In a system comprising an customer providing a service to a plurality of client devices, a method and system for providing an customer-specific digital certificate to a client device of the plurality of client devices is disclosed. The method comprises receiving, in an intermediate certificate authority, a pre-generated digital certificate and an encrypted client device private key encrypted according to a private key encryption key PrKEK, receiving, from the client device, a request for the customer-specific digital certificate, the request comprising at least one of client device identifying information and information identifying the customer, the request signed according to a pre-provisioned client device digital certificate, and transmitting the customer-specific digital certificate and the encrypted client device private key to the client device.

A module for implementing a protective barrier against liquid runoff and/or flooding comprising a retention member adapted to retain a liquid body on a front area located at a front side of the protective barrier, one or more sensors adapted to acquire at least one information about the module or about the liquid body, a relief valve, the relief valve being adapted to be actuated from a closed state to an open state according to the information acquired and provided by the sensor, and related system and method.

The present invention relates to a polymer expanding material in infiltration or seepage multi-water environment and a preparation method thereof, belonging to a technical field of polymer expanding foam materials. The polymer expanding material includes the following parts of materials by weight: 20-30 parts of rosin polyester polyol, 20-50 parts of isocyanate, 20-40 parts of PhireGuard® MB-512, 5-10 parts of HFO-1233zd, 1-2 parts of surfactant, 0.01-1 part of catalyst, and 0.01 parts of benzoyl chloride. The present invention has high sand fixing body strength, fast curing speed, good elastoplasticity, good pouring property and permeability, and good expanding property, which is suitable for infiltration or seepage multi-water environment, especially for dam infiltration, piping, and other problems during construction and subsequent operation of water conservancy projects.

The present invention relates to a retractable floodwall unit that comprises a foundation unit having a plurality of guide tracks along side walls of the foundation unit, a floodwall panel stowed in the foundation unit; and a power system for raising and lowering the floodwall panel. The foundation unit includes a first housing unit enclosing an actuator of the power system, and the floodwall panel includes a plurality of guides that mate with the guide tracks of the foundation unit.

A movable tsunami buffer dam has a unit configured such that a plurality of separate units, each of which having a shape in which a frame made of a light material is sandwiched by a pair of plates made of a light material, is stacked with said plates disposed in a pile; and a locking member for locking said unit to a ground surface such that said unit can rise up from said ground surface and collapse onto said ground surface. The separate units has a structure in which water from a tsunami can advance into a space formed between said plates by said frame.

A required thickness is ensured due to said unit being configured such that said separate units are stacked, and the manufacturing cost is reduced to a greater extent than in the case of a dam configured from a single separate unit of said required thickness, because the big size lumber for obtaining the units is very expensive. The unit is installed in a state of being collapsed on said ground surface at normal times, and when a tsunami arrives, said unit rising up due to the force of the tsunami and the buoyancy of the seawater, resisting the passage of the tsunami and reducing the power of the tsunami.

A debris flow drainage channel is provided. The debris flow drainage channel is applicable to debris flows with large gully bed longitudinal slopes. The debris flow drainage channel has an upstream step section and a downstream step section. The debris flow drainage channel also has a step pool disposed between the upstream step section and the downstream step section. The pool section has a cable net cage bottom protection, a cable net cage buffer layer and block stones.

A debris flow drainage channel is provided. The debris flow drainage channel is applicable to debris flows with large gully bed longitudinal slopes. The debris flow drainage channel has an upstream step section and a downstream step section. The debris flow drainage channel also has a step pool disposed between the upstream step section and the downstream step section. The pool section has a cable net cage bottom protection, a cable net cage buffer layer and block stones.

A water supply control system is disclosed that comprises a computer-implemented control system coupled to a plurality of gates, one or more pumps, and a plurality of sensors. The computer-implemented control system is configured to receive a request to transfer excess water from a non-water supply lake to a water supply lake and determine, based at least in part on data from the plurality of sensors and geographic locations of the non-water supply lake and the water supply lake, whether transferring water as requested will cause or worsen a flood event. In response to a determination that transferring water as requested will not cause or worsen a flood event, the computer-implemented control system is further configured to issue a command to cause a gate associated with a dam at the non-water supply lake to open such that water is transferred from the non-water supply lake to the water supply lake.

A stowable flood barrier system comprising: first and second barrier modules each comprising a frame and a barrier panel pivotable with respect to the frame between a stowed position and a deployed position, in which deployed position a base of the barrier panel is sealed against the frame and a free edge of the barrier panel extends clear of the frame to present a barrier segment between lateral edges of the barrier panel, wherein the first and second barrier modules are sealable together in the deployed position along the lateral edges of their respective barrier panels to form a linked flood barrier.

A laterally sliding type opening/closing gate of a torsion structure of reasonable cost is implemented. The gate includes: the torsion structure having a closed cross-section consisting of a thin wall installed such that it may cross a sluice and be composed such that its cross-section may make an in-plane rotation around a restriction point on the cross-section and that a torsion moment generated by an applied load and reaction force on the restriction point is transmitted to its terminal due to its torsion rigidity; and a rail that is installed such that it may cross the sluice; and a plurality of axle type supports that has a function of a restriction point and moves along the rail.