In this study, an electro-mechanical valve （EMV） system for the intake valve ofa fottr stroke, single cylinder, overhead valve and spark ignition （SI） engine was designed and constructed. An engine with the EMV sy...In this study, an electro-mechanical valve （EMV） system for the intake valve ofa fottr stroke, single cylinder, overhead valve and spark ignition （SI） engine was designed and constructed. An engine with the EMV system and a standard engine were tested to observe the effects of the EMV on engine performance and emissions at different speeds under full load. The EMV engine showed improved engine power, engine torque and break specific fuel consumption （BSFC）. A 66% decrease in CO emissions was also obtained with the EMV system, but hydrocarbons （HC） and NOx emissions increased by 12% and 13% respectively.展开更多
Piezoelectric ceramics based on PZT ceramics were prepared in solid state reaction with mixture of PbO, TiO2 and ZrO2, etc. XRD and SEM were used to confirm that the main phase in the material is tetragonal P4mm symme...Piezoelectric ceramics based on PZT ceramics were prepared in solid state reaction with mixture of PbO, TiO2 and ZrO2, etc. XRD and SEM were used to confirm that the main phase in the material is tetragonal P4mm symmetry. Samples sintered are of high density. Measurement on polarized products indicate that dielectric constant, piezoelectric constant, electromechanic coupling factor and mechanical quality factor are epsilon(r)=2015, d33=578.06X10(12)C/N, K-33=0.81 and Q(m)=543.8,,respectively.展开更多
基金Project supported by T.R.Prime Ministry State Planning Organization,Turkey
文摘In this study, an electro-mechanical valve （EMV） system for the intake valve ofa fottr stroke, single cylinder, overhead valve and spark ignition （SI） engine was designed and constructed. An engine with the EMV system and a standard engine were tested to observe the effects of the EMV on engine performance and emissions at different speeds under full load. The EMV engine showed improved engine power, engine torque and break specific fuel consumption （BSFC）. A 66% decrease in CO emissions was also obtained with the EMV system, but hydrocarbons （HC） and NOx emissions increased by 12% and 13% respectively.
文摘Piezoelectric ceramics based on PZT ceramics were prepared in solid state reaction with mixture of PbO, TiO2 and ZrO2, etc. XRD and SEM were used to confirm that the main phase in the material is tetragonal P4mm symmetry. Samples sintered are of high density. Measurement on polarized products indicate that dielectric constant, piezoelectric constant, electromechanic coupling factor and mechanical quality factor are epsilon(r)=2015, d33=578.06X10(12)C/N, K-33=0.81 and Q(m)=543.8,,respectively.
