In the view of rapid depletion of fossil fuels and rise in price of crude oil, there is emergent focus and need to search for alternative fuels. As we know that there is huge demand of diesel for transportation sector, captive power generation, agricultural sector and industrial sector, to accommodate those demands biodiesel is being viewed as a substitute for diesel. Biodiesel is an engine fuel that is prepared by chemical reaction of fatty acids and alcohol, which usually means combining vegetable oil with methanol in the presence of a catalyst (usually sodium hydroxide). But before using biodiesel as a substitute for engine fuel, there are two major problems associated, first one is “cold flow property of biodiesel” and second one is termed as “stability of biodiesel”. In this paper our main focus will be on cold flow property of biodiesel and its impact on engine performance. Some of the cold flow properties such as cloud point, pour point and cold filter plugging point are responsible for solidification of fuel causing blockage in fuel lines filters which further leads to fuel starvation in engine operation during starting operation. This paper also provides several remedial measures for improving the cold flow properties of biodiesel.

Impact of cold flow properties of biodiesel on engine performance

https://cyberleninka.org/article/n/1328037.pdf

Evaluation and enhancement of cold flow properties of palm oil and its biodiesel

Modeling viscosity of butanol and ethanol blends with diesel and biodiesel fuels

Prediction of viscosity of biodiesel blends using various artificial model and comparison with empirical correlations

An overview of engine durability and compatibility using biodiesel–bioethanol–diesel blends in compression-ignition engines

Measurement, correlation and prediction of biodiesel blends viscosity

Measurements and correlations of physico-chemical properties to composition of pseudo-binary mixtures with biodiesel

Background: COVID-19 vaccination started in Romania in December 2020. Child vaccination started in 2021 with children aged 12–15 years in August. For children aged 5–11 years, vaccination started in January 2022. The aim of our study was to describe COVID-19 vaccination hesitancy in Romanian children and vaccine acceptability in the general population. As parental consent is required for child vaccination in Romania, these aspects have a significant association. Methods: An analytical cross-sectional survey was conducted in October and November 2021 during the peak of the 4th COVID-19 wave. Results: After validation, 1645 participants formed the main study group: median age 35 years, 72.83% women, and 35.44% from the medical domain. In total, 1311 (79.70%) participants were vaccinated against COVID-19 and 188 (11.42%) had vaccinated their 12–18-year-old children against COVID-19. Parents’ level of education, geographic area of residence, and COVID-19 vaccination status were significantly associated with COVID-19 vaccination. The hesitancy factors of child vaccination included the novelty of COVID-19 vaccines (62, 47.32%), fear of adverse reactions (32, 24.42%), and anti-vaccinism in general (29, 22.13%). In the studied group, only 188 (11.42%) participants recommended vaccination of 5–11-year-old children. Vaccine acceptability was higher in the general population (1311, 79.70%) than in the medical domain (326 out of 583, 55.91%). General vaccine hesitancy was based mainly on beliefs regarding inefficiency (131, 39.22%) and fears about the side effects of the vaccine (76, 22.75%). Conclusions: Overall, the acceptability of COVD-19 vaccines in the Romanian population was influenced by the level of education, area of residence, and being a COVID-19-vaccinated parent. Public health intervention programs are essential.

/pdf/covid-19-parental-vaccine-hesitancy-in-romania-nationwide-3rcxxnru.pdf

COVID-19 Parental Vaccine Hesitancy in Romania: Nationwide Cross-Sectional Study

With the development of oil industry, diesel fuel resulted to be more appropriate as fuel for high-speed diesel engines, than vegetable oil, the first fuel used by Rudolf Diesel to test the diesel engine. Vegetable oils could represent an alternative to heavy fuel oil used in the low-speed marine diesel engines. Nowadays, diesel fuel is commercialized blended with up to 6% biodiesel. In the future, this percent is expected to increase. Taking into account these perspectives, it is necessary to know the behavior of the fuel components, when variations of temperature occur. Experimental densities and viscosities data for a vegetal oil, diesel fuel and biodiesel were reported here in the temperature range of 20 o C to 60 o C, and the accuracy of empirical models proposed to predict these properties at different temperatures was evaluated.

/pdf/study-of-density-and-viscosity-variation-with-temperature-2aj7caxdy1.pdf

Study of density and viscosity variation with temperature for fuels used for Diesel engine

For now, biodiesel is the commonly accepted biofuel as a substitute for diesel fuel in internal combustion engines. Diesel fuel blends with up to 20% biodiesel can be used in diesel engines without any modification. A lot of studies regarding diesel fuel+biodiesel blends properties are presented in the literature. Some of the important properties of diesel fuel+biodiesel blends can be evaluated from other blends properties. For example, density and viscosity of biodiesel blends can be predicted based on blend refractive index. More than that, refractive index can be used as a reliable physical property to predict transesterification reaction progress. As a result, the refractive index of diesel fuel+biodiesel blends is important in order to characterize these blends or to monitor the evolution of transesterification process of vegetable oils or animal fats. The refractive index of diesel fuel+biodiesel blends can be experimentally determined or evaluated based on refractive indices of diesel fuel and biodiesel. The aim of this study was to estimate the accuracy of refractive index of diesel fuel +biodiesel blends calculation, using models initially proposed to evaluate the refractive index of a binary liquid mixture. It was shown that the refractive index of diesel fuel+biodiesel blends can be accurately predicted from refractive indices of the components of the blend. Wiener, Heller and Edward equations can be recommended to predict with a great accuracy the refractive index of diesel fuel+biodiesel blends.

/pdf/estimation-of-the-refractive-index-of-diesel-fuel-biodiesel-jqwhprt0a2.pdf

Irina Nita

Papers

Measurement, correlation and prediction of biodiesel blends viscosity

Measurements and correlations of physico-chemical properties to composition of pseudo-binary mixtures with biodiesel

COVID-19 Parental Vaccine Hesitancy in Romania: Nationwide Cross-Sectional Study

Study of density and viscosity variation with temperature for fuels used for Diesel engine

Estimation of the refractive index of diesel fuel+biodiesel blends