Abstract: New homopolymers formed by malonic (meth)acrylamide monomer units according to the following formula: ##STR1## wherein R is H or CH.sub.3 ; X is H or an alkaline metal or NH.sub.4.sup.+ ; and copolymers formed by (meth)acrylamide monomer units (I) and monomer units (II).

Abstract: The present invention relates to a process for the oligomerization of light olefins or mixtures thereof, wherein a reaction is brought about between olefins with a carbon number of between 2 and 20 and synthetic zeolites containing silicon, titanium and gallium oxides which in the calcined, anyhdrous state have the following empirical formula:pHGaO.sub.2 .multidot.qZTiO.sub.2 .multidot.SiO.sub.2,where p is of a value greater than zero and less than or equal to 0.050 and q is of value greater than zero and less than or equal to 0.025, with the H.sup.+ of HGaO.sub.2 being at least partly exchangeable or exchanged with cations.

Abstract: When used as occlusion agents or to cause fractures in a petroleum reservoir, polymer gels crosslinked with polyvalent metal ions can be removed by the use of special complexing agents.

Abstract: An underwater sub-surface safety valve block is connected between a well head located at the sea bottom, and the lower end of a riser. This allows the production tube and/or the service tube of the completion string to be closed by means of gate valves. This sub-surface safety valve block comprises a valve body provided with a vertical through-bore tightly closed at its upper end by a packer to which the upper portion of the completion string is connected. The bottom is tightly closed by a tubing hanger to which the lower portion of the completion string is connected. The packer and the tubing hanger are fastened inside the through-bore by means of a mechanical hooking which can be disengaged by means of a hydraulic controlled action. They are each provided with a through-channel in order to connect the respective production tubes with the central region of the through-bore, which can be closed by means of a gate valve.

Abstract: A reversible mechanical coupling to be clamped in a suitable seat by means of clamping levers and wedges, in which the clamping levers are pivoted to arms rigid with said wedges by two lateral pivots which are inserted through vertical slots in said arms and are retained at the lower end of said slots by the narrow but forcible mouth of springs of tuning-fork shape mounted in correspondence with said slots, said clamping levers being also provided with laterally projecting pegs which are inserted in suitably shaped guides provided in protection casins interposed between the clamping levers and fixed to the coupling body.

Abstract: A process is disclosed for oligomerizing light olefins or their mixtures, which consists in reacting said olefins, possibly diluted with an inert gas, by means of synthetic zeolites containing oxides of silicon, titanium and aluminum, which have, in their calcined and anhydrous state, the following empirical formula:pHAlO.sub.2 .multidot.qTiO.sub.2 .multidot.SiO.sub.2'wherein p has a vlue larger than zero and smaller than, or equal to, 0.050 and g has a value larger than zero and smaller than, or equal to, 0.025, and the H.sup.+ of HAlO.sub.2 can be at least partially substitutable or substituted with cations.

Abstract: A process is disclosed for oligomerizing light olefins or mixtures thereof, which consists in reacting said olefins, possibly diluted with an inert gas, by means of synthetic zeolites containing oxides of silicon, titanium and iron, having, in their calcined and anhydrous state, the following empirical formula:pHFeO.sub.2. qTiO.sub.2.SiO.sub.2,wherein p has a value larger than zero and smaller than, or equal to, 0.050 and g has a value larger than zero and smaller than, or equal to 0.025, and the H.sup.+ of HFeO.sub.2 can be at least partially substitutable or substituted with cations.

Abstract: Heliborne beam for supporting at its two ends metric photocameras suitable to industrial stereophotogrammetric surveys, constituted by a plurality of cylindrical tubular sections linked in sequence with each other by means of flanges, and supported manually rotatable, but not longitudinally sliding with their center section inserted inside three clamp collars mounted, through double-effect cylindrical shock absorbers, on a base or bench fastened on to the floor of helicopter's cabin; at the end of the beam, two cylindrical housings with aerodynamic closure elements and provided with "eyelid" door, inside which the photocameras are supported by means of a frame linked to the housing by means of two respectively radial and axial shock absorbing units, and provided with two inner guides into which the side supporting pins of the said photocamera are inserted.

Abstract: A reversible mechanical coupling for tensional anchorages includes a cylindrical body having a widened portion of conical shape capable of causing a set of clamping levers to be radially expanded by pivoting around a lower linking ring controlled to move coaxially with the cylindrical body by a first set of oleodynamic cylinders supported by the cylindrical body. The clamping levers are kept in contact with the body by springs, and are in mechanical interference, in their expanded position, with a conical surface provided in the seat for the coupling. A set of vertical guides is for provided on the upper portion of the cylindrical body for guiding a set of wedges pivoting around an upper linking ring controlled to move coaxially with the cylindrical body by a second set of oleodynamic cylinders supported by the body.

Abstract: This invention relates to organosiloxane compositions which have application as protective coatings for soft substrates. The compositions of the invention include a substituent selected from each of the following classes of compositions: organo-alkoxysilanes; polyoxymethylenes; monocarboxylic organic acids; and optionally inorganic hydroxyacids. The coatings formed form these compositions have properties as adhesion promoters and are abrasion resistant.

Abstract: A measuring head suitable for determining the pressure of fission gases released inside non-instrumented bars of nuclear fuel (which have reached high irradiation levels), and for connection to said bars by a method which allows no escape of said active gases and does not cause appreciable disturbance either to the fuel or to the released fission gases.

Abstract: "Three-conical" signal for industrial surveys stituted by a vertical transparent cylinder, inside which two conical axial cavities are excavated, unsymmetrical, opposite to each other, and painted in luminescent orange color, whose vertices are connected by a vertical cylindrical bore; said vertical cylinder is supported by a base which supports in its turn within the lower conical cavity a parabolic reflector and a lamp, and is provided atop with a conical cap axially provided with a small transparent vertical cylinder, ending with a sharp conical top, and being provided in its lower portion with a surface having the shape of a spherical cap.

Abstract: A method for the stereophotogrammetric survey of a large-dimension object is provided in which the object and a chain having two reference markers thereon spaced apart at a known distance are photographed from a height of about 30 m with two synchronized metric photographic cameras spaced apart by about 6 m. Depth measurements (Z axis) are made on a stereoscopic model reproduced by a stereoplotter at eight sets of points grouped in the eight conventional perimetral locations of photogrammetric orientation at the crests and troughs of the ripples or undulations of the water or ground, respectively. The mean of the depth measurements is calculated to determine the mean horizontal plane and the model is correctly orientated with respect to the horizontal plane by suitable rotation.

Abstract: A process for preparing an alkaline metal salt of a polyethoxycarboxylic acid defined by the formulaR'(OR).sub.m (OCH.sub.2 CH.sub.2).sub.n-1 (OCH.sub.2)COOMby oxidation in the presence of a platinum or palladium catalyst, of a polyethoxy alcohol of the formulaR'(OR).sub.m (OCH.sub.2 CH.sub.2).sub.n OH,followed by reactivating the catalyst in the reaction mixture and recovering in active form the insoluble and soluble catalyst fractions. The alkaline metal salts of polyethoxycarboxylic acids thus produced are useful as surfactants, which can be employed in the recovery of oil from wells of medium and high salinity.

Abstract: This invention relates to a method for preparing thin sections for the microscopic study of small fragments of rock, dust, microfossils or miscellaneous debris, agglomerated into pellets of special characteristics. The method according to the invention comprises the use of a plate of plastic material containing a series of cells which are filled with an agglomerate consisting of rock fragments surrounded with epoxy resin. Said plate is then heated in an oven to a temperature not exceeding 75.degree. C. for some hours in order to accelerate the hardening of the resin and to obtain said pellets.