Tribological Behavior of Mild Steel under Canola Biolubricant Conditions

New lubricants based on vegetable oil were developed in this study. Different blends of canola oil mixed with fully synthetic two stock engine oils were developed (0, 20%, 40%, 60%, and 80% of synthetic oil). The viscosity of the prepared blends was determined at different temperatures (20°C–80°C). Tribological experiments were conducted to investigate the effect of the newly developed oil on the wear characteristics of mild steel material compared with stainless steel when subjected to adhesive wear loading. The weight loss (WL) and the specific wear rate (SWR) of the mild steel using each of the prepared lubricants were determined. Scanning electron microscopy was used to examine the worn surface of the mild steel. The results revealed that pure canola oil as a lubricant performed competitively against a blend of 80% synthetic and 20% canola oils. The viscosity of the canola oil and its various blends with synthetic oil are controlled by the environmental temperature since an increased temperature reduces the viscosity. Also, the experimental results revealed that operating parameters play the main role in controlling the wear behavior of mild steel since increasing the sliding distances increases the weight loss. The specific wear rate exhibited a steady state after about 5 km sliding distance, and different blends influenced the applied loads and velocity differently. The mixing ratio of canola and syntactic oil was not particularly significant since the pure canola oil exhibited competitive wear performance compared with the blends. However, an intermediate mixing ratio (40%–60% synthetic oil mixed with 60%–40% canola) can produce a slightly low specific wear rate among other things.

Effects of canola or olive oil on plasma lipids, lipoprotein-associated phospholipase A2 and inflammatory cytokines in patients referred to coronary angiography

Background: The potential cardioprotective benefits of olive oil (OO) and canola oil (CO) consumption have been shown in some studies. The present study was conducted to compare the effects of CO and OO on plasma lipids, some inflammatory cytokines, and lipoprotein-associated phospholipase A2 (Lp-PLA2) mass and activity in patients undergoing coronary angiography.Methods: A randomized, controlled, parallel-arm, clinical trial involving 48 patients (44 men and 4 women, aged 57.63 ± 6.34 years) with at least one classic cardiovascular risk factor (hypertension, dyslipidemia, or diabetes) who referred to coronary angiography was performed. Patients were randomly divided into two groups and received 25 mL/day refined olive oil (n=24) or canola oil (n=24) for 6 weeks. Plasma lipids, some selected inflammatory markers, and Lp-PLA2 levels were measured at the baseline and after the intervention.Results: CO consumption produced a significant reduction in plasma Lp-PLA2 mass (-0.97 ± 1.84 vs 0.34 ± 1.57 ng/mL, p = 0.008 for CO and OO, respectively), whereas the mean changes of IL-6 concentration were significantly lower after OO consumption compared with CO (-9.46 ± 9.46 vs -0.90 ± 6.80 pg/mL, p = 0.008 for OO and CO, respectively). After 6 weeks of intervention, no significant changes were observed in plasma Lp-PLA2 activity, complement C3, C4, and lipid profile in two intervention groups.Conclusions: Daily consumption of either of the refined olive or canola oils during a relatively short time could improve one of the inflammatory CVD risk factors.Trial registration: IRCT20160702028742N5 at www.irct.ir (04/19/2019)

Mechanical and bio-lubricated friction performance of PA6G for gear applications

The PA6G blue is a polymeric material for great versatility of engineering applications that required good mechanical and tribological properties such as gears. The focus of this study was to investigate the mechanical properties as well as the friction and wear resistance of a commercial PA6G blue under biodegradable external lubrication, to evaluate its potential use for gear applications. Firstly, the PA6G blue was characterized by FTIR analysis in order to identify the characteristic chemical groups of this polymer. The mechanical characterization was performed by tension and hardness tests according to the standards ASTM D638 and ASTM E10, respectively. Subsequently, friction tests were carried out on a tribometer with pin-on-disk configuration based on the ASTM G99 standard, in dry and lubricated conditions. Natural castor and canola oils were employed as bio-lubricants, as well as their mixture at 50% by volume. The results exhibited that the PA6G blue exhibit good mechanical performance as that required by gear fabrications. Besides, the friction performance showed a low friction coefficient of 0.11 in the dry condition that decreased about 50% in lubricated tests, obtaining a friction coefficient value of 0.054.