Abstract: The present application includes a rotor blade having an erosion protective coating, the coating being a cermet material configured to protect against erosion during the operation of the rotor blade. Further, the present application includes a method of selectively applying the erosion protective coating, a method of selectively repairing/reapplying the erosion protective coating, and a process of developing an erosion surface model map of an optimized erosion protective coating pattern and thickness.

Abstract: A turbomachine component is provided having at least two sub-components that are separated by a parting joint and each have a sealing surface at the parting joint, at least one of the two sealing surfaces being convex in order to form a linear contact of the two sealing surfaces. At least one of the sealing surfaces has a coating on it which includes a hard material, is a maximum of 30 ?m thick and is applied using a vapour deposition method, or a coating which includes a chrome-containing alloy, is a maximum of 30 ?m thick and is applied by a vapour deposition method, or is a maximum of 300 ?m thick and applied using a thermal spraying method.

Abstract: Methods for modifying a plurality of cooling holes of a component include disposing a recess-shaped modification in a recess of the component comprising a plurality of cooling hole outlets, wherein the recess-shaped modification is formed to substantially fill the recess and comprising a plurality of modified cooling holes passing there through. The method further includes aligning the plurality of modified cooling holes of the recess-shaped modification with the plurality of cooling hole outlets of the component, and, bonding the recess-shaped modification disposed in the recess to the component, wherein the plurality of modified cooling holes of the recess-shaped modification is fluidly connected with the plurality of cooling holes of the component.

Abstract: A turbine assembly is provided having a hollow aerofoil having a cavity with an impingement tube insertable inside the cavity and used for impingement cooling of an inner surface of the cavity, and a platform arranged at a radial end of the hollow aerofoil, and a cooling chamber used for cooling of the platform which is arranged relative to the hollow aerofoil on an opposed side of the platform. The cooling chamber is limited at a first radial end from the platform and at an opposed radial second end from a cover plate. The impingement tube is formed from a leading piece and a trailing piece. The leading piece extends in span wise direction at least completely through the cooling chamber from the platform to the cover plate and the trailing piece terminates in span wise direction at the platform.

Abstract: A washing water pump device includes a washing water pump and a control unit configured to control operation of the washing water pump. The control unit is configured to receive and evaluate signals relating to a state of a vehicle and/or ambient conditions of the vehicle. The power (L) of the washing water pump is dynamically actuatable based on the received and evaluated signals.

Abstract: A pumping system for moving water of a swimming pool includes a water pump, a variable speed motor, and an arrangement for controlling the variable speed motor. The pumping system further includes an auxiliary device operably connected to the arrangement for controlling, and an arrangement for providing two-way communication between the arrangement for controlling and the auxiliary device. The arrangement for controlling is capable of receiving a parameter from the auxiliary device through the arrangement for providing two-way communication. In one example, the arrangement for controlling is capable of independently controlling the variable speed motor without receipt of a parameter from the auxiliary device. In addition or alternatively, the arrangement for controlling is operable to selectively alter operation of the motor based upon the parameter.

Abstract: A method of making safe operation of a rotary assembly of a turbomachine including a turbine and a rotary machine, the method anticipating an event of exceeding a predetermined threshold speed by repetitively performing a prediction cycle including: measuring magnitudes relating to operation of the turbomachine, including real speed of rotation of its rotary assembly; based on the magnitudes, estimating driving and resisting torques applied to the rotary assembly; preparing a representative value representative of the difference between these two torques; and calculating a predicted speed of rotation for the rotary assembly at a given time horizon based on the representative value and the real speed of rotation. An action is taken on the operation of the turbomachine to limit an extent to which its rotary assembly exceeds the threshold speed in the event of the predicted speed of rotation exceeding the threshold speed.

Abstract: Disclosed are systems and methods for monitoring the performance of a plurality of reciprocating compressors having components made by at least two different manufacturers. A source of reciprocating compressor data associated with a plurality of reciprocating compressors and a source of reciprocating compressor component specifications associated with the plurality of reciprocating compressors are in communication with a computer processor.

Abstract: Urea solution pumps having leakage bypass flowpaths and methods of operating the same are disclosed. Certain embodiments are pump apparatuses including an inlet passage in flow communication with a source of urea solution and a pump chamber, an outlet passage in flow communication with the pump chamber and an exhaust after treatment system, a diaphragm facing the pump chamber and coupled with an actuator, a first housing member coupled with a second housing member form a seal around the pumping chamber, a leak collection chamber surrounding the seal, and a return passage in flow communication with the leak collection chamber and the inlet passage. Urea solution that leaks from the pump chamber past the seal is received by the leak collection chamber and flows through the return passage to the pump inlet passage.

Abstract: A method for mechanically heating a liquid mixture of substances is described. In a liquid-ring pump (1), a foam phase is compressed and the compression heat is transferred to the mixture of substances. An apparatus designed as a liquid-ring pump (1) for mechanically heating a liquid mixture of substances is also described. Said liquid-ring pump (1) comprises an impeller (12) eccentrically arranged in a cup-shaped pump housing (11) as well as a tangential suction port (13) and a tangential delivery port (14). A gas port (15) for introducing an inert process gas extends into the suction port (13) and/or into the cup-shaped pump housing (1).

Abstract: Compressor device that comprises a compressor element that is equipped with a compression chamber with at least one coolant inlet, and which furthermore comprises a gas outlet, a gas/coolant separation tank connected to it, and, a cooling circuit with a cooler that extends between the separation tank and the coolant inlet, and which is equipped with control means to adjust the temperature of the coolant flow supplied to the compressor element, whereby the aforementioned control means comprise a first and a second sub-controller, each with a different target parameter, whereby the control means also comprise switching means to place one of the two sub-controllers in an activated state and the other sub-controller in a deactivated state.

Abstract: A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programmed to operate the plurality of fan units at peak efficiency by computing the power consumed in various configurations and selecting the configuration requiring minimum power to operate.

Abstract: A suction chamber for use in a horizontal fluid pumping system is supported by a fixed vertical bracket, which is attached to a platform. The suction chamber is positioned between a motor and a pump in the horizontal pumping system. The pumping system may also include a thrust bearing chamber positioned between the motor and the suction chamber. The pumping system may also include a bearing chamber adapter positioned between the thrust bearing chamber and the suction chamber. The suction chamber has a suction chamber pump end and a suction chamber motor end. The suction chamber enables both motor-end seal removal and pump-end seal removal. In both motor end seal removal and pump end seal removal, the suction chamber of the invention remains connected to the vertical bracket. The pumping system may also include an integrated lifting device connected to the vertical bracket to lift the thrust bearing assembly.

Abstract: A center shaft of a bent axis type axial piston pump/motor includes an outer race, which is attached to a shaft attachment hole of a cylinder block, has a shaft portion accommodation hole at one end and has a spring accommodation hole at the other end, and an inner shaft, which includes a shaft supporting spherical head portion having a large outer shape dimension at a distal end of a shaft base portion and attached to the shaft portion accommodation hole of the outer race through the shaft base portion.

Abstract: A hydraulic pressure supply system of an automatic transmission for a vehicle may be provided with first and second pump chambers and may supply hydraulic pressure generated at the first and second pump chambers selectively to a high pressure portion or the high pressure portion and a low pressure portion. The hydraulic pressure generated at the first pump chamber may be supplied to the high pressure portion through a high-pressure regulator valve, and the hydraulic pressure generated at the second pump chamber may be supplied to the low pressure portion through a low-pressure regulator valve or may be supplied to the high-pressure regulator valve according to switching operation of a switch valve.

Abstract: A compressor assembly having a high velocity muffler system which produces a particle-free compressor pump feed while reducing noise output from the compressor assembly during compressing operations. The high velocity muffler system is maintenance-free and comprises an inertia filter. The compressor assembly uses a method for producing a compressor pump feed and reducing noise during compressing operations by processing a gas through the high velocity muffler system which has an inertia filter and a muffler chamber to produce a compressor pump feed which can be compressed by a pump assembly.

Abstract: An axial flow fan of the present invention includes: an impeller having a hub and vanes disposed at equal intervals on an outer peripheral portion of the hub; a rotor shaft located at the center of the impeller; a motor portion rotating the impeller around the rotor shaft as an axis; a casing surrounding an outer periphery of the impeller; a base portion supporting the motor portion; and a stationary blade located in a blowout opening side of air flow, the stationary blade connecting the base portion and the casing, wherein the stationary blade has on its surface a guide portion allowing air flow flowing along the surface to be rectified and guided from a direction of the blowout opening to an outside.

Abstract: A vacuum pump includes a pump inlet, a pump outlet, a rotor rotatable about an axis of rotation, at least one process gas pump stage for conveying a process gas present at the pump inlet from the pump inlet to the pump outlet, a motor space, and a drive motor which is arranged in the motor space, is configured for rotationally driving the rotor and which has a motor stator, wherein at least one gas path is provided for the process gas from the pump inlet to the pump outlet which leads through the motor space and which leads at least sectionally along the motor stator or through the motor stator.

Abstract: The invention relates to a pump unit that can be driven by an electric motor, in particular for providing vacuum for a pneumatic brake booster, including a pump housing that can be closed by a working-chamber cover and at least one elastic displacement element, wherein a working chamber is bounded between the displacement element and the working-chamber cover and wherein inlet valves and outlet valves and inlet channels and outlet channels associated with the valves are associated with the working chamber. According to the invention, in order to reduce noise emissions, devices for reducing a contact surface between the working-chamber cover and the pump housing are provided.

Abstract: A synthetic jet ejector (201) is provided which includes a chassis (203); first (205) and second (207) opposing synthetic jet actuators mounted in the chassis; and a controller (209) which controls the first and second synthetic jet actuators and which is in electrical contact with the first and second synthetic jet actuators by way of flexible circuitry (211, 213).

Abstract: A sealed compressor comprises a sealed container (101) which accommodates an electric component (105) and a compression component (106); wherein the compression component (106) includes a shaft (110) including a main shaft section (111) and an eccentric shaft section (112), a cylinder block (114), a piston (126), and a main bearing unit (120) mounted to the cylinder block (114) and supporting the main shaft section (112) such that the main shaft section (112) is rotatable, a thrust ball bearing (132) mounted to a thrust surface (130) of the main bearing unit (120); and the thrust ball bearing (132) includes a plurality of balls (134) held in a cage (133), an upper race (135) having main surfaces one of which is in contact with upper portions of the balls (134); and a lower race (136) having main surfaces one of which is in contact with lower portions of the balls (134) and; a restricting means for restricting a displacement of the upper race (135) with respect to the shaft (110).

Abstract: A wet rotor pump with an axial flux motor that includes a stator and a rotor. The stator is arranged in a dry zone while the rotor on an impeller is arranged in a wet zone. The rotor is formed by one or more samarium cobalt (SmCo) permanent magnets.

Abstract: A power cable assembly supplies power to and suspends in a well an electrical well pump. The assembly includes metal tubing having a longitudinal tubing center line and a cylindrical side wall. Power cable has an exterior delta shape when viewed in a cross-section. The delta shape defines three exterior side surfaces that face radially outward and join each other at corners. Power cable has three insulated power conductors wrapped helically with a metal strip. The power cable is located in the tubing with the corners deformed against an inner diameter of the tubing.

Abstract: A dynamic pressure bearing apparatus includes a bearing portion; a shaft; a substantially annular bushing; a radial dynamic pressure bearing portion; and a seal gap. A minute horizontal gap extending radially is defined between an upper surface of the bearing portion and a lower surface of the bushing. The seal gap is arranged to be in communication with an exterior space through the horizontal gap.

Abstract: The pump is provided with a plurality of pumping chambers and electrically activatable valves. An elastic membrane is arranged in each pumping chamber and divides the same into a first and a second chamber section. Each valve is connected to the second chamber section of a pumping chamber. When a pressure drop is applied over the valve and the valve is activated (i.e. opened), the pressure in the second chamber section changes, which causes the membrane to move, which in turn leads to a change of the volumes of both chamber sections. This e.g. allows to pump well-defined amounts of fluid from the chamber sections to a drug dispensing device.

Abstract: Disclosed is a pump unit of an electronic control brake system installed in a bore formed in a modulator block, the pump unit including a motor having a rotating shaft, a carrier having a center portion thereof installed on the rotating shaft, and provided with connecting shafts that are spaced apart from the center portion to both sides by a predetermined interval to be disposed in line with each other, a pressing member installed on each of the connecting shafts, and a first piston pump and a second piston pump each provided with a piston configured to be reciprocated by making contact with an outer circumferential surface of the pressing member according to rotation of the carrier, the first piston pump and the second piston pump disposed in line with each other.

Abstract: An improved membrane valve and method for manufacturing such membrane valve. The improved membrane valve can be used for transferring fluids or gases in hermetic or semi-hermetic compressors, including a method and system for manufacturing a membrane valve and a membrane valve with applications for use in several motors, particularly in hermetic or semi-hermetic compressors which use, as a refrigeration fluid, an appropriate type of gas thus promoting the refrigeration physical affect. A body and a membrane of the membrane valve are produced from substantially thin metallic plates separately in accordance to an available process and can be subjected to rounding in order to eliminate live corners, and then juxtaposed thus composing the valve, with the above mentioned membrane on one side, fitted to the body which is fixed through a connection process and, on the other side, left free to oscillate.

Abstract: A rotary positive displacement pump for fluids, in particular for the lubrication oil of a motor vehicle engine (60), has a displacement that can be regulated by means of the rotation of a stator ring (12) having an eccentric cavity (13) in which the rotor (15) of the pump (1) rotates. The stator ring (12) is configured as a multistage rotary piston for displacement regulation and is arranged to be directly driven by a fluid under pressure, in particular oil taken from a delivery side (19) of the pump or from a point of the lubrication circuit located downstream the oil filter (62). The invention also concerns a method of regulating the displacement of the pump (1) and a lubrication system for a motor vehicle engine in which the pump (1) is used.

Abstract: In a variable capacity vane pump in which a discharge capacity of a pump chamber is varied by varying an amount of eccentricity of a cam ring relative to a rotor, a port inner wall surface that extends around an inner peripheral cam surface of the cam ring when the cam ring moves in a direction for increasing the amount of eccentricity of the cam ring relative to the rotor is formed on an intake port.

Abstract: A compressor includes a casing, a motor fixed to the casing, a vertically extending drive shaft coupled to the motor, and a compression mechanism driven by the drive shaft to compress a fluid. A shaft-inside oil supply path is provided in the drive shaft. Oil at a bottom of the casing is supplied through the shaft-inside oil supply path to a sliding portion of the drive shaft above the motor. The compressor includes a shaft-inside oil discharge path provided in the drive shaft, and an oil discharge coupled to a lower end of the drive shaft. The shaft-inside oil discharge path extends from an upper portion to a lower portion of the motor. The oil discharge pump discharges the oil that has been supplied to the sliding portion of the drive shaft to the bottom of the casing through the shaft-inside oil discharge path.

Abstract: In a gear pump, an outer rotor and an inner rotor are disposed in a rotor installation chamber defined by a pump body and a pump cover. A suction port groove and a discharge port groove are formed in at least one of the pump body and the pump cover. A narrowing portion is formed at a portion of a radially outer side wall portion of the suction port groove, the portion being close to a terminal end wall portion of the suction port groove. The narrowing portion narrows the groove width in the radial direction. A pressurizing region that pressurizes oil in the gear chamber is formed between the narrowing portion and the terminal end wall portion.

Abstract: A variable capacity screw compressor comprises a suction port, at least two screw rotors and a discharge port being configured in relation to a selected rotational speed that operates at least one screw rotor at an optimum peripheral velocity that is independent of a peripheral velocity of the at least one screw rotor at a synchronous motor rotational speed for a rated screw compressor capacity. A motor is configured to drive the at least one screw rotor at a rotational speed at a full-load capacity that is substantially greater than the synchronous motor rotational speed at the rated screw compressor capacity. A variable speed drive receives a command signal from a controller and generates a control signal that drives the motor at the selected rotational speed.

Abstract: An improved bearing housing of a rotary screw compressor is described. The bearing housing is generally shorter than a convention bearing housing. The bearing housing can be configured to enclose and support radial bearings of the screw compressor. The bearing housing can be configured not to enclose axial bearings of the screw compressor in an axial direction.

Abstract: Compressor device that is at least provided with a screw compressor with a compression chamber that is formed by a compression housing, with a drive motor that is provided with a motor chamber formed by a motor housing and with an outlet for the discharge of compressed air that is connected to a pressure vessel via an outlet pipe, whereby the compression housing and the motor housing are connected directly to one another to form a compressor housing, whereby the motor chamber and the compression chamber are not sealed off from one another and whereby the outlet pipe between the pressure vessel and the screw compressor is free of closing means.

Abstract: A rotary machine, for directing a quantity of fluid from an inlet to an outlet, comprises one or more elliptical or near-elliptical rotors having planetary rotation within a housing. The interior cavity of the housing comprises an inverse apex region that is in contact with the rotor during its rotation. In various embodiments the rotor and housing can be symmetric or asymmetric in cross-section. Features are described that can improve the operation of the machine for various end-use applications. Such features include cut-outs that are fluidly connected to the inlet or outlet ports of the machine, mechanisms for reducing variation in output flow rate from the rotary machine, linings for the interior cavity of the housing, pressure relief mechanisms, dynamic apex seals and other sealing mechanisms.

Abstract: The present disclosure provides methods to improve the properties of a porous structure formed by a rapid manufacturing technique. Embodiments of the present disclosure increase the bonding between the micro-particles 5 on the surface of the porous structure and the porous structure itself without substantially reduce the surface area of the micro-particles. In one aspect, embodiments of the present disclosure improves the bonding while preserving or increasing the friction of the structure against adjacent materials.

Abstract: Methods and apparatus for producing an object, the method comprising: performing an Additive Manufacturing process to produce an intermediate object from provided metal or alloy, whereby the intermediate object comprises regions having a contaminant concentration level above a threshold level; based upon one or more parameters, determining a temperature and a duration; and performing, on the intermediate object, a contaminant dispersion process by, for a duration that is greater than or equal to the determined duration, heating the intermediate object to a temperature that is greater than or equal to the determined temperature and less than the melting point of the metal or alloy, the contaminant dispersion process being performed so as to disperse, within the intermediate object, a contaminant from regions of high contaminant concentration to regions of low contaminant concentration until the intermediate object comprises no regions having a contaminant concentration level above the threshold level.

Abstract: A pivotable tundish (1) for continuous casting a metal alloy. The tundish comprises a body (3) comprising a first chamber (5), a second chamber (7), a first passage (12) between the first chamber and the second chamber, and a second passage (16) between the second chamber and a mold (9). The first chamber is adapted to receive and hold a base metal constituting the base for forming the metal alloy by addition of alloying elements. The metal alloy is fed from the second chamber to the mold through the second passage. The second chamber further comprises a first portion (30) and a second portion (32), and a third passage (36) between the first portion and the second portion. In the casting state the metal alloy is formed while casting by adding the alloying elements to the second portion of the second chamber.

Abstract: Vehicle parts, and more particularly wire and wire assembly parts, manufactured from a non-heat-treatable, wrought aluminum alloy are disclosed. The wire and wire assembly parts are shaped into different forms that meet certain strength and bendability requirements and are capable of being manufactured using forming, threading and swaging. The aluminum alloy used to manufacture the parts is a non-heat-treatable, wrought alloy formed predominantly from aluminum (Al) metal, which is alloyed primarily with magnesium (Mg), and which also includes silicon (Si), iron (Fe), copper (Cu), manganese (Mn), chromium (Cr), zinc (Zn), titanium (Ti), beryllium (Be) and other elements.

Abstract: It is intended to provide a sterilization method for heat-resistant bacterial spores, with which an effective sterilization effect is attained under heating conditions milder than conventional conditions, and which hardly affects the quality of an object to be sterilized. The sterilization method includes performing a first heat treatment step having the main object of damaging spores and then performing a second heat treatment step having the main object of inactivating the damaged spores and being performed at a temperature lower than that of the first heat treatment step.

Abstract: Fragrance systems are provided that can be used in conjunction with heating, ventilation, and air-conditioning systems. The fragrance systems can inject a fragrance into an airstream that is supplied to a space such as a room of a building or a vehicle cabin. In some embodiments, the speed a fan of the fragrance system can be automatically modulated in a pre-determined relationship to the speed of a fan of the HVAC system. Accordingly, a desired level of fragrance can be automatically maintained as desired within the airstream that is supplied to the space, even when the HVAC fan speed or other conditions fluctuate.

Abstract: The present invention provides a system and method for treating carpet that includes a hollow tube having a first end and a second end, wherein the tube further includes: a plurality of injection holes located near the second end of the tube, a pointed tip located at the second end of the tube, and a lug moveably attached to the tube; the method including inserting the tube into a carpet by penetrating the pointed tip into the carpet; lifting the tube up via the lug such that a portion of the carpet is pulled away from padding located underneath the carpet; and inserting fluid into the tube at the first end of the tube such that the fluid is injected into the carpet via the injection holes.

Abstract: The invention relates to an irradiation apparatus for inactivating pathogens and/or leukocytes in a biological fluid such as a platelet suspension and/or plasma comprising: a casing (2), a support member (3) for carrying at least one irradiation bag (19) containing the biological fluid, a light source (4) comprising two banks of light (5, 6) disposed above and below the support member (3), and an agitating system (25) for moving the support member (3), the light source generating UVC light of suitable intensity to inactivate pathogens and/or leukocytes and the agitation system moving the support member in an orbital path with predetermined amplitude and rotational frequency suitable to expose the whole biological fluid to UVC.

Abstract: A solid body of dazomet for use in internal remedial treatments of wood and methods of applying such solid bodies to wooden structures and manufacturing such solid bodies. The solid bodies can be easily transported and inserted into treatment holes in utility poles, wooden pilings, and other wooden structures, delivering a precise, accurate dose of insecticide and fungicide that combats internal decay in the wood.

Abstract: An arrangement for extracorporeal life support is further developed in such a way that a pump actuating signal produces a wave-like surging and subsiding pump output for a pulsatile flow. The pump is preferably a non-occlusive blood pump, such as a diagonal pump, for example. In a preferred variant of embodiment the control signal is provided by an ECG. This allows the diastolic pressure to be increased in order to improve the oxygen balance of the heart muscle.

Abstract: The present subject matter is directed to a device for spectroscopy. The device includes an excitation source configured to illuminate a sample with wavelengths. The device also includes a spatial heterodyne interferometer configured to receive Raman wavelengths from the sample.

Abstract: Apparatus for performing an assay to detect the presence of an analyte in a test sample. A housing defines a slot for receiving a sample collector, and a capsule contains a buffer liquid, the capsule being sealed by an openable lid, and being connected to the housing such that insertion of a sample collector into the slot causes the lid to open releasing the buffer liquid into the slot. The housing further defines an incubation chamber containing or configured to receive a reagent, and an aperture permitting liquid communication between the slot and the incubation chamber. The apparatus comprises one or more test elements, a substantially liquid tight sealing member separating the incubation chamber and the test element(s), and an activation mechanism operable to open the liquid tight sealing member thereby bringing at least a portion of the or each test element into liquid communication with the incubation chamber.

Abstract: A plant for producing hydrogen peroxide by an autoxidation process (AO-process) comprising hydrogenating an anthraquinone in a working solution, oxidizing the hydrogenated anthraquinone with oxygen to form hydrogen peroxide and extracting the hydrogen peroxide from the working solution, the plant comprising at least one skid mounted module selected from the group consisting of a skid mounted module comprising at least one hydrogenator (hydrogenation reactor) to hydrogenate the anthraquinone in the working solution (hydrogenation skid 1); a skid mounted module comprising at least one oxidizer (oxidation reactor) to oxidize the hydrogenated anthraquinone with oxygen to form hydrogen peroxide (oxidizer skid 2); optionally a skid mounted module comprising at least one means to compress air (process air compressor skid 3), to feed oxygen, in particular oxygen from the air, into an oxidizer of skid 2, and in case of presence of skid 3 a further skid mounted module comprising at least one means to recover the solven

Abstract: An embedded multifunctional air purifier for kitchen installed in a predetermined space of a cupboard includes a casing, a hood, an exhaust module, an electrostatic dust collector, a front filter, a gas detection module, a photocatalyst module and a vitamin C filter. With the design of the hood, the exhaust module is covered by the hood to reduce noises when the air purifier is used. Besides the removal of fumes and odors, filtration and disinfection, the air purifier can also produces fresh air with vitamin C, and alerts users to prevent a gas poisoning incident when a toxic gas leak occurs.

Abstract: A catalyst system for exhaust gas purification which comprises a first-stage base metal catalyst located upstream and a second-stage base metal catalyst located downstream, wherein the first-stage base metal catalyst comprises at least one oxide support selected from the group consisting of alumina, ceria, zirconia, yttria, and titania and Cu metal and/or a Cu oxide supported thereon, and in cases where the amount of NOx in the exhaust gas has become or exceeded an NOx criterion, the state of the exhaust gas is switched from slightly rich to rich.