Search Results (1,275)

This work presents a proof of concept for a short-range high spectral resolution lidar (SR-HSRL) optimized for aerosol characterization in the first kilometer of the atmosphere. The system is based on a compact, high-repetition-rate diode-based fiber laser with a 300 MHz linewidth and 5 ns pulse duration, coupled with an iodine absorption cell. A central challenge in the instrument’s development was identifying a laser source that offered both sufficient spectral resolution for HSRL retrievals and nanosecond pulse durations for high spatiotemporal resolution, while also being compact, tunable, and cost-effective. To address this, we developed a methodology for complete spectral and temporal laser characterization. A two-day field campaign conducted in July 2024 in Tsukuba, Japan, validated the system’s performance. Despite the relatively broad laser linewidth, we successfully retrieved aerosol backscatter coefficient profiles from 50 to 1000 m, with a spatial resolution of 7.5 m and a temporal resolution of 6 s. The results demonstrate the feasibility of using SR-HSRL for detailed studies of aerosol layers, cloud interfaces, and aerosol–cloud interactions. Future developments will focus on extending the technique to ultra-short-range applications (<100 m) from ground-based and mobile platforms, to retrieve aerosol extinction coefficients and lidar ratios to improve the characterization of near-source aerosol properties and their radiative impacts. Full article

Arsenic (As) mobility in aquifer systems is mainly governed by its adsorption and desorption behaviour at the sediment-water interface, directly influencing its environmental availability and risks to water quality. This study explores the adsorption-desorption behaviour of inorganic As species through batch experiments on environmental sediments collected from three representative depths, selected to reflect local contrasting geochemical, mineralogical, and granulometric characteristics of the Como basin aquifer (Northern Italy). This setting was selected as a case study owing to its notable gradient in As concentration in groundwater: the shallow aquifers host concentrations typically below 10 µg/L, while the deep aquifer reaches concentrations of about 250 µg/L. Statistical analyses (ANOVA and simple linear regression) identified Mn- and Al-(hydr)oxide content, grain size, and mineralogy as strong predictors of As(V) retention, whereas As(III) showed no significant correlation with individual sediment properties within the tested conditions. Shallow, Mn- and Al-rich sediments exhibited higher adsorption capacity and corresponded to lower dissolved As in groundwater, while deeper, finer-grained sediments with lower oxide content coincided with elevated groundwater As concentrations. Desorption experiments indicated that As(III) dominated the released fraction, reflecting its greater mobility under variable pH and redox aquifer conditions. These results provide mechanistic insight into sediment-water interactions controlling As distribution in multilayer aquifers, supporting improved risk assessment and management of As in complex groundwater systems. Full article

This paper presents a comprehensive study of an ESP32 microcontroller-based self-balancing mobile robot system designed in conjunction with an Android app for Bluetooth control. The robot employs an MPU6050 accelerometer/gyroscope to execute dynamic equilibrium control for robotic balance. This study explores the design of a system composed of an ESP32-based dual-platform architecture. The firmware for the ESP32 executes real-time motor control and sensor processing, while the Android application provides the user interface, data visualization, and command transmission. The system achieves stable operation with tilt angle variations of ±2.5° ($\sigma =0.8°$, n = 50 trials) during normal operation with a PID controller tuned to KP = 6.0, KI = 0.1, and KD = 1.5. In experimental tests, control latency was measured at 38–72 ms (mean = 55 ms, $\sigma =12$ ms) over distances of 1–10 m with a robust Bluetooth connection. Extended operational tests indicated the reliability of both autonomous obstacle avoidance mode and manual control exceeding 95%. Key contributions include gyro drift compensation using a progressive calibration scheme, intelligent battery management for operational efficiency, and a dual-mode control interface to facilitate seamless transition between manual and autonomous operation. Processing of real-time telemetry on the Android application allows visualization of important parameters like tilt angle, motor speeds, and sensor readings. This work contributes to a cost-effective mobile robotics platform (total cost: USD 127) through the provision of detailed design specifications, implementation strategies, and performance characteristics. Full article

Field workers require expeditious and pertinent access to information to execute their duties, frequently in arduous environments. Conventional document search interfaces are ill-suited to these contexts, while fully automated approaches often lack the capacity to adapt to the variability of situations. This article explores a hybrid approach based on the use of specialized small language models (SLMs), combining natural language interaction, context awareness (static and dynamic), and structured command generation. The objective of this study is to demonstrate the feasibility of providing contextualized assistance for mobile agents using an intelligent conversational agent, while ensuring that reasonable resource consumption is maintained. The present case study pertains to the supervision of illumination systems on a university campus by technical agents. The static and the dynamic contexts are integrated into the user command to generate a prompt that queries a previously fine-tuned SLM. The methodology employed, the construction of five datasets for the purposes of evaluation, and the refinement of selected SLMs are presented herein. The findings indicate that models of smaller scale demonstrate the capacity to comprehend natural language queries and generate responses that can be effectively utilized by a tangible system. This work opens prospects for intelligent, resource-efficient, and contextualized assistance in industrial or constrained environments. Full article

Traditional methods for documenting cultural heritage often remain inadequate for preserving structural data, making it virtually impossible to archive architectural works that no longer survive. This study investigates the use of augmented reality (AR) technology to improve the sustainability of architectural heritage in the digital environment. The former People’s House (Halkevi) building, once located in Konya, Türkiye but no longer standing, was selected as the case study. Drawing on available photographs and historical documents, a 3D model of the building was generated using Autodesk Revit, further refined in 3ds Max, and transferred to an interactive digital platform via AR applications (ARki, Augmentecture, and a custom AR solution developed with Unity 3D + Vuforia). These applications offer an accessible solution for art and architectural historians thanks to their user-friendly interfaces and the fact that they do not require coding knowledge. Among the tested AR platforms, the Unity + Vuforia-based application yielded the most consistent performance, especially in terms of interactivity, visual stability, and environ-mental integration. The findings indicate that augmented reality can serve as a practical tool for the digital documentation of cultural heritage, demonstrating that researchers without advanced technical expertise can effectively utilize these technologies. This study contributes to digital heritage preservation by proposing a simplified AR-based methodology that reduces the need for cross-disciplinary expertise, enabling wider participation of local stakeholders in the documentation and visualization of lost architectural heritage. Full article

This paper presents a case study on the integration of embedded IoT hardware with a modern Android application, demonstrated through the development of a compact autoclave system for small-scale food sterilization. The device is controlled by an ESP8266-based module and communicates securely with a Kotlin-based Android app via MQTT using HiveMQ. The app incorporates advanced Android design patterns such as coroutines, LiveData, Navigation UI, and DataStore. Each device is uniquely addressable and fully configurable from the mobile interface. The work highlights Android’s role as a powerful interface for managing embedded IoT systems. Full article

Industry Revolution Five (Industry 5.0) will shift the focus away from technology and rely more on to the collaboration between humans and AI-powered robots. This approach emphasizes a more human-centric perspective, enhanced resilience, optimized workplace processes, and a stronger commitment to sustainability. The humanoid robot market has experienced substantial growth, fueled by technological advancements and the increasing need for automation in industries such as service, customer support, and education. However, challenges like high costs, complex maintenance, and societal concerns about job displacement remain. Despite these issues, the market is expected to continue expanding, supported by innovations that enhance both accessibility and performance. Therefore, this article proposes the design and implementation of low-cost, remotely controlled humanoid robots via a mobile application for home-assistant applications. The humanoid robot boasts an advanced mechanical structure, high-performance actuators, and an array of sensors that empower it to execute a wide range of tasks with human-like dexterity and mobility. Incorporating sophisticated control algorithms and a user-friendly Graphical User Interface (GUI) provides precise and stable robot operation and control. Through an in-house developed code, our research contributes to the growing field of humanoid robotics and underscores the significance of advanced control systems in fully harnessing the capabilities of these human-like machines. The implications of our findings extend to the future development and deployment of humanoid robots across various industries and societal contexts, making this an ideal area for students and researchers to explore innovative solutions. Full article

In today’s increasingly complex and multimodal mobility environments, passengers are confronted with fragmented information, inconsistent user interfaces, and limited context-adaptivity across public transport systems and services. These challenges hinder a positive mobility experience, reduce trust, and limit the broader adoption of sustainable transport options. This paper addresses these gaps by introducing a structured, user-centered development methodology for Visually Interactive Companion Technologies in Ubiquitous Passenger Information Systems (VICUPISs). The approach incorporates system characteristics, contextual factors, and a comprehensive process framework. Drawing on applied research and development projects, the methodology defines a five-phase development cycle—from field to concept and back—combining expert insights and user participation across iterative development stages. A central contribution is the integration of a rich context model spanning eight dimensions, enabling adaptive, multimodal, and personalized interaction across mobile, embedded, and public displays. The methodology also incorporates AI-supported adaptivity and addresses the resulting challenges for usability evaluation. Sustainability is considered at three levels: resource-efficient system development, long-term extensibility and adaptability of digital systems, and support for a modal shift toward environmentally friendly public transport. The proposed methodology offers a replicable and transferable foundation for designing human-centered, future-ready information systems in public mobility, complemented by practical heuristics and insights from two case studies of sustainable transport ecosystems. Full article

The integration of microstructured current collectors offers a potential pathway to enhance interface properties in solid-state battery architectures. In this work, we investigate the influence of surface morphology on the electrochemical performance of Zn/Na_2.99Ba_0.005OCl/Cu electrodeless pouch cells by fabricating copper thin films on microstructured parylene-C substrates using a combination of colloidal lithography and reactive ion etching. O₂ plasma etching times ranging from 0 to 15 min were used to tune the surface topography, resulting in a systematic increase in root-mean-square roughness and a surface area enhancement of up to ~30% for the longest etching duration, measured via AFM. Kelvin probe force microscopy-analyzed surface potential showed maximum differences of 270 mV between non-etched and 12-minute-etched Cu collectors. The results revealed that the chemical potential is the property that relates the surface of the Cu current collector/electrode with the cell’s ionic transport performance, including the bulk ionic conductivity, while four-point sheet resistance measurements confirmed that the copper layers’ resistivity maintained values close to those of bulk copper (1.96–4.5 µΩ.cm), which are in agreement with electronic mobilities (−6 and −18 cm²V⁻¹s⁻¹). Conversely, the charge carrier concentrations (−1.6 to −2.6 × 10²³ cm⁻³) are indirectly correlated with the performance of the cell, with the samples with lower CCC_bulk (fewer free electrons) performing better and showing higher maximum discharge currents, interfacial capacitance, and first-cycle discharge plateau voltage and capacity. The data were further consolidated with Scanning Electron Microscopy and X-ray Photoelectron Spectroscopy analyses. These results highlight that the correlation between the surface morphology and the cell is not straightforward, with the microstructured current collectors’ surface chemical potential and the charge carriers’ concentration being determinant in the performance of all-solid-state electrodeless sodium battery systems. Full article

Robust, reliable, and secure communications are essential for efficient railway operation and keeping employees and passengers safe. The Future Railway Mobile Communication System (FRMCS) is a global standard aimed at providing innovative, essential, and high-performance communication applications in railway transport. In comparison with the legacy communication system (GSM-R), it provides high data rates, ultra-high reliability, and low latency. The FRMCS architecture will also benefit from cloud computing, following the principles of the cloud-native 5G core network design based on Network Function Virtualization (NFV). In this paper, an approach to the management of virtualized FRMCS applications is presented. First, the key management functionality related to the virtualized FRMCS application is identified based on an analysis of the different use cases. Next, this functionality is synthesized as RESTful services. The communication between application management and the services is designed as Application Programing Interfaces (APIs). The APIs are formally verified by modeling the management states of an FRMCS application instance from different points of view, and it is mathematically proved that the management state models are synchronized in time. The latency introduced by the designed APIs, as a key performance indicator, is evaluated through emulation. Full article

At present, there are some challenging issues for diamond electroplating devices, such as poor particle–cathode contact uniformity, low conductivity, inefficient deposition, and complex disassembly/cleaning process of the device. To overcome these issues, an ultrasonic oscillation-assisted nickel electroplating device is innovatively designed and presented in this paper. The device features: (1) innovative architecture enabling rapid disassembly; (2) ultrasonic enhancement of diamond particle mobility (frequency × amplitude); (3) optimized electrical contact interfaces. In this paper, the effects of electroplating current, output power of ultrasonic oscillator and diamond particle size on nickel electroplating onto diamond surface are further studied particularly by ultrasonic assisted electroplating. The experimental results show that the ultrasonic oscillation assisted electroplating greatly improves the uniformity of the coating on the diamond surface and effectively prevents the adhesion between diamond particles. While the process parameters are electroplating current of 3 A, output power of ultrasonic oscillator 900 W, diamond particle size of 120/140, the weight-gain rate is 20.6%, the nickel content of the coating reaches 81.95%, and the coating is excellent uniformed without agglomeration. The research presented provides fundamental understanding for further development and application of ultrasonic oscillation-assisted electroplating technology particularly for broad precision engineering purposes. Full article

Klebsiella pneumoniae is an important pathogen associated with multidrug resistance and virulence in both human and animal populations. While its prevalence and resistance patterns are well documented in clinical settings, data on K. pneumoniae in food-producing animals remain scarce. This study aimed to isolate and characterize multidrug-resistant K. pneumoniae strains from healthy rabbits raised for human consumption, with a focus on antimicrobial resistance genes, plasmid content, and associated mobile genetic elements. A total of 295 fecal samples were collected from rabbits across 20 commercial farms in northern Portugal. Isolates were confirmed using MALDI-TOF MS, tested for hypermucoviscosity, and subjected to antimicrobial susceptibility testing (EUCAST). Whole-genome sequencing (WGS) was performed to determine sequence types (STs), resistance genes, plasmids, and resistance determinants for metals and biocides. Six K. pneumoniae isolates were recovered, showing extensive antimicrobial resistance profiles, including ESBL genes such as bla_CTX-M-15, bla_SHV-28, and bla_TEM-1. The most frequent ST was ST307. Multiple genes resistant to heavy metals were identified. Plasmid analysis revealed the presence of IncFII, IncN, and ColRNAI types. Network analysis showed clusters of genetically related isolates and highlighted shared resistance mechanisms. The presence of multidrug-resistant K. pneumoniae in healthy rabbits destined for human consumption underscores the zoonotic potential of this species and the need for surveillance in the animal–food–human interface. These findings contribute to a better understanding of resistance ecology in the context of One Health. Full article

Halide perovskite-based memristors are promising neuromorphic devices due to their unique ion migration and interface tunability, yet their conduction mechanisms remain unclear, causing stability and performance issues. Here, we engineer interstitial Ag⁺ ions within a quasi-two-dimensional (quasi-2D) halide perovskite ((C₆H₅C₂H₄NH₃)₂Cs_n−1Pb_nI_3n+1) to enhance device stability and controllability. The introduced Ag⁺ ions occupy organic interlayers, forming thermodynamically stable structures and introducing deep-level energy states without structural distortion, which do not act as non-radiative recombination centers, but instead serve as efficient charge trapping centers that stabilize intermediate resistance states and facilitate controlled filament evolution during resistive switching. This modification also leads to enhanced electron transparency near the Fermi level, contributing to improved charge transport dynamics and device performance. Under external electric fields, these Ag⁺ ions act as mobile ionic species, facilitating controlled filament formation and stable resistive switching. The resulting devices demonstrate exceptional performance, featuring an ultrahigh on/off ratio (∼10⁸) and low operating voltages (∼0.31 V), surpassing existing benchmarks. Our findings highlight the dual role of Ag⁺ ions in structural stabilization and conduction modulation, providing a robust approach for high-performance perovskite memristor engineering. Full article

This study aims to clarify the temperature-dependent degradation mechanisms of the steel–concrete interface in NaCl solution environments at the nanoscale, focusing on the key components of calcium silicate hydrate (C-S-H, the primary hydration product of cement) and iron oxyhydroxide (γ-FeOOH, a critical component of steel passive films in highly alkaline environments). Using Materials Studio software (2023) and molecular dynamics simulations, the evolution of the interface’s performance under temperatures ranging from 300 K to 390 K (corresponding to 27 °C to 117 °C) is systematically investigated. The results reveal that elevated temperatures degrade the performance of C-S-H/γ-FeOOH interfaces through three main mechanisms: (1) The stability of the hydration shell around aggressive ions is weakened, enabling these ions to occupy the coordination positions of calcium ions on the interface and form stable ion pairs with surface calcium ions, thereby weakening interfacial bonding. (2) The mobility of surface calcium ions is enhanced, reducing the strength of the interaction of ion pairs and diminishing the mediating role of calcium ions in connecting the C-S-H and γ-FeOOH phases. (3) Hydrogen bond stability at the interface decreases, as indicated by reduced hydrogen bond angles and numbers, coupled with increased hydrogen bond lengths. The above three reasons lead to a decrease in adsorption energy in the C-S-H/γ-FeOOH interface, which degrades the interface bond’s performance. Full article

Optical fiber composite insulators are essential for photoelectric current measurement, yet insulation failure at embedded optical fiber interfaces remains a major challenge to long-term stability. This study proposes a strategy to replace conventional silicone rubber with cycloaliphatic-like epoxy resin (CEP) as the shed-sheathing material. Three optical fibers with distinct outer coatings, ethylene-tetrafluoroethylene copolymer (ETFE), thermoplastic polyester elastomer (TPEE), and epoxy acrylate resin (EA), were evaluated for their interfacial compatibility with CEP. ETFE, with low surface energy and weak polarity, exhibited poor wettability with CEP, resulting in an interfacial tensile strength of 0 MPa, pronounced dye penetration, and rapid electrical tree propagation. Its average interfacial breakdown voltage was only 8 kV, and the interfacial leakage current reached 35 μA after hygrothermal aging. In contrast, TPEE exhibited high surface energy and strong polarity, enabling strong bonding with CEP, yielding an average interfacial tensile strength of approximately 46 MPa. Such a strong interface effectively suppressed electrical tree growth, increased the average interfacial breakdown voltage to 27 kV, and maintained the interfacial leakage current below 5 μA even after hygrothermal aging. EA exhibited moderate interfacial performance. Mechanism analysis revealed that polar ester and ether groups in TPEE enhanced interfacial electrostatic interactions, restricted the mobility of CEP molecular chain segments, and increased charge traps. These synergistic effects suppressed interfacial charge transport and improved insulation strength. This work offers valuable insight into structure–property relationships at fiber–resin interfaces and provides a useful reference for the design of composite insulation materials. Full article