Transportation Engineering Research Articles

Efficient Deep‐Blue (465 nm) Perovskite Quantum Dot‐Based Light‐Emitting Diodes via Triphenylamine Derivative Tailored Hole Transport Engineering

Efficient Deep‐Blue (465 nm) Perovskite Quantum Dot‐Based Light‐Emitting Diodes via Triphenylamine Derivative Tailored Hole Transport Engineering

Determinación de la densidad vehicular en ciudades intermedias por medio de visión por computador

The objective of this research work is to calculate the vehicle density of cities through the use of computer vision. To carry out the study, we captured videos of vehicular traffic at 8 intersections in the city of Loja using a drone and a high-resolution camera. Subsequently, we used the Python language and the YOLOv8 library to count vehicles of different categories, such as small vehicles, trucks, and motorcycles. Through mathematical formulas used in transportation engineering, the values ​​of vehicle density, vehicle flow rate, and average spacing were obtained. As results, we have that the machine learning model using YOLOv8 has an accuracy of 90% in detecting and classifying vehicles, and thanks to its use, the road with the highest vehicle density was identified. The practical applications of this work could improve vehicle flow and help competent organizations related to traffic management make decisions.

Modeling and simulation of technological innovation diffusion of high-performance construction materials in transportation engineering

This study focuses on the diffusion process of technological innovations in high-performance construction materials (HPCMs) within the field of transportation engineering. The aim is to explore the impact of various factors on this process through modeling and simulation. The research employs a multi-agent modeling approach to construct a simulation model of the diffusion of technological innovations of HPCMs among firms and owners. It analyzes the impact of firms’ strategy choices, knowledge sharing, and government policies on the diffusion of technological innovations of HPCMs. Through simulation experiments, this study reveals the impact of the proportion of firms choosing followership or innovation strategies on the efficiency of technology diffusion within complex networks, as well as the double-edged effect of knowledge sharing. Additionally, the findings indicate that adjustments of government policies at different stages of diffusion have a significant impact on market dynamics. This study provides theoretical foundations and practical recommendations for promoting the research and application of high-performance construction materials, thereby advancing green and sustainable development in transportation engineering.

Spectrally Pure, High Operational Dynamic Range, Deep Red Micro-LEDs.

III-nitride-based micro-light-emitting diodes (micro-LEDs) are currently under rapid development for next-generation high-resolution and high-brightness displays and augmented/virtual reality (AR/VR) technologies. However, it remains elusive to achieve red-emitting III-nitride micro-LEDs with a microscale size, high efficiency, and high spectral stability, posing significant impediments to the development of full-color micro-LEDs. In this work, through detailed strain engineering and control of charge carrier transport, we achieved pure red emission (≥620 nm) micro-LEDs over 2 orders of magnitude of injection current variation. We show both theoretically and experimentally that the combination of a short-period InGaN/GaN superlattice and a thick n-type GaN interlayer can not only relieve the quantum-confined Stark effect in the active region but also suppress parasitic emission from the superlattice. The optimized deep red micro-LEDs with a device lateral dimension of ∼1 μm feature a maximal external quantum efficiency of over 3% emitting at ∼660 nm.

Defect engineering of charge transport and photovoltaic effect in BiFeO3 films

Bismuth ferrite (BiFeO3) is an attractive multiferroic material, extensively explored in photoferroelectric investigations. However, its applications are hindered by the high leakage current, requiring precise control of charge transport properties. Defect engineering has emerged as a promising strategy to address this issue: controlling the defect chemistry, particularly oxygen vacancies, is key to tuning the electrical properties. This study investigates the influence of 5% ▪ - and 2% ▪ -doping on the dark and light-induced charge transport properties of polycrystalline BiFeO3 films. Our results demonstrate that ▪ reduces dark conductivity by decreasing oxygen vacancy concentration with no change in the physical nature of the charge transport mechanism. In contrast, ▪ modifies the charge transport mechanism, increasing low-field (E < 100kVcm-1) dark conductivity while drastically reducing high-field (E > 250kVcm-1) dark conductivity. This tuning of the defect chemistry is also key to enhance the photovoltages of the bulk photovoltaic effect in BiFeO3. High photoinduced electric fields up to 7kVcm-1 and low photoconductivity values are obtained with ▪ -doping, while high short-circuit photocurrent values are obtained with ▪ -doping.

Identification of corrosion nature using acoustic emission in representative scale samples

Monitoring corrosion is critically important across numerous applications, given its occurrence in key industrial sectors such as energy production, transportation, and civil engineering to prevent leaks and failures. Especially, determining the exact nature of corrosion phenomena could help planning specific maintenance operations, reducing costs and risks. Machine Learning methods have demonstrated capacities to discriminate corrosion phenomenona. An important step to create precise Machine Learning models is the quality of training datasets. With this goal in mind, this paper presents experiments performed on different metallic samples to create specific corrosion forms, respectively pitting and uniform corrosion to train a supervised model. This model is evaluated on 316L steel samples prone to endure both pitting and uniform corrosion. The usage of supervised learning is then discussed compared to other methods.

Electronic and thermal transport engineering of a highly earth-abundant and low-cost Sn-based thermoelectric material

Tin monosulfide (SnS), composed of abundant, low-cost, and environmentally friendly elements, has garnered significant attention in the field of thermoelectrics due to its analogous electron and phonon transport properties to SnSe. However, undoped SnS exhibits a limited charge carrier concentration, resulting in poor electrical conductivity. In this study, a dual doping approach was employed, introducing both cationic (Na and Pb) and anionic (Se and Te) dopants into polycrystalline SnS. This approach yielded a notable enhancement in electrical properties and a reduction in thermal conductivity. As a result of these modifications, the figure of merit (zT) reached 0.38 at approximately 525 K. Specifically, the power factor increased to 2.25 μWcm−1K−2, while the total thermal conductivity was reduced to 0.3 Wm−1K−1. These findings highlight the potential of synergistic cation and anion doping strategies to significantly improve the thermoelectric performance of SnS at relatively lower temperatures, offering a pathway for further exploration of cost-effective thermoelectric materials based on SnS.

Two branches solutions for mixed convection flow of thermally Williamson nanofluid flow with heat transfer due to magnetized shrinking sheet

AbstractThe study of magnetohydrodynamics (MHD) and thermal radiation over‐stretching and shrinking sheets has significant applications in a wide range of fields, from chemical manufacturing to transport engine cooling systems, electronic chip cooling, plasma, the nuclear‐powered sector, saltwater, etc. The present study aims to numerically and theoretically analyze the movement of thermally magnetized Williamson nanofluid owing to an extended/contracting sheet. The regulating flow equations are converted to self‐similar equations through similarity transformation, and then numerically solved by bvp4c using MATLAB software. A comparison of the present numerical study with the published study is quite impressive. The investigation demonstrates that the self‐similar equations disclose the two branches for the limited shrinking factor range. For the stretching case, only one solution exists. As a result, the most fundamentally feasible solution has been determined by the linear assessment of temporal stability. For the aim of stability analysis, the lowest eigenvalue sign indicates the stability or instability of a solution. Through stability analysis, it is witnessed that the first solution (first branch) is stable. Due to the presence of the Lorentz force effect, it is perceived that the velocity curves decline in the whole channel. The point to be noted here is that the velocity of the lower branch compared to the upper branch is higher. The reduced Skin Friction is increased in the first branch and declines in the second branch for the two different values of magnetic factor.

The Correlation Between Academic Performance in CELE-Related Subjects and CELE Performance Among Bachelor of Science in Civil Engineering Students at Nueva Ecija University of Science and Technology

This study investigated the relationship between academic performance in CELE-related subjects and CELE performance among Bachelor of Science in Civil Engineering (BSCE) students at Nueva Ecija University of Science and Technology (NEUST). A quantitative research design employing correlation analysis was utilized. The sample consisted of 322 random BSCE students who had taken CELE in the last five exam dates. The results revealed a significant positive correlation between students' performance in their Mathematics, Surveying, and Transportation Engineering (MSTE) and Structural Engineering and Construction (SEC) subjects during their BSCE program and their corresponding achievements on the PRC board exam. However, no significant correlation emerged between students' performance in their Hydraulics and Geotechnical Engineering (HGE) subjects during their BSCE program and their performance on the corresponding section of the PRC board exam. Additionally, the results indicated a significant positive correlation between students' weighted GPAs during their BSCE program and their performance on the PRC board exam.These findings suggest that strong academic performance in CELE-related subjects is associated with success on the CELE, highlighting the importance of a well-aligned curriculum and educational strategies. However, further research is needed to explore causative factors and provide a more comprehensive understanding of the dynamics influencing CELE performance.

Mobbing Exposed by Deck Cadets at Onboard Training during the Internship Period

The aim of this study is to determine whether oceangoing officer candidates encounter mobbing “psychological terror in the workplace” during their onboard training period and analyze whether there is a dimensional difference between the mobbing behaviors experienced by the deck cadets. The attendees of the study are a total 212 oceangoing officer candidates who have sea experience and are studying for a BSc degree in maritime transportation engineering. The demographic information of cadets, along with the details about the internship process and the Leymann Inventory of Psychological Terror (LIPT) items was analyzed using statistical tests by SPSS and association rule mining methods with the SPSS modeler. The study results demonstrate that, regardless of the ship type or internship duration, the cadets were subjected to mobbing in the sub-dimension of Self-expression and communication and Occupational situation and quality of life. The cadets who reported experiencing occupational stress indicated that their career expectations changed after the internship. The presence of “only one cadet on board” was identified as a significant antecedent factor affecting not only Self-expression and communication and Occupational situation and quality of life but also occupational stress and changes in work expectations after internship.

Interaction analysis between single pile and multilayered saturated soils under horizontal transient loading

This study employs the coupled finite element-boundary element method to investigate the dynamic response of single pile subjected to horizontal transient loading, which is a common scenario in high-rise building, transportation, and ocean engineering. Firstly, the single pile is modeled as a Timoshenko beam and then discretized with the finite element method (FEM). The transient solution for multilayered saturated soils due to a horizontal load, serving as the kernel function for the boundary element method (BEM), aids in the derivation of the flexibility matrix of the soils. Considering the pile-soil displacement coordination conditions, the coupled FEM-BEM equation is constructed and solved to characterize the pile-soil interaction. Since the pile discretization pattern is applied consistently to the soils, it is more effective than the discretization of infinite domain in the finite element analysis. The validity of the presented method is confirmed through comparison with the full FEM numerical simulations, demonstrating the correctness and enhanced computational efficiency. Finally, parametric studies are carried out to discuss the effects of pile's length-diameter ratio, soil's shear wave velocity and stratification.

Porous transport layer influence on overpotentials in PEM water electrolysis at low anode catalyst loadings

Achieving widespread use of polymer electrolyte membrane water electrolysis (PEMWE) for clean hydrogen generation requires enhancing the efficiency and utilization of low iridium-loaded electrolyzers. Novel porous transport layer (PTL) design and engineering can play a critical role in addressing this challenge. Despite the fact that the PTL is an important component of PEM electrolyzers, it has received little attention, particularly in terms of the mechanistic understanding of the influence of PTL characteristics on overpotentials. Herein, we investigate the impact of the PTL porosity, thickness, and structure on the PEM water electrolyzer performance. We demonstrate that improving the contact between PTL and the catalyst layer by inserting a microporous layer facilitates electron transfer and oxygen removal leading to reduced cell voltage. We observe that this strategy proves particularly effective at low catalyst loadings.

Detailed particle breakage of crushable granular materials under cyclic shearing conditions using dyed gypsum technique

Particle breakage of granular materials under cyclic shearing is related to a variety of engineering problems in geotechnical and transportation engineering. However, there is limited understanding regarding the detailed evolution law of breakage under cyclic shearing. To this end, a series of cyclic simple shear tests were conducted on artificially dyed gypsum particles. It was observed that, in contrast to the particle size distribution of the whole sample, the fractional particle size distributions of gap-graded samples followed a unified breakage evolution path as those of the uniformly graded ones and tended towards fractional fractal distributions. These results have inspired the introduction of the fractional breakage index. Moreover, the breakage-plastic work relationship was further extended to describe the breakage of fractional particles, incorporating the effect of the number of cycles on the plastic work distribution. Finally, based on the concept of breakage-packing, a predictive model for plastic work-breakage-deformation of crushable granular materials under cyclic shearing was proposed. These results have the potential in understanding the detailed particle breakage evolution and establishing a predictive framework for the breakage-induced deformation of crushable granular materials.

Modeling and significance assessment of road construction participant and user benefits using expert evaluation methods

Human activities are related to obtain economic, technical, social and environmental benefits. The road construction process participants and road users have direct or indirect benefits from elaboration of new infrastructure. The number of the benefits received by individual entities is publicly discussed by politicians, lobbyists, experts and other decision-makers without having quantitative estimates of benefits, i.e., often relying on intuition or considering theoretical reasoning. The paper suggests a system of 19 benefit entities (criteria) assigned the ranks given by experts. The study involved three categories of experts, including 35 road engineers, 36 transport engineers and 61 road users. The values of the concordance coefficients obtained as a result of the conducted research were found significantly higher than critical values and showed that the opinions of the experts in each category were consistent (not contradictory). This made it possible to consider the average of the opinions of the expert group as a reliable result of solving the problem. Rank averages were replaced by the normalized weights of criteria using Average Rank Transformation into Weight-Linear (ARTIW-L) and – Nonlinear (ARTIW-N) methods. The global averages of criterion weights were used employing the Inverse Hierarchy for Assessment Main Criteria Importance (IHAMCI) method thus calculating the normalized weights of the road-related classified entities (three main criteria). The findings prove that road users benefit the most (weight 0.3485), the road construction contractor (weight 0.3325) is in the next position and the road owner (investor) takes the weight equal to 0.3190. The generated research data can be used for justifying the rationality of road investment.

Managing uncertainties in urban junction design: a case study of the FAHP method in Chettia

The essay delves into how an urban crossroads in Chettia, Algeria was reconstructed using the Fuzzy Analytic Hierarchy Process (FAHP) method to assess and choose the best design from multiple alternatives. The inherent uncertainties in this type of project can be effectively managed by using fuzzy algorithms, which mimic human reasoning in decision-making. A comprehensive and organised study is made possible by the methodology's foundational premise on a hierarchical problem classification into 32 criteria and sub-criteria. To establish the weightings of these criteria and lay the groundwork for comparing alternatives, the FAHP approach is employed, which is well-known in the area of multi-criteria decision-making. The feasibility and efficacy of this method are illustrated in the case study pertaining to the reconstruction of the Chettia intersection. A global performance indicator was used to rate the four solutions that the experts reviewed. When it comes to building and maintaining rural road networks, this strategy is invaluable for making educated decisions. In this case, the FAHP method provides a rigorous and methodical way to choose the optimal design. It enables the management of the uncertainties inherent in this type of urban infrastructure project while considering various complicated and sometimes contradicting aspects. Urban planners and transportation engineers may benefit much from this concept if it were applied to other comparable projects.

Electronic and Transport Engineering of A-Type Antiferromagnets with Ferroelectric Sandwich Structure: Toward Multistate Nonvolatile Memory Applications.

Achieving higher-order multistates with mutual interstate switching at the nanoscale is essential for high-density storage devices; yet, it remains a significant challenge. Here, we demonstrate that integrating A-type antiferromagnetic semiconductors sandwiched between ferroelectric layers is an effective strategy to achieve high-performance multistate data storage. Taking the Sc2CO2/VSi2P4 bilayer (bi-VSi2P4)/Sc2CO2 van der Waals multiferroic heterostructure as an example, our first-principles calculations show that by switching the polarization direction of the upper and bottom ferroelectric Sc2CO2 layers, antiferromagnetic bi-VSi2P4 can exhibit four distinct states with different band structures. The intriguing band structure engineering stems from the polarization-field-induced band shift and interface charge transfer. Accordingly, the proposed Sc2CO2/bi-VSi2P4/Sc2CO2-based multiferroic device can achieve four different resistance states, accompanied by fully spin-polarized currents and giant tunneling electroresistance ratios. Our results propose a viable strategy for realizing nonvolatile electrical control of antiferromagnets at the nanoscale and provide insights into the development of advanced memories.

Exploring the role of configurational accessibility of alleyways on facilitating wayfinding transportation within the organic street network systems

Despite the significant role of alleyways in urban spatial configuration and accessibility as critical structures of urban infrastructure, there remains a noticeable gap in understanding their specific role in urban transportation policies. The main aim of the present study is to investigate the role of configurational accessibility of alleyways in facilitating wayfinding within organic street network systems. A mixed method was applied using Space Syntax and empirical observations. Moreover, Pearson correlations and t-tests were used to discern the association between variables and compare independent groups using SPSS software. The findings from the syntactical analysis strongly indicate that alleyways significantly impact configurational accessibility within urban network systems. Furthermore, the complex and labyrinthine structure of organic alleyways was found to significantly hinder the intelligibility of urban areas, making navigation more challenging. The results revealed a significant correlation between vehicle mobility and connectivity values, with higher levels of mobility consistently linked to increased connectivity values. The outcomes also indicated that alleys connected to main streets play a crucial role in facilitating wayfinding within urban network systems. This study contributes to a more profound understanding of the role of alleyways in urban network systems for urban planners and transportation engineers, paving the way for more targeted sustainable urban planning strategies.

Analisa Pengaruh Hambatan Samping terhadap Kinerja Ruas Jalan pada Jalan Raya Kedu, Reco Kabupaten Wonosobo

According to the 1997 Indonesian Road Capacity Manual (MKJI), a road section is defined as the length of the road between and not influenced by major signalized or unsignalized intersections and has the same characteristics along the entire length of the road. Side obstacles are one of the factors causing traffic jams. Traffic jams are caused by an imbalance between the increase in vehicle ownership and the growth in available road infrastructure, as well as the effective capacity of existing road sections being smaller than the planned road capacity due to roadside obstacles. Traffic engineering is needed to monitor and maintain the continuity of transportation. According to the Institute of Transportation Engineers, USA, Traffic Engineering is a stage of transportation engineering which involves the design, geometric planning and traffic operations of all kinds of roads, road networks, terminals, surrounding land and relationships with other types of transportation.

Foreword

The Congress of Automotive and Transport Engineering is an annual scientific event initiated in 1990 by the Society of Automotive Engineers of Romania (SIAR) and various Romanian universities with an interest in Automotive and Transport Engineering. This Congress is endorsed by EAEC (European Automotive Engineers Cooperation). The XXXII-nd edition of SIARS’s International Congress with the theme “Automotive and Transport Engineering” and the XVII-th European Automotive Congress was organized for the third time by Department of Mechanical Machines, Equipment and Transportation from the Politehnica University Timisoara. The Congress purpose is to gather members from academia, industry and government affiliated presenting their possibilities for investigations and latest research, to achieve collaborations in the near future in the field of automotive and transport engineering. The Congress hosted 201 participants from Europe, United States of America, Moldova presenting their scientific achievements within plenary sessions and congress sections. Thus, the auditorium had the opportunity to: • Gain insight into the cutting edge automotive and transport industry and ideas for future developments; • Update their skills and knowledge by attending focused technical sessions; • Network with potential new partners, clients and suppliers; • View the latest technology products and services in the technical exhibition. The papers included in this volume were selected by the Scientific Committee amongst the ones presented within the Congress and are covering the latest issues such as advanced powertrain and propulsion, automotive design and testing, terrain vehicles, advanced engineering methods, materials, automotive technology and maintenance, road safety, mobility of things. EAEC-MVT 2022 Student Congress was integrated into the main congress and offered students from around the world the opportunity to participate at an international conference and to present their papers on the main congress topics. This was also the meeting place for the young students (SIAR junior’s members) in an International Congress. We hope that these papers will be of interest to experts from academia and industry around the world and we wish them to create a favourable framework for addressing key issues in the field of Automotive and Road Transport Engineering that concern contemporary society today. Yours faithfully, EAEC-MVT 2022 Proceedings Editors List of Acknowledgement, Organizing Committee, Sponsors are available in this Pdf.

Curving and running resistance of freight trains: current experience with on-track measurements

Curving resistance affects the railway vehicle running through curves. For its estimation in train dynamics calculations, different empirical formulas are used in various countries. It is practically impossible to determine its exact value because of its dependency on various – to some extent random – parameters. In the framework of the experimental research of running resistance of freight trains at the Faculty of Transport Engineering of the University of Pardubice, measurements in regular operation conditions on the Czech railway network were realised in recent years. Because some of these results can be used to quantify the curving resistance, the applied evaluation methods and the relevant results are presented in this paper. Besides that, a new general formula of running resistance for freight trains, based on the measurement results, is proposed. Attention is also paid to the effect of track quality on the vehicle running resistance.