A wireless communication system (300) and method for providing two-way trunked communication. A controller (305) allocates frequencies to a plurality of transceivers (312-324). For a call initiated by a dispatcher (330) of the system, the controller (305) assigns only a first frequency, for downlink communication from a transceiver (312) to mobile stations (350, 352). For a call initiated by a mobile station (350), the controller (305) assigns a second frequency for uplink communication from the mobile station (350) to a transceiver (312), and a third frequency for downlink communication of a repeat transmission from the transceiver (312) to mobile stations (350, 352). Frequency utilisation may be improved, particularly when a high proportion of call time is for dispatcher calls.

Method for production of nanoporous activated carbons with high nitrogen contents, characterised in that chitosan is swelled, next it is subjected to protonisation and depolymerisation, then it is mixed with a solution of carbonates and heated in an atmosphere with low chemical reactivity. Afterwards, it is treated with acid, washed out, filtered off and dried. For the swelling, distilled water is used. Depolymerisation and protonisation are carried out using an aqueous solution of HC1. After the depolymerisation process, an aqueous solution of sodium carbonate is added. The heating is carried out under nitrogen at 600-800°C for at least 1 hour. After heating, HC1 or HNO3 is used.

The present invention relates to an electrical energy measuring system (5) for a mobile electrical power system (11a, 21a) comprising an electrical energy storage (12, 22) connected by an electrical energy transmission system to at least one electrical energy receiver and/or at least one electrical energy source, and to at least one output connectable to a stationary electrical power system (3), comprising an input measuring system (51 ); a system of digital processing of signals (52); and at least one main register (54) which is connected to an output of said system of digital processing of signals (52) and in which electrical measuring signals representing electrical energy flow through the electrical transmission line of the storage (12, 22) are registered, wherein the measuring system is characterized in that it additionally comprises at least two registers comprising: at least one first register (541, 5411 ) in which EE measuring signals of electrical energy flowing between the EE storage (12, 22) of the system MEPS and the system SEPS, representing an EE flow in an output electrical energy transmission line (133, 233), are registered, and the second register (542) in which EE measuring signals of electrical energy flowing within the system MEPS (11a) between the EE storage (12) and the EE receiver and/or the EE source, representing an EE flow in an receiver/source electrical energy transmission line (134), are registered; which registers are connected to the output of the system of digital processing of signals (52) through a switching redirection system (56) in which a through path of a signal transmission is dependent on a state of its control inputs, wherein the switching redirection system transfers a signal from one of its inputs, which is connected to the output of the system of digital processing of signals (52), to a selected one of its at least two outputs, wherein each of these at least two outputs is connected to a different of the at least two registers (541, 5411, 542), depending on a state of a signal at the first control input (5614) thereof, wherein the first control input is connectable to a source (61 ) of a signal of a status of a connection of the output of EE transmission line of the system MEPS to the system SEPS.

A composite passive armor protection having geometric solids embedded in a matrix, characterized in that it consists of the parallel non- adjacent plates (1, 2), wherein the upper plate (2) has grooves (3), in which are resting the geometric solids (4) embedded in a light alloy matrix (5), preferably to a level above one half of their total height, while the space between the parallel plates is a layer of light alloy (6).

A composite passive armor protection comprises a structure, embedded in the light alloy matrix (1), wherein said structure is made of geometric solids (2), resting on brackets (3), passing through the holes in plate (4), wherein said brackets (3) have precuts in the walls located at a height above and below the plate (4), wherein in said precuts in the walls are secured rods (5) in such a way that they form a grid, wherein the geometric solids (2) are embedded in the light alloy matrix (1), preferably to a level above one half of their total height, and wherein the rods (5) are preferably fixed in such a way that their longitudinal axes coincide with the axes of the geometric solids (2).

A composite passive armor protection comprises a structure embedded in the light alloy matrix (1), wherein said structure is made of elements in the form of geometric solids (2), resting on a frame in the form of a grid made of the permanently connected layers of tubes (3), wherein preferably through the tubes (3) are passing fibers (4), and the geometric solids (2) are embedded in the light metal alloy matrix (1) to a level above one half of their total height.

The invention solves a problem of a carriage (1) assembly for an airplane transporting system on an airport apron, from a parking location to a runway and from a landing to the parking location with an airplane's engine off. The carriage assembly is formed by a guiding groove (3) with a rectangular cross-section, a floor (5) of which being provided with lower guide rails (6), and side walls (7) of which being provided with side guide rails (8), and the carriage (1) is constituted by a spatial structure (9), having a bottom part (10) and side parts (11), the carriage (1) being provided with a lower vehicle wheels set (12), fixed at the bottom part (10) of the carriage (1), and a side vehicle wheels set (13) fixed at both side parts (11) of the carriage (1).

A composite passive armor protection comprises a structure, embedded in the light alloy matrix (1), wherein said structure is made of geometric solids (2), resting on brackets (3), passing through the holes in plate (4), wherein said brackets (3) have through-holes located at a height above and below the plate (4), wherein in said through-holes are secured rods (5) in such a way that they form a grid, wherein the geometric solids (2) are embedded in the light alloy matrix (1), preferably to a level above one half of their diameter, and wherein the rods (5) are preferably fixed in such a way that their longitudinal axes coincide with the axes of the geometric solids (2).

Method for testing the abrasive wear of machine parts in high temperature and with high unit pressures and a unit for testing the abrasive wear of machine parts in high temperature and with high unit pressures, enabling the establishing of abrasive wear occurring during the operation of machinery exposed to high temperature and high unit pressures, where the steel becomes plastic, eg. in hot forging tools. The method consists of a counterpiece (4) having the form of a rod being placed axially in a container (1) heated to a temperature in the range of (500-1000) K, ending in a sample (5) with an axial hole (6) and a side channel (7), and then is pressed out through a slot closed with a sliding element (8), created between the surface of the sliding element (8) and the side channel (7) in the sample (5), by acting with a shaft (9) of a punch (10) on the counterpiece (4) placed in the opening of the sample (5), creating unit pressures in the range of (300-1200) MPa, whereas the speed of movement of the sliding element relative to the slot is 100 m/min.

The object of the invention is the lift used primary in wheelchairs for adjusting the positioning of the seat, and simultaneously for changing the positioning of the person sitting in the wheelchair. According to the invention, the upper frame (1) consists of a horizontal stable part (2) and tilt plate (3). The tilt plate (3) is rotationally and slidably deposited with bolts (8) in the guides (4) of the stable part (2). The second support of the tilt plate (3) is the tilt arms (5) which are connected with the tilt plate (3) rotationally with the use of the bolts (6). The tilt arms (5) are deposited with the lower end in the bolt (7), fixed in the stable part (2) of the upper frame (1). The tilt system constitutes an actuator (9), deposited with one end rotationally in the stable part (2), and with the second end rotationally fixed with the lever (10). The lever (10) is permanently deposited on the axis (11), where also the cam (12) is seated. In the cam (12) there is a slit (13), where the bolt (14) seated in arms (5) is displaced. The basis of the lift is the lower frame (16), where the arms (17) and (18) of the scissor jack mechanism are rotationally fixed.