A linear compressor includes a cylinder that defines a compression space of a refrigerant and has a cylindrical shape, and a piston disposed in the cylinder and reciprocating along an axis of the cylinder. The cylinder includes a gas inlet on an outer circumferential surface and a supply port radially passing through the cylinder and communicating with the gas inlet. The gas inlet includes a first gas inlet and a second gas inlet disposed behind the first gas inlet, and the supply port includes a first supply port communicating with the first gas inlet and a second supply port disposed behind the first supply port and communicating with the second gas inlet. A flow rate passing through the first supply port is different from a flow rate passing through the second supply port.

A linear compressor includes a cylinder that defines a compression space of a refrigerant and has a cylindrical shape, and a piston disposed in the cylinder and reciprocating along an axis of the cylinder. The cylinder includes a gas inlet on an outer circumferential surface and a supply port radially passing through the cylinder and communicating with the gas inlet. The gas inlet includes a first gas inlet and a second gas inlet disposed behind the first gas inlet, and the supply port includes a first supply port communicating with the first gas inlet and a second supply port disposed behind the first supply port and communicating with the second gas inlet. A flow rate passing through the first supply port is different from a flow rate passing through the second supply port.

A blower including a duct configured to allow air to flow in and out and a plurality of blades disposed to be parallel to the duct. Each of the blades including a first part, a second part, and an airflow generator configured to generate airflow in a direction from the inlet to the outlet by applying a voltage between the first electrode and the second electrode which are disposed between a first electrode on a side of the inlet, a second electrode on a side of the outlet, and a dielectric. In a cross section of the blade in the airflow direction when cut in a cross section perpendicular to each of the blades, the first part has a thickness decreasing in a direction toward the inlet and the second part has a thickness decreasing in a direction toward the outlet.

The present invention relates to an inflatable tandem surf bodyboard, methods of making, and a kit that includes a tandem surf bodyboard, an air pump, a maintenance kit, and a carry bag. The tandem surf bodyboard can accommodate more than one rider, allowing two riders to share and surf a wave. The inflatable tandem surf bodyboard comprises a base that is cut into the shape of a surf bodyboard, a base fabric layer applied over the base, an intermediate portion material that forms an air chamber, an upper layer that is fastened to the intermediate portion material, a deck pad layer that is applied over the upper layer, a first rail layer that is applied around the perimeter of the surf bodyboard sealing the edges, and a second rail layer that is applied over the first rail layer. An air inlet allows the tandem surf bodyboard to be inflated.

The present invention relates to an inflatable tandem surf bodyboard, methods of making, and a kit that includes a tandem surf bodyboard, an air pump, a maintenance kit, and a carry bag. The tandem surf bodyboard can accommodate more than one rider, allowing two riders to share and surf a wave. The inflatable tandem surf bodyboard comprises a base that is cut into the shape of a surf bodyboard, a base fabric layer applied over the base, an intermediate portion material that forms an air chamber, an upper layer that is fastened to the intermediate portion material, a deck pad layer that is applied over the upper layer, a first rail layer that is applied around the perimeter of the surf bodyboard sealing the edges, and a second rail layer that is applied over the first rail layer. An air inlet allows the tandem surf bodyboard to be inflated.

The disclosed systems and methods are related to a positive displacement compression for use in various applications including gas processing, air conditioning, refrigeration, etc., to produce an isothermal compression to enhance the compression efficiency. The heat exchange enhanced compression is conducted by the use of cylinders partially filled with incompressible fluid (e.g., oil) acting as a piston compressing working fluid (e.g., CO.sub.2). The isothermal compression is contemplated in various modifications. A variety of heat exchange (cooling) techniques may be arranged either within the compression chamber or the compression process may be embedded in the heat exchanger to cool down the working fluid (for example, CO.sub.2).

A fluid mover and method of operating includes a pair of spaced electrodes, a power supply electrically coupled to the pair of spaced electrodes, and at least one environment sensor. The fluid mover also includes a controller configured to controllably operate at least one of the power supply or the pair of spaced electrodes.

A power end frame assembly for a reciprocating pump that includes a first and second end plate segment each including annular bearing support surfaces configured to support a crankshaft bearing assembly. At least one middle plate segment is disposed between the first and second end plate segments and includes an annular bearing support surface configured to support a crankshaft bearing assembly. The annular bearing support surfaces of the first and second end plate segments and the at least one middle plate segment each have a diameter and are coaxially aligned. The diameter of at least one of the first and second end plate segments is different from the diameter of the at least one middle plate segment to facilitate insertion and removal of the crankshaft bearing assembly from the power end frame assembly.

A nano gas pump for generating gas flow, gas compression and gas rarefication is disclosed, which provides up to several orders of magnitude pressure difference, operates over a wide range of pressure from several millitorr to several atmospheres, and with pumping speeds from several nano liters to several liters per minute. The nano gas pump does not require any moving parts and generate gas flow using steep temperature gradients of more than 100 milli Kelvin over a mean free path of the local gas in the direction of the gas flow. Temperature gradients are created and restricted mostly to the gas doing the work, through an arrangement of PNP, NPN, PP, NN thermoelectric segments together with conductive interconnects. Contact resistance which drastically reduces the efficiency of a nanoscale thermoelectric heat pump is mitigated by overlapping thermoelectric segments and electric connections. Several exemplary embodiments are described based on linear (straight) and non-linear (turn) gas flow paths. Various staging configurations are also described.

A linear compressor includes a cylinder that defines a compression space of a refrigerant and has a cylindrical shape, and a piston disposed in the cylinder and reciprocating along an axis of the cylinder. The cylinder includes a gas inlet on an outer circumferential surface and a supply port radially passing through the cylinder and communicating with the gas inlet. The gas inlet includes a first gas inlet and a second gas inlet disposed behind the first gas inlet, and the supply port includes a first supply port communicating with the first gas inlet and a second supply port disposed behind the first supply port and communicating with the second gas inlet. A flow rate passing through the first supply port is different from a flow rate passing through the second supply port.