Abstract: An instrument for boring dental radicular canals in which the conicity of the active part of the tapered stem of the instrument is not constant but the angle of its opening is greater at its rear portion, positioned beyond the diameter D.sub.9, than the angle of opening of its front portion positioned between its end and the diameter D.sub.9 so that a dental canal bored with the instrument has a bell-mouthed shape.

Abstract: The length of the active part of each drill of the set is inversely proportional to the diameter of the cutting edge of each drill, that prevents the drills of the set being too much engaged in the coronary canal, since the depth of the working depends with precision from the used drill.

Abstract: A photoionization detector for a gaschromatographic apparatus includes an ionization chamber provided with a polarizing electrode and a collector electrode. The electrodes are mounted on and heated by a base portion of the detector. A lamp with a window spaced from the chamber and mounted on the base portion through supporting means having low thermal conductivity is provided. A gas curtain of a gas that is transparent to the said lamp radiation is provided at least between the window and the ionization chamber and comprises a first portion of substantially still gas acting as thermal insulant and a second portion of flowing gas also acting as sweep gas for the lamp window.

Abstract: A luminous flux measuring device has a gain slaving circuit (10, 9), that receives an electrical output signal (m) produced by a photoreceiver (1) and includes a gain control circuit (9) and a comparator (10). The gain slaving circuit is connected to an A/D converter and a computer to record and evaluate the signal (m) and has a slave memory containing characteristic values (a,b) of a continuous function (f). The gain slaving circuit produces a slave signal (HT) according to the flux received (.PHI.) by the photoreceiver which signal is sent to the gain control circuit so that G=f(m).

Abstract: The central part of the instruments of the boring set, prior to the portion having the cutting edges, has a section of a polygonal shape. The lateral faces of the central part are either convex, for the instruments of small diameter, plane for the instruments of middle diameter and concave for the instruments of largest diameter, in such a way that the curve of the bending moments of the instruments of the set is substantially rectilinear. Thus the variation of the bending moments of the instruments is linear, while, in previously known sets of instruments, the curve is exponential. Hence, the flexibility of the instruments of the set is satisfactory for the entire set of instruments, while; in the known conventional sets, if previously flexibility of the small instruments of the set is satisfactory, the instruments of largest diameter will be too rigid, and vice versa.

Abstract: Superparamagnetic particles are separated from a suspension thereof in a first fluid and re-suspended in the same or another fluid in a container by subjecting them to a first application of a magnetic field to draw the particles to a surface or zone of the container and subsequently re-suspending the particles in the fluid within the container by a second application of a magnetic field. Apparatus is disclosed including a container (1), electromagnets (2,3) for producing the first and second applications of magnetic fields, reagent receptacles (7), and a wash flask (8). A particle counting device may also provided and such apparatus may be used to count cells.

Abstract: A set of instruments for boring of radicular dental canals, in which the diameter D1 of each instrument, measured at the root of the pointed end portion thereof, varies according to a geometrical progression as well as the diameter D2 of each instrument measured at the root of the cutting edges. Hence, the variation is more pronounced for the diameters D2, larger than the diameters D1, than it is for the diameters D1. The conicity of the stem of the instruments increases in this manner from one instrument to another, so as to permit a the dentist to form the radicular canals with a specially funnelled shape which is best suited for some obturations, especially those to be treated with gutta-percha.

Abstract: This invention relates to a method and a device for the ellipsometric measurement of physical parameters representative of a sample.The measured values I.sub.om, I.sub.sm and I.sub.cm are calculated (51, 52) from the signal (50) which represents the measured intensity I(t).In a first step (55, 57), initial theoretical values I.sub.st /I.sub.ot and I.sub.ct /I.sub.ot are produced from initial estimations (56) of the physical parameters. In a second step (58, 59) subsequent estimations (59) of physical parameters are determined from which subsequent theoretical values I.sub.st /I.sub.ot and I.sub.ct /I.sub.ot are deduced (55, 57). The second step is reiterated to an Nth estimation (59) of the physical parameters, so as to minimise the difference between the theoretical values and those measured.The physical parameters are evaluated (54) in the course of the Nth estimation.

Abstract: A set of instruments for boring dental radicular canals in which the conicity of the rear part of the set positioned beyond the diameter D.sub.9 of the instruments, increases more for the first instruments of the set than for the last ones. The conicity of the front part of the instruments does not increase much for the first instruments of the set, but does increase for the last ones. Hence, while using successively the instruments of a set, the dentist bores first the coronary portion of the tooth, then its medium portion and then its apical portion. The end part of the instruments, between the point thereof and their diameter D.sub.3, situated at 3 mm from the point, is provided with one or several grooves for elimination of the dental scraps, but which have no cutting edges so that this part of the instruments functions only for their guidance.

Abstract: This invention provides a process for determining the nitrogen content of a sample involving (a) combusting the sample in a combustion reactor in the presence of oxygen, which oxygen is introduced into the combustion reactor in pulse form; (b) reducing the resulting combustion gases by flowing them in a flow of helium or other noble carrier gas through a Cu-containing reduction reactor; (c) performing the steps of (i) making anhydrous in a water trap the reduced gases, (ii) flowing the reduced gases through a gas-chromatographic column in order to carry out a gas-chromatographic separation of N.sub.2 from CH.sub.4 possibly present within the reduced gases, and (iii) removing CO.sub.2 from the reduced gases using a CO.sub.2 trap, with the proviso that step (i) immediately precedes step (ii); and (d) analyzing the resulting gases by detecting thermal conductivity.

Abstract: A device for automatically feeding samples to an elemental analysis combustion apparatus. The device has a housing for the sample and is rotatable from an external sample receiving position to a sample feeding position. The housing is insulated from the atmosphere and is connected to the combustion apparatus. The moving body is a truncated cone which is rotatable about its axis within a seat.

Abstract: A circuit interconnecting device for industrial applications comprising a card-edge connector arranged on a mainboard and associable, by means of a connector located on a card for interconnection, with external control devices; the card for interconnection also exhibiting output connectors as well as a circuit section for interfacing with the external control devices.

Abstract: The determination of the halogen content in a substance is carried out by oxidative combustion of the sample under a continuous flow of gas, in the presence of oxygen, the gases coming out of the combustion reactor being then carried by gas flow to analysis equipment.

Abstract: Particles in a fluid are counted by passing the fluid through an optical cell and an image of said particles is projected onto an array of charge coupled devices such that the area of the image of each particle at the said array is approximately the same as the area of at least a single charge coupled device, and signals from the individual charge coupled devices are processed to provide information concerning at least the number of said particles passing through the optical cell. A particle counter disclosed comprising an optical cell (1) through which is passed a fluid containing particles to be counted, means (2) for illuminating the particles in the optical cell and optical means (3) for providing an image of the particles on an array of charge coupled devices (5) such that the area of the image of each particle at the said array is approximately the same as the area of at least a single charge coupled device. The particles may fluoresce and a transmittance filter (4) may be provided.

Abstract: An anlytical equipment and method for the selective detection of individual oxygenated compounds in complex organic mixtures, in particular fuels, comprising, downstream an equipment of chromatographic separation, a cracking reactor, a catalytic hydrogenation microreactor and a FID detector. The cracking reactor is provided with a catalyst under the form of metal elements, made of palladium, inserted inside the capillary tube though which flows the gas under test. Thanks to the present equipment, the analytical process, based on the specific response of oxygenates to the method of flame ionization detection (O-FID), foresees that the cracking reaction takes place at temperatures below 1000 degrees C. and, consequently allows to keep the cracking reactor at stand-by temperatures below 700 degrees C.

Abstract: The invention concerns a process and a device for splitless vaporizing injection of samples into equipments of gas chromatographic analysis.The technique is applied specially when liquid samples generate volumes of vapors which cannot be housed inside the vaporizing chamber.Inside the vaporisation chamber, kept at high temperature, evaporation of the sample solvent forms a cool zone where the solutes are retained while the solvent vapors expand out of the vaporizing chamber and leave the injector. The sample liquid is kept in place within the vaporization chamber by suitable obstacles or by a packing material. At the end of solvent evaporation, i.e. when cooling ceases, the injection zone returns to the regulated injector temperature and the compounds to be analysed are transferred to the column by the carrier gas.

Abstract: A signal conditioning circuit allows for adjustment of DC offset (zero) and gain (span) by use of a number of resistors and jumpers in an Op Amp circuit. By arranging both the zero and span resistors in a trinary weighted sequence (1/3/9), only 3 resistors and 3 jumpers will be needed for +/- 130% adjustment range in 26 steps of less than 10% each. The total requirement for both the zero and span adjustment in the conditioning circuit is 6 resistors and 6 jumpers, reducing component count, printed circuit space requirements and simplifying jumper settings.

Abstract: The present invention relates to the industrial field of wiring apparatus for cables and in particular to a connecting system for cables in intrinsic-safety industrial instrumentation boards. Directly on the assembling board where the intrinsic-safety modules for the protection of the process control systems are allocated, a plurality of connecting modules of the cross-wiring type are disposed to a card on which the intrinsic-safety modules relating to various protection devices are also disposed. In this manner all connecting cables coming from the various sensors distributed in an industrial plant can converge to this card in order to be sent to a central processing unit in a homogenous typology. The connecting modules are implemented on each card depending upon the plant extension and the amount of sensors present thereon.

Abstract: A diffraction grating, comprises a plurality of grooves formed by a plurality of first facets having a first set of propagative optical characteristics. All facets are generally positioned with a first orientation. A plurality of second facets have a second set of propagative optical characteristics and are generally positioned with a second orientation. The first facets are oriented to diffract light incident on them. The second facets are oriented and have propagative characteristics which prevent perturbation of the diffracted light.

Abstract: A double spectrograph system is disclosed. An entrance slit receives and passes light to be analyzed. A first focusing diffraction grating receives that light. A second focusing diffraction grating receives light reflected by the first focusing diffraction grating. The first and second focusing diffraction gratings both have the characteristic of forming planar substantially anastigmatic spectra. Mounting means keeps the first and second gratings at positions symmetrical about an imaginary plane and with their respective focal planes substantially coincident with each other and the imaginary plane. An exit slit receives the light after it has been reflected by the first grating to the second grating and from the second grating to the exit slit.