Investigation on Ignition Coil Specification for Dilution Combustion System

To improve thermal efficiency of internal combustion engine, dilution combustion system, such as lean burn and Exhaust Gas Recirculation (EGR) system, have been developed with spark ignition coils generating large discharge current and energy. Several researches have clarified that large discharge current increases discharge channel stretch and decreases possibility of discharge channel blow-off and misfire. However, these investigations don\u27t mention effect of discharge current profile on combustion speed and discharge channel behaviour enough. Purpose of this research is to investigate relation among dilution rate, combustion speed, discharge channel behaviour and discharge current. To achieve this purpose, five coils having different current profiles were evaluated by combustion test and in-cylinder optical measurement test with research single cylinder engine. The combustion test results showed a correlation between dilution limit and initial combustion period. And optical measurement test results showed a correlation of initial combustion period with discharge channel stretch. Moreover, saturation of discharge channel stretch were observed from a certain discharge current value on up. Based on these results, adequate coil for dilution system was selected. Finally, the coil was equipped on a vehicle and performance test was conducted. The vehicle with LP-EGR system was stably driven with 18% of EGR rate, and 2.3% of fuel reduction rate were verified in the WLTC mode. The selected high energy ignition coil was contributing reduction of misfire during EGR operation

Study of combustion timing control in hydrogen mixed gas engine

This study focuses on the combustion timing control in hydrogen mixed combustion of a spark ignition gas engine. Especially, we examined the effect of hydrogen mixed ratio and air excess ratio on the combustion feature under same engine conditions. The 50% mass fraction burning timing (MFB50T) is within the specified range under MBT condition, independent of hydrogen mixed ratio and air excess ratio. We also examined the combustion phase estimation method using the existing sensor of the engine. The MFB50T can be estimated by the peak timing of angle speed

Early, Noninvasive Clinical Indicators of Kidney Prognosis in Primary Nephrotic Syndrome: A Retrospective Exploratory Study

This retrospective exploratory study aimed to identify early clinical indicators of kidney prognosis in primary nephrotic syndrome (NS). Univariate Cox proportional hazards regression analysis identified clinical parameters in the 2-month period after initiating immunosuppressive therapy (IST); it predicted 40% reduction in the estimated glomerular filtration rate (eGFR) in 36 patients with primary NS. Time-dependent receiver operating characteristic curve analysis was used to evaluate the performance of the predictors for the cumulative incidence of 40% reduction in the eGFR up to 8 years after initiating IST. The mean follow-up period was 71.9 months. The eGFR was reduced by 40% in four patients. Significant predictors for time to 40% reduction in the eGFR were as follows: an increase in the serum soluble urokinase plasminogen activator receptor (s-suPAR) 2 months after initiating IST (Δs-suPAR (2M); hazard ratio (HR) for every 500 pg/mL increase: 1.36, P=0.006), s-suPAR at 2 months after initiating IST (s-suPAR (2M); HR for every 500 pg/mL increase: 1.13, P=0.015), urinary protein-to-creatinine ratio (u-PCR) (u-PCR (2M); HR for every 1.0 g/gCr increase: 2.94, P=0.003), and urinary liver-type fatty acid-binding protein (u-L-FABP) (u-L-FABP (2M); HR for every 1.0 μg/gCr increase: 1.14, P=0.006). All four factors exhibited high predictive accuracy for cumulative incidence of 40% reduction in the eGFR up to 8 years after initiating IST, with areas under the receiver operating characteristic curve of 0.92 for Δs-suPAR (2M), 0.87 for s-suPAR (2M), 0.93 for u-PCR (2M), and 0.93 for u-L-FABP (2M). These findings suggest that Δs-suPAR (2M), s-suPAR (2M), u-PCR (2M), and u-L-FABP (2M) could be useful indicators of initial therapeutic response for predicting kidney prognosis in primary NS