ABSTRACT
A two-step treatment of mahua oil was conducted to synthesize mahua biodiesel using heterogeneous biomass-based catalyst derived from mahua shell. Mahua oil having higher free fatty acid (FFA) content (about 19%) was esterified to reduce the FFA content up to 1%. The esterification process was carried out using 200 mL mahua oil, 5:1 molar ratio (methanol:oil), and 2.25 weight% of H2SO4 at a temperature of 60 °C for 3 h. Post esterification, a set of 16 experiments were created using a Box-Behnken design (BBD)-based response surface methodology (RSM) approach to conduct the transesterification of the esterified oil. Molar ratio, catalyst loading, reaction temperature, and reaction time were the four input variables chosen for the design of experiments. The optimized conditions for maximum biodiesel yield (87.7%) were found to be 14.88 molar ratio, 3.578% catalyst loading, 69.7 °C reaction temperature, and 81.9 min reaction time. The Diesel RK engine simulation tool which was experimentally validated for baseline diesel fuel was used for numerical simulation of mahua biodiesel. The performance, combustion, and emission behavior of mahua biodiesel analyzed using numerical simulation presented the sustainability of mahua biodiesel as an alternate fuel.
ABSTRACT
The stillbirth rate is among the most important indicators of access to and quality of care during pregnancy. This study investigated the factors related to the stillbirth rate in the Yazd province, Iran. The current research is descriptive and cross-sectional and the results of Shahdieh city cohort study which was conducted on 4756 women were used. Data related to the history of stillbirth, demographic characteristics, fertility history and, various female diseases were extracted from the results of the cohort study. The result shows that 7.2% of studied women had a history of stillbirth. Among the multiple variables, predictor variables including education level, marriage age, age of the first conception, number of children, consanguineous marriage, Employment status, and diseases like diabetes, hypertension, and history of depression had a significant relationship with a history of stillbirth (P ≤ .05). The stillbirth rate in Shahedieh is high compared to the global stillbirth Rate, but it is comparable with the stillbirth Rate in Yazd province. Although Yazd province, as one of the industrial hubs of Iran, has relatively acceptable indicators of income, employment, and medical and health facilities and welfare compared to other provinces, this study showed that factors such as diabetes, hypertension, low level of women's education, consanguineous marriage, and women's employment status and social welfare can affect Stillbirth Rate.
