Abstract: The invention relates to a legrest for a wheelchair, provided with a footrest and a calfrest. In a first, supporting position (ready for use), this footrest and calfrest are designed for supporting at least a part of a leg of a user seated during use in the wheelchair. The calfrest can be moved to a non-supporting, second position (ready for transfer), wherein the calfrest is located outside the space which is occupied by the legs of a wheelchair user upon sitting down in and/or rising from the wheelchair. The pivotal direction of the calfrest is then such that the path of travel between said first and second position is located substantially outside the space occupied by the legs of the wheelchair user in the first, supporting position.

Abstract: The invention relates to a method for the regeneration of a reactor and the use of said method for the improved performance of production processes for desired products.

Abstract: The invention relates to a method for controlling the alertness of a human subject and a light source for use in this method and use of a light source for this method. The method comprises exposure of a human subject during an exposure period to suitable light radiation without substantially influencing the phase of a melatonin cycle. Melatonin is a sleep-hormone that can be used to control the alertness of a human subject The suitable light radiation being specified by an output fraction of melatonin suppressive radiation (Melatonin Watt/Watt) and light output (lumen/Watt), the output fraction and light output being adjusted to obtain the desired effect on the phase of said cycle.

Abstract: The present invention concerns a process for producing silylalkylboranes containing the structural feature Si—C—B, new molecular silylalkylboranes, new molecular silyalkylborazines, new oligoborocarbosilazanes and polyborocarbosilazanes, a process for their production and their use as well as silicon boron carbide nitride ceramics and a process for their production.

Abstract: The present invention relates to novel processes for preparing borylsilylamines, novel amines, novel borosilazane compounds, novel oligoborosilazane or polyborosilazane compounds which have the structural feature Si—N—B, ceramic material and methods of producing and using them.

Abstract: A system and method for compressing gas uses a hydraulic pump and a hydraulic accumulator to compress gases in gaseous form. The accumulator is divided into a hydraulic chamber and a pneumatic chamber. The pneumatic chamber of the accumulator can be pneumatically connected to a gas supply and a gas receptacle that needs filled. One-way directional flow valves are used to permit the flow of gas from the gas supply to the pneumatic chamber and from the pneumatic chamber to the gas receptacle, but to prevent the flow of gas in the opposite direction. A motor drives the hydraulic pump, which moves pressurized oil into the hydraulic chamber of the accumulator. The pressurized oil within the hydraulic chamber of the accumulator compresses the gas within the pneumatic chamber of the accumulator, forcing the into a tank or other receptacle that needs filled. The invention can be used to compress a variety of gases at different flow rates, volumes, and pressures.

Abstract: Nitride or oxidenitride based red to yellow pigments, such as tantalum(V) nitride and oxidenitrides containing tantalum may be produced by passing ammonia over nitridable metal compounds, in particular oxide compounds, at 700 to 1250° C. According to the invention, nitriding proceeds in a rotary tube or fluidised bed reactor in the presence of an oxide from the series SiO2, ZrO2, GeO2, SnO2, TiO2 and HfO2 under conditions under which this oxide is substantially not nitrided.

Abstract: Molecular silylalkylboranes, a process for their preparation, oligo- or polyborocarbosilazanes, a process for their preparation and their use and silicon carbonitride ceramics and a process for their preparation.

Abstract: A fluid swivel of the type that includes a transfer chamber (56) formed between inner and outer main parts (52, 54), is constructed so sand and other particles settling out of the fluid, does not find its way into the lower gap passage (86) and quickly wear out a seal. A second of the main parts has a lower wall with a raised barrier (110) close to the top (122) of the lower gap passage. The first main part lower wall forms a first barrier (112) in the form of a projection that lies closely over the second barrier. The two barriers are closely spaced to form an entrance region (120) leading to the lower gap passage, with the entrance region including an upstream entrance part (132) that extends vertically or at an upward incline to discourage the migration of sand therealong.

Abstract: The present invention relates to new polymeric silaborocarboazanes, a process for their preparation and their use.

Abstract: Colored pigments are provided from the green-yellow to red spectrum based on oxide-nitrides with two or three different cations Q, R and S in the crystal lattice, wherein the nitrogen to oxygen atomic ratio is determinative for the color. These pigments crystallise in the pyrochlore, spinel or elpasolite structure. Pigments in the perovskite are as provided with increased color brilliance. The color of the pigments can be adjusted in a wide range of the color spectrum during their preparation within a substance class with the cations Q, R and S and while retaining the crystal structure, by increasing or lowering the atomic ratio N to O in the oxide-nitride and bringing about the required charge balancing by replacing an equivalent quantity of the cation Q with the valency q by a cation R with the valency q+1.

Abstract: Oxonitrides with a perovskite of the general formula LnTaOn.sub.2, where Ln is a rare-earth element, and which exhibit an enhanced brightness, are produced by annealing a powder mixture consisting of a Ta (V) compound and a Ln compound in a reducing atmosphere that contains ammonia. Added to the powder mixture being annealed is a mineralizing agent from the series of alkali metal or alkaline earth halides, Na.sub.3 AlF.sub.6, Na.sub.2 SiF.sub.6, AlF.sub.3 or of the ammonia salts of carbonic acid or a mono- or dicarboxylic acid with 1 to 4 C atoms in a quantity of 0.1 to 10 parts by weight, relative to 1 part by weight of the mixture of the Ta and Ln compounds. Such oxonitrides can be used as pigments that are yellow-orange to reddish brown in color.

Abstract: Gels based on a network of oxygen-bridged metal and/or semi-metal atoms and produced using a hydrolytic sol-gel process are often not homogeneous. Known non-hydrolytic sol-gel processes give rise to gels containing halogen.A novel non-hydrolytic sol-gel process has been found which gives rise to halogen-free and homogeneous gels and to xerogels obtainable therefrom.In this process, one or more compounds (I) from the series of metal or semi-metal alkoxides, oxoalkoxides, amides or oxoamides are condensed, with elimination of carboxylic acid esters or carboxylic acid amides, until gelation occurs with one or more compounds (II) from the series of metal or semi-metal carboxylates or oxocarboxylates in an anhydrous organic solvent containing no hydroxyl groups.Preferred gels and xerogels contain in the network metal or semi-metal atoms from main group and subgroup III to V and from the rare-earth elements.

Abstract: An improved method for producing tantalum (V) nitride by means of nitriding an oxidic tantalum (V) compound is described. The Ta.sub.3 N.sub.5 product obtained in accordance with this method may be used as a red coloring pigment, particularly for coloring plastics and varnishes. An improved color intensity can be achieved and/or the reaction time can be shortened using the process in accordance with the invention. The process includes nitriding tantalum (V) hydrated oxide with the composition of the formula Ta.sub.2 O.sub.5. aq with a hydrate content (i.e., aq content) in a range of 14 to 17% by weight. The nitridation preferably takes place in the presence of a fluxing agent such as ammonium carbonate or boric acid.

Abstract: The present invention relates to polymeric multinary azanes built up from units of the general formula [E(NR.sup.1 R.sup.2).sub.a (NR.sup.3).sub.b/2 ], wherein E may be B,Al,Ga,In,Si,Ge,Ti, Zr, Hf,V,Nb,Ta,Cr,Mo or W and R.sup.1,R.sup.2,R.sup.3 may be H, C.sub.1 -C.sub.6 alkyl, vinyl or phenyl; methods for the preparation of these polymers and their use as precursors for high-performance ceramics.

Abstract: The present invention relates to new trichlorosilylamino-alanes, new aluminosilazane compounds, new oligo or polyaluminosilazane compounds having the structural feature .tbd.Si--NH--Al, a silicon-aluminium nitride ceramic powder, ceramic material based on SiN and AlN, processes for the preparation of these substances and the use of the polyaluminosilazanes and of the ceramic materials.

Abstract: Oxonitrides with a perovskite of the general formula LnTaON.sub.2, where Ln is a rare-earth element, and which exhibit an enhanced brightness, are produced by annealing a powder mixture consisting of a Ta (V) compound and a Ln compound in a reducing atmosphere that contains ammonia. Added to the powder mixture being annealed is a mineralizing agent from the series of alkali metal or alkaline earth halides, Na.sub.3 AlF.sub.6, Na.sub.2 SiF.sub.6, AlF.sub.3 or of the ammonia salts of carbonic acid or a mono- or dicarboxylic acid with 1 to 4 C atoms in a quantity of 0.1 to 10 parts by weight, relative to 1 part by weight of the mixture of the Ta and Ln compounds. Such oxonitrides can be used as pigments that are yellow-orange to reddish brown in color.

Abstract: The present invention relates to polymeric boro- and aluminosilazanes corresponding to the general formula[(SiL.sub.2).sub.a (AlL.sub.2).sub.1-a L.sub.2 ].sub.xand[(SiL.sub.2).sub.a (BL).sub.1-a L.sub.2 ].sub.x,whereina=0-1whereinL means half a bridging --NR-group, or an organoamino (--NR) group, when L is attached to a silicon or aluminum atom, and wherein L means a hydrogen atom, half a bridging --NR-- group or an organoamino (--NR) group, when L is attached to a boron atom,in which each silicon and aluminum atom is triply coordinated by four nitrogen atoms and each boron atom by at least two nitrogen and at most one hydrogen atom, a process for the preparation of these polymers and their use as precursor compounds for ceramic high performance materials.

Abstract: An improved method for producing tantalum (V) nitride by means of nitriding an oxidic tantalum (V) compound is described. The Ta.sub.3 N.sub.5 product obtained in accordance with this method may be used as a red coloring pigment, particularly for coloring plastics and varnishes. An improved color intensity can be achieved and/or the reaction time can be shortened using the process in accordance with the invention. The process includes nitriding tantalum (V) hydrated oxide with the composition of the formula Ta.sub.2 O.sub.5 .multidot.aq with a hydrate content (i.e., aq content) in a range of 14 to 17% by weight. The nitridation preferably takes place in the presence of a fluxing agent such as ammonium carbonate or boric acid.

Abstract: Silicon boron nitride ceramics are produced from polyborosilizanes obtained from polymerized Cl.sub.3 Si--NH--BClX wherein X is --Cl or --NH--Si--Cl.sub.3.