bluuebunny/crossref_metadata_2025 huggingface dataset:
Liver failure after Bacillus cereus food poisoning, an under-recognized entity: A case report
Authors: Chatelanat Olivier , de Lorenzi-Tognon Mikaël , Spahr Laurent , Cherkaoui Abdessalam , Stephan Roger , Ongaro Marie , Kaiser Laurent , Goossens Nicolas
Published: November 2024

BACKGROUND

Bacillus cereus (B. cereus ) is known to cause 2 types of foodborne diseases; the diarrheal and emetic syndromes. They are largely underreported due to their usually self-limiting course. Rare and sometimes fatal cases of liver failure, pulmonary hemorrhage and cerebral oedema have been reported mainly in children and young adults. We present here a case of liver failure associated with B. cereus food poisoning in a middle-aged patient.

CASE SUMMARY

A 48-year-old female patient presented to the emergency department for emesis, diarrhea, chills without fever, asthenia and diffuse abdominal cramps that started less than 30 minutes after eating a rice salad. Her past medical history was relevant for cholecystectomy and a cured Hashimoto’s disease. She did not take any medication, drugs and declared a consumption of one glass of wine per week. In the emergency department, she was treated with acetaminophen, metoclopramide, ondansetron, and an intravenous normal saline infusion. Blood gas analysis revealed a metabolic acidosis with hyperlactatemia, coagulation revealed a low prothrombin activity [32 %; normal values (N): 70-140] and a low Factor V activity (15%; N: > 70). Transaminases were elevated with hyperbilirubinemia, elevated lipase and rhabdomyolysis. N-acetylcysteine treatment was introduced. Abdominal echography revealed no signs of chronic hepatopathy or hepatomegaly. Day after the admission, psychomotor activity improved, transaminases and lipase started decreasing. Rhabdomyolysis gradually worsened to peak on day 3. Screening tests for liver disease were negative for viral and autoimmune cause of liver failure. Stools cultures were positive for colonies of the B. cereus group which were also identified in the rice salad samples processed whereas blood cultures were negative. The patient’s condition improved gradually including her liver function parameters and psychomotor activity which allowed her discharged home on day 9.

CONCLUSION

We describe a rare case of hepatocellular dysfunction due to a foodborne B. cereus intoxication in an adult patient. Even if it is uncommon, the severity of liver dysfunction reported and mechanism of the cereulide toxin toxicity on liver suggest that acetaminophen should be avoided in case of a foodborne intoxication and n-acetylcysteine could be a potential therapy helping to prevent hepatocytes necrosis due to the oxidative stress induced by mitochondrial dysfunction.
Physics Based On-Board Exhaust-Temperature Prediction Model for Highly Efficient and Low-Emission Powertrain
Authors: Yamaguchi Seiya , Tomita Masayuki , Urakawa Shinji , Ookubo Seiichi
Published: November 2024

Modern automotive powertrains are operated using many control devices under a wide range of environmental conditions. The exhaust temperature must be controlled within a specific range to ensure low exhaust-gas emissions and engine-component protection.

In this regard, physics-based exhaust-temperature prediction models are advantageous compared with the conventional exhaust-temperature map-based model developed using engine dyno testing results. This is because physics-based models can predict exhaust-temperature behavior in conditions not measured for calibration. However, increasing the computational load to illustrate all physical phenomena in the engine air path, including combustion in the cylinder, may not fully leverage the advantages of physical models for the performance of electric control units (ECUs).

This study proposes an onboard physics-based exhaust-temperature prediction model for a mass-produced engine to protect the engine exhaust system and reduce exhaust emissions. The combination of simplified combustion in the cylinder and heat transfer in the engine airpath model enables us to minimize the calculation load in the ECU and simultaneously predict the exhaust temperature. In-cylinder combustion is estimated accurately using the basic engine operation parameters, volumetric efficiency, and ignition timing. Convection heat transfer, thermal conduction, and radiation are considered in this model in a simple one-dimensional form.

Results show that the predicted exhaust temperature is consistent with the measured temperature during engine dyno and vehicle testing. Even under the EV operation mode in a series hybrid system, low heat loss from the exhaust gas to the pipe wall owing to the heat transfer of natural convection is predicted accurately. Additionally, the detailed heat-transfer model accurately predicts the exhaust temperature after the engine is started in the series hybrid mode. Thus, this newly developed physical exhaust-temperature model is suitable for the engine exhaust-system protection and catalyst-activation management of our mass-produced vehicle.
Effects of Fuels Properties on Combustion and Emissions Characteristics of Light Duty GCI Engine
Authors: Qahtani Yasser Al , Raman Vallinayagam , Viollet Yoann , Alhajhouje Abdullah , Cenker Emre , AlRamadan Abdullah
Published: November 2024

Our research group developed Gasoline Compression Ignition (GCI) fuel matrix based on the fuel properties, specifications and fuel sources in an effort to standardize the GCI fuel. This study attempts to experimentally validate the standardized GCI fuels to comply with the operational regimes of GCI engine. Two of the formulated GCI fuels (GCI7 and GCI8) with varying physical and chemical properties, and composition were investigated in a single cylinder compression ignition (CI) engine. In addition to fuel effects, the engine variables were parametrically varied at low (3 bar IMEP) and medium (7 bar IMEP) load conditions. At low loads, the fuel chemical effects played a crucial role in governing the combustion while physical effect had a negligible impact. Due to lower cetane number of GCI8 fuel, combustion is predominantly premixed for GCI8 fuel but GCI7 fuel shows a more pronounced diffusion combustion phase. The low temperature heat release (LTHR) is evident only for GCI8 fuel due to higher octane rating (RON = 60) whereas GCI7 fuel (diesel like) showed negligible LTHR phase. Despite improvements in engine operating parameters, the combustion performance of GCI8 is lower than GCI7 fuel. However, after improving the fuel injection strategies, GCI8 fuel showed improved peak in-cylinder pressure and heat release compared to GCI7 fuel. Double injection advanced the combustion phasing, shortened the ignition delay, and improved the burn rate when compared to single injection. Fuel composition played a crucial role in emission formation in that smoke emission is increased for GCI7 due to higher fraction of aromatics in the fuel compared to GCI8. The increased premixed effect due to lower cetane number of GCI8 decreased the fuel to air equivalence ratio and in-cylinder temperature in that NOX emission is reduced.
Performance and Emissions of a Hydrogen Dual-Fuel Engine Using Diesel and HVO as Pilot Fuels
Authors: Mukhtar Ghazian Amin , Tange Kota , Nakatani Satoshi , Horibe Naoto , Kawanabe Hiroshi , Morita Gin , Hiraoka Kenji , Koda Kazuyuki
Published: November 2024

A comprehensive experimental study of hydrogen–diesel dual-fuel and hydrogen-hydrotreated vegetable oil (HVO) dual-fuel operations was conducted in a single-cylinder diesel engine (bore 85.0 mm, stroke 96.9 mm, and compression ratio 14.3) equipped with a common rail fuel injection system and a supercharger. The hydrogen flow rate was manipulated by varying the hydrogen excess air ratio from 2.5 to 4.0 in 0.5 increments. Hydrogen was introduced into the intake pipe using a gas injector. Diesel fuel and HVO were injected as pilot fuels at a fixed injection pressure of 80 MPa. The quantity of pilot fuel was set to 3, 6, and 13 mm3/cycle. The intake and exhaust pressures were set in the range of 100–220 kPa in 20 kPa increments. The engine was operated at a constant speed of 1,800 rpm under all conditions. The pilot injection timing was varied such that the ignition timing was constant at the TDC under all conditions. The results demonstrated that smoke was lower when HVO was used as the pilot fuel than when diesel fuel was used, and that knocking occurred at lower excess air ratios of hydrogen when diesel fuel was used as the pilot fuel than when HVO was used. This is owing to the longer ignition delay of diesel fuel compared to that of HVO. The wider distribution of diesel fuel compared to that of HVO accelerates the chemical reactions in the premixed mixture, leading to autoignition. In addition, misfiring occurred when diesel fuel was used under low boost pressure operating conditions. This was attributed to differences in the ignition properties of the pilot fuel. These results demonstrate that HVO can be operated over a wider load range and at a wider hydrogen excess air ratio than diesel fuel operation.
Emission Characteristics of TCR Diesel Fuels in Comparison to Diesel Fuels Derived from other Sources
Authors: Seeger Jan , Taschek Marco
Published: November 2024

In this work we demonstrate the influence of different refined TCR refining diesel fuels on emission, power and efficiency in comparison to reference Diesel fuel (homologation fuel for Euro 6 emission testing), hydrotreated vegetable oil (HVO) and a blend of poly(oxymethylene)dimethyl ether (OME3) with reference Diesel. The emission characteristics of such TCR fuels used in a production type Diesel engine with modern common rail system has up to now not been tested. The comparison was performed at an engine test bench equipped with a Hatz 4H50 TIC direct injection common rail Diesel engine. For different engine operation points exhaust gas emissions and particulate matters were measured and the results analyzed.
Prediction of WLTC Mode Drive Fuel Consumption for Vehicles Running on Blended Gasoline
Authors: Moriyoshi Yasuo , Kuboyama Tatsuya , Kawakami Sota , Wang Zhiyuan
Published: November 2024

It is becoming increasingly clear that research into alternative fuels, including drop-in fuels, is essential for the continued survival of the internal combustion engine. In this study, the authors have evaluated olefinic and oxygenated fuels as drop-in fuels using a single-cylinder engine and considering fuel characteristic parameters. The authors have assessed thermal efficiency by adding the EGR amount from 0 to the maximum value that allows stable combustion at the theoretical air-fuel ratio. Next, we attempted to predict fuel efficiency for three types of passenger cars (Japanese small K-car N/A, K-car T/C, and Series-HV) by changing the fuels. We created a model in OpenModelica to estimate fuel efficiency during WLTC driving. The results indicated that fuel economy could potentially be improved by adding an olefin fuel that burns stably even with a large amount of EGR and an oxygen fuel whose octane number increases. It was observed that the fuel economy improvement rate was particularly notable for Series-Hybrid Vehicle (HV) with operating under specific load and engine speed conditions.
Numerical Evaluation of Fuel-Air Mixing in a Direct-Injection Hydrogen Engine Using a Multi-Hole Injector
Authors: Torelli Roberto , Wu Bifen , Park Ji-Woong , Pei Yuanjiang
Published: November 2024

Hydrogen as a chemical energy carrier is considered as one of the most promising options to achieve effective decarbonization of the transportation sector, due to its carbon-free chemical composition. This is particularly true for applications that rely on internal combustion engines (ICEs), although much research is still needed to achieve stable, reliable, and safe operations of the engine. To this purpose, direct injection (DI) of gaseous hydrogen during the compression stroke offers great potential to avoid backfire and largely reduce preignition issues, as opposed to port-fuel injection. Recently, much research has been dedicated, both experimentally and numerically, to understanding the physics and chemistry connected with hydrogen’s mixing and combustion processes in ICEs. This work presents a computational fluid dynamics (CFD) study of the hydrogen DI process in an optical engine operating at relatively low tumble conditions. Gaseous hydrogen pressurized at 86 bar is introduced directly into the combustion chamber via a centrally mounted 13-hole injector. Numerical simulations are carried out with the CONVERGE software. The turbulent flow exchange and in-cylinder charge motion are modeled with an unsteady Reynolds-averaged Navier-Stokes formulation closed by the renormalization group k-ε model. Several configurations of the computational mesh are investigated to evaluate its role in the prediction of the hydrogen jet’s early development and the resulting in cylinder mixture distribution. In the sections that follow, an evaluation of the effect of injector geometry features and start of injection timing on the evolution of the fuel-air mixture is presented. The numerical results are systematically compared against experimental planar laser-induced fluorescence data from the literature to assess the performance of the CFD model and establish best practices for modeling relatively high-pressure injection of hydrogen using multi-hole injectors in ICEs.
Quantifying Environmental and Health Impacts of Conventional Diesel and Methane Diesel RCCI Engine Emissions: A Numerical Analysis
Authors: Yadav Neeraj Kumar , Chandel Amit Singh , Maurya Rakesh Kumar , Padhee Srikant Sekhar
Published: November 2024

A reactivity-controlled compression ignition (RCCI) engine offers ultralow soot and nitrogen oxide (NOx) emission in addition to higher thermal efficiency than diesel or compression ignition (CI) engines. However, the higher emissions of unburned hydrocarbons (HC) and carbon monoxide (CO) from RCCI engines pose a significant challenge that hinders their adoption in the future automotive sector. Additionally, HC includes several hydrocarbons that harm human health and the environment. This study aims to minimize HC and CO formation and emissions by implementing different injection strategies, including adjustments to spray angle configuration, injection timing, and fuel premixing ratio. Additionally, the study examines how different injection strategies affect the spatial and temporal distribution of HC and CO inside the combustion chamber. To achieve this objective, a numerical investigation is conducted on a single-cylinder diesel engine modified to operate in RCCI mode, utilizing a detailed reaction mechanism with ANSYS FORTE. The reaction mechanism comprises 137 species and 1,022 reactions, using n-heptane and CH4 as fuel surrogates. Initially, the computational model is developed using engine geometry and validated against experimental results for conventional diesel and RCCI modes, after which a parametric investigation is conducted. The results demonstrate that, among injection strategies, the spray configuration has the greatest impact on HC and CO emissions. Narrow spray configuration in RCCI combustion leads to a significant decrease in HC and CO emissions. HC and CO emissions increase with advanced injection timing and a higher fuel premixing ratio. RCCI engines exhibit lower acidification potential and eutrophication potential equivalent emissions compared to conventional diesel engines.
Effect of Fuel Chemical Structure on Soot Formation in Sustainable Aviation Fuels
Authors: Yi Junghwa , Manin Julien , Wan Kevin , Lopez Pintor Dario , Nguyen Tuan , Dempsey Adam
Published: November 2024

Sustainable Aviation Fuels (SAFs) offer great promises towards decarbonizing the aviation sector. Due to the high safety standards and global scale of the aviation industry, SAFs pose challenges to aircraft engines and combustion processes, which must be thoroughly understood. Soot emissions from aircrafts play a crucial role, acting as ice nuclei and contributing to the formation of contrail cirrus clouds, which, in turn, may account for a substantial portion of the net radiative climate forcing. This study focuses on utilizing detailed kinetic simulations and soot modeling to investigate soot particle generation in aero-engines operating on SAFs. Differences in soot yield were investigated for different fuel components, including n-alkanes, iso-alkanes, cycloalkanes, and aromatics. A 0-D simulation framework was developed and utilized in conjunction with advanced soot models to predict and assess soot processes under conditions relevant to aero-engine combustion. The simulations, conducted under combustion and inert conditions, revealed that aromatic fuels significantly enhance soot yield, exhibiting accelerated growth toward larger aromatics under both combustion and pyrolysis conditions. The results also highlight the necessity for higher gas temperatures for PAHs to grow, in agreement with pyrolysis experiments indicating soot onset temperatures between 1400 and 1500K. Furthermore, the study assessed the influence of precursors on soot formation, challenging the appropriateness of using C2H2 or mono-aromatics as precursors with the tested soot models. The simulation results indicate that such precursors lead to large errors, advocating for the use of larger PAHs as precursor in these soot models, as suggested by the models’ validation space. Finally, this work also explores the impact of fuel structure on soot formation, contributing to ongoing efforts to replace aromatics with cycloalkanes in jet fuels through examining reference fuel blends representative of petroleum-based jet fuel and cycloalkane-based SAFs. The “SAF” blends result in a reduced soot yield compared to the jet fuel surrogate, underscoring SAFs’ capability to diminish emissions in the aviation industry.
Effect of Lash Sensitivity on Engine Brake Performance and Valvetrain Dynamics
Authors: Jadhav Priyanka Dnyaneshwar , Bagal Nilesh , Milind T. R. , Joshi Vasu
Published: November 2024

Engine brakes (EB) are more effective in decelerating the heavy-duty (HD) vehicles and maintaining constant speed during downgrading. Therefore, commercial vehicle OEM’s along with regulations, demand the acclimating of engine brake system. To achieve this, it is equally important to adopt to variable valve actuation (VVA) dynamic valvetrain (VT) system. To help develop these systems, Model Based Product Development approach is used primarily at Eaton.

In current work, the effect of valve lash sensitivity on EB performance and VT dynamics is studied using multi physics GT-SUITE models. This helps to understand the impact of lash on valve lift opening, lift loss and overall VT system compliance. In addition to the above VT dynamics, its effect on EB power is also studied. This is done using a medium duty 6-cylinder GT-POWER engine model, which is developed from Fast Response Model (FRM) database. The model is validated using Frictional Mean Effective Pressure (FMEP) motoring engine test (empirical) data. A type 3 VT dynamic model is developed to replicate the mechanism and validated using valve lift proximity sensor data. The validated engine performance and mechanical dynamic models are then integrated in such a way that the engine model imposes the cylinder and port pressures on the valves within VT dynamic model; and the resultant valve lift from VT dynamic model is again fed into engine model. This integrated model captures the dynamic variation of the valve lift along with the lash sensitivity.

A study for EB performance loss due to the system lash, is important to develop the correct valve lifts. Also, lash sensitivity impacts the performance of VT dynamics. So, the effect of lash sensitivity on other dynamic phenomenon such as contact forces, valve closing velocity and contact stresses are analyzed in this work. Therefore, the study helped to optimize the valve lift with ramp for lash sensitivity to meet all VT design limits along with maximum brake power within the required peak cylinder pressure constraint.
Multidisciplinary and Integrated Approach to Predict Automotive Axle System Efficiency
Authors: Dambir Gaurav
Published: November 2024

In today’s competitive automotive market, customers are now looking for system efficiency as one of the important design parameters of system performance along with durability and reliability. It is essential to ensure products are designed to utilize maximum input power and have better system efficiency. In automotives, transmission and axle systems are power transmitting elements from prime mover to wheels and are one of the main contributors to overall vehicle efficiency. Hence, predicting and assessing overall system efficiency of these aggregates is of paramount importance. System efficiency is driven by component power losses for various speeds and torques, which are arising out of component design parameters, complex interaction within system, operating conditions, lubrication, temperatures etc.

To capture multi-physics of speed and torque dependent losses of automotive axle, multidisciplinary and integrated approach is proposed in this paper, Efficiency predictive model is developed in simulation tool by modelling detailed system consists of power transmitting components and flexible housings. Churning losses of hypoid gears, differential system, and auxiliary components etc. which are speed dependent, are evaluated by Computational Fluid Dynamics (CFD) principles. Frictional losses of hypoid gears and bearings are evaluated by different ISO methods. With these, total system losses are evaluated including oil seal losses, and overall system efficiency is calculated thereby. Developed methods are applied to commercial vehicle axle and validated with physical test. This helps to evaluate system loss components and their respective contributions.

Developed predictive methods can be easily extended to e-axle system efficiency prediction. Using these methods, system efficiency and power losses can be predicted and analyzed at design stage before prototypes are built and help to carry out required design changes to improve system efficiency. Actionable insights from predictive model helps to ensure axle system and components are designed for better efficiency right at initial stage of design.
Environmental Impacts of a Low-Profile Full Electric Specialized Tractor: A Case Study on Different Battery Pack Configurations
Authors: Mendecka Barbara Malgorzata , Tribioli Laura , Lombardi Simone , Federici Leonardo , Bella Gino
Published: November 2024

The electrification of agricultural machinery, such as tractors, presents an opportunity to mitigate environmental impacts associated with traditional diesel-powered equipment. Central to this transition are the battery packs that power electric tractors, the choice of which can significantly influence the tractor's overall environmental footprint. This paper conducts a comparative case study to assess the environmental impacts of different battery pack configurations in a low-profile, full-electric tractor model tailored for orchard and vineyard applications. Parametric analysis is conducted using a one degree-of-freedom 4WD tractor model to assess power needs for traction across varied working conditions, including slope, speed, and terrain characteristics. Also, by integrating life cycle optimization, dynamic modeling, and scenario analysis this study evaluates the environmental performance of various battery pack options, considering factors such as raw material extraction, manufacturing, operation, and end-of-life disposal. By merging insights from dynamic analysis and environmental assessment, this research seeks to optimize battery pack configurations, facilitating the development of sustainable, high-performance electric tractors for specialized agricultural settings. Results demonstrate that autonomous electric tractors are capable of matching or exceeding the daily work rate of conventional counterparts while achieving significant reductions in emissions and energy consumption.
Energy Efficiency Evaluation of a Hybrid Electric Tractor-Semi-Trailer Prototype
Authors: Surcel Marius-Dorin , Mercier Steve , Bonsi Adime Kofi
Published: November 2024

The objective of the project was to evaluate the energy efficiency of a hybrid electric tractor-semi-trailer combination prototype. The prototype was developed for log hauling application by integrating an existing tractor with an electric semi-trailer to improve fuel consumption and reduce greenhouse gas emissions. One of the conventional axles of the quad axle semi-trailer was replaced with a drive axle powered by an electric motor. Tests were conducted on a 105 km test route with a maximum difference in elevation of 355 m, including a hilly section with a length of 89 km. The results indicated fuel savings ranging from 10.5% to 14% per test run, with an average fuel savings of 12% when the electric drive axle was engaged. The hybrid electric tractor semi-trailer consumed 17.5% less fuel up-hill and 9.4% less down-hill. Throughout each test run, the battery’s state of charge fluctuated, averaging between 88% at the start and 52% at the end. Prior to each run, the batteries were recharged using the regenerative system’s acceleration-deceleration cycles, lasting approximately one hour. The tests showed an average GHG emission reduction of 23.3 kg/100 km when the electric drive axle was activated on the hybrid electric tractor semi-trailer. Considering an average annual mileage of 100 000 km, the prototype hybrid electric tractor semi-trailer shows a potential to reduce annual GHG emissions of 23 tonnes per vehicle. These reductions will provide the cost-benefits that are of strong interest to the forest sector as they continue the move towards reducing carbon footprint. In addition, operational benefits of having a powered rear-axle on the trailer were confirmed to provide traction benefits, and safety improvements for forestry trailers operating in challenging terrain.
Enhancing Heat Transfer in Immersion Cooling of Battery Packs - Using ALTP Heat Flux Sensors
Authors: Weiss Lukas , Karathanassis Ioannis , Rueppel Bastian , Smith Timothy , Wensing Michael
Published: November 2024

The effectiveness of immersion cooling for the thermal management of Electric-Vehicle (EV) batteries is crucially influenced by the thermophysical and rheological properties of the heat-transfer liquid. This study emphasizes upon the design requirements for such a fluid in terms of bulk properties, i.e., high electrical resistivity and thermal conductivity, low viscosity, but also relevant to the rheological properties maximizing the heat transfer rate. Key concepts of the implemented research constitute: (i) the promotion of vortical motion in the laminar flow regime, which, in turn, enhances heat transfer by disrupting boundary layers; (ii) vortex stabilization through the addition of viscoelasticity-inducing agents in the base heat-transfer liquid. To improve cooling efficiency, the primary objective is to maximize the achievable heat transfer rate for minimal pumping losses. Hence, a multi-objective optimization process must be set in place where the optimal coolant rheology is dependent on the geometrical features of the battery module. The overall framework of interdependent research activities comprises: (i) the characterization of viscoelastic flow with the use of Particle Image Velocimetry (PIV) in a flow loop with benchmark geometries; (ii) heat-transfer measurements employing a novel Atom Layer Thermopile (ALTP) sensor and (iii) dedicated computational fluid dynamics (CFD) modelling using the Phan-Thien-Tanner constitutive equation for elastic stresses. While there are tailored designs for efficient heat transfer in immersion-cooling paradigms needed, in this paper we concentrate on heat flux measurements when cooling a bluff body. In this work results on heat transfer in the wake behind a square rod were analyzed and discussed. High-viscosity liquids have higher heat transfer at equivalent Re-number. An improvement of heat-transfer due to viscoelastic flow behavior is indicated for high-viscosity liquids, but the trend must be proven with additional experiments. PIV based flow analysis shows a mismatch between the flow pattern and the heat transfer surface.
Automatic Parameter Scheduling of Equivalent Circuit Battery Models Using Local Linear Model Trees and Amplitude-Modulated Pseudo-Random Excitation Signals
Authors: Prior Jack , Bates Luke , Whelan Steve , Mason Byron , Knowles James , Stocker Richard
Published: November 2024

The automotive industry is moving rapidly to electrification through development of Battery Electric Vehicles (BEV). Development and sizing of the battery and powertrain requires a detailed understanding of battery cell behavior under different conditions. Achieving this is difficult due to the range of cells available and the large range of condition variables of each cell. Equivalent-circuit models are used for BEV development. However, conventional battery cell characterization testing to parameterize these models are time and resource intensive. Characterization can be performed using well-known techniques such as Hybrid Pulse Power Characterization (HPPC) or Galvanostatic Intermittent Titration Technique (GITT) which are used to optimize parameters of an ESC model pertinent to the dynamics of its voltage response. However, the discrete State-of-Charge (SoC) intervals and demand current amplitudes of these experiments are not optimized for a balance of time and model effectiveness. There is scope to develop methods that can excite a range of current amplitudes and SoC points in a shorter timeframe whilst revealing non-linearities in the system’s time response. In this work an excitation signal design is presented that aims to maximize the amount of information gained about the dynamics of the battery across the SOC range within a short timeframe. An automated means of parameter-scheduling an ESC model is also introduced to best utilise the data from such a randomized, unstructured experiment. The excitation signal design takes the form of pulse signals with pseudo-randomly generated amplitudes and duration, constrained to ensure a specified test duration. This data is used to characterize a variant of the ESC model that automatically schedules parameters of the model via self-organizing Locally Linear Model Trees (LoLiMoT). The resulting models have strong predictive capability even in the extreme low SOC condition, resulting in an 18% reduction in Mean Absolute Error when compared to an ESC model without parameter scheduling over a validation cycle. This constitutes a strong step toward rapid, robust battery modelling processes for the purpose of cell selection and simulation for powertrain/vehicle design.
Understanding Energy Footprints of the Existing School Bus Fleets - A Case Study
Authors: Moon Joon , Hanif Athar , Ahmed Qadeer
Published: November 2024

Vehicle electrification has gained prominence in various industries and offers sustainability opportunities, especially in the context of heavy-duty vehicles such as school buses. Despite the prevalence of conventional diesel school buses (CDSB), the adoption of electric school bus (ESB) and other eco-friendly alternatives is increasing. In the United States alone, there has been a notable increase in the adoption of ESBs, indicating substantial growth. The electrification of school buses not only promises energy savings, but also offers health benefits to children, reduced greenhouse gas emissions, and environmentally friendly transportation practices, aligned with broader eco-friendly initiatives. This paper investigates the potential for energy savings and reduction in environmental footprint through electrification of school buses in the Columbus, OH area. Analyzing current bus routes and road terrain data allows one to estimate energy demand and environmental impact, accounting for the unique characteristics of school bus operations, such as low-speed travel and frequent stops. The study suggests that electrifying school buses in the region could lead to approximately 61% of energy savings.
A Study of the Effectiveness of Student Perception-Based AI Feedback in College Writing Classes
Authors: Cheong Yunam
Published: November 2024

This study examined the educational effectiveness of AI-based automated evaluation feedback tools in college writing courses. Amid active discussions on the use of AI in liberal arts education, the study applied AI automated evaluation tools to actual writing classes and analyzed the results. The findings show that AI feedback positively influenced students' motivation for writing and achieved a high level of satisfaction in areas such as spelling, vocabulary, grammar, and expression correction accuracy. AI automated evaluation feedback helps reduce the feedback burden on instructors and assists them in providing meaningful feedback to students. It is expected that AI-based automated writing feedback tools will contribute to fostering AI literacy. This case study is significant in that it offers insights for effectively incorporating AI automated evaluation feedback into college writing courses.
Analysis of University Students Liberal Arts Curriculum Perception and Needs
Authors: Kim Kyeong-Eon , Lee Sang-Ki
Published: November 2024

This purpose of this study is to analyze the perceptions and needs of students at University C regarding ‘liberal arts education’ and to draw implications for the reorganization and operation of the liberal arts curriculum. To this end, a survey was conducted on the perceptions and needs of the monitoring group of University C, and in-depth interviews and data analysis were conducted. A total of 91 students participated in the survey, responding to their perceptions of liberal arts education in general and their needs, and the researchers reviewed and analyzed 40 final reports submitted by the liberal arts education monitoring group. Five students, three from the humanities/social sciences and two from the natural sciences/ engineering, who were excellent members of the Liberal Arts Monitoring Group, were interviewed in-depth, focusing on information that could not be found in the survey and final reports nor could be confirmed through interviews. The analysis revealed the following perceptions and needs for liberal arts education.
First, students at College C perceived that liberal arts education was necessary overall, but tended to perceive it as less important than education involving their majors. Second, students perceived that the liberal arts curriculum at College C was below average in reflecting their needs. Third, while the survey showed a strong preference for lecture-style classes, the data analysis and in-depth interviews showed that the curriculum should be improved with more interactive teaching and learning methods. Fourth, students at University C felt burdened and fatigued by the relative evaluation method centered on memorization and written evaluation, and demanded a change to an evaluation system that focuses more on the meaning of learning.
Based on these findings, the university's dedicated organization for liberal arts education needs to make efforts to change the students' perceptions of the importance and value of liberal arts education and key information for academic guidance. In addition, efforts should be made to reflect student needs in the reorganization and operation of the liberal arts curriculum by establishing and operating student organizations such as student liberal arts curriculum committees and student liberal arts education monitoring groups, or even through competitions. In addition, the dedicated organization for liberal arts education should support liberal arts instructors and share teaching and learning methods that are more in line with liberal arts education through regular seminars for dedicated faculty members. Finally, it is necessary for educators to improve the evaluation system that focuses on students' learning activities in the student evaluation process, and to increase the satisfaction level of liberal arts courses through ‘clarity of evaluation criteria’ and ‘instructor feedback on grades’, and to improve instructors' awareness of student evaluations and to foster their evaluation expertise.
Student Perceptions of ChatGPT in Mandatory EFL Writing Classes at a Korean University : A Case Study
Authors: Richards Andrew , Jones Stuart
Published: November 2024

This study explored to what extent students at a Korean university perceive ChatGPT as useful in mandatory university EFL writing classes. In addition, preferences regarding methods of instruction and the outlook for future classes of a similar nature in the era of ChatGPT were also examined. 239 students enrolled at a university located on the outskirts of Seoul responded to a survey questionnaire consisting of a combination of multiple choice, 10-point Likert scale, and open-ended questions, which was used as the primary data collection method. Data analysis was conducted using general qualitative analysis for open ended questions and descriptive statistics for multiple choice and 10-point Likert scale questions. In addition, if consent was given, survey participants were contacted by e-mail to discuss responses in further detail. Despite concerns relating to ownership of learning and overreliance, the findings indicate generally positive perceptions of ChatGPT in terms of assisting with grammar, vocabulary, brainstorming, and proofreading. Conventional approaches (e.g., human teacher, in person lessons, and inter student / teacher communication) are still highly desired although the increasing influence of ChatGPT cannot be ignored. There is a belief that mandatory EFL writing classes currently play a vital role at Korean universities, and there is a strong preference for them to continue. Administrational and educational implications are also discussed.
The Perceived Improvement in Learning Competencies of Low-achieving College Students through Participation in a Board Game Design and Development Process
Authors: Jang Hyunjung , Lee Seonga , Eom Wooyong
Published: November 2024

The purpose of this study is to examine the extent to which low-achieving college students perceive an improvement in their learning competencies through their experience of participating in the design and development processes of a board games. The research questions are as follows. First, what learning competencies do low-achieving college students perceive to have improved through the board game design and development process? Second, what are the relationships between the keywords of the learning competencies that low-achieving college students perceive to have improved through the board game design and development process? For this study, reflective journals from 97 low-achieving college students who participated in the board game design and development process were analyzed. Specifically, keywords related to the learning competency improvement were derived, and the relationships between these keywords were analyzed. The findings are as follows First, low-achieving college students perceived that their collaboration skills improved the most through the experience of participating in the board game design and development process, followed by problem-solving skills, communication skills, learning transfer, and interaction skills. Second, the keywords related to learning competency improvement perceived by low-achieving college students were found to be significantly interconnected. Collaboration skills were strongly linked to problem-solving skills, communication skills, learning transfer, creativity, and interaction. Problem-solving skills were closely connected to experience of success and creativity. The results of this study provide valuable insights for designing and implementing tailored programs aimed at enhancing the learning competencies of low-achieving college students.
Current Status of the Autonomous Major Selection System (Undeclared Major System) and the Direction of Operation
Authors: Nam JinSook
Published: November 2024

This paper is a study on the current state of the university's the autonomous major selection system and the direction of its operation. To this end, we examined the concept, implications and current status of the undeclared major system, and expressed opinions on the direction of operation. Additionally, it assesses the potential impact of this system on university education.
The autonomous major selection system, known by various names such as the Undeclared Major System, Wide-Area System, and Liberal (autonomous) Major Department, allows students to enter university without committing to a specific department. Students typically spend one year studying broadly before choosing a major. While this system has its advantages and disadvantages, past implementations have generally received more negative feedback than positive.
Due to policies from the Ministry of Education, universities must thoroughly prepare for the non-major system, which will be implemented in earnest starting from the 2025 academic year. Several considerations are crucial to ensure the successful operation of the Undeclared Major System. Universities need to carefully examine and proactively address issues such as curriculum design, student management, and administrative support. Opinions on these matters have been presented in this paper.
The critical point is that the non-major system must robustly address the fundamental questions of what a university's core mission is, what should be taught, how to cultivate talent, and how to provide education for the future. Only then can this system be effectively established in each university, ensuring a cohesive academic ecosystem.
Reescribiendo el pasado: la relevancia de incorporar la perspectiva de género en la clase de historia
Authors: Álvarez Sepúlveda Humberto Andrés
Published: November 2024

En este capítulo se fundamentan los beneficios y desafíos de la incorporación de la perspectiva de género en la clase de historia, subrayando el modo en que esta integración puede transformar tanto la comprensión del pasado como la dinámica educativa actual. Metodológicamente, este estudio se sustenta en una revisión de alcance de publicaciones de diversas bases de datos, tales como Wos, Scopus, Scielo, Dialnet y ProQuest. Se adoptó un enfoque cualitativo bajo un paradigma humanista, utilizando un método inductivo, diseño narrativo de tópico y un enfoque interpretativo. Los hallazgos revelan que la integración del enfoque de género puede contribuir significativamente a la construcción de una sociedad más democrática porque fomenta la valoración de la diversidad de experiencias humanas y desafía las desigualdades de género persistentes. Se concluye que el enfoque de género tiene el potencial para formar ciudadanos críticos y reflexivos capaces de liderar el cambio social.
Reflexiones sobre la rotación, estrés y precariedad laboral en el sector turístico de Cancún, Quintana Roo, México
Authors: Fernández Rodríguez Anastacio Gustavo , Gómez Vargas Mariana del Pilar , Dominguez Can Lilibeth Ariany , Pacheco Cocom Mirna Yasmin
Published: November 2024

El crecimiento turístico en el estado de Quintana Roo, México, a partir de los años setenta ha ido en aumento, desde el número de hoteles y cuartos ofrecidos al turista hasta los puestos laborales para operar el destino. Estos últimos gracias a una alta movilidad migratoria para incorporarse como fuerza laboral al sector hotelero en función de las temporadas altas y bajas, sin embargo, estos puestos han sido cuestionados por la problemática acentuada en la salud, desprendiendo conceptos relacionados al estrés laboral, la rotación de personal y la precariedad laboral. En ese sentido, la propuesta documental presentada trata de reflexionar como las condiciones laborales en el destino turístico de Cancún sobre las categorías de rotación de personal y el estrés laboral han llevado a un planteamiento teórico de la existencia de precariedad en el trabajo. Como conclusión se exponen que las externalidades de estos conflictos sociales van más allá, dejando entrever las tensiones por la vivienda, la violencia e inseguridad en el destino, los procesos de subcontratación y la segregación espacial, en un espacio que debiera ser seguro y con una política social enfocada en el desarrollo personal y de bienestar.
Criterios sensoriales del diseño universal y tecnologías de apoyo para la inclusión
Authors: Peña Marín Gustavo Adolfo
Published: November 2024

La inclusión de criterios sensoriales ha sido una carencia en el Diseño Universal (DU), especialmente en tecnologías para personas con discapacidad (PcD) y adultos mayores con limitaciones sensoriales. Aunque se ha reflexionado sobre este tema en los últimos 25 años, la implementación de respuestas inclusivas sigue siendo deficiente, particularmente en la interacción sensorial con el entorno. Desde el Doctorado en Diseño y Creación de la Universidad de Caldas, se ha investigado sobre percepciones sensoriales a través de proyectos en Colombia y Guatemala, con el objetivo de definir criterios de diseño que aborden el ocio inclusivo y la dignidad. Utilizando la metodología “Investigación Empírica A Través del Diseño” (IEATD), diseñadores colaboraron con PcD visual y auditiva para desarrollar Dispositivos de Sustitución Sensorial (DSS) basados en tecnologías de apoyo de uso libre. Estos DSS mejoraron la experiencia perceptiva y el acceso a contextos de ocio inclusivo en el hogar y espacios culturales.
Estrategia didáctica y competencia digital en docentes de la educación secundaria rural en Cajamarca
Authors: Carrasco Huaman Dilser Ivan , Herrera Vargas José Wilder , Becerra Diaz Alexander , Vidaurre Yerrén Manuel
Published: November 2024

La investigación tuvo como finalidad diseñar una táctica didáctica para enriquecer las aptitudes digitales de los profesores de una institución educativa rural de Cajamarca durante el periodo 2023. La metodología empleada fue descriptivo-propositiva. Para recolectar los datos se usó la técnica de encuesta y entrevista mediante cuestionarios, que se aplicó a los catedráticos en estudio. Además, para examinar la índole de la problemática investigada, se acudió a teorías como la del “aprendizaje por descubrimiento de Bruner”, la del “aprendizaje social de Bandura” y la de “conectividad de Siemens”. Los hallazgos evidencian que los docentes de la de la institución educativa rural, carecen de competencia digital, ignoran el manejo de computadoras y creación de contenidos digitales, y no usan en su práctica pedagógica sus escasos conocimientos tecnológicos, por lo que su nivel de saberes digitales es mínimo. Por esta razón, se propone una propuesta de capacitación en herramientas digitales.
EMPLEO PÚBLICO LOCAL Y FUNCIÓN DIRECTIVA
Authors: Castillo Blanco Federico A.
Published: November 2024

SUMARIO: I. ¿NUEVOS PARADIGMAS PARA LA ORGANIZACIÓN DEL SISTEMA DE DIRECCIÓN POLÍTICA Y ADMINISTRATIVA DEL GOBIERNO LOCAL? II. EL SISTEMA DE DIRECCIÓN PUBLICA EN NUESTRO GOBIERNO LOCAL: DE LA INEXISTENCIA DE SISTEMA A LA USURPACIÓN POLÍTICA DE LA FUNCIÓN DIRECTIVA. 1. Las carencias de nuestro sistema de dirección pública en el ámbito local. 2. Las premisas sobre las que debe asentarse una reflexión sobre el sistema de dirección pública en el Gobierno local. III. LAS MEDIDAS CONTEMPLADAS EN LA LEY DE MODERNIZACIÓN DEL GOBIERNO LOCAL REFERIDAS A LA DIRECCIÓN PUBLICA. IV. LA FUNCIÓN DIRECTIVA EN EL ESTATUTO BÁSICO DEL EMPLEADO PUBLICO ¿UNA OPORTUNIDAD PERDIDA PARA EL GOBIERNO LOCAL? 1. El personal directivo. 2. El Personal Eventual 3. Los Funcionarios con Habilitación de Carácter Estatal. a) Un breve apunte sobre la progresiva desnaturalización de estos funcionarios. b) Los Funcionarios con Habilitación de Carácter Estatal en el Estatuto Básico del Empleado Público. V. A MODO DE CONCLUSIÓN: EL DEBATE CONTINUA.