Abstract: User queries are received, with each query requesting a service from a server. Overlapping experiments are performed on at least a portion of the queries, with each experiment modifying one or more parameters associated with the queries or parameters associated with processing of the queries, and with the experiments organized into layers. Two or more experiments in different layers are allowed to be performed on the same query, and for any given layer, at most one experiment is allowed to be performed on the same query.

Abstract: User queries are received, with each query requesting a service from a server. Overlapping experiments are performed on at least a portion of the queries, with each experiment modifying one or more parameters associated with the queries or parameters associated with processing of the queries, and with the experiments organized into layers. Two or more experiments in different layers are allowed to be performed on the same query, and for any given layer, at most one experiment is allowed to be performed on the same query.

Abstract: User queries are received, with each query requesting a service from a server. Overlapping experiments are performed on at least a portion of the queries, with each experiment modifying one or more parameters associated with the queries or parameters associated with processing of the queries, and with the experiments organized into layers. Two or more experiments in different layers are allowed to be performed on the same query, and for any given layer, at most one experiment is allowed to be performed on the same query.

Abstract: A method of operating a fan control system associated with a radiator may include rotating a fan in a first direction at an operating speed to direct cool air toward the radiator for a first predetermined period of time. After expiration of the first predetermined period of time, rotation of the fan in the first direction may be decelerated. The method may also include accelerating the fan in a second direction opposite to the first direction and rotating the fan in the second direction at a predetermined speed for a second predetermined period of time. After expiration of the second predetermined period of time, rotation of the fan in the second direction may be decelerated, and the fan may then be accelerated in the first direction to the operating speed.

Abstract: A method of operating a fan control system associated with a radiator may include rotating a fan in a first direction at an operating speed to direct cool air toward the radiator for a first predetermined period of time. After expiration of the first predetermined period of time, rotation of the fan in the first direction may be decelerated. The method may also include accelerating the fan in a second direction opposite to the first direction and rotating the fan in the second direction at a predetermined speed for a second predetermined period of time. After expiration of the second predetermined period of time, rotation of the fan in the second direction may be decelerated, and the fan may then be accelerated in the first direction to the operating speed.

Abstract: A pressurized cyclonic combustion method and a cylindrical burner apparatus for pressurized combustion of particulate solid fuels to produce a pressurized clean effluent gas. In the burner, the particulate solids such as wood chips are fed tangentially into a primary combustion chamber at its inlet end and flow at high tangential velocity in a helical path through the burner. Oxygen-containing combustion gas such as air is supplied tangentially at high velocity through multiple ports spaced along the burner length to maintain and/or increase the high tangential velocity and produce high centrifugal forces on the particulate solids and provide for prolonged combustion and produce high burner volumetric heat release rates exceeding about 400,000 Btu/hr ft.sup.3. A choke opening is provided centrally located at the combustion chamber outlet end for promoting prolonged combustion of solid fuel paarticles upstream of a quench zone. A secondary combustion chamber is provided downstream of the choke opening.

Abstract: A pressurized cyclonic combustion method and a cylindrical burner apparatus for pressurized combustion of particulate solid fuels to produce a pressurized clean effluent gas. In the burner, the particulate solids such as wood chips are fed tangentially into a primary combustion chamber at its inlet end and flow at high tangential velocity in a helical path through the burner. Oxygen-containing combustion gas such as air is supplied tangentially at high velocity through multiple ports spaced along the burner length to maintain and/or increase the high tangential velocity and produce high centrifugal forces on the particulate solids and provide for prolonged combustion and produce high burner volumetric heat release rates exceeding about 400,000 Btu/hr ft.sup.3. A choke opening is provided centrally located at the combustion chamber outlet end for promoting prolonged combustion of solid fuel particles upstream of a quench zone. A secondary combustion chamber is provided downstream of the choke opening.

Abstract: A pressurized cyclonic combustion method and a cylindrical burner apparatus for pressurized combustion of particulate solid fuels to produce a pressurized clean effluent gas. In the burner, the particulate solids such as wood chips are fed tangentially into a primary combustion chamber at its inlet end and flow at high tangential velocity in a helical path through the burner. Oxygen-containing combustion gas such as air is supplied tangentially at high velocity through multiple ports spaced along the burner length to maintain and/or increase the high tangential velocity and produce high centrifugal forces on the particulate solids and provide for prolonged combustion and produce high burner volumetric heat release rates exceeding about 400,000 Btu/hr ft.sup.3. A choke opening is provided centrally located at the combustion chamber outlet end for promoting prolonged combustion of solid fuel particles upstream of a quench zone. A secondary combustion chamber is provided downstream of the choke opening.