Abstract: This catalyst system simultaneously removes ammonia and enhances net NOx, conversion by placing an NH3—SCR catalyst formulation downstream of a lean NOx, trap. By doing so, the NH3—SCR catalyst adsorbs the ammonia from the upstream lean NOx, trap generated during the rich pulses. The stored ammonia then reacts with the NOx, emitted from the upstream lean NOx, trap—enhancing the net NOx, conversion rate significantly, while depleting the stored ammonia. By combining the lean NOx, trap with the NH3—SCR catalyst, the system allows for the reduction or elimination of NH3 and NOx, slip, reduction in NOx. spikes and thus an improved net NOx, conversion during lean and rich operation.

Abstract: This catalyst system simultaneously removes ammonia and enhances net NO, conversion by placing an NH3-SCR catalyst formulation downstream of a lean NOx trap. By doing so, the NH3-SCR catalyst adsorbs the ammonia from the upstream lean NOx trap generated during the rich pulses. The stored ammonia then reacts with the NOx emitted from the upstream lean NOx trap—enhancing the net NOx conversion rate significantly, while depleting the stored ammonia. By combining the lean NOx trap with the NH3-SCR catalyst, the system allows for the reduction or elimination of NH3 and NOx slip, reduction in NO. spikes and thus an improved net NOx conversion during lean and rich operation.

Abstract: This catalyst system simultaneously removes ammonia and enhances net NO, conversion by placing an NH3-SCR catalyst formulation downstream of a lean NOx trap. By doing so, the NH3-SCR catalyst adsorbs the ammonia from the upstream lean NOx trap generated during the rich pulses. The stored ammonia then reacts with the NOx emitted from the upstream lean NOx trap-enhancing the net NOx conversion rate significantly, while depleting the stored ammonia. By combining the lean NOx trap with the NH3-SCR catalyst, the system allows for the reduction or elimination of NH3 and NOx slip, reduction in NOx spikes and thus an improved net NOx conversion during lean and rich operation.

Abstract: A method and system for simultaneously regenerating a particulate filter coupled to an internal combustion engine and for desulfating a lean NOx trap disposed downstream of the particulate filter. The method includes adjusting at least one engine operating parameter to maintain a desired air fuel ratio for gases exiting the particulate filter in accordance with a difference between a reference set point air fuel ratio level and the air fuel ratio of gases exiting the particulate filter and wherein the reference set point level is changed between a rich air fuel ratio and a lean air fuel ratio as a function of the air fuel ratio of the gases exiting the lean NOx trap.

Abstract: A method and system for simultaneously regenerating a particulate filter coupled to an internal combustion engine and for desulfating a lean NOx trap disposed downstream of the particulate filter. The method includes adjusting at least one engine operating parameter to maintain a desired air fuel ratio for gases exiting the lean NOx trap in accordance with a difference between a reference set point air fuel ratio level and the air fuel ratio of gases exiting the lean NOx trap and wherein the reference set point level is changed between a rich air fuel ratio and a lean air fuel ratio as a function of the air fuel ratio of the exiting the lean NOx trap.

Abstract: A torsional damper coupling for dampening torsional vibration between a prime mover and a dynamometer. The torsional damper coupling includes a compression ring with a plurality of pockets that retain a plurality of spring members. The compression member is disposed between body and cover members that each have a plurality of recesses that retain a portion of the spring members. The compression member is coupled to one of a prime mover and a dynamometer while the body member is coupled to the other of the prime mover and dynamometer. Torsional vibration caused by the prime mover is dampened by the spring members which resist relative movement between the compression member and the body member. The spring members are readily available off-the-shelf coil springs. A solid ring bearing couples the compression member to the body member and facilitates relative movement between the body member and the compression member.