However, in the example of FIGS 4 6, {HEAD ~ the pump} 53 is operable to perform {TAIL ~ the discharge} and suction of fluid separately in the fluid channel 44 of the first layer and the fluid channel 54 of the second layer 
However , in the example of FIGS 4 6 , { HEAD ~ the pump } 53 is operable to perform { TAIL ~ the discharge } and suction of fluid separately in the fluid channel 44 of the first layer and the fluid channel 54 of the second layer
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH