Search

Approximately 25% of global carbon emissions come from food production. Renewable fuels are crucial for curbing greenhouse gas (GHG) emissions from vehicles, non-road machines, and agricultural machinery. Tractors, key to modern farming, are central to these efforts. As agriculture strives for sustainability, alternative fuels like methanol and hydrotreated vegetable oil (HVO) are arousing interest because they are renewable and offer potential for blending for use in diesel engines. Methanol and HVO have limited solubility in direct mixing, so the addition of a co-solvent is essential. This study addresses the research gap regarding the properties of HVO and methanol blends with co-solvents. It investigated the impact of three co-solvents, 1-dodecanol, 1-octanol, and methyl butyrate, on the miscibility of HVO and methanol. The experimental measurements cross-varied the co-solvent type with different blending ratios (MeOH5 and MeOH10). Investigated parameters include fuel density, kinematic viscosity, distillation properties, and surface tension. The co-solvents enabled the formation of a singular, clear, and homogeneous phase in methanol-HVO blends. The co-solvent 1-dodecanol demonstrated the highest solubilizing capacity for MeOH5 and MeOH10 blends, followed by 1-octanol. Adding co-solvents led to increased fuel density, decreased kinematic viscosity, and small changes in surface tension. These findings contribute to the optimization of methanol–HVO fuel blends for efficient and environmentally friendly use in vehicles, non-road machinery, and agricultural machinery. [ABSTRACT FROM AUTHOR]

Methanol and hydrotreated vegetable oil (HVO) are complementary in the context of achieving ultra-low emission levels via low temperature combustion. HVO is a high-quality fuel fully compatible with compression ignition engines. Standalone methanol combustion is relatively straight-forward according to the Otto principle, with a spark ignited or in conventional dual-fuel ("liquid spark") engines. These two fuels have by far the largest reactivity span amongst commercially available alternatives, allowing to secure controllable partially premixed compression ignition with methanol–HVO emulsification. This study investigates the corrosion of aluminum, carbon steel, stainless steel, and a special alloy of MoC210M/25CrMo4+SH, exposed to different combinations of HVO, HVO without additives (HVOr), methanol, and emulsion stabilizing additives (1-octanol or 1-dodecanol). General corrosive properties are well determined for all these surrogates individually, but their mutual interactions have not been researched in the context of relevant engine components. The experimental research involved immersion of metal samples into the fuels at room temperature for a duration of 60 days. The surfaces of the metals were inspected visually and the dissolution of the metals into fuels was evaluated by analyzing the fuels' trace metal concentrations before and after the immersion test. Furthermore, this study compared the alterations in the chemical and physical properties of the fuels, such as density, kinematic viscosity, and distillation properties, due to possible corrosion products. Based on these results, methanol as 100% fuel or as blending component slightly increases the corrosion risk. Methanol had slight dissolving effect on aluminum (dissolving Al) and carbon steel (dissolving Zn). HVO, HVOr, and methanol–HVOr–co-solvents were compatible with the metals. No fuels induced visible corrosion on the metals' surfaces. If corrosion products were formed in the fuel samples, they did not affect fuel parameters. [ABSTRACT FROM AUTHOR]

System complexity is challenging for development of marine mid-speed engines when striving to meet increasingly stringent emission targets. Control-oriented modeling offers a solution, cutting calibration time and enabling robust control strategies. Simultaneously, real-time, physics-based engine models (digital twins) are emerging as they offer better predictive capability and scalability than typical mean-value, data-driven approaches. This study explored development of a control-oriented digital twin of a Wärtsilä 4L20 marine engine. Starting from a detailed one-dimensional model (GT-Suite), it explored reduction strategies toward a fast-running engine model (FRM), balancing the calculation speed and accuracy trade-off. Finally, the FRM was tested for real-time implementation on a target machine. Comprehensive experimental data from the 4L20 platform in the VEBIC Engine Laboratory provided the baseline for model calibration. Model calibration and validation covered four representative operating points and involved correlation of crank-angle, resolved in-cylinder pressures, thermal state at several locations of the engine air-path and relevant performance indicators. The results shed new light on the feasibility of digital twins in the marine engine domain. The obtained FRM was three times faster than real-time, while the accuracy loss was comfortably within the 5% tolerance levels for the governing outputs, including crank angle resolved in-cylinder pressure. The grid-resolved simulation was obtained with four times fewer flow components and internal discretization length of 100% and 150% of the cylinder bore for intake and exhaust components respectively. The balance between predictivity, accuracy and real-time surplus, was ultimately more favorable than in state of the art automotive applications and enables exploring further coupling with semi-predictive emission sub-models. The real-time capable FRM is considered applicable in hardware-in-the-loop simulation, and this application is scheduled in a follow-up project. [ABSTRACT FROM AUTHOR]

Background. Although various low-trauma fractures among older adults are said to be a major public health concern in contemporary societies with aging populations, reliable epidemiologic information on their secular trends is scarce. Methods. We assessed the current trend in the number and incidence (per 100,000 persons) of low-trauma fractures of the calcaneus and foot of older adults in Finland, a European Union country with a well-defined white population of 5.2 million, by taking into account 'all persons 50 years old or older who were admitted to Finnish hospitals for primary treatment of such injury in 1970-2005. Results. The number and raw incidence of low-trauma fractures of the calcaneus and foot among Finns 50 years old or older rose considerably between the years 1970 and 2005, from 64 (number) and 5.6 (incidence) in 1970 to 294 and 15.2 in 2005. For the study period, the age-adjusted incidence of fracture was higher in men than women and showed a clear increase in both sexes in 1970-2005, from 7.3 to 17.4 in men (138% increase), and from 4.3 to 12.5 in women (191% increase). A similar finding was observed in the age-specific incidences. Assuming that the observed increase in the age-specific fracture incidence continues in the 50-year-old or older group and the size of this population increases as predicted, the annual number of low-trauma fractures of the calcaneus and foot in this population will be two times higher in the year 2030 (approximately 550 fractures annually) than it was during 2001-2005. Conclusions. In Finnish persons aged 50 years or older, the number of low-trauma fractures of the calcaneus and foot has risen considerably in 1970-2005 with a rate that cannot be explained merely by demographic changes. Further studies are needed to explore the exact reasons for the rise and possibilities for fracture prevention. Key Words: Calcaneus and loot--Elderly adults--Epidemiology--Falls--Low-trauma fractures--Secular trends.

Background. Although fall-induced injuries among older adults are said to be a major public health concern in modern societies with aging populations, reliable epidemiologic information on their secular trends is limited. Methods. We determined the current trend in the number and incidence (per 100,000 persons) of fall-induced severe cervical spine injuries (fracture, cord injury, or both) of older adults in Finland, a European Union country with a well-defined white population of 5.2 million, by taking into account all persons aged 50 years or older who were admitted to all Finnish hospitals for primary treatment of such injury in 1970-2004. Similar patients aged 20-49 years served as a reference group. Results. The number and raw incidence of fall-induced cervical spine injury among Finns aged 50 years or older rose considerably between the years 1970 and 2004, from 59 (number) and 5.2 (incidence) in 1970 to 228 and 12.0 in 2004. The relative increases were 286% and 131%, respectively. Throughout the study period, the age-standardized incidence of injury was higher in men than women, and showed a clear increase in both sexes in 1970-2004 from 8.5 to 17.4 in men (105% increase), and from 2.8 to 6.4 in women (129% increase). A similar finding was observed in the age-specific incidences of the study group. In the reference group, the annual number and incidence of injury decreased slightly over time. Assuming that the observed increase in the age-standardized or age-specific injury incidence continues in Finns aged 50 years or older and the size of this population increases as predicted, the annual number of fall-induced cervical spine injuries in this population will be about 100% higher in the year 2030 (about 400 injuries annually) than it was during 2000-2004 (about 200 injuries annually). Conclusions. In Finnish persons aged 50 years or older, the number of fall-induced severe cervical spine injuries seems to show an alarming rise with a rate that cannot be explained merely by demographic changes. The finding underscores an increasing influence of falls on health and well-being of our older adults; therefore, wide-scale fall-prevention measures should be urgently adopted to control this development.