RESUMO
The disproportionate use of petroleum products and stringent exhaust emissions has emphasized the need for alternative green fuels. Although several studies have been conducted to ascertain the performance of acetone-gasoline blends in spark-ignition (SI) engines, limited work has been done to determine the influence of fuel on lubricant oil deterioration. The current study fills the gap through lubricant oil testing by running the engine for 120 h on pure gasoline (G) and gasoline with 10% by volume acetone (A10). Compared to gasoline, A10 produced better results in 11.74 and 12.05% higher brake power (BP) and brake thermal efficiency (BTE), respectively, at a 6.72% lower brake-specific fuel consumption (BSFC). The blended fuel A10 produced 56.54, 33.67, and 50% lower CO, CO2, and HC emissions. However, gasoline remained competitive due to lower oil deterioration than A10. The flash-point and kinematic viscosity, compared to fresh oil, decreased by 19.63 and 27.43% for G and 15.73 and 20.57% for A10, respectively. Similarly, G and A10 showed a decrease in total base number (TBN) by 17.98 and 31.46%, respectively. However, A10 is more detrimental to lubricating oil due to a 12, 5, 15, and 30% increase in metallic particles like aluminum, chromium, copper, and iron, respectively, compared to fresh oil. Performance additives like calcium and phosphorous in lubricant oil for A10 decreased by 10.04 and 4.04% in comparison to gasoline, respectively. The concentration of zinc was found to be 18.78% higher in A10 when compared with gasoline. A higher proportion of water molecules and metal particles were found in lubricant oil for A10.
RESUMO
For evaluating the significance of renewable alternative fuels for optimized engine performance and lower emissions, methanol has been extensively utilized as a blend with gasoline in spark-ignition engines. However, rare attempts have been rendered to examine the consequence of methanol-gasoline fuel blends (M6, M12, and M18) on lubricant oil operating for a longer period in engines. The highest and least decrease of 9.62% and 6.68% in kinematic viscosity (KV) was observed for M0 and M18, respectively. However, the flash point (FP) of degraded lubricant oil for M6, M12, and M18 was 3%, 5%, and 7% higher than that of M0, respectively. Total acid number (TAN) and ash content of degraded lubricant oil for M18 were the highest among M0, M6, and M12. An inclusive optimization of engine performance, emissions, and lubricant oil properties has been made for various methanol-gasoline fuel blends at distinct operating conditions by employing the response surface methodology (RSM) technique. RSM-based optimization portrayed the composite desirability value of 0.73 for 2137.13 watt brake power (BP), 6.08â N-m torque, 0.37â kg/kwh brake-specific fuel consumption, 22.10% brake thermal efficiency, 4.02% carbon monoxide emission, 7.15% carbon dioxide emission, 134.12â ppm hydrocarbon emission, 517.02â ppm nitrogen oxides emission, 12.44â cst KV, 203.77°C FP, 2.23â mg/g KOH TAN, and 2.65%wt ash content as responses for fuel blend M8 at 3400â rpm and higher loading condition. RSM predicted results demonstrated significant compliance with empirical findings, with absolute percentage error (APE) below 5% for each response. However, the highest APE of 4.68% was obtained for FP owing to inefficient desirability as a consequence of manual testing. The least APE of 1.57% was obtained for torque because of the highest desirability. Overall, the RSM predicted results of the designed models are effective and viable. RSM technique was found to be effective for the optimization of the broader engine characteristics spectrum.
RESUMO
Background Venous thromboembolism (VTE) is a condition that occurs when a blood clot forms in veins. Hospitalization increases the risk of VTE so timely risk assessment and adequate prophylaxis for VTE should be done to prevent this potentially fatal complication. Local problem Data from developing countries regarding VTE prophylaxis is scarce. VTE is a neglected area of research in Pakistan. So this closed-loop clinical audit was conducted to evaluate the VTE risk assessment and prophylaxis practices and to analyze the importance of educational intervention in improving the standard of care. Patients and methods We adopted the National Institute for Health and Care Excellence (NICE) guidelines for VTE prophylaxis as an audit standard. We collected data on a specially designed proforma by prospectively reviewing the hospital notes of patients in the Medical Ward of Northwest General Hospital and Research Center, Peshawar, Pakistan. Phase A included 60 patients and after educational intervention, Phase B was conducted with 90 patients. Intervention The results of Phase A were presented in the Clinicopathological Conference (CPC) meetings of the hospital. Healthcare workers were educated regarding the risks of VTE and the importance of timely prophylaxis. Posters were also displayed in the ward for highlighting the importance of VTE prophylaxis. Results In Phase A, only 5% of patients were risk assessed for VTE and of those eligible for prophylaxis only 22.2% received the prescription. Phase B showed a significant adherence to standard practices. In Phase B, 100% of patients were risk assessed for VTE and 75% received the prophylaxis. Conclusion There was poor compliance with standard VTE risk assessment and prophylaxis prescribing practices. However, a simple and effective educational intervention markedly improved patient care in terms of VTE strengthening the impact of clinical audits in the improvement of care.