Abstract: The invention relates to a communication system and a method for providing a mobile telecommunication service. A communication network transmits messages on the basis of at least one internet protocol. A network connection computer connects an access network for mobile computers and the communication network. The access network is equipped with several access points comprising corresponding access point connection computers, which are configured to create a communication connection between variable access points and the mobile computers. An authorization verification computer establishes and manages trusted relationships between several communication elements. The network connection computer and the access point connection computer are configured to execute packet filtering during the receipt and transmission of messages for the secure protection of the communication system.

Abstract: An extruder screw includes a screw shaft with several screw elements which can be or have been detachably slipped onto this shaft, the screw shaft having an external gearing and the screw elements having an internal gearing which engage the external gearing. The profile of the teeth of the external and the internal gearing are asymmetric, whereby in relation to a preferred direction of rotation of the extruder screw, the torque-transferring flanks of the teeth of the external and the internal gearing make a smaller angle with the perpendicular to the axis of rotation than do respective opposing flanks, at the teeth, of the external and internal gearing.

Abstract: The invention provides a compact and economical welding control system having an integrated power section. To this end, a switching module is provided for the power section of a welding control system. The switching module has a switching device, at least one cooling body, a current supply and an insulating element which provides a potential-free coolant arrangement. The invention is advantageous in that the potential-free coolant arrangement allows the coolant bodies to be shortened so that less space is required inside the control system and the control system can therefore have a more compact structure. The invention enables even the requirements in terms of the coolant bodies to be reduced, allowing the use of cost-effective cooling tubes or even cooling pipes that are directly connected to the cooling body.

Abstract: The invention provides a compact and economical welding control system having an integrated power section. To this end, a switching module is provided for the power section of a welding control system. The switching module has a switching device, at least one cooling body, a current supply and an insulating element which provides a potential-free coolant arrangement. The invention is advantageous in that the potential-free coolant arrangement allows the coolant bodies to be shortened so that less space is required inside the control system and the control system can therefore have a more compact structure. The invention enables even the requirements in terms of the coolant bodies to be reduced, allowing the use of cost-effective cooling tubes or even cooling pipes that are directly connected to the cooling body.

Abstract: A solar panel, through which a fluid is circulated, includes a transparent central panel, with a number of channels extending through the panel from one end to another. A manifold is attached to each end of the transparent central panel so that distributing chambers within the manifolds direct the fluid to move between adjacent channels within the central panel. The solar panel additionally includes a transparent support structure above the central panel and a lower support structure below the panel. Dark, opaque material below the central panel absorbs heat and warms the fluid.

Abstract: An extruder screw, consisting of a screw shaft with several screw elements, which can be or have been detachably slipped onto this shaft, the screw shaft having an external gearing and the screw elements having an internal gearing, which engages the external gearing, the profile of the teeth of the external and the internal gearing being asymmetric, whereby in relation to a preferred direction of rotation of the extruder screw, the torque-transferring flanks of the teeth of the external and the internal gearing make a smaller angle with the perpendicular to the axis of rotation than do respective opposing flanks, at the tooth, of the external and internal gearing.

Abstract: A gas burner includes a distribution chamber formed between walls within the burner, with the walls extending parallel to one another. A shut-off valve, adjacent to an inlet hole through which a gas, preferably hydrogen, used as a fuel, enters the distribution chamber, closes when the pressure of the gas being supplied drops below a predetermined level, so that air is not allowed to flow backward into the apparatus supplying the gas, thus preventing potentially explosive conditions.

Abstract: An electrical power generator includes a concave reflector formed to reflect light parallel to its central axis toward the central axis, on a surface of an energy receiving structure that preferably has a surface covered with photovoltaic cells facing outward from the central axis in directions perpendicular to the central axis. A cooling fluid is circulated though channels in a structure mounting the photovoltaic cells. The concave reflector is mounted to pivot about two axes of revolution, being driven by one or two motors to track the movement of the sun across the sky.

Abstract: An electrolytic generator for producing hydrogen and oxygen switches polarities of electrodes to minimize the accumulation of electroplated electrode material driven from one electrode to the other. The generator contains two or more electrolytic cells in a lower portion, with an upper portion, including gas receiving receptacles. Preferably, water extends upward past a division between the upper and lower portions. In a first version, the upper portion, which is attached for gas collection through flexible hoses, is moved from one cell in the lower portion to another when the polarity is switched. In a second version, the upper portion remains stationary while the lower portion is moved to another upper portion as the polarity is switched.

Abstract: A system includes a mobile telephone, such as a cellular telephone, and a base unit that is formed as an article that is ordinarily worn by the user of the telephone. The telephone transmits a radio-frequency proximity signal that is received in the base unit, which sounds an alarm if the distance between the telephone and the base unit increases so that the proximity signal is not received. The base unit may also generate a radio-frequency signal causing the telephone to produce an audible signal so that it can be easily found.

Abstract: A simple and efficient means of checking the registration authorization is proposed by the method and the device for checking the registration authorization prior to the start of the re-registration process based on a registration query from a mobile radio terminal to at least one access device for an intra-domain handover in a mobile communication network. In the network, a token which has been sent by an access device to a mobile radio terminal and has been stored in at least one trust table of at least one access device, is received by at least one further access device during a registration query from a mobile radio terminal and compared with tokens stored in at least one trust table prior to the start of the registration for the purpose of verifying the registration authorization, and the registration is started if an authorization is present.

Abstract: A thermochemically stable oxidic thermal insulating material presenting phase stability, which can be used advantageously as a thermal insulating layer on parts subjected to high thermal stress, such as turbine blades or such like. The thermal insulating material can be processed by plasma spraying and consists preferably of a magnetoplumbite phase whose preferred composition is MMeAl11O19, where M is La or Nd and where Me is chosen from among zinc, the alkaline earth metals, transition metals, and rare earths, preferably from magnesium, zinc, cobalt, manganese, iron, nickel and chromium.

Abstract: The invention relates to a thermochemically stable oxidic thermal insulating material presenting phase stability, which can be used advantageously as a thermal insulating layer on parts subjected to high thermal stress, such as turbine blades or such like. The thermal insulating material can be processed by plasma spraying and consists preferably of a magnetoplumbite phase whose preferred composition is MMeAl11O19, where M is La or Nd and where Me is chosen from among the alkaline earth metals, transitional metals and rare earths, preferably from magnesium, zinc, cobalt, manganese, iron, nickel and chromium.

Abstract: A thermochemically stable oxidic thermal insulating material presenting phase stability, which can be used advantageously as a thermal insulating layer on parts subjected to high thermal stress, such as turbine blades or such like. The thermal insulating material can be processed by plasma spraying and consists preferably of a magnetoplumbite phase whose preferred composition is MMeAl11O19, where M is La or Nd and where Me is chosen from among zinc, the alkaline earth metals, transition metals, and rare earths, preferably from magnesium, zinc, cobalt, manganese, iron, nickel and chromium.

Abstract: Apparatus for contact exposing each side of a substrate to a different image on a mask includes a first-side imaging station for imaging the first side of the substrate, a second-side imaging station for imaging the second side thereof, an intermediate station between the imaging stations for inverting the substrate. In each imaging station, the substrate is moved longitudinally with a transport carriage, from which it is transferred to an imaging carriage to be driven to an imaging point at which illumination through the mask occurs. The imaging carriage moves in both longitudinal and transverse directions, providing for both exposure to a mask covering the substrate and for step-and-repeat exposure of multiple portions of the substrate to a smaller image. Before exposure, the top surface of the substrate is aligned to be parallel to the adjacent mask, fiducial markings in the substrate are aligned with fiducial markings on the mask, and air is evacuated from the area between the mask and the substrate.

Abstract: A test system for applying electrical tests to circuits on flexible substrates includes a first transport system moving frames, each of which is configured for holding a single such flexible substrate, a loading station in which the substrates are individually loaded onto the frames, a testing station in which the electrical tests are applied, and an unloading station in which the substrates are removed from the frames. Within the testing station, each frame is disengaged from the first transport system and fastened to a second transport system, which moves the frame in a pattern causing a number of segments of the substrate within the frame to be placed between probe arrays adjacent each of the opposite sides of the substrate. These arrays are each aligned with visual markings on the adjacent side of the substrate, and the arrays are then moved into engagement with the substrate for the testing process.

Abstract: An electronic device fastened to a baggage item includes a microprocessor, data storage, radio circuits, and a radio antenna. When the baggage item is checked by a traveler at an airport, identification information corresponding to a code printed on the traveler's boarding pass is transmitted to the electronic device and recorded in its data storage. The traveler then proceeds to the gate of his flight, where the code printed on his boarding pass is read. The electronic device transmits stored identification information, so that the baggage item is loaded onto the aircraft only when the code printed on the boarding pass has been read at the gate.

Abstract: A capsule, which is resistant to stomach acids, is shaped like a medical pill, and can be orally taken in the same manner. This capsule includes a pair of plastic shells surrounding a circuit board, and, in an alternative embodiment, a microprocessor. The circuit board includes memory circuits for storing personal identification data, which is made available when needed, but which cannot be changed without a code number or word. A battery, an antenna for wireless access, and a metal disk supporting the location of the capsule with metal detectors may be added. A device with such additional features can also be used to identify luggage, to be transported on commercial airliners, as belonging to the holder of the ticket and/or boarding card.