Described are a test apparatus and a test method for the wetted perimeter of coal seam water injection. In the test apparatus, a columnar insulator is provided between an upper electrode and a lower electrode, circular insulating tapes are located at the outer edges of the upper electrode and the lower electrode, a circular reverse osmosis membrane is provided at the middle of the circular insulating tape, the upper electrode, lower electrode, circular insulating tapes and circular reverse osmosis membrane form an enclosed chamber which is filled with solid sodium chloride, and cotton yarns are packed among the upper resin backing plate, lower resin backing plate, circular insulating tapes and the inner walls of water permeable perforated pipes. The upper electrode is provided with an electrode lead which passes through the columnar insulator, the lower electrode and the lower resin backing plate and goes out from the tail connecting end.

Personnel and vehicle collision avoidance devices configured to be used in collision avoidance systems are disclosed. The collision avoidance devices are configured to be aware of the context (e.g. position, location, state, status, etc.) in which the person or vehicle is. This awareness allows the devices to avoid transmitting non-hazardous proximity warnings when the context does not warrant the transmission of proximity warnings, and to transmit special critical proximity warnings when the context warrants the transmission of such proximity warnings. To detect the context, the devices comprise one or more context-awareness mechanisms (e.g. user input interfaces, sensors, infra-red receivers, etc.), each of which being capable of detecting one or more particular contexts. A collision avoidance system comprising these personnel and vehicle collision avoidance devices is also presented.

A personal safety system in the form of a refuge chamber includes at least one main room and a cooling device provided for cooling the ambient air of the main room in the form of a CO.sub.2 cooling system (10). The CO.sub.2 cooling system (10) has a heat exchanger (28) and a first and a second pressure reducer (20, 32) upstream and downstream of heat exchanger (28), respectively. The heat exchanger (28) has a plurality of alternatingly or cyclically usable cooling coils. A process is provided for the operation of such a refuge chamber.

A personal safety system in the form of a refuge chamber includes at least one main room and a cooling device provided for cooling the ambient air of the main room in the form of a CO.sub.2 cooling system (10). The CO.sub.2 cooling system (10) has a heat exchanger (28) and a first and a second pressure reducer (20, 32) upstream and downstream of heat exchanger (28), respectively. The heat exchanger (28) has a plurality of alternatingly or cyclically usable cooling coils. A process is provided for the operation of such a refuge chamber.

An overhead railway and trolley for transporting miners out of a mine. The railway is formed by connected rails that are mounted to a roof of a mine. The trolley is mounted to a bottom flange of the rails and includes wheel assemblies having at least two wheels mounted side-by-side, and each is configured to engage and roll along a top surface of the bottom flange. The trolley has a clicker that is configured to engage protrusions extending away from the bottom flange. The clicker permits the trolley to travel out of the mine but prevents it from traveling into the mine. The trolley also includes a pair of handles that are configured to be gripped by a miner standing on a floor of the mine as he travels from the beginning of the railway to the ending (i.e., the egress direction).

An overhead railway and trolley for transporting miners out of a mine. The railway is formed by connected rails that are mounted to a roof of a mine. The trolley is mounted to a bottom flange of the rails and includes wheel assemblies having at least two wheels mounted side-by-side, and each is configured to engage and roll along a top surface of the bottom flange. The trolley has a clicker that is configured to engage protrusions extending away from the bottom flange. The clicker permits the trolley to travel out of the mine but prevents it from traveling into the mine. The trolley also includes a pair of handles that are configured to be gripped by a miner standing on a floor of the mine as he travels from the beginning of the railway to the ending (i.e., the egress direction).

Personnel and vehicle collision avoidance devices configured to be used in collision avoidance systems are disclosed. The collision avoidance devices are configured to be aware of the context (e.g. position, location, state, status, etc.) in which the person or vehicle is. This awareness allows the devices to avoid transmitting non-hazardous proximity warnings when the context does not warrant the transmission of proximity warnings, and to transmit special critical proximity warnings when the context warrants the transmission of such proximity warnings. To detect the context, the devices comprise one or more context-awareness mechanisms (e.g. user input interfaces, sensors, infra-red receivers, etc.), each of which being capable of detecting one or more particular contexts. A collision avoidance system comprising these personnel and vehicle collision avoidance devices is also presented.

Personnel and vehicle collision avoidance devices configured to be used in collision avoidance systems are disclosed. The collision avoidance devices are configured to be aware of the context (e.g. position, location, state, status, etc.) in which the person or vehicle is. This awareness allows the devices to avoid transmitting non-hazardous proximity warnings when the context does not warrant the transmission of proximity warnings, and to transmit special critical proximity warnings when the context warrants the transmission of such proximity warnings. To detect the context, the devices comprise one or more context-awareness mechanisms (e.g. user input interfaces, sensors, infra-red receivers, etc.), each of which being capable of detecting one or more particular contexts. A collision avoidance system comprising these personnel and vehicle collision avoidance devices is also presented.

Example inflatable air barriers are disclosed herein. Some example barriers disclosed herein include one or more inflatable tubes for maintaining a sealed airlock leading to an underground shelter. Such shelters provide miners with temporary refuge in the event of a mining incident involving the release of contaminated air. Some example barriers disclosed herein include one or more of the following: an inflatable tube with an air permeable section, a resiliently compressible foam body or other resilient member for supporting a deflated tube, a magnet for providing a secure seal, an inflatable tube with interchangeable end caps, elastic bands for securing the position of an inflatable tube, or an inflatable tube with one or more windows.

Example inflatable air barriers are disclosed herein. Some example barriers disclosed herein include one or more inflatable tubes for maintaining a sealed airlock leading to an underground shelter. Such shelters provide miners with temporary refuge in the event of a mining incident involving the release of contaminated air. Some example barriers disclosed herein include one or more of the following: an inflatable tube with an air permeable section, a resiliently compressible foam body or other resilient member for supporting a deflated tube, a magnet for providing a secure seal, an inflatable tube with interchangeable end caps, elastic bands for securing the position of an inflatable tube, or an inflatable tube with one or more windows.