To understand the occurrence of backfire in hydrogen fueled engines using an external (inducted) fuel supply, a fundamental study was completed using a modified experimental engine. A relation was found between the crevice volume in the combustion chamber and the occurrence of backfire. The results showed that the crevice around the spark plug electrode was not a major cause of backfire, but the combustion state of the mixture in the piston top land crevice, second land, and ring groove did have a direct affect on backfire occurrence. By increasing the top land crevice volume and the amount of blow-by gas, the equivalence ratio before backfire occurred was extended.
In-cylinder turbulence of an engine was generated by an intake pressure effect and inertia effect during the intake process and it was generated and decreased by the compression effect of a piston during the compression process. The separate measurement of the turbulence generated by these factors during each process was necessary to generate high turbulence around the spark timing. A single-shot rapid intake compression expansion machine (RICEM) was manufactured and evaluated for this purpose. The RICEM could carry out the intake and compression processes separately or in a row. It was proved that the RICEM simulated not only high temperature and high pressure field but also the same flow pattern as a real engine. The turbulence generated by each factor was measured in the swirl field of the RICEM. As the result, it was also found that enhancing the turbulence by the compression effect of a piston with improvement of the flow at the beginning of the compression process was desirable.
SummaryA novel HPLC method with electrochemical detection has been developed for the determination of salmon calcitonin (sCT). sCTwas separated from other components in its formulations on a narrow-bore reversedphase C18 column with 33 % acetonitrile in 0.05 M phosphate buffer (pH 6.5) at a flow rate of 0.2 mL min -1. Electrochemical oxidation of sCT at a glassy carbon electrode occurred at 0.87 V relative to the Ag/AgC1 reference electrode. The limit of quantitation was 0.1 ng and the calibration curve was linear in the concentration range 0.5-20 ng; the correlation coefficient was 0.998. The method was successfully applied for the quantitation of sCT in commercial injection and nasal spray formulations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.