Transportation Devices Research Articles

Temperature-controlled shape transformation of PtCo alloy catalysts for enhanced ammonia oxidation in anion-exchange membrane direct ammonia fuel cells

Low-temperature anion-exchange membrane direct ammonia fuel cells (AEM-DAFCs) are emerging as attractive and environmentally friendly energy devices for small-scale transportation. However, challenges arise in the ammonia oxidation reaction (AOR) owing to the high activation energy required for direct ammonia modification and the issue of decreased activity in the AOR caused by the strong adsorption of ammonia and nitrogen species, necessitating solutions. In this study, we aimed to address the challenges related to the ammonia activation energy and ammonia adsorption capacity by alloying Pt and Co. Furthermore, during the fabrication of the PtCo catalysts, the synthesis process was controlled at different reaction temperatures to produce core–shell and hollow structures. In particular, the PtCo catalyst synthesized at 60 °C (PtCo-60), with a particle size of 7.65 nm in the hollow structure, exhibited the highest electrochemically active surface area among the PtCo catalysts produced (∼43.0 m2 g−1). This increase in the active surface area owing to structural changes was attributed to the increase in AOR activity. The onset potential of PtCo-60, adjusted for particle size and structure, was determined to be 0.454 V vs. RHE, with a mass activity of 128 A gPt−1, in cyclic voltammetry experiments using 1 M KOH +1 M NH4OH. Ultimately, in the AEM-DAFC unit cell test conducted at 80 °C, an output density of 11.33 mW cm−2 was achieved.

Vibrational and stability analysis of planar double pendulum dynamics near resonance

AbstractThe focus of this paper is to examine the motion of a novel double pendulum (DP) system with two degrees of freedom (DOF). This system operates under specific constraints to follow a Lissajous curve, with its pivot point moving along this path in a plane. The nonlinear differential equations governing this system are derived using Lagrange's equations. Their analytical solutions (AS) are subsequently calculated using the multiple-scales method (MSM), which provides higher-order approximations. These solutions are considered new, as the traditional MSM has been applied to this novel system for the first time. Additionally, the accuracy of these solutions is validated through numerical results obtained using the fourth-order Runge–Kutta method. The solvability conditions and characteristic exponents are determined based on resonance cases. The Routh–Hurwitz criteria (RHC) are employed to assess the stability of the fixed points corresponding to the steady-state solutions. They are also used to demonstrate the frequency response curves. The nonlinear stability analysis is performed by examining the stability and instability ranges. Resonance curves and time history plots are presented to analyze the behavior of the system for specific parameter values. The investigation delves into a comprehensive analysis of bifurcation diagrams (BDs) and Lyapunov exponent spectra (LEs), aiming to uncover the various types of motion present within the system. Systematic examination of these charts reveals critical insights into transitions between stable, quasi-stable, and chaotic dynamical behaviors. This work has practical applications in various fields, such as robotics, pump compressors, rotor dynamics, and transportation devices. It can be used to study the vibrational motion of these systems.

Emerging Advanced Photo‐Rechargeable Batteries

AbstractThe depletion of fossil fuels necessitates the efficient utilization of solar energy and the urgent resolution of its instability, intermittency, and storage challenges. Photo‐rechargeable batteries, which integrate solar cells and energy storage batteries to convert solar energy into electricity and store it as chemical energy, have gradually emerged as a novel research direction to meet the energy demands of various standalone applications such as building facades, mobile transportation devices, and outdoor settings. This review elucidates the device structure, working principles, and key parameters of photo‐rechargeable batteries. Furthermore, various photo‐rechargeable battery systems such as lithium‐ion battery, lithium‐sulfur battery, sodium‐ion battery, zinc‐ion battery, and aluminum‐ion battery are categorized and summarized, detailing their composition, operational mechanisms, and photoelectric performance. Finally, the future research directions of photo‐rechargeable batteries are delineated, advocating for the exploration of dual‐functional materials that integrate light conversion and energy storage. Specifically, emphasis is placed on studying the compatibility between optical and energy storage materials, investigating new battery operation mechanisms under illumination conditions, considering the imperative of achieving high stability and overall efficiency to enhance device performance, and elucidating the future application pathways of these technologies.

Directive transportation in smart cities with line connectivity at distinctive points using mode control algorithm

This article examines the operational functionality of intelligent transport systems to enhance smart cities by reducing traffic congestion. Given the increasing populations of smart cities, there is a growing demand for public transit systems to address the issue of traffic congestion. Therefore, the suggested system is developed using a few parametric design models, which combine point-to-point protocol and mode control optimization. The multi-objective parametric design for a smart transportation system is conducted using min–max functions to minimize the waiting time period for end users. Furthermore, customers are given the option to utilize a line following mechanism that offers suitable connectivity, along with independent identification and revitalize functions. The predicted model effectively eliminates the delay produced by transportation devices when positioning units are involved, ensuring that individual messages are delivered without any interruptions. In order to evaluate the results of the proposed system model, four different scenarios were examined. A comparison analysis revealed that the suggested method achieves a suitable directional flow for 96% of smart transport units. Additionally, it reduces delays and waiting periods by 2% and 6% respectively, while increasing energy consumption by 29%.

Recyclable bio-based epoxy resin thermoset polymer from wood for circular economy

Due to their extraordinary durability and thermal stability, Epoxy Resin Thermosets (ERTs) are essential in various industries. However, their poor recyclability leads to unacceptable environmental pollution. In this study, Wu et al. successfully synthesized a completely bio-based ERT using lignocellulose-derived building blocks which exhibit outstanding thermal and mechanical properties. Remarkably, these bio-materials degrade via methanolysis without the need of any catalyst, presenting a smart and cost-effective recycling strategy. Furthermore, this approach could be employed for fabricating reusable composites comprising glass fiber and plant fiber, thereby expanding its applications in sustainable transportation, coatings, paints or biomedical devices.

Design and Experimental Study of Banana Bunch Transportation Device with Lifting Mechanism and Automatic Bottom-Fixing Fruit Shaft

In addressing the challenges of high labor intensity, cost, and potential mechanical damage to banana fruit in orchards, this study presents the design of a banana bunch transport device featuring a lifting mechanism and an automatic fruit shaft bottom-fixing system. The device is tailored to the planting and morphological characteristics of banana bunches, aiming for efficient, low-loss, and labor-saving mechanized transport. Key design considerations included the anti-overturning mechanism and the lifting system based on transportation conditions and the physical dimensions of banana bunches. A dynamic simulation was conducted to analyze the angular velocity and acceleration during the initial conveying stages, forming the basis for the fruit shaft bottom-fixation mechanism. A novel horizontal multi-point scanning method was developed to accurately identify and secure the fruit shaft bottom, complemented by an automated control system. Experimental results showed a 95.83% success rate in identification and fixation, validated by field trials that confirmed the necessity and stability of the fixation mechanism. To enhance the durability of the fruit shaft bottom-fixation mechanism, a multi-factor test was conducted, optimizing the device’s maximum travel speed and minimizing the banana bunch’s oscillation angle. Field tests showed an oscillation angle of 8.961°, closely matching the simulated result of 9.526°, demonstrating the reliability of the response surface analysis model. This study offers a practical and efficient solution for banana bunch transport in orchards, showcasing significant practical value and potential for wider adoption.

해양 모빌리티 산업의 확장성을 위한 차세대 개인용 잠수정 디자인 연구

The growth of coastal areas presents important challenges in terms of the development and diversification of marine leisure industries. As the demand and interest in underwater leisure activities increases due to the experience-oriented trend of the future generation, the need for new underwater transportation devices that can meet market demands has emerged. In this study, I investigated the main features of transportation devices that enable comfortable leisure activities underwater, especially compact recreational submersibles, which are currently growing rapidly, through leading overseas cases. Based on the analysis, I propose a design for a compact submarine that emphasizes its scalability as marine mobility by integrating electric batteries and AI-based autonomous technology. Future transportation will bring multidimensional innovation. The transition to electric and autonomous driving promotes the development of intelligent maritime transportation and fosters innovative mobility services. Through research on personal submersibles, I provide users with a new immersive experience and present the possibility of expanding the future marine leisure industry.

Research on the design and damping control of rocket maritime transportation device

Research on the design and damping control of rocket maritime transportation device

Magnetically Actuated Transport Pipeline with Self-Perception

Soft transportation devices with high flexibility, good stability, and quick controllability have attracted increasing attention. However, a smart soft transportation device with tactile perception and a non-contact actuating mode remains a challenge. This work reports a magnetic soft pipeline (MSP) composed of sensor film, a magnetorheological elastomer (MRE) cavity pipeline, and heater film, which can not only respond well to tactile compression stimuli but also be transported by magnetic actuation. Notably, the sensor film was integrated on the upper surface of an MRE pipeline, and the relative resistance change (∆R/R0) of the MSP was maintained at 55.8% under 2.2 mm compression displacement during 4000 loading cycles. Moreover, the heater film was integrated on the lower surface of the MRE pipeline, which endows the MSP with an electrothermal heating characteristic. The temperature of the MSP can be increased from 26.7 °C to 38.1 °C within 1 min under 0.6 V. Furthermore, the MSP was attracted and deformed under the magnetic field, and the ∆R/R0 of the MSP reached 69.1% under application of a 165 mT magnetic field density. Benefiting from the excellent perception and magnetic deformation performances, the magnetic actuate transportation of the MSP with self-sensing was successfully achieved. This multi-functional soft pipeline integrated with in situ self-sensing, electrothermal heating, and non-contact magnetic actuating transportation performance possess high potential in smart flexible electronic devices.

Grain boundary microstructure engineering of Li1.3Al0.3Ti1.7(PO4)3 electrolytes with a low-temperature-prepared nanopowder and Bi2O3 additive

All-solid-state lithium batteries have great potential applying to the fields of transportation and portable devices because of their high safety and energy density as the power source. As a critical component of device, solid-state electrolyte has been paid much attention. Given the excellent physical and chemical stability, Li1+xAlxTi2-x(PO4)3 (LATP)-based electrolyte has been considered as one of the most promising electrolytes for the next generation batteries. However, a further promotion of its ionic conductivity becomes extremely difficult, originating mainly from the poor connection of grains and a low relative density of LATP. Here, the nanosized and homogenous LATP (x = 0.3) powders were synthesized through reducing the agglomeration of precursor powders and preparing at low temperatures. It is revealed that uniformly superfine LATP powders are able to improve the microstructure of grain boundaries during the pellet sintering process, thereby reducing the grain boundary resistance. Furthermore, as-synthesized nanosized powders mixed with Bi2O3 additive present a better enhancement on the connection of grains and the relative density in LATP. On the basis of this understanding, we prepared LATP electrolytes with 0.5 wt% Bi2O3 exhibiting a high ionic conductivity of 8.56 × 10−4 S/cm, a high relative density of 94.4 % and a low activation energy of 0.27 eV, which is demonstrated as a prospective electrolyte in all-solid-state lithium battery LiFePO4/PEO/LATP/PEO/Li.

Development of a mathematical model of stabilisation of device for small-sized cargo transportation

The relevance of the study is conditioned by the need to improve the efficiency and safety of transportation of small-sized cargo. The purpose of this study was to build a mathematical model of the dynamics of stabilisation of device for small-sized cargo transportation. For this, the equations of motion of the system were formulated in the form of a system of second order Lagrange differential equations of the second kind. A grey box approach was used to determine the unknown coefficients of the equations of motion. To implement the approach, an optimisation criterion was constructed that reflected the parameters of the root-mean-square and maximum absolute errors of the differences between theoretical and experimental data of the tilt angle and angular velocity of the device. A modified Ring-Rot-PSO particle swarm method was used to minimise the criterion. The unknown parameters of the device model were found, and the adequacy of the obtained mathematical model was assessed by individual components of the criterion, which proved the adequacy of the obtained mathematical model. To find the unknown parameters, namely the coefficients of the equation of motion of the device, a grey box approach was applied. For this, experimental studies of the device stabilisation were performed, and the difference function was formed as an objective function of theoretical, obtained based on analytical equations of motion and experimental data. The objective function was minimised using the modified particle swarm method Ring-Rot-PSO. As a result of the optimisation, the unknown parameters of the system were obtained: the moments of inertia of the frame I1c = 5.52·10-4 kg·m² and the wheel Iwc = 2.75·10-3 kg·m², the wheel mass mw = 3.31·10-1 kg. These data allowed obtaining an adequate mathematical model model of the stabilisation of the device, which underlies further solving of the problem of synthesising optimal control of its motion

Dielectric topological metasurfaces based in-plane control of light propagation by using valley degrees of freedom

Metasurface has garnered widespread attention due to its remarkable ability of precise light manipulation. The emergence of topological photonics has brought novel topological phenomena and holds the promise of introducing new optical functionalities to the metasurfaces. In this paper, by introducing valley degrees of freedom into metasurfaces, we design and numerically simulate topological-nanostructure-enabled on-chip chiral light propagation and multistage beam splitting, as well as holographic display by integrating a beam-splitting metasurface with valley photonic crystals (VPCs). Importantly, the proposed on-chip topological optical devices exhibit broadband response covering 1480–1660 nm and low transmission losses with the maximum efficiency reaching 82 %. Our work is expected to bring new optical functionalities to the metasurface based devices and can be widely applied in fields of optical fiber communications, on-chip optical transportation and smart wearable devices, which require high-efficiency, broadband and highly-integrated optoelectronic elements and devices.

Theoretical research on dynamic modeling of rigid–flexible coupling system with double joint folded wing

For meeting the requirements of tactical missiles seeking miniaturized launch devices for storage, transportation, and launch, a tube-launched missile wing is adopted, which folds before launch and quickly unfolds after launch. As a structure installed on the missile body to generate the required aerodynamic force for manipulating the missile, the tube-launched missile wing can effectively stabilize the missile’s flight attitude. At present, most research on the unfolding mechanism of missile folding wings is focused on one-time folding. When the wingspan is large, multiple folding is required to meet the launch requirements of modern tube-launched missiles. Therefore, this article designs a dual-joint folding wing deployment mechanism and studies the rigid–flexible coupling dynamic modeling and related technologies of folding wings based on this structure. Based on the inertial coupling between large-scale rigid body motion and structural flexible deformation, the folding wing breaks through the element convergence of the model and achieves the applicability of the structural model through zero-order approximation model analysis and other technologies. Simulation results show that the hybrid coordinate method can fully and accurately display the vibration information of flexible folding wings. At different speeds, the first-order coupling model is more advanced than the zero-order coupling model. In addition, increasing rotational speed, increasing wing thickness, and reducing wing span length can effectively increase the fundamental frequency of wing flutter. The structural design of folding wings has shown important reference significance.

On the Stability of a 3DOF Vibrating System Close to Resonances

Abstract Purpose In the current work, the motion of a three degrees-of-freedom (DOF) dynamical system as a vibrating model is examined. The proposed system is of high importance in vibration engineering applications, such as the analysis of the control of flexible arm robotics, flexible arm vibrational motion as a dynamic system, pump compressors, transportation devices, rotor dynamics, shipboard cranes, and human or walking analysis robotics. Methods Lagrange's equations (LE) are used to derive the equations of motion of the controlling system. The analytic solutions (AS) are obtained utilizing the multiple-scales method (MSM) up to the third order. Results The framework for removing secular terms provides the requirements for the solvability of this problem. Various resonance scenarios are categorized and the modulation equations (ME) are constructed. To graphically demonstrate the beneficial impacts of the distinct parameters of the problem, the time histories (TH) of the approximate solutions as well as the resonance curves (RC) are depicted. The Runge-Kutta algorithm (RKA) is employed to obtain the numerical solutions (NS) of the regulating system. Conclusion A comparison of the AS and NS reveals the accuracy of the perturbation approach. The stability/instability zones are studied using Routh-Hurwitz criteria (RHC), and then they are examined using a steady-state situation. Basically, the used perturbation method is considered a traditional method that is applied to solve a new dynamical system. Then, the achieved results are considered new because they weren’t obtained previously, which indicates the novelty of this work.

Molten air—A new class of high capacity batteries

The present invention relates to rechargeable electrochemical battery cells (molten air batteries). The cells use air and a molten electrolyte, are quasi-reversible (rechargeable) and have the capacity for multiple electrons stored per molecule, have high intrinsic electric energy storage capacities. The present disclosure also relates to the use of such in a range of electronic, transportation and power generation devices, including as greenhouse gas reduction applications, electric car batteries and increased capacity energy storage systems for the electric grid. US patent 10637115 is for the invention of air and carbon or CO2 Molten Air batteries, while US patent 11094980 is for the invention of air and metal, boron and a variety of salt/Molten Air batteries.

Recent Advancements in Light-responsive Supercapacitors

Abstract: With so many of our daily activities related to electricity, from telecommunication to laptops and computers, the use of electric energy has skyrocketed in today's technology-based world. Energy output must rise to meet rising energy demand. Still, as fossil fuels are running out, we must turn to more renewable energy sources, particularly solar energy, which can be harnessed and converted to electricity by solar-powered cells. The issues, however, are brought about by the sunlight's unpredictable energy output. The energy produced by solar cells should therefore be stored using energy storage technologies. This notion led to the development of the photo-supercapacitor, a device that combines a solar cell with a supercapacitor to store the energy generated by the solar cells. However, recently researchers developed light-responsive materials for supercapacitors that could be used directly as electrode materials and deposited on various transparent and conductive substrates. Such light-responsive supercapacitors could be operated directly by shining solar light without using any solar cell. A light-responsive supercapacitor's efficiency is primarily influenced by the active materials used in its electrode fabrication. The main components of high-energy conversion, which improves a light-responsive supercapacitor's performance and shelf life, are photoactive materials, counter electrodes, compatible electrolytes, and transparent substrate performances. Furthermore, light-responsive supercapacitors are cutting-edge and promising energy storage devices that can self-charge under light illumination by converting light to electrical energy and storing it for later use. They are considered a novel approach to energy issues in electrical transportation, electronic equipment, and on-chip energy storage devices. Thus, this review paper opens up an avenue for the direct utilization of photoactive nanomaterials for electrochemical energy storage and demonstrates the substantial potential for the fabrication of advanced light-responsive supercapacitors. This study also covers the fundamentals of how this exciting field works, the historical trajectory of how far it has come, and the promising prospects for its future.

A novel generalized prognostic method of proton exchange membrane fuel cell using multi-point estimation under various operating conditions

The proton exchange membrane fuel cell has been introduced into the fields of transportation, power production, and mobile devices. Especially, priority is given to promoting the application in commercial vehicles. However, more severe fluctuations in power demands give new challenges to the lifespan of fuel cells. The accurate state estimation and reasonable degradation prediction can assist in improving the lifetime of fuel cell devices. To realize the on-road prediction, herein, a novel generalized prognostic method called the Multi-point Square-root central difference Kalman filter (MP-SRCDKF) is proposed. First of all, an extended mathematical model is introduced. Later, the sensitivity analysis and parameter recognition are conducted based on the Sobol’ method and the jellyfish searching algorithm. The performance of the SRCDKF method is compared under static and quasi-dynamic conditions, which is further extended into the road condition and verified under the dynamic cycle condition temporarily. In the end, the remaining useful life prediction under various operating conditions is discussed. Furthermore, the generalized method can provide an approach for prognostic decision-making and the updating of the dynamic polarization curve to expand the lifetime and optimize the control system.

Preparation and application of high sound insulation polyurethane composite film through glass fiber reinforcement

AbstractLaminated glasses have been widely used in buildings, physical protections, and vehicles because of their safety, sound insulation, thermal insulation, and other performance. In recent years, the high sound insulation performance of laminated glass intermediate films in the frequency range of low or high frequencies has attracted more and more attentions. In this work, a glass fiber/polyurethane elastomer composite (PU‐MGF) film with high transparency and impact resistance has been successfully synthesized, 5 dB of the transmission loss increased at 1600–6000 Hz, and 3.6 dB increased at 63–1600 Hz compared with the control polyurethane film. This is a significant progress in the laminated glass industry. In addition, the transmittance of the composite reaches over 75%. The excellent impact resistance of the laminated glass, based on PU‐MGF film, has been confirmed through falling ball impact test, demonstrating its ability to withstand multiple impacts without spattering. The PU‐MGF film prepared in this work exhibits great potential for applications in building windows, transportation, and soundproof devices.

A Multidimensional Readiness Index for the Electrification of the Transportation System in China, Norway, and Sweden

The main objective of this paper is to develop a readiness index model that can serve as an analytical tool for exploring the achievements of the electrification of transportation systems. We have applied this readiness index model to evaluate the readiness positioning of China, Norway, and Sweden towards transportation electrification. We have chosen these three countries as they represent diversity among countries adopting electric transportation system solutions. Our developed readiness index model has four key dimensions: technological readiness, political readiness, societal readiness, and economic readiness. The embeddedness of all four dimensions in one model provides a multi-perspective way of analyzing and evaluating the readiness levels of countries moving towards transforming their transportation system. Therefore, we named the model a “multidimensional readiness index”. Our main conclusions are that political processes and decisiveness are the most important factors, followed by societal needs and economic ability, with the current technology as the fourth. Without the participation of dedicated and determined political decision makers, the other three factors are challenging to obtain. Political decision makers need to facilitate economic means to support the transformation in society and affected industries to balance the economic disadvantages of the electrically powered vehicle systems until they pass the cost disadvantage turning point. The development of relevant technology is no longer the significant barrier it was at the beginning of this transformation about 20 years ago. The technology for electrically powered transportation systems and devices is widely available now, although it is continuously evolving and being improved. Associated industries cannot be expected to initiate, finance, take risks, and take the lead in this global societal transformation without clear and strong political support.

Introduction: Perceiving and conceiving the Asian city1

AbstractAsian cities are the setting of a vast agglomeration of transportation devices and services. These means of transport are inseparable from distinct concepts and images of the city. Interventions into modes of urban transport are inspired by visions for the future of urban life and quotidian practices of traversing urban space foster particular experiences that produce distinct ideas about the city. This special issue takes the multiplicity of mobility practices in Asian cities as a point of departure to interrogate connections between embodied experiences and collective representations. Drawing on three bodies of literature that deal with the topics of urban imaginaries, infrastructures as well as the body and the city, this introduction provides a theoretical framework for the study of connections between perception and conception of cities that informs the contributions to this special issue. It sets the stage for a set of three interconnected questions that guide the contributions: How do people affectively engage with urban spaces through practices of bodily movement? How are these practices of movement related to and generative of specific ideas and representations of the city? How do these practices of movement transform, challenge, subvert, or conform to dominant ideas and representations of the city?