Experimental investigations of a single cylinder genset engine with common rail fuel injection system

Performance and emissions characteristics of compression ignition (CI) engines are strongly dependent on quality of fuel injection. In an attempt to improve engine combustion, engine performance and reduce the exhaust emissions from a single cylinder constant speed genset engine, a common rail direct injection (CRDI) fuel injection system was deployed and its injection timings were optimized. Results showed that 34°CA BTDC start of injection (SOI) timings result in lowest brake specific fuel consumption (BSFC) and smoke opacity. Advanced injection timings showed higher cylinder peak pressure, pressure rise rate, and heat release rate due to relatively longer ignition delay experienced

Systematic study of incomplete fusion reactions: Role of various entrance channel parameters

263-266The evaporation residues, populated through complete and incomplete fusion processes in the reaction of 18O+ 165Ho, have been analyzed via excitation function measurements at projectile energies ≈ 4-7 MeV/nucleon. The cross-sections measured experimentally have been compared with the predictions of the compound nucleus model code PACE-4 calculations which only considers complete fusion (CF) reaction cross-sections. The experimental cross-section of the reaction residues populated through xn and pxn channels matches well with the theoretical model code PACE-4 predictions. On the other hand, α-emitting channels show an enhancement in the measured cross-section over PACE-4 calculations which reveals the occurrence of incomplete fusion (ICF) at the studied energy range. The relative percentage of incomplete fusion has been calculated from the experimental data and its dependence on various entrance channel parameters like projectile energy, mass-asymmetry, α-Q value and Coulomb factor (ZPZT) has been studied. The strength of incomplete fusion function obtained in the 18O+ 165Ho interaction has been compared with the previously studied systems. Results of the present study indicate that 18O (two neutron excess) projectile shows more incomplete fusion contribution as compared to 12C,13C and 16O projectiles due to its relatively small negative α-Q value

Suitability Assessment of an Indigenous Heterogeneous Thoracic Phantom for Patient-Specific Quality Assurance in Radiotherapy

Introduction: Patient-specific quality assurance (PSQA) assumes a vital role in precise and accurate radiation delivery to cancer patients. Since the patient body comprises heterogeneous media, the present study aimed to fabricate a heterogeneous thoracic phantom for PSQA.Material and Methods: Heterogeneous thoracic (HT) phantom was fabricated using rib cage madeup of bone equivalent material, kailwood to mimic lungs and wax to mimic various body parts. Physical density of all these materials used in phantom fabrication was measured and compared with that of the corresponding part of actual human thorax. One beam was planned on the computed tomography (CT) images of phantom and actual patient thorax region. Dose distribution in both the plans was measured and analyzed.Results:The estimated densities of heart, lung, ribs, scapula, spine, and chest wall tissues were 0.804±0.007, 0.186±0.010, 1.796±0.061, 2.017±0.026, 2.106±0.029 and 0.739±0.028 respectively in case of HT phantom while 1.038±0.010, 0.199±0.031, 1.715±0.040, 2.006±0.019, 1.929±0.065 and 0.816±0.028 g/cc, respectively in case of actual human thorax region.The depths of isodose curves in HT phantom were also comparable to the isodose curve’s depths inreal patient. PSQA results were within ±3% for flat beam (FB) and flattening filtered free beam (FFFB) of 6 megavolts (MV) energy.Conclusion: Density and dose distribution pattern in HT phantom were similar to that in actual human thorax region. Thus, fabricated HT phantom can be utilized for radiation dosimetry in thoracic cancer patients. The materials used to develop HT phantom are easily available in market at an affordable price and easy to craft

The future of ship engines: Renewable fuels and enabling technologies for decarbonization

Shipping is one of the most efficient transportation modes for moving freight globally. International regulations concerning decarbonization and emission reduction goals drive rapid innovations to meet the 2030 and 2050 greenhouse gas reduction targets. The internal combustion engines used for marine vessels are among the most efficient energy conversion systems. Internal combustion engines dominate the propulsion system architectures for marine shipping, and current marine engines will continue to serve for several decades. However, to meet the aggressive goals of low-carbon-intensity shipping, there is an impetus for further efficiency improvement and achieving net zero greenhouse gas emissions. These factors drive the advancements in engine technologies, low-carbon fuels and fueling infrastructure, and emissions control systems. This editorial presents a perspective on the future of ship engines and the role of low-life cycle-carbon-fuels in decarbonizing the marine shipping sector. A selection of zero-carbon, net-zero carbon, and low-lifecycle-carbon-fuels are reviewed. This work focuses on the opportunities and challenges of displacing distillate fossil fuels for decarbonizing marine shipping. Enabling technologies such as next-generation air handling, fuel injection systems, and advanced combustion modes are discussed in the context of their role in the future of low-CO2 intensity shipping

Utilization of mechanical power and associations with clinical outcomes in brain injured patients: a secondary analysis of the extubation strategies in neuro-intensive care unit patients and associations with outcome (ENIO) trial

Background: There is insufficient evidence to guide ventilatory targets in acute brain injury (ABI). Recent studies have shown associations between mechanical power (MP) and mortality in critical care populations. We aimed to describe MP in ventilated patients with ABI, and evaluate associations between MP and clinical outcomes. Methods: In this preplanned, secondary analysis of a prospective, multi-center, observational cohort study (ENIO, NCT03400904), we included adult patients with ABI (Glasgow Coma Scale ≤ 12 before intubation) who required mechanical ventilation (MV) ≥ 24 h. Using multivariable log binomial regressions, we separately assessed associations between MP on hospital day (HD)1, HD3, HD7 and clinical outcomes: hospital mortality, need for reintubation, tracheostomy placement, and development of acute respiratory distress syndrome (ARDS). Results: We included 1217 patients (mean age 51.2 years [SD 18.1], 66% male, mean body mass index [BMI] 26.3 [SD 5.18]) hospitalized at 62 intensive care units in 18 countries. Hospital mortality was 11% (n = 139), 44% (n = 536) were extubated by HD7 of which 20% (107/536) required reintubation, 28% (n = 340) underwent tracheostomy placement, and 9% (n = 114) developed ARDS. The median MP on HD1, HD3, and HD7 was 11.9 J/min [IQR 9.2-15.1], 13 J/min [IQR 10-17], and 14 J/min [IQR 11-20], respectively. MP was overall higher in patients with ARDS, especially those with higher ARDS severity. After controlling for same-day pressure of arterial oxygen/fraction of inspired oxygen (P/F ratio), BMI, and neurological severity, MP at HD1, HD3, and HD7 was independently associated with hospital mortality, reintubation and tracheostomy placement. The adjusted relative risk (aRR) was greater at higher MP, and strongest for: mortality on HD1 (compared to the HD1 median MP 11.9 J/min, aRR at 17 J/min was 1.22, 95% CI 1.14-1.30) and HD3 (1.38, 95% CI 1.23-1.53), reintubation on HD1 (1.64; 95% CI 1.57-1.72), and tracheostomy on HD7 (1.53; 95%CI 1.18-1.99). MP was associated with the development of moderate-severe ARDS on HD1 (2.07; 95% CI 1.56-2.78) and HD3 (1.76; 95% CI 1.41-2.22). Conclusions: Exposure to high MP during the first week of MV is associated with poor clinical outcomes in ABI, independent of P/F ratio and neurological severity. Potential benefits of optimizing ventilator settings to limit MP warrant further investigation

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Field-Testing of Biodiesel (B100) and Diesel-Fueled Vehicles: Part 3—Wear Assessment of Liner and Piston Rings, Engine Deposits, and Operational Issues

AbstractThis study investigated the use of biodiesel (B100) and baseline mineral diesel in two identical unmodified vehicles to realistically assess different aspects of biodiesel’s compatibility and durability issues with modern common rail direct injection (CRDI) engine-powered vehicles. Two identical vehicles were operated for 30,000 km under identical operating conditions during a field-trial using biodiesel (B100) and mineral diesel. Exhaustive experimental results from this series of tests are divided into four sections, and this is the third paper of this series of four papers, which covers comparative feasibility and wear analyses, underlining the effect of long-term use of biodiesel on wear of cylinder liner and piston rings compared to baseline mineral diesel-fueled vehicle. Surface microstructures at three locations of the cylinder liner were evaluated using scanning electron microscopy (SEM). Wear was found to be relatively lower at all locations of liners from biodiesel-fueled vehicle compared to diesel-fueled vehicle. Surface roughness of cylinder liners measured at different locations showed that it reduced by ∼30–40% at top dead center (TDC), ∼10–20% at mid-stroke, and ∼20–30% at bottom dead center (BDC) for both vehicles, showing higher wear close to TDC compared to mid-stroke and BDC locations. Loss of piston-ring weight was significantly lower for biodiesel-fueled vehicle. Engine tear-down observations and carbon deposits on various engine components were recorded after the conclusion of the field trials. During these field-trials, engine durability-related issues such as fuel-filter plugging, injector coking, piston-ring sticking, carbon deposits in the combustion chamber, and contamination of lubricating oils were found to be relatively lower in biodiesel-fueled vehicle. Overall, no noticeable durability issues were recorded because of the use of biodiesel in CRDI engine-powered vehicle.</jats:p