bluuebunny/crossref_metadata_2025 huggingface dataset:
Prehemolytic impact of phenothiazine drugs on the attachment of spectrin network in red blood cells
Authors: Parvanova Boyana , Tacheva Bilyana , Ivanov Ivan
Published: October 2023

Introduction: Chlorpromazine, thioridazine, and trifluoperazine are phenothiazine drugs that cause colloid-osmotic hemolysis of human erythrocytes by unknown mechanism. To clarify this mechanism, the impact of these drugs on the βsp (1.4 MHz) and γ1sp (9 MHz) dielectric relaxations was investigated. Each relaxation was shown to reduce its strength on the severing specific bridge that connects the spectrin network with the lipid membrane. For βsp relaxation, this is the spectrin-actin-glycophorin C bridge while for γ1sp relaxation this is the spectrin-ankyrin-band 3 bridge.

Aim: To elucidate the mechanisms of the effects of phenothiazine drugs in prehemolytic concentrations on the red blood cell plasma membrane using scanning temperature-dependent (thermal) differential dielectric spectroscopy.

Materials and methods: Erythrocytes were isolated from freshly drawn blood and 100 μl of them were suspended in 1 ml isotonic solution of 10 mM NaCl and mannitol (working medium) containing the indicated concentration of the drug for 10 min at 23°C. The treated erythrocytes were isolated, suspended in working medium, hematocrit 0.55, and heated (heating rate 1.5°C/min) above the denaturation temperature of spectrin (TA≈49.5°C) in order to obtain the differential dielectric spectroscopy data. The complex admittance, Y* = Y’+j.Y”, of the tested suspensions was continuously measured and separated into its real (Y’) and imaginary (Y”) parts using Solartron 1260 Impedance Frequency Analyzer.

Results: At pre-hemolytic concentrations, each drug inhibited these two relaxations, predominantly the γ1sp relaxation. The results could be interpreted in terms of a sigmoid effect of the drugs on the spectrin-ankyrin-band 3 bridge severing it at concentration just prior to the start of massive hemolysis.

Conclusions: The study points at the possible mechanism of erythrocyte damage after treatment with phenothiazine drugs at prehemolytic concentrations. This is probably due to the disruption of the bridges between the phospholipid bilayer and the submembrane spectrin network.
Diagnostic benefits of 18F-FDG PET/CT in cases of prosthetic infective endocarditis
Authors: Dobreva-Yatseva Bistra , Nikolov Fedya , Raycheva Ralitsa , Botushanova Albena , Koleva Maria , Tokmakova Mariya
Published: October 2023

Infective endocarditis (IE) is a difficult-to-diagnose provocative disease that causes significant morbidity and mortality. The first-line imaging test for the diagnosis of IE is echocardiography. However, in cases of prosthetic IE or IE associated with intracardiac devices, its sensitivity is limited. A new diagnostic tool, 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT), improves diagnosis in these difficult cases. The most recent European guidelines for IE (2015) include this imaging modality as a primary diagnostic criterion. We present a case of culture-negative prosthetic IE diagnosed with 18F-FDG PET/CT.
Innovative approach for developing solitary wave solutions for the fractional modified partial differential equations
Authors: Noor Saima , Alshehry Azzh Saad , Khan Asfandyar , Khan Imran
Published: October 2023

The current work investigates solitary wave solutions for the fractional modified Degasperis-Procesi equation and the fractional gas dynamics equation with Caputo's derivative by using a modified extended direct algebraic method. This method transforms the targeted fractional partial differential equations (FPDEs) into more manageable nonlinear ordinary differential equations, which are then turned into systems of nonlinear algebraic equations with a series-based solution assumption. Using Maple 13, the solitary wave solutions are then obtained by solving the obtained systems. The method produces multiple innovative solitary wave solutions for both equations, which are graphically depicted as 3D and 2D graphs and provide important insights into their behaviors. These insights help us to comprehend wave behavior and the physical processes represented by these equations. Furthermore, the suggested technique exhibits dependability and efficacy in dealing with complicated FPDEs, which bodes well for future studies on the subject.
MHD effects on Casson fluid flow squeezing between parallel plates
Authors: Al-Hanaya Amal , Alotaibi Munirah , Shqair Mohammed , Hagag Ahmed Eissa
Published: October 2023

We introduce this work by studying the non-Newtonian fluids, which have huge applications in different science fields. We decided to concentrate on taking the time-dependent Casson fluid, which is non-Newtonian, compressed between two flat plates. in fractional form and the magnetohydrodynamic and Darcian flow effects in consideration using the semi-analytical iterative method created by Temimi and Ansari, known as TAM, this method is carefully selected to be suitable for studying the Navier-Stokes model in the modified form to express the studied case mathematically. To simplify the partial differential equations of the system to the nonlinear ordinary differential equation of order four the similarity transformations suggested by Wang (1976) are used. The TAM approach demonstrates a high degree of accuracy, efficiency, and convergence when applied to the resolution of both linear and nonlinear problems, and the results in this article are used to study the effect of the related factors like squeeze number Sq, Casson parameterβ, magnetohydrodynamic parameter Mg and permeability constant Mp and examining the skin friction coefficient effect. The velocity profile is studied numerically, which is tabulated and graphically represented to show and confirm the theoretical study. We can conclude that the success of the proposed method in studying time-dependent Casson fluid, which is non-Newtonian, compressed between two flat plates provides opportunities for additional study and advancements in fluid mechanics using the techniques.
Investigation and analysis of the numerical approach to solve the multi-term time-fractional advection-diffusion model
Authors: Aghdam Yones Esmaeelzade , Mesgarani Hamid , Asadi Zeinab , Nguyen Van Thinh
Published: October 2023

In this paper, a methodical approach is presented to approximate the multi-term fractional advection-diffusion model (MT-FAD). The Lagrange squared interpolation is used to discretize temporal fractional derivatives, and Legendre polynomials are shifted as an operator to discretize the spatial fractional derivatives. The advantage of these numerical techniques lies in the orthogonality of Legendre polynomials and its matrix operations. A quadratic implicit design as well as its stability and convergence analysis are evaluated. It should be noted that the theoretical proof obtained from this study represents the first results for these numerical schemes. Finally, we provide three numerical examples to verify the validity of the proposed methods and demonstrate their accuracy and effectiveness in comparison with previous studies shown in [W. P. Bu, X. T. Liu, Y. F. Tang, J. Y. Yang, Finite element multigrid method for multi-term time fractional advection diffusion equations, Int. J. Model. Simul. Sci. Comput., 6 (2015), 1540001].
Optimization of sponge iron (direct reduced iron) production with Box-Wilson experimental design by using iron pellets and lignite as reductant
Authors: Sönmez İbrahim , Şahbudak Kemal
Published: October 2023

Turkey’s iron ores may be used to manufacture sponge iron, and the country’s coal resources, which are plentiful despite being of poor quality, can be used as a reducing agent. With such a production, Electric Arc Furnace based on scrap imports, will be an alternative raw material for steel production, and this will create high value due to the usage of domestic resources. In this study, sponge iron production was tried to be optimized by using local sources. For this purpose, the effects of time, temperature and [CFix/FeTotal] weight ratio on the Reduction Degree (%) of the important parameters effective in the production of sponge iron by using Divriği Iron Pellets and Dodurga Lignite as a reductant were studied using a Box-Wilson experimental design. The optimum parameters were determined as 82.59 min, 996.73 °C and 0.49, and the highest Reduction Degree (%) value was calculated as 96.46%. The sponge iron obtained with a 71.91% Reduction Degree contains 97.12% Fe, of which 7.12% is oxidized. It is evident that higher Fe contents may be attained with research carried out in optimum parameters.
Apple recognition and picking sequence planning for harvesting robot in the complex environment
Authors: Ji Wei , Zhang Tong , Xu Bo , He Guozhi
Published: October 2023

In order to improve the efficiency of robots picking apples in challenging orchard environments, a method for precisely detecting apples and planning the picking sequence is proposed. Firstly, the EfficientFormer network serves as the foundation for YOLOV5, which uses the EF-YOLOV5s network to locate apples in difficult situations. Meanwhile, the Soft Non-Maximum Suppression (NMS) algorithm is adopted to achieve accurate identification of overlapping apples. Secondly, the adjacently identified apples are automatically divided into different picking clusters by the improved density-based spatial clustering of applications with noise (DBSCAN). Finally, the order of apple harvest is determined to guide the robot to complete the rapid picking, according to the weight of the Gauss distance weight combined with the significance level. In the experiment, the average precision of this method is 98.84%, which is 4.3% higher than that of YOLOV5s. Meanwhile, the average picking success rate and picking time are 94.8% and 2.86 seconds, respectively. Compared with sequential and random planning, the picking success rate of the proposed method is increased by 6.8% and 13.1%, respectively. The research proves that this method can accurately detect apples in complex environments and improve picking efficiency, which can provide technical support for harvesting robots.
Factors which Influence the Frequency of Cognitive Assessment in the Emergency Department
Authors: Zakaria Mohd Idzwan , Suhaimi Salimah , Pin Tan Maw , Mokhtar Mohd Amin Mohd , Zahedi Ahmad Zulkarnain Ahmad
Published: October 2023

Background: The practice of safe emergency medicine requires accurate and adequate assessments. However, screening for cognitive deficits is not performed regularly in the emergency department (ED). This study aimed to determine factors influencing the frequency of cognitive testing by ED doctors. Methods: This study included all doctors working in the EDs of three teaching hospitals. A 17-item online survey instrument that collected information on sex, experience, perceived prevalence, perception, and practice of cognitive assessment was distributed through electronic mail and data messaging services. Results: Of the 210 participants, 72 were male. The estimated mean with standard deviation prevalence of cognitive impairment in older patients in the ED was 39.5%±19.7%. Among the participating ED doctors, 75.8% performed cognitive testing up to 10% of the time. Moreover, the participants ranked cognitive impairment the lowest compared to the other four chronic conditions in terms of its impact on hospitalization outcomes. Multiple linear regression revealed that the doctors’ perceptions of the responsible personnel and the importance of cognitive testing, as well as their lack of expertise, were independently associated with the frequency of testing. Conclusion: Lack of expertise, perception of the importance of cognitive testing, and lack of consensus on which discipline is responsible for performing cognitive testing in older patients in the ED were the limiting factors in performing cognitive testing in the ED. Improving perception and awareness of the importance of cognitive assessment as a screening tool could improve the detection and overall management of older patients.
GT-Suite Modeling of Thermal Barrier Coatings in a Multi-Cylinder Turbocharged DISI Engine for Catalyst Light-Off Delay Improvement
Authors: Ravikumar Avinash , Bhatt Ankur , Gainey Brian , Lawler Benjamin
Published: October 2023

Catalytic converters, which are commonly used for after-treatment in SI engines, exhibit poor performance at lower temperatures. This is one of the main reasons that tailpipe emissions drastically increase during cold-start periods. Thermal inertia of turbocharger casing prolongs the catalyst warm-up time. Exhaust enthalpy management becomes crucial for a turbocharged direct injection spark ignition (DISI) engine during cold-start periods to quickly heat the catalyst and minimize cold-start emissions. Thermal barrier coatings (TBCs), because of their low thermal inertia, reach higher surface temperatures faster than metal walls, thereby blocking heat transfer and saving enthalpy for the catalyst. The TBCs applied on surfaces that exchange heat with exhaust gases can increase the enthalpy available for the catalyst warm-up. A system-level transient heat transfer study using experimental or high-fidelity simulation techniques to evaluate the TBC application on various surfaces would be expensive. In this work, a reduced-order system-level modeling methodology in GT-Suite was leveraged to evaluate TBCs on exhaust ports, manifold, and runners. A multi-cylinder turbocharged DISI engine was modeled in GT-Suite, with capability to model a layer of TBC on internal surfaces. The model was calibrated using measured data from steady state operating conditions due to lack of transient cold start data. Following the TBC analysis, a theoretical study to infer the effects of turbocharger casing heat loss on the catalyst warm-up was performed. The TBCs showed no tangible benefit in the catalyst light-off delay when applied on the combustion chamber walls but showed a 20-second faster catalyst light-off when an 800-micron thick TBC was applied on the exhaust flow path walls (exhaust ports, manifold and runners). The turbocharger casing/housing heat transfer was shown to have a considerable effect on the catalyst light-off delay. An additive benefit to the catalyst light-off delay was achieved by insulating the combustion chamber walls, the exhaust flow path walls, and the turbocharger casing together which was predicted to be 25 seconds faster than the baseline.
Artificial Neural Network-Based Emission Control for Future ICE Concepts
Authors: Wetering Maarten van de , Danninger Alois , Vos Bart
Published: October 2023

The internal combustion engine contains several actuators to control engine performance and emissions. These are controlled within the engine ECU and follow a specific operating strategy to achieve objectives such as NOx reduction and fuel economy. However, these two goals are conflicting and a compromise is required. The operating state depends on system constraints such as engine speed, load, temperature levels, and aftertreatment system efficiency. This results in constantly changing target values to stay within the defined limits, especially the legal emission limits. The conventional approach is to use multiple operating modes. Each mode represents a specific compromise and is activated accordingly. Multiple modes are required to meet emissions regulations under all required conditions, which increases the calibration effort. This new control approach uses an artificial neural network to replace the conventional multiple mode approach. The desired engine emission and temperature limits, for example based on SCR conversion efficiency, are sent to the artificial neural network, which controls the actuators to meet the desired limits. It also enables the lowest possible fuel consumption or, for example, the highest possible exhaust gas enthalpy within the given system state. A simulation environment was created to investigate the benefits of this approach. A cold heavy-duty emission cycle was simulated with the conventional and the new approach. While both approaches had the same tailpipe NOx emissions during the emission cycle, the new approach achieved a fuel consumption reduction of 0.9%. Since this method allows semi-automatic calibration and training of the artificial neural network, the manual calibration effort can be reduced compared to the conventional approach as an additional advantage. In conclusion, this study introduced a new approach to the control of the internal combustion engine and demonstrated through simulations that the new control approach can further optimize the synergies between the engine and the exhaust gas aftertreatment.
Analysis
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Redo plots of compression stroke timing sweep.
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of a Split Injection Strategy to Enable High Load, High Compression Ratio Spark Ignition with Hydrous Ethanol
Authors: Gandolfo John , Kumar Mohit , Gao Mingyang , Lawler Benjamin , Gainey Brian
Published: October 2023

High compression ratios are critical to increasing the efficiency of spark ignition engines, but the trend in downsized and down sped configurations has brought attention to the nominally low compression ratios used to avoid knock. Knock is an abnormal combustion event defined by the acoustic sound caused by end-gas auto-ignition ahead of the flame front. In order to avoid engine-damaging levels of knock, low compression ratios and retarded combustion phasing at high loads are used, both of which lower efficiency. Low carbon alternative fuels such as ethanol or water-based alcohol fuels combine strong chemical auto-ignition resistance with large charge cooling characteristics that can suppress knock and enable optimal combustion phasing, thus allowing an increase in the compression ratio.

Of course, these high cooling potential fuels are not immune to knock at high loads at high enough compression ratios and are subject to the same combustion phasing strategies (i.e., spark retard) that diminish efficiency. In this work, an injection strategy is characterized in which the cooling potential of water-based alcohol fuel such as hydrous ethanol (WE92 - 190 proof, 92% ethanol, 8% water by mass) is taken advantage of in order to suppress knock at high load conditions. This work explores the implications of extending the injection window into the compression stroke. The results demonstrated a maximum 1 percentage point increase in net fuel conversion efficiency and 2.0 degree CA50 advance at 17 bar IMEPn with 15% of the total fuel injected in the compression stroke.
Experimental Study of Low Thermal Inertia Thermal Barrier Coating in a Spark Ignited Multicylinder Production Engine
Authors: Bhatt Ankur , Gandolfo John , Vedpathak Kunal , Jiang Chen , Jordan Eric , Lawler Benjamin , Gainey Brian
Published: October 2023

Thermal barrier coatings (TBCs) have long been studied as a potential pathway to achieve higher thermal efficiency in spark ignition engines. Researchers have studied coatings with different thicknesses and thermophysical properties to counteract the volumetric efficiency penalty associated with TBCs in spark ignition. To achieve an efficiency benefit with minimal charge heating during the intake stroke, low thermal inertia coatings characterized by their larger temperature swings are required. To study the impact of low thermal inertia coatings in spark ignition, coatings were applied to the cylinder head, piston crown, intake and exhaust valve faces, and intake and exhaust valve backsides. Tier III EEE E10 certification gasoline was used to keep the experiments relevant to the present on-road vehicles. This study is aimed at analyzing durability of the coatings as well as efficiency and emissions improvements. Thus, a 100-hr. durability test was conducted to assess the durability of the coatings. Pseudo-cold start testing was also compared between the coatings and metal baseline to investigate any benefits pertaining to emissions reduction during cold starts. These experimental results show that low thermal inertia coatings can be developed for spark ignition engines that survive a 100-hr. durability test, though there is no significant change in steady state engine performance with the application of these coatings. However, there was a substantial reduction in particulate matter and unburned hydrocarbon emissions during pseudo-cold start testing.
Effects of the Combustion Enhancer Containing Alkyl Nitrate (CEN) to Dodecane and HVO as Pilot Fuels on a Compression Ignition Engine Operating in Dual-Fuel with Ammonia
Authors: Samson Richard , Morin Anne-Gaëlle , Foucher Fabrice
Published: October 2023

Ammonia is a widely used and known chemical. Today it is seen as a carbon free solution to fuel thermal engines especially in applications where other solutions would not be realistic. For marine applications, electrical or fuel cells solutions for example would not allow spans long enough to sustain big cargo ships ranges. Engine manufacturer such as MAN, Wartsila or Win-GD have already announced the development of marine engine running on ammonia. But while ammonia is a non-CO2 emitting fuel, it has some caveats such as being gaseous in standard conditions and hard to ignite. As it is now, ammonia is usually used in compression ignition engines with the help of highly reactive carbonated pilot fuels. Many forms of dual-fuel combustion are conceivable, although all the simple ones use a carbon-based fuel and quite often originated from fossil oil. The addition of High Reactivity Fuel to Ammonia is an interesting combustion mode that can be used to calibrate different fuel parameters and explore the mechanisms surrounding ammonia ignition and combustion. In this study Dodecane or HVO are used as the pilot fuel with a combustion enhancer containing alkyl nitrates (CEN). The pilot fuels injections were maintained to stay at 2% of the total energy provided by the fuel & the pilot fuel. The effects of the combustion additive were observed and measured. Adding 1% of volume fraction of the additive the Dodecane/HVO pilot fuel allows for better cycle to cycle stability (Coefficient of Variation – CoVIMEP) and higher Indicated Mean Effective Pressure (IMEP). 10% of volume fraction additive in the pilot fuel further increases engine power output and smoothens the combustive event by lengthening it. It was difficult to truly investigate the emissions due to ammonia FTIR spectrum, but in this study IMEP, with the IMEP, CoVIMEP, noticeable crank angle degrees (CA10, CA50, CA90) and Indicated Thermal Efficiency (ITE) were measured with ammonia preheated (80°C) while kept at ambient pressure at intake. Three IMEP values (12 – 8 – 4 bar) were targeted for a one-cylinder engine with a displacement of 0.499L and a compression ratio of 16.4. The strategy of this study allowed to conclude that the combustive additive and the pilot fuel used in relatively low ratios vs. ammonia (2% energetic ratio) have a synergetic activity allowing for better ignition (than the pilot fuel alone), better cycle to cycle stabilization, better power output, and displacing the combustive event toward ammonia combustion in conditions (richness and engine loads) where it’s been otherwise repeatedly observed impossible.
Design Development and Testing of the Fuel Supply System with Metalized Fuels for Power Plants of Vehicles
Authors: Dudukalov Yuri , Ternyuk Mykola , Hlushkova Diana , Bushnov Valery , Sorokin Volodymyr , Kholodov Mykhailo
Published: October 2023

The demand for multi-environmental modes of transportation is driven by the overall trend of increasing mobility and the necessity of movement across various alternating environments (land, water, underwater, aerial, and airspace). However, the specific energy density of hydrocarbon fuels cannot ensure efficient operation of power systems for such multi-environmental vehicles. A promising solution to this problem involves the utilization of boron-containing metallized fuels through the creation of specialized fuel supply systems. Based on a general method of optimization synthesis for technical objects, new fuel supply systems were synthesized with different levels of process control and degrees of automation, as well as an adjustable hybrid fuel delivery system that allows the application of components in varying aggregate states. During testing, operational characteristics were determined primarily for the implemented metallic hybrid transformer fuel delivery system. In our view, it holds the greatest potential for the utilization of metallized fuels, as it provides an expanded range of applications, increased functions, and structures. This is also linked to the possibility of employing boron in the α-modification, where atomic-level processes ensure maximum combustion efficiency. Thus, the new fuel supply system offers functionality across diverse environments, creating genuine prerequisites for the efficient operation of power systems for multi-environmental modes of transportation.
An Innovative Diesel Burner for Thermal Management of Exhaust Emission Control System
Authors: Kang Hongjae
Published: October 2023

An innovative on-board diesel burner driven by a rotating gliding arc plasma has been developed for thermal management of diesel catalysts. The unique features of the burner, such as abnormally fast ignition process, removal of black carbons deposited on the parts of the burner, extended flammability limits, have been revealed through various burner and engine lab tests. After these basic tests, intensive field tests have been conducted to evaluate the practical feasibility of the burner. In the field tests, about 200 sets of the burner and DPF (Diesel Particulate Filter) have been installed in various kinds of low speed heavy-duty (HD) vehicles, which are vehicles for towing airplane, mixer (Ready-Mixed Concrete) cars, cargo trucks operated in military bases. The field tests show that all of the filters and burners have been operated for more than 4 years without maintenance problems. The tests also show that emissions of HC (Hydrocarbons), which results in white smoke emissions in a cold season, can be significantly reduced by applying several techniques simultaneously, which are fast ignition process, extending flammability limits, precise control of fuel supply, etc.
How to Accomplish a More Sustainable Internal Combustion Engine Using Life Cycle Analysis: A Demo
Authors: Dudley Joshua Paul , Laurell Mats , Thuve Christoffer , Klövmark Henrik
Published: October 2023

The Sustainable Development Goals were adopted by all United Nation Member States in 2015 to ensure a sustainable planet and improved living conditions for everyone, everywhere. The light duty vehicle (LDV) fleet has exceeded one billion, with most vehicles being powered by internal combustion engines. Transportation is responsible for 60% of global fossil oil consumption. Air pollution is a large problem in cities often attributed to road transport. Vehicles comprise of over 70 material categories, indicating the complexity of sustainable material management. A hypothesis was established, that a sustainable engine (SE) could significantly reduce the environmental impact of transportation and, be realized by combining available technologies. A life cycle analysis was conducted on a 145 kW 2-litre Miller-cycle gasoline 48V-mild-hybrid engine with EU6d exhaust aftertreatment system (EATS), assessing seven mid-point categories. The environmental impacts were used to establish sustainable lifecycle target levels for carbon dioxide equivalent (CO2eq), carbon monoxide (CO), nitrous oxides (NOx) and total-hydrocarbons (THC). A system solution was designed and manufactured to meet the proposed targets. Recycled materials have been applied and verified to multiple components, realizing a 71% reduction in cradle-to-gate Climate Change (CC) impact for the complete engine. An exhaust aftertreatment system (EATS) was developed and tested via a method using a vehicle emissions test cycle adopted on a dynamic engine bench. Considerations were performed for the possibility to use recycled platinum group materials (PGMs) in the catalytic converter. Air pollutant levels were reduced over 90% for the first 390s of the Worldwide Harmonized Light Vehicles Test Procedure (WLTP). A renewable gasoline was tested achieving a 65% lower fuel life cycle climate change impact. Over the complete engine and fuel life cycle a 61% reduction in climate change impact was achieved. The method and demonstrated technology provide insights into a sustainable system solution for an internal combustion engine. Challenges were identified and discussed in relation to primary data collection, establishing circular supply chains and quantifying targets.
Characterization of an Integrated Three-Way Catalyst/Lean NOx Trap System for Lean Burn SI Engines
Authors: Sandhu Navjot Singh , Leblanc Simon , Yu Xiao , Reader Graham , Zheng Ming
Published: October 2023

The push for environmental protection and sustainability has led to strict emission regulations for automotive manufacturers as evident in EURO VII and 2026 EPA requirements. The challenge lies in maintaining fuel efficiency and simultaneously reducing the carbon footprint while meeting future emission regulations. Alcohol (primarily methanol, ethanol, and butanol) and ether (dimethyl ether) fuels, owing to their comparable energy density to existing fuels, the comparative ease of handling, renewable production, and suitable emission characteristics may present an attractive drop-in replacement, fully or in part as an additive, to the gasoline/diesel fuels, without extensive modifications to the engine geometry. Additionally, lean and diluted combustion are well-researched pathways for efficiency improvement and reduction of engine-out emissions of modern engines. Modern spark ignition (SI) engines typically employ various in-cylinder emission reduction techniques along with a three-way catalyst (TWC) based exhaust after-treatment system to comply with emission standards. However, the periodic lean-rich oscillations for this TWC system necessitate the SI engine to operate at near stoichiometric mixture conditions, which limits the viability of lean burn for SI engines. Lean NOx trap (LNT) system can reduce the engine out NOx under lean conditions at a cost of fuel efficiency penalty due to regeneration. In the present study, the feasibility of using a coupled TWC-LNT system with extensive dilution to achieve ultra-low tailpipe emissions is investigated. Relevant engine-out exhaust conditions from an SI engine, including flow, temperature, and exhaust species, operating at different dilution conditions were replicated on a heated aftertreatment flow bench. A comprehensive analysis of species before and after the catalyst sections was performed using Fourier-transformed infrared (FTIR) and mass spectrometers to study and quantify the conversion and formation of species, including ammonia, methane, and hydrogen, under different engine-out conditions. The results the integration of LNT to a TWC catalyst improves the conversion efficiency of reducing species during the lean operation period. TWC and LNT catalyst simultaneously achieve high conversion efficiency at ~350°C. The LNT regeneration behavior is noticeably affected by the presence of preceding TWC catalyst. The temperature rise because of the oxidation reactions on TWC can deteriorate the LNT regeneration efficiency beyond 400°C.
Performance and In-Cylinder Pressure-Based Diagnosis of a Single-Cylinder Variable Compression Engine Developed for Education and Research
Authors: Henao Castañeda Edison de Jesús , Monroy Mauricio , Romero Carlos
Published: October 2023

The object of this paper is to present the operability of a variable compression ratio engine developed to study the combustion characteristics of alternative fuels under different speed and load regimes when exploitation parameters are changed. The variable compression ratio engine is a modification of a commercial single-cylinder diesel engine with adjustable combustion chamber volume, fuel, and ignition systems, envisioned to operate in spark ignition or compression ignition mode. After explaining the experimental plan, designed to evaluate the engine performance comprehensively, a sample of the engine performance and thermodynamic results under spark ignition mode for a chosen condition of speed and load operation with three compression ratio values (9, 12, 14) and three gasoline-ethanol blends is detailed. Torque, power, fuel consumption, and in-cylinder-pressure-related indicated parameters for the experimental cases carried out, are compared. The results show the suitability of the developed engine to evaluate the influence that changes in fuel-mix composition, compression ratio, and tuning parameters have on the performance and combustion response of the engine.
Valvetrain System for Exhaust Rebreathing on a Light-Duty Gasoline Compression Ignition (GCI) Engine
Authors: Sellnau Mark , Whitney Christopher , Shah Ashish , Kunz Timothy , Dinkel Mike
Published: October 2023

The global automotive industry is undergoing a significant transition as battery electric vehicles enter the market and diesel sales decline. It is widely recognized that internal combustion engines (ICE) are needed for transport for years to come, however, demands on fuel efficiency, emissions, cost, and performance are extremely challenging. Gasoline compression ignition (GCI) is one approach to achieving demanding future efficiency and emissions targets. A key technology enabler for GCI is partially premixed, compression ignition (PPCI) combustion, which involves two high-pressure, late, fuel injections during the compression stroke. Both NOx and smoke emissions are greatly reduced relative to diesel engines, and this reduces aftertreatment (AT) requirements significantly.

Exhaust rebreathing (RB) is used for robust low-load and cold operation. This is enabled by use of 2-Step, mode switching rocker arms to allow switching between rebreathe and normal combustion modes. Exhaust rebreathing involves reinduction of hot exhaust gases into the cylinder during a second exhaust lift event during the intake stroke to help promote autoignition. The amount of exhaust rebreathing is controlled by exhaust backpressure created by the vanes on the variable nozzle turbine (VNT) turbocharger. Due to higher cycle temperatures when rebreathing, exhaust HC and CO may be significantly reduced, while combustion robustness and stability also improve. Increased charge dilution during rebreathing can also lower NOx emissions. Importantly, exhaust rebreathing significantly increases exhaust temperatures to maintain active catalysis in the AT system for ultra-low tailpipe emissions.

A 2-step valvetrain system was designed and developed for exhaust rebreathing on a 2.6l light-duty gasoline compression ignition engine. Tri-roller, switching rocker arms with hydraulically actuated lock pins were built for low friction. The 2-step actuation system was designed for fast response using a pulse-width-modulated oil control valve that regulated the oil pressure feeding the switching rocker arms.

Tests were conducted on the dynamometer demonstrating robust combustion with high exhaust temperatures and active catalysis at low load operation. Calibration mapping tests were also conducted. Overall, the tests demonstrated the simplicity and robustness of the exhaust rebreathing approach while delivering low exhaust emissions.
Calculation of Thermal Boundary Conditions for Hydrogen Internal Combustion Engines
Authors: Bell David , Grimley Peter , Hynous Jan , Shapiro Evgeniy , Osborne Richard , Valenta Lukáš
Published: October 2023

Hydrogen has been identified as a promising decarbonization fuel in internal combustion engine (ICE) applications in many areas including heavy-duty on- and off-road, power-generation, marine, etc. Hydrogen ICEs can achieve high power density and very low tailpipe emissions. However, there are challenges; designing systems for a gaseous fuel with its own specific mixing, burn rate and combustion control needs, which can differ from legacy products.

The primary pollutant of concern for Hydrogen ICEs is NOx which can be addressed by running the engine at very lean equivalence ratios and the use of Exhaust Gas Recirculation (EGR). Computation Fluid Dynamics (CFD) is a valuable tool to model the combustion characteristics under different conditions, as presented in SAE-2023-01-0197 [1], which can also be used to predict thermal loading. Being able to determine the thermal distribution and temperatures of the power cylinder components has always been critical to the design and development of ICE programmes. This remains a key requirement when considering hydrogen as an alternative fuel for both clean sheet hydrogen ICE designs and implementation of fuel conversions. Significant improvements have been made in recent years in the speed and accuracy of CFD analytical tools for combustion and thermal prediction, but these still present lead times that can preclude their use in early concept work or parametric studies.

SAE-2022-01-0597 [2] presented a new analytical FE-based tool, complementary to 3D CFD, that calculates thermal boundary conditions using physical models and semi-empirical correlations. This paper presents the extension of this tool to support alternative fuels including hydrogen, with validation on a Euro VI HD Diesel engine converted to operate on hydrogen gas using direct injection. Results and measurements are presented at full and part-load conditions including a lambda (λ) swing to investigate the effect of different equivalence ratios on structural temperature.
Design and Simulation of Extended-Range Lithium-Titanate Battery Electric Commercial Vehicle
Authors: Cheng Yu Chi , Huang K. David , ZHANG Jun Cheng
Published: October 2023

It is a kind of range-extended electric vehicle (REEV) using a lithium-titanate battery but can use as a hybrid electric vehicle (HEV). The proposal aims to use a battery of just the right size as the power core of the system to help the engine maintain maximum efficiency. The performance of the lithium-titanate battery is between battery and capacitor. It also has anti-overcharge, anti-over-discharge, and high-temperature stability, suitable for use in vehicles. The engine only works when the SOC is low, independent of the power requirement. By increasing the battery to the extent that it can supply the motor, the system directly suppresses the influence of power on the engine speed, and the engine runs completely at the optimal BSFC. The lithium-titanate battery has a rate of up to 5C, which directly shortens the working time of the engine. The battery will not be as large as an EV, and the vehicle still has a certain amount of pure electric mileage. Even without additional charging, the engine can be quickly charged to work in the best BSFC in the shortest time. The difference from the previous REEV is the battery type and engine displacement. The relatively low energy density of the lithium-titanate battery complements the engine instead of an EV with an extended-range engine. The purpose of the extra charge is simply to reduce fuel consumption and improve overall efficiency while on the move. The design of rechargeable or non-rechargeable will greatly increase the flexibility of use. Regarding simulation scenarios with a 75kg driver on board, the novel design exhibits a fuel efficiency improvement of 46.2% compared to the 1.5L gasoline model of the CMC Veryca. Moreover, when accommodating both a 75kg driver and a 600kg cargo load, the new design results in a fuel saving of 42.4% when contrasted with the 1.5L gasoline version.
Impact of Active Cooling on the Thermal Management of 3-Level NPC Converter for Hybrid Electric Vehicle Application
Authors: Rahman S M Imrat , Ozkan Gokhan , Arsalan Ali , Chamarthi Phani Kumar , Papari Behnaz , Edrington Christopher S.
Published: October 2023

The application of power electronic converters (PEC) in electric vehicles (EVs) has increased immensely as they provide enhanced controllability and flexibility to these vehicles. Accordingly, the interest in developing innovative and sustainable technologies to ensure safe and reliable operation of PECs has also risen. One of the most difficult challenges experienced during the development of reliable PECs is the design of proper thermal management systems for controlling the junction temperature and reducing the thermal cycling of power semiconductors. The addition of Active Thermal Control (ATC) can mitigate these concerns. Moreover, the performance of the thermal management system can be enhanced further by the integration of active cooling methods. An active cooling system consumes external energy for circulating cooling air or liquid within the PECs. This study investigates the impact of ATC and active liquid cooling on the thermal performance of SiC-based semiconductor devices of a three-level Neutral-Point-Clamped (NPC) inverter that drives the Permanent Magnet Synchronous Machine (PMSM) of an EV. A Cauer-based thermal model, including a heat sink and thermal pad, is developed to explore the combined effect of ATC and active cooling on the thermal performance of the semiconductor switches. The effectiveness of the proposed thermal management system is demonstrated through results obtained from MATLAB/Simulink. Compared to the average junction temperature without any ATC and minimum coolant flow rate, a 1.37% reduction in average temperature was observed when both ATC and maximum coolant flow rates were applied. Moreover, a 23.59% reduction in the largest thermal cycle was observed when both ATC and maximum coolant flow rates were applied.
A PN-Measurement System for Small Engine Applications
Authors: Schurl Sebastian , Kupper Martin , Krasa Helmut , Schmidt Stephan , Sturm Stefan , Heidinger Andreas
Published: October 2023

Particulates are among the most harmful emission components of internal combustion engines (ICE)). Thus, emission limits have been widely introduced, e.g., for light- and heavy-duty vehicles. Although there are still engine applications without particulate limitations, the measurement of particulate mass (PM) and particulate number (PN) emissions is therefore of special interest for the development and operation of ICE. For this purpose, a measurement system for PN consisting of a custom-built sample conditioning and dilution system, and a TSI 3790-A10 [1] condensation particle counter (CPC) as particle number counter (PNC) was designed and built. In this work, we present the conditioning and dilution system, the operational parameters, and results from the particle concentration reduction factor (PCRF) calibration. The sampling system was developed in accordance with the current global technical regulations (GTR15) [2] and consists of a heated sampling probe, up to three dilution stages and a catalytic stripper for volatile particle removal (VPR). In order to be able to cover a variety of engines and provide the wide measurement range of eleven orders of magnitude, further dilution stages were implemented in the system. With the help of a variable mixing chamber dilution and an additional ejector diluter, PCRFs between 1:200 and 1:5000 can be used. The primary dilution stage consists of an ejector-diluter calibrated to a dilution ratio of 1:23,4 at 20 °C. The catalytic stripper arranged in the system consists of an oxidation catalyst and a sulphate trap. A PCRF calibration was done using a Jing miniCAST [3] as a particle source, producing a polydisperse combustion aerosol which is passed through a dilution bridge, a VPR and a differential mobility analyzer (DMA). The DMA allows to select monodisperse modes according to mobility diameters of the particles. The PCRF was measured by a reference CPC (TSI 3775). Calibrations were done at 15, 23, 41, 60 and 100 nm for the eight different dilutions, resulting in 40 measurements.
Assisted Steering Control for Distributed Drive Electric Vehicles
Based on Combination of Driving and Braking
Authors: Wu Dongmei , Wang Cheng , Du Changqing , Zhang Yichao
Published: October 2023

This paper presents a low-speed assisted steering control approach for
distributed drive electric vehicles. When the vehicle is driven at low speed,
the braking of the inner-rear wheel is combined with differential drive to
reduce the turning radius. A hierarchical control structure has been designed to
achieve comprehensive control. The upper-level controller tracks the expected
yaw rate and vehicle side-slip angle through a Linear Quadratic Regulator (LQR)
algorithm. The desired yaw rate and vehicle side-slip angle are obtained
according to the reference vehicle model, which can be regulated by the driver
through the accelerator pedal. The lower-level controller uses a quadratic
programming algorithm to distribute the yaw moment and driving moment to each
wheel, aiming to minimize tire load rate variance. Simulation and real vehicle
tests compare three steering modes: front-wheel steering only, front-wheel
steering + differential drive assisted steering, and front-wheel steering +
differential drive combined with differential braking assisted steering. The
results show that the proposed coordinated control of drive and braking reduces
the vehicle’s turning radius by 20% compared to just front-wheel steering, which
is beneficial for improving the handling of distributed drive vehicles.
Gear Fault Diagnosis for Vehicle Electric Drive Systems Based on
Stator Currents
Authors: Gong Hao , Wang Feng , Zhu Xiaoyuan
Published: October 2023

With the popularization of electric vehicles, the safety performance of electric
vehicles has drawn much attention. However, the gears of electric vehicles are
more prone to failure at high speeds, which can affect the safety performance of
the vehicle. This topic proposes a electromechanical coupling model, which is
composed of a permanent magnet synchronous motor model, a vehicle longitudinal
dynamics model and a transmission system model, and will be applied to gear
fault diagnosis. First, the sensitivity of the gear fault to the stator current
signal, the electromagnetic torque signal and the q-axis current signal is
investigated based on the time-varying meshing stiffness obtained by the
potential energy method. The discrete wavelet algorithm is used to decompose the
stator current signal, and the d1 component with obvious fault
information is obtained. Then, the singular spectral entropy is selected to
realize the feature extraction of the stator current signal by comparing the
influence of the fault degree on different feature parameters. Finally, the
support vector machine is used for the identification of gear faults, and the
accuracy of the identification reached 93.3%. The results show that support
vector machine can be used as a high precision algorithm for gear fault
identification, thus improving the safety performance of electric vehicles.
Performance Requirements for Cooperative Adaptive Cruise Control (CACC) and Platooning™ ASN File
Authors:   V2X Vehicular Applications Technical Committee
Published: October 2023

This Abstract Syntax Notation (ASN.1) file precisely specifies the structure of the data used to support the implementation of SAE International Standard 2945/6. Using the ASN.1 specification, a compiler tool can be used to produce encodings as required by the encoding rules identified in the standard. Both this file and the SAE J2735 ASN.1 files are necessary to collectively implement the data exchange described in the J2945/6. The combined library can be used by any application (along with the additional logic of the application) to exchange the data over an interface conformant to J2945/6.

SAE J2945/6 specifies the interface and requirements for Cooperative Adaptive Cruise Control (CACC) and Platooning. It provides the information necessary to build interoperable systems that support CACC, which rely on the exchange of Cooperative Control Messages.