Search Results (1,857)

The need for reliable software for data acquisition, processing and communication with laboratory instruments, as well as for extending laboratory findings to real-scale structures, is imperative. In this context, ReplicaXLite is presented: an open-source software framework designed to facilitate and organize structural experimental testing on seismic tables. The software enables the creation of digital twin models and real-time sensor data recording. Furthermore, it allows for the processing, storage and visualization of results within a graphical interface. It features two primary modes of operation: (a) via terminal with specific Application Programming Interfaces (APIs) and (b) via a Graphical User Interface (GUI), adapting to the user’s expertise level. The software lies on top of open-source libraries like OpenSeesPy and opstool. It supports many material types, such as concrete, steel, fibers and composites, among others. Models produced by ReplicaXLite demonstrate strong agreement with experimental data across varying structural configurations. For both acceleration and displacement, the framework yielded satisfactory accuracy at the top slab with mean envelope correlations ranging from 0.91 to 0.97 and mean Pearson correlations generally between 0.83 and 0.95 for varying seismic intensities (0.1 g to 1.4 g). The numerical framework successfully captured global stiffness degradation, with Normalized Root Mean Square Errors (NRMSE) well-constrained between 2.3% and 7.9% across both acceleration and displacement response metrics. The architecture allows for the one-click execution of custom user codes, providing full access to the source code and the ability to perform live toolkit modifications via the “app.” terminal variable. Finally, it provides mid-simulation modification of the mass and elements of the model. Full article

Vehicle recharge time is a key barrier to widespread adoption of battery electric trucks, where megawatt class charging could be used to achieve refueling times comparable to internal combustion vehicles. This work presents the design and validation of a megawatt-capable rechargeable energy storage system (144 kWh, 40P384S) together with a physics-based modeling framework for safe 1 MW operation. The pack architecture is reconfigurable, enabling nominal 750 V (80P192S) propulsion mode as well as 1125 V and 1500 V charging modes compatible with the Megawatt Charging System (MCS). An equivalent circuit model is developed to relate cell-level parameters to pack-level power, heat generation, and temperature rise, providing guidance on feasible charge profiles and thermal limits. A Simulink-based digital twin of the reconfigurable pack is then used to analyze sensitivity to current sensor mismatch and to verify protection logic for multiple bus voltage configurations. Finally, pack tests up to 1 MW confirm the model-predicted operating envelope and illustrate practical constraints imposed by charger voltage and pack resistance. The combined hardware and modeling approach provides a reusable platform for studying extreme fast charging of medium- and heavy-duty BEV packs-class charging -capable rechargeable energy storage system (144 kWh, 40P384S) together with a physics-based modeling framework for safe 1 MW operation. The pack architecture is reconfigurable, enabling nominal 750 V (80P192S) propulsion mode as well as 1125 V and 1500 V charging modes compatible with the Megawatt Charging System (MCS). An equivalent-circuit model is developed to relate cell-level parameters to pack-level power, heat generation, and temperature rise, providing guidance on feasible charge profiles and thermal limits. A Simulink-based digital twin of the reconfigurable pack is then used to analyze sensitivity to current–sensor mismatch and to verify protection logic for multiple bus-voltage configurations. Finally, pack tests up to 1 MW confirm the model-predicted operating envelope and illustrate practical constraints imposed by charger voltage and pack resistance. The combined hardware and modeling approach provides a reusable platform for studying extreme fast charging of medium- and heavy-duty BEV packs. Full article

Background: Immunobiologicals are thermolabile products that require strict storage and transportation conditions to maintain their immunogenic efficacy, particularly in countries where logistical and operational challenges are evident, such as Brazil. Methods: A holistic multiple case study, carried out in five regions of Brazil, in 2022, with 42 workers from different instances of the cold chain was conducted. As a source of evidence, data were collected through interviews and analysis of printed documents and analyzed using Thematic Content Analysis, using the analytical technique of cross-case synthesis. Results: The influence of geoclimatic diversity and transportation modes on immunobiological logistics was highlighted. Challenges and requirements were identified, as well as aspects of monitoring during transportation and distribution. Among the main challenges were long distances, poor road conditions, seasonality and the need to share vehicles due to the unavailability of exclusive transportation. Conversely, positive practices were highlighted, such as the use of air-conditioned vehicles, dataloggers and properly prepared thermal boxes. Conclusions: It is necessary to adopt mitigation strategies that consider regional inequalities and promote equity, through raising awareness among managers, investing in logistical infrastructure and expanding good practices in order to guarantee the universal and qualified distribution of immunobiologicals in the country. Full article

The current energy transition has shifted the power system paradigm, including distributed resources (mostly renewables) and energy storage systems, the proper incorporation of which is beneficial for the power system but can also cause issues such as network instability, grid congestion or issues with power quality. Moreover, the exponential electrification of loads, especially ones with dynamic behavior, due to most sectors switching to electric mode, with prominent examples including mobility, heating, hydrogen production and marine applications, can pose challenges for the system operators. The purpose of this paper is to highlight the effects of this transition from the perspective of the distribution and transmission systems in Europe generally, but also in Greece specifically, by presenting key performance indicators (technical, economic, environmental, and social) related to expected EU targets, as well as selected real-life applications, future trends and challenges. Full article

Variations in the groundwater chemical environment are a critical factor affecting the mechanical property degradation and structural alteration of coal measure strata. Addressing the engineering challenges commonly encountered in coal mining areas of Northwest China, where groundwater with varying pH leads to difficulties in controlling surrounding rock in underground spaces, this study established a comprehensive experimental methodology integrating mechanical loading, nuclear magnetic resonance (NMR) quantitative pore analysis, and scanning electron microscopy (SEM) microstructural characterization. The study revealed the mechanical degradation mechanisms and microstructural evolution characteristics of coal measure coarse sandstone under groundwater environments with different pH values (6–10). With prolonged immersion time, the peak strength and elastic modulus of the coarse sandstone exhibited exponential decay across all pH environments. NMR analysis revealed that the porosity evolved through a path of “increase–decrease–re-increase,” while the macroscopic mechanical failure mode shifted from brittle to brittle-ductile and finally to ductile characteristics. Micropores continuously transformed into medium and large pores, and the macroscopic failure mode exhibited a transition from brittle to brittle-ductile. The findings indicate that groundwater with varying acidity/alkalinity systematically alters the integrity and load-bearing capacity of coal measure coarse sandstone through the complex mechanism of “mineral dissolution (acidic H⁺ corrosion, alkaline OH⁻ hydrolysis)—structural damage—pore/fracture evolution—mechanical degradation.” This mechanism not only reveals the essence of progressive rock damage in weak acid to moderately strong alkaline environments but also provides important insights for the integrity, sealing capacity, and permeability modification of various underground engineering applications, such as CO₂ geological storage, unconventional natural gas development, and underground space utilization. Full article

In the context of high penetration of distributed energy resources and new load integration, existing research primarily focuses on capacity optimization under pre-established interconnection structures, addressing issues such as uneven spatiotemporal distribution of loads and low equipment utilization in distribution transformer areas. However, these studies lack a planning-stage interconnection object selection mechanism. To address this, this paper proposes a planning-oriented flexible interconnection potential assessment and optimization configuration method for distribution transformer areas. First, a quantitative interconnection potential assessment model is developed, integrating load rate improvement after interconnection and geographical connection costs, enabling the ranking and selection of candidate transformer area combinations. On this basis, a flexible interconnection system optimization configuration model is established, aiming to minimize the overall system cost, and collaboratively optimizing converter and energy storage capacities. A case study of 20 distribution transformer areas in a certain city shows that the optimal transformer area combination increases the load factor from 64.6% to 79.4%, an improvement of 22.9%; when considering energy storage configuration, the total economic cost of the interconnection system is reduced by approximately 20.2% compared to the independent operation mode. The results validate the effectiveness of the proposed method in improving equipment utilization and reducing the system’s total lifecycle cost, providing decision support for flexible planning of urban distribution networks. Full article

The future growth of alkali metal-based batteries requires an understanding of how ion size affects the exchange mechanisms. In this work, we present a direct, comparative electrochemical study of MXene-based electrodes mechanism vs. lithium (Li⁺), sodium (Na⁺), and potassium (K⁺) ions using the same electrochemical conditions. This controlled method enables an extensive investigation of the size-dependent interactions between the MXene structure and alkali metal ions. X-ray photoelectron spectroscopy and Raman analysis of TMAOH-treated Ti₃C₂T_x MXene electrodes show that delamination and cycling alter vibrational modes and the surface chemistry. Voltage profile study reveals diverse storage behaviors: Li⁺ has a prominent intercalation plateau, Na⁺ shows intermediate properties, and K⁺ displays sloping profiles, indicating surface-dominated adsorption. The significant correlation between ionic radius and electrochemical reversibility is shown by long-term cycling data over 300 cycles, which show greater capacity retention and stability for Li⁺ and progressively lower performance for Na⁺ and K⁺. These findings provide new mechanistic insights into MXene–ion interactions and build the foundation for developing MXene-based materials for specific alkali-ion chemistries in next-generation energy storage devices. Full article

Organizations usually rely on stringent access control mechanisms where access policies are an important asset. Their storage or transmission in plaintext can compromise sensitive access rules. It is important in dynamic environments where access decisions are made in real time such as Zero Trust (ZT). Existing ZT approaches were found to oversee the aspect of securing these policies. This investigation presents a Multi-layer Access Policy Encryption System for ZT systems (MAPE-ZT). The first stage uses the trapdoor index to generate a secure index to find the applicable access policies. Advanced Encryption Standard-256 is used in counter mode for the encryption of the policies. They are re-encrypted using the Ciphertext-Policy Attribute-Based Encryption (CP-ABE) to allow decryption based on a matching set of attributes. Various experiments using quantitative metrics, including comparison with baseline access control systems simulation, scalability evaluation, storage overhead, etc., highlight the efficacy of the MAPE-ZT and establish new benchmarks. The result count entropy for the policies ranged 3.84–4.21 for different scales of policies. The evaluation in different scales of systems shows that the MAPE-ZT reduces various observable patterns even if the deployment size grows. Its unique design of securing policies makes this approach scalable for multi-domain integration. Full article

To address the challenges associated with inter-module energy interaction and mode adjustment at load ports in distributed energy systems in the context of the energy transition, this paper proposes and designs a multi-port wireless energy interaction system based on LC series resonance and multi-coil magnetic coupling. The system aims to facilitate flexible energy interaction among power sources, energy storage units, and loads, as well as multi-modal port regulation. The system employs a multi-coil coupled full-bridge topology combined with a phase-shift control strategy to achieve energy exchange and power regulation among multiple ports. To meet the power demands of different ports, a port state control method incorporating a mode preset mechanism is proposed, enabling the intermediate port to switch seamlessly among input (source), output (load), and active relay modes. This paper analyzes the operating modes of a single port and establishes the dynamic mathematical model of the overall three-coil system as well as the small-signal model of the port output. Furthermore, it investigates the energy interaction mechanism to derive the operating characteristics and conditions under different modes, and elucidates the energy relay mechanism with zero active power consumption. A three-port hardware experimental platform was constructed based on a dsPIC33 controller. Experimental results indicate that: (1) the prototype achieved a maximum transmission power of 100 W; (2) the peak system efficiency reached $83.1\%$ under different load conditions; and (3) during mode switching, the system response time was less than 200 ms with no significant overshoot. The study demonstrates that the proposed topology and control strategy effectively realized dynamic energy interaction and seamless mode switching among multiple ports, providing a theoretical basis and engineering reference for multi-port energy interaction and wireless power transfer networks. Full article

Rural households in cold regions still rely heavily on coal for cooking and domestic hot water, while single renewable energy sources suffer from intermittency and limited system-level assessment. This study proposes a solar–biogas complementary energy supply system integrating evacuated-tube solar collectors, an above-ground anaerobic digester, thermal storage, and biogas utilization for rural residential applications in Minqin, Northwest China. A dynamic system-wide model was developed by coupling TRNSYS with nonlinear representations of anaerobic fermentation and biogas boilers, enabling hour-by-hour simulation of energy production, conversion, storage, and consumption. Field measurements were used for validation, and the root mean square deviation between simulated and measured temperatures and gas production remained below 10%. During the heating season, the solar subsystem supplied 10% of the digester heating demand and 90% of the domestic hot-water load, while the biogas subsystem contributed 9.29% and 90.71%, respectively. The system delivered 4728.96 MJ of heat against a seasonal demand of 4636.22 MJ, fully meeting user requirements. A comprehensive 3E (energy–environment–economic) assessment shows that, compared with traditional rural energy supply modes, the proposed system reduces CO₂ and NOx emissions by 65.85% and 98.13%, respectively, and demonstrates favorable economics with a benefit–cost ratio of 2.41 and a discounted payback period of 3.27 years. The proposed modeling and evaluation framework provides a replicable solution for clean energy substitution and circular waste utilization in rural areas. Full article

In the big-data-driven artificial intelligence era, similarity search, as a core operation in machine learning and data mining, demands high speed, energy efficiency, and scenario adaptability. Conventional electronic content-addressable memory (ECAMs) suffer from inherent RC delay bottlenecks, whereas existing optical content-addressable memory (OCAMs) are restricted by fixed bit-widths and limited distance metrics. In this work, we propose a variable bit-width all-optical CAM leveraging multi-segment modulators and phase-change material (PCM) Sb₂Se₃. The multi-segment memory unit (MSMU) therein compresses N-bit binary data into a single analog photonic unit, supporting direct data writing/loading without digital-to-analog converters (DACs) and flexible trade-offs between precision, storage capacity, noise immunity, and energy while enabling Hamming and nonlinear distance metrics. A six-element three-bit OCAM prototype was fabricated on a silicon nitride silicon-on-insulator (SiN-SOI) platform. Despite the absence of integrated high-speed phase shifters, the device still achieves reliable optical data storage and retrieval. K-nearest neighbor (kNN) simulations based on experimentally derived statistical data—validated on the iris, wine, and breast cancer datasets—show that the three-bit operating mode achieves classification accuracy comparable to Manhattan/Euclidean distances at high signal-to-noise ratios (SNRs), while the one-bit mode exhibits strong noise robustness. Energy consumption is 364 fJ/bit (3-bit) and 890 fJ/bit (1-bit). This work provides a high-speed, energy-efficient, and reconfigurable all-optical similarity search solution with experimentally verified device performance and dataset-validated applicability, showing great potential for widespread deployment in data-intensive machine learning and data-mining applications. Full article

Bidirectional Interleaved Converters (BICs) are widely used in Battery Energy Storage Systems (BESSs) due to their modular structure, high efficiency, and reduced current ripple. However, under partial-load operation, conventional control strategies with fixed or purely current-based phase shedding repeatedly activate the same converter branches, resulting in increased switching losses, thermal imbalance, and uneven aging of power semiconductors. This paper proposes a temperature-adaptive control strategy for BICs aimed at improving light-load efficiency while actively balancing thermal stress between converter branches. The approach combines a current-adaptive phase-shedding algorithm with a temperature-based branch rotation mechanism, where real-time transistor junction temperature is used as the primary decision variable for branch activation and deactivation. An electro-thermal real-time simulation model of a two-branch BIC is developed using the Controller Hardware-in-the-Loop (CHIL) methodology in the Typhoon HIL environment. The proposed control strategy is validated through real-time CHIL experiments in both boost and buck operating modes under representative battery load profiles. The results demonstrate a reduction in average and peak transistor junction temperatures, improved thermal distribution between converter branches, and more uniform branch utilization, while preserving stable current regulation and power flow. The presented method represents a practical extension of conventional phase-shedding techniques and provides an implementation solution for improving efficiency and reliability of BICs in BESS applications. Full article

Ensuring product integrity across Malaysia’s East Malaysian states (Sabah and Sarawak) requires a cold chain that is resilient to tropical heat, long multimodal routes, intermittent power, and dispersed rural populations. This paper proposes a sustainability-first architecture for vaccine and blood component logistics that combines World Health Organization and the United Nations International Children’s Emergency Fund Effective Vaccine Management (EVM 2.0) criteria with energy-aware transport planning, solar-hybrid edge refrigeration, phase-change materials, and digital temperature monitoring compliant with ISO 23412 for temperature-controlled delivery services. In this study, a mixed-methods methodology was employed, including (1) route and mode optimization under temperature risk and carbon intensity constraints; (2) equipment right-sizing using duty-cycle energy models and IEC 60068 environmental tests as design baselines; (3) governance with real-time earned value management (EVM) and key performance indicators (KPIs); and (4) scenario analysis for riverine, road, air, and drone last-mile segments relevant to remote East Malaysian communities. Results from realistic logistic scenarios indicate a 45–65% reduction in dose-weighted temperature-excursion minutes, 28–41% reduction in CO₂e per successful dose delivered, and 35–52% reduction in product loss compared with status quo planning. For blood components, solar-hybrid storage and mixed-mode routing reduced breach risk by 37% while maintaining red cells (2–6 °C), platelets (20–24 °C, continuous agitation surrogate), and fresh frozen plasma (≤−18 °C) requirements aligned with WHO guidance and Malaysia’s national transfusion policies. We provide a reference architecture, implementation bill of materials, and an EVM-aligned KPI dashboard to guide scale-up. Full article

In this paper, a fault diagnosis and location method for internal short circuit faults of transformer winding in pumped storage power stations based on recurrent surge oscillography is proposed, and the comprehensive performance of three injection pulses of square wave, lightning pulse and sine pulse is compared. Firstly, the winding structure of the pumped storage transformer is analyzed, and a pulse injection scheme suitable for its structural characteristics is proposed. On this basis, the wave process and response characteristics of the injected pulse under inter-turn and inter-phase short circuit faults are analyzed, and a fault diagnosis scheme is proposed. Furthermore, the improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) and the novel Teager energy operator (NTEO) are used to obtain the time taken by the injection pulse to reach the fault point, and the precise location of the fault coil is realized by combining the traveling wave theory. Finally, the simulation results show the effectiveness of the proposed fault diagnosis and location method. At the same time, the comparative analysis shows that the comprehensive performance of the square wave pulse is the best. Full article

This paper presents a patented design of a gravity flow rack with an energy recovery system, intended for pallet storage in first-in–first-out (FIFO) and last-in–first-out (LIFO) modes. Compared with conventional flow racks, the proposed solution integrates control of load-unit motion dynamics with energy recovery, thereby reducing losses and stabilising pallet flow. A Rack Energy Performance Index (REPI) is proposed to enable quantitative assessment of the energy consumption of storage racks in intralogistics applications. The research methodology comprised: (i) development of the mechanical architecture and pallet guidance principles; (ii) numerical modelling in the MSC Adams environment at Technology Readiness Level 3 (TRL-3); and (iii) validation using a full-scale prototype installed in a logistics centre. Operational tests confirmed stable operation, the required throughput, and the capability for energy compensation and recovery during storage cycles. The results indicate that energy-recovering racks can support the design of energetically passive warehouses. Full article