid-gas-granular material mixture is produced. The upper portion of the reactor includes a device for disembedding the granular material from the fluid, a device for degasing the three-phase liquid-gas-granular material mixture, and a device for separating the granular material from the fluid to produce a fluid discharge.

Abstract: The invention provides a device for creating an excitation field in an apparatus using nuclear magnetic resonance. The structure for creating this field comprises a number of conductors spaced evenly apart at the periphery of a circular cylinder. What characterizes the invention is that, for producing a homogeneous field inside this cylinder, it is sufficient to cause a current to flow through these conductors whose intensity is proportional to the cosine of the angle which locates this conductor with respect to a reference axis system.

Abstract: An apparatus for the anaerobic filtration of waste water includes a filter of filling material through which the waste water to be treated is passed from the bottom to the top. The filter includes upper and lower superposed layers of filling material separated by an intermediate layer of material. The lower layer is in the form of an ordered arrangement of the material thereof. The upper and intermediate layers each include a loosely packed arrangement of the material thereof.

Abstract: Waste water to be treated is introduced into a filter including granular material for supporting the biomass resulting from an anaerobic treatment operation. During such treatment operation biogas is formed, and the waste water being treated and the granular material supporting the biomass are continuously circulated by injecting a portion of the biogas into a tube extending vertically upwardly through the filter.

Abstract: Method for charging a sealed storage cell battery according to which the battery is heated when its temperature lies below a determined value and the intensity of the charge current is lowered by being shunted to heat the battery when the voltage of the battery reaches a given value, characterized in that the said value of the voltage of the battery supplies the signal which causes the heating of the battery; and device for implementing the method.