Reliable Storage Research Articles

Innovative Approaches to Bridging Energy Supply and Demand Gaps Through Thermal Energy Storage: A Case Study

This study investigates innovative solutions for balancing energy supply and demand using long-term thermal energy storage (TES) systems, with a focus on tank thermal energy storage (TTES) for European buildings, which account for approximately 40% of energy consumption in the European Union. Research conducted at the Technical University of Košice explores the potential of TTES systems for efficient and long-term energy storage. The accumulation is carried out in three existing underground tanks of different volumes. Among various outputs, we present the cooling process resulting from covering the water surface and the effect of tank size on cooling. The findings indicate that covering the water surface in the tanks can effectively double the energy retention time, thereby extending the cooling period. A tank with a larger volume cools slower and better ensures the formation of temperature layers. Temperature layering allows for better utilization of the tanks’ potential in terms of energy. The overall result is a significant reduction in heat losses and CO₂ emissions. These results demonstrate the critical role of TTES in stabilizing renewable energy sources, especially solar energy, to support sustainable energy solutions in buildings by providing reliable and long-term energy storage.

Recent Advances in Lithium Iron Phosphate Battery Technology: A Comprehensive Review

Lithium iron phosphate (LFP) batteries have emerged as one of the most promising energy storage solutions due to their high safety, long cycle life, and environmental friendliness. In recent years, significant progress has been made in enhancing the performance and expanding the applications of LFP batteries through innovative materials design, electrode engineering, and manufacturing techniques. This review paper provides a comprehensive overview of the recent advances in LFP battery technology, covering key developments in materials synthesis, electrode architectures, electrolytes, cell design, and system integration. This review paper aims to provide a comprehensive overview of the recent advances in lithium iron phosphate (LFP) battery technology, encompassing materials development, electrode engineering, electrolytes, cell design, and applications. By highlighting the latest research findings and technological innovations, this paper seeks to contribute to the continued advancement and widespread adoption of LFP batteries as sustainable and reliable energy storage solutions for various applications. We also discuss the current challenges and future prospects for LFP batteries, emphasizing their potential role in sustainable energy storage solutions for various applications, including electric vehicles, renewable energy integration, and grid-scale energy storage.

Efficient Traceability Systems with Smart Contracts: Balancing On-Chain and Off-Chain Data Storage for Enhanced Scalability and Privacy

The growing importance of traceability in supply chains requires robust, transparent, and efficient systems to ensure the integrity and authenticity of product journeys. This paper presents a comprehensive characterisation and data model for a generic blockchain-based traceability system, highlighting its implementation using smart contracts on Ethereum-compatible networks, as the Ethereum Virtual Machine (EVM), with its pioneering implementation of smart contracts and its extensive ecosystem; it provides a robust environment for developing decentralised applications. We discuss the advantages of using blockchain technology to notarise traceability activities, ensuring immutability and transparency by exploring two main scenarios, namely one where hash keys (i.e, cryptographic digests) are stored on-chain while detailed data remain off-chain, and another where all traceability data are fully stored on-chain. Each approach is evaluated for its impact on scalability, privacy, storage efficiency, and operational costs. The hash key method offers significant advantages in reducing blockchain storage costs, enhancing privacy, and maintaining data integrity, but it depends on reliable off-chain storage. Conversely, the full on-chain approach guarantees data immutability but at a higher cost and lower scalability. By combining these strategies, a balanced solution can be achieved, leveraging the strengths of both methods to provide a reliable, efficient, and secure blockchain-based traceability system, which is illustrated with a practical implementation to support traceability in the timber sector in Galicia, Spain. This paper aims to provide valuable insights for researchers and practitioners looking to implement or enhance traceability systems using blockchain technology, demonstrating how smart contracts can be effectively utilised to meet the demanding requirements of modern supply chains.

Multi scale systematisation of damage and failure modes of high-pressure hydrogen composite vessels in aviation, Part 1: Methodology

In the development of composite Compressed Gaseous Hydrogen (CGH2) storage vessels the multitude of design, material and manufacturing parameters introduce uncertainties. In addition with complex interacting failure modes such as delamination, matrix and fibre failure high safety margins are needed.The aim of this paper is to enable the decrease of safety margins by developing a fundamental methodology to systematise superimposed loads and their propagation across length scales and load domains to enable the reliability assessment and development of CGH2 vessels in aircraft with high reliability and maximum gravimetric storage density. Therefore, the objectives are to analyse existing development strategies, to derive requirements for a new development approach and to define its underlying logic and procedure. This results in a methodology to systematise potentially occurring load cases, corresponding stresses and resulting failure modes of CGH2 vessels in aircraft along the length scales from the aircraft super-system to the material level.

A Case Study on Integrating an Eco-Design Tool into the Construction Decision-Making Process

To enhance the sustainability of construction and meet the sector’s environmental agenda, it is essential to comprehensively scrutinize the environmental, social, and economic impacts of construction projects from the project’s design stage. Such assessment is of utmost importance to minimize the impacts of both new construction and rehabilitation projects and is particularly critical during the selection of building materials and construction solutions. This work reports improvements in functionality and user-friendliness of an eco-design tool (UAveiroGreenBuilding) targeting the construction/rehabilitation sector and previously developed within our research group. The optimized version of the eco-design tool underwent validation through the assessment of competitive window frame materials (e.g., wood, PVC, and aluminum) for potential implementation in a rehabilitation project. Windows with PVC frames were identified as the preferred window configuration due to their superior environmental performance and favorable economic profile. Additionally, a digital communication interface was developed to connect the eco-design tool with building information modeling (BIM) projects, achieved through a routine integrated using a Dynamo application. Such successful integration not only streamlined and expedited the data transfer process by obviating the need for manual input but it also enabled the storage of environmental data throughout the life cycle of the project using a simple and reliable data storage protocol.

Information and computing system based on smart contracts for online voting

The purpose of research.The actual problem in voting systems is not the prevention of fraud and the failure to ensure the integrity of elections. Therefore, the task of building a system of safe and transparent voting is urgent.The purpose of the research is design and develop an information and computing system based on smart contacts for online voting.Methods. The presented system has the form of a decentralized system that can overcome a number of limitations, such as the likelihood of human error, falsification of voting results and problems with accessibility, using blockchain technology, which provides protection against unauthorized access and transparent record keeping.The use of smart contract technology also ensures that the voting process will be automated, transparent and secure. Thanks to the ability to execute self-executing contracts based on predefined rules, smart contracts can eliminate the need for intermediaries, reduce the likelihood of errors and ensure a high degree of accountability.Results. In order to evaluate the effectiveness of the developed system, testing was carried out, after which a comparative analysis was made with other similar systems.The system can ensure that votes are counted accurately and cannot be manipulated, thereby increasing confidence in the results of the voting process. In addition, the system can potentially reduce the costs associated with traditional voting methods and improve accessibility for voters, since it can be accessed remotely via a web interface.In general, the system will be of interest to various organizations and individuals seeking to conduct safe and transparent voting processes.Conclusion. The use of this software product will provide security and convenience when participating in various online voting, reliable storage of votes and the provision of detailed statistics on the conducted voting.

QLTI-09. CLINICAL TRIALS IN NEURO-ONCOLOGY: DESIGN, LOGISTICS, CHALLENGES, AND PRACTICAL CONSIDERATIONS

Abstract Timely, secure and reliable transportation, precise handling and storage of biological specimens are critical for the success of clinical research. Research in neuro-oncology often involves complex assays such as next-generation sequencing where the integrityof brain tumor specimens is paramount. These challenges are pronounced in most Lower Middle-Income Countries (LMIC), due to climatic factors and infrastructure limitations, necessitating stringent measures to preserve sample quality and their genetic data integrity for downstream analysis. In this study, we conducted extensive cohort analysis on 80 tissues randomly picked samples of the 3600 samples collected across India to assess the impact of collection protocols, transportation logistics, and long-term storage on the genetic material of tissues. The quality and quantity of the isolated nucleic acids was determined by BioAnalyzer and Qubit parameters. Tissue samples were collected and stored at -80°C in RNAstable® within 4-12 hrs of collection. The DNA and RNA obtained from tissue samples stored for over one year was found to be of good quality with corresponding DNA Integrity Number (DIN) and RNA Integrity Number (RIN)between 7-9. Also, optimum quantity of DNA and RNA was obtained for whole exome and transcriptome sequencing. Upon sequencing, these samples showed good read coverage of 100X or more. These findings provide critical insights into the measures necessary for optimizing sample preservation and transportation to ensure accurate research outcomes. The results indicate that appropriate sample collection, transportation, and long-term storage of bio-specimens can be used effectively for future research. Additionally, the outcome underscores the potential for long-term studies in neuro-oncology using archived biological samples without compromising data integrity.

Possible structures of skyrmion states in chiral ferromagnetic films with spatially modulated uniaxial anisotropy.

In this paper, the stabilization conditions, structure, and properties of possible vortex-like inhomogeneities, including kπ-skyrmions k = 0, 1, 2, 3, 4, in a uniaxial multilayer disk with a columnar defect in the center are investigated based on micromagnetic modeling. Their stability diagrams depending on the Dzyaloshinskii-Moriya interaction, the magnitude of magnetic anisotropy and the defect parameters are determined. New types of vortex-like inhomogeneities that can arise in such samples are found. The obtained data can be used to create artificial regions of nucleation, capture and pinning of magnetic skyrmions, which can provide greater reliability of data storage in spintronic logical devices.&#xD.

A DFT Study of Band-Gap Tuning in 2D Black Phosphorus via Li+, Na+, Mg2+, and Ca2+ Ions.

Black phosphorus (BP) and its two-dimensional derivative (2D-BP) have garnered significant attention as promising anode materials for electrochemical energy storage devices, including next-generation fast-charging batteries. However, the interactions between BP and light metal ions, as well as how these interactions influence BP's electronic properties, remain poorly understood. Here, we employed density functional theory (DFT) to investigate the effects of monovalent (Li+ and Na+) and divalent (Mg2+ and Ca2+) ions on the valence electronic structure of 2D-BP. Molecular orbital analysis revealed that the adsorption of divalent cations can significantly reduce the band gap, suggesting an enhancement in charge transfer rates. In contrast, the adsorption of monovalent cations had minimal impact on the band gap, suggesting the preservation of 2D-BP's intrinsic electrical properties. Energetic and charge analyses indicated that the extent of charge transfer primarily governs the ability of ions to modulate 2D-BP's electronic structure, especially under high-pressure conditions where ions are in close proximity to the 2D-BP surface. Moreover, charge polarization calculations revealed that, compared with monovalent cations, divalent cations induced greater polarization, disrupting the symmetry of the pristine 2D-BP and further influencing its electronic characteristics. These findings provide a molecular-level understanding of how ion interactions influence 2D-BP's electronic properties during ion-intercalation processes, where ions are in close proximity to the 2D-BP surface. Moreover, the calculated diffusion barrier results revealed the potential of 2D-BP as an effective anode material for lithium-ion, sodium-ion, and magnesium-ion batteries, though its performance may be limited for calcium-ion batteries. By extending our understanding of interactions between ions and 2D-BP, this work contributes to the design of efficient and reliable energy storage technologies, particularly for the next-generation fast-charging batteries.

Leveraging lithium-ion batteries for decarbonization in the oil and gas industry

The oil and gas industry is undergoing a significant transformation as it seeks to reduce its carbon footprint and transition towards more sustainable energy practices. Lithium-ion (Li-ion) batteries are playing a crucial role in this energy transition, providing reliable energy storage solutions that enhance operational efficiency, enable the integration of renewable energy sources, and reduce greenhouse gas emissions. This paper explores the application of Li-ion batteries in the oil and gas industry, presenting a life cycle analysis (LCA) methodology to evaluate their environmental impact, defining a system boundary, and offering examples of how these batteries facilitate decarbonization and the energy transition.

Computational Exploration of Adsorption-Based Hydrogen Storage in Mg-Alkoxide Functionalized Covalent-Organic Frameworks (COFs): Force-Field and Machine Learning Models.

Hydrogen is a clean-burning fuel that can be converted to other forms. of energy without generating any greenhouse gases. Currently, hydrogen is stored either by compression to high pressure (>700 bar) or cryogenic cooling to liquid form (<23 K). Therefore, it is essential to develop safe, reliable, and energy-efficient storage technology that can store hydrogen at lower pressures and temperatures. In this work, we systematically designed 2902 Mg-alkoxide-functionalized covalent-organic frameworks (COFs) and performed high-throughput (HT) computational screening for hydrogen storage applications at 111, 231, and 296 K. To accurately model the interaction between Mg-alkoxide sites and molecular hydrogen, we performed MP2 calculations to compute the hydrogen binding energy for different types of functionalized models, and the data were subsequently used to fit modified-Morse force field (FF) parameters. Using the developed FF models, we conducted HT grand canonical Monte Carlo (GCMC) simulations to compute hydrogen uptakes for both original and functionalized COFs. The generated data were subsequently used to evaluate the materials' gravimetric and volumetric storage performance at various temperatures (111, 231, and 296 K). Finally, we developed machine learning (ML) models to predict the hydrogen storage performance of functionalized structures based on the features of the original structures. The developed model showed excellent performance with a mean absolute error (MAE) of 0.061 wt % and 0.456 g/L for predicting the gravimetric and volumetric deliverable capacities, enabling a quick evaluation of structures in a hypothetical COF database. The screening results demonstrated that the Mg-alkoxide functionalization yields greater improvements in volumetric H2 storage capacities for COFs with smaller pores compared to those with larger (mesoporous) pores.

Developing a trustworthy national health data space: public needs and policy implications

Abstract Background The ongoing development of a national health data space in Switzerland presents an opportunity to transform health delivery and care by enabling large-scale secondary health research. Central to this development is the Health2030 strategy, which calls for the establishment of public trust in the reliability and security of data collection, storage, and exchange. Methods We conducted four focus groups across the German, French and Italian-speaking regions of Switzerland to inform the development of the Swiss health data space that fosters public trust. To inform Swiss policy, we held a panel discussion with patient experts and healthcare professionals to translate the focus group findings into governance and public communication requirements. We synthesized our findings using a thematic analysis approach and proposed a guiding health policy strategy. Results Citizens perceive the health data space as trustworthy conditional on the delivery of its promised higher levels of transparency, security, and lower risk compared to other data sharing initiatives. To ensure its trustworthiness, citizens call for the provision of value-based consent to control data access based on the actors involved and research purposes, alongside implementing accountability measures for data misuse. Governance framework requirements entail establishing an advisory group for the health data space with sufficient representation of the Swiss population, including members of the public, patient advisory groups, and researchers. Public communication requirements call for ongoing monitoring of public opinion on health data space, alongside establishing public engagement initiatives, such as public fora, to inform ongoing progress. Conclusions Policy efforts should prioritize the meaningful involvement of relevant stakeholders throughout all stages of the health data space development to foster trust. Central to these efforts is balancing public expectations with their practical implementation. Key messages • For the health data space to be trustworthy, citizens require transparency on their data use and the security measures taken, value-based consent for data access, and accountability measures. • Diverse representation in governance and continuous public involvement are key policy measures to build public trust in the development of national health data spaces.

Design of reliable standalone utility-scale pumped hydroelectric storage powered by PV/Wind hybrid renewable system

With a target of 35 % renewable energy in the country’s energy mix by 2030, the goal of this research is to support the Libyan government’s plan to maximize the use of environmentally friendly and sustainable energy sources. This will be accomplished by making effective use of the region’s plentiful natural resources. The feasibility of wind and solar energy has been established by local research, and the presence of highlands that can store pumped hydropower (PHS) makes hybrid renewable energy systems (HRES) even more feasible. These systems might offer a sizable edge over competitors in the regional energy market. In this study, PHS was utilized to stabilize electricity production in addition to storing energy. A hydropower turbine provides electricity to the load, and the PHS system is powered by a PV/wind supply. By lowering the volatility of wind and photovoltaic power generation, the suggested system could offer a more dependable renewable energy source without requiring complicated control mechanisms. This strategy could encourage a wider adoption of renewable energy, which could be especially advantageous for developing nations. Under particular load and climate conditions, the energy production of different solar PV array and wind turbine farm configurations was estimated using the System Advisor Model (SAM) software. The ideal HRES configuration consists of a 290 MW wind farm, a 154 MW solar PV field, and a 508 MW PHS system. This configuration will provide 100 % of the annual electrical demand of 513 GWh, plus a 20 % safety margin. The levelized cost of energy (LCOE), estimated at $211.65/MWh, is reduced by this configuration. It is anticipated that the $929.02 million initial investment will be recovered in 11 years, and the system will turn a profit in the following 9 years. Also, the planned HRES will stop 532.17 tons of CO2 emissions from being released each year.

Graphene wrapped porous polyaniline/manganese oxide nanocomposites with enhanced structural stability and conductivity for high‐performance symmetric supercapacitor

AbstractManganese oxides have emerged as promising electrode materials for supercapacitors. Despite extensive efforts to improve their conductivity and structural stability through various manganese oxide/conductor nanocomposites, achieving efficient and reliable energy storage electrode materials has remained challenging. In this study, we propose a meticulous “dual enhancement” strategy, where three‐dimensional (3D) nanostructured polyaniline/manganese oxide composites (PM) are synthesized via an in situ method and further integrated with graphene wrapping to form polyaniline/manganese oxide/graphene nanocomposites (PMG). Electrochemical characterization reveals that PMG exhibits a remarkable specific capacitance of up to 403 F g−1 (at 1 A g−1), with a favorable capacitance retention of 80.2% after 5000 cycles, along with a wide potential window. This enhancement is attributed to the synergistic effects of polyaniline, which provides a supportive framework and electron transport pathways, and graphene, which offers external protection and enhances conductivity pathways. Assembled symmetrical supercapacitors demonstrate outstanding energy density (32.7–23.3 Wh kg−1) and power density (720–4500 W kg−1) at a high operating voltage of 1.8 V, surpassing the performance of many reported high‐performance supercapacitors. This study provides valuable insights for advancing manganese oxide electrode materials and is expected to catalyze their widespread adoption in energy storage applications.Highlights “Dual enhancement” is implemented by PANI supporting and rGO wrapping. The conductivity and structural stability of composite electrode is greatly enhanced. Improved capacitance (403 F g−1, 1 A g−1) and cycling stability (80.2%) is achieved. The symmetrical supercapacitor has high voltage and energy density (32.7 Wh kg−1).

Performance of Small-Scale Hermetic Storage Systems Under Periodic Access

This study characterizes the grain management performance of a novel integrated grain drying and storage system (iGDSS) adapted from 208 L drums to combat postharvest loss in developing countries through providing in situ mechanized drying and hermetic storage. The six-month storage trials of 14% moisture content maize compared different access mechanisms and two levels of pest pressure: 0 and 10 maize weevils/kg grain. This experiment allowed comparisons of differential oxygen consumption rates in small-scale hermetic systems with and without storage pests, which has not been widely reported in the literature. The iGDSS system was found to maintain grain quality parameters in dry grains with and without storage pests. After six months of storage, the results demonstrated no statistically significant difference in the moisture content, test weight, germination, proportion of broken and damaged kernels, and presence of colony-forming units between inoculated and non-inoculated systems. The iGDSS was also found to maintain oxygen intrusion rates of 0.10–0.13% O2/day, below recommended thresholds of 0.15% required to maintain benefits of modified atmosphere storage. These results indicate that the iGDSS can provide safe and reliable grain storage to smallholder farmers in developing countries, and that the drying functions of iGDSS can promote outcomes in hermetic storage.

Transition-metal-based hydrides for efficient hydrogen storage and their multiple bond analysis: A first-principles calculation

Hydrogen energy plays a growing role in the present energy market and attracts more attention in scientific researches and commercial application. Hydrogen energy has an increasing attractive in energy market due to its high energy density, pollution-free utilization usage and wide availability. Current challenge which obstructs large-scale application is safe and reliable hydrogen storage, which requires finding promising materials to promote hydrogen energy. Therefore, we have predicted three potential lithium-transition metal-based hydrides LiTM3LiH8 (TM = Sc, Ti V) for hydrogen storage based on first principles calculation. The stability analysis based on formation energy, elastic constants and phonon spectra confirms all hydrides are stable and feasible in practical application. Besides, they have a increasing ductility in the order of Sc, Ti and V. Among all studied materials, LiV3LiH8 has the best mechanical characteristics due to its excellent ductility and high Young's modulus (123.19 GPa), which are beneficial for resistance to adverse external surroundings. The electronic properties suggest that all hydrides metallic in band structures. Meanwhile, we analyzed how hydrogen was storage and the binding information from multiple perspectives, including the charge analysis, DOS, ELF and COHP. From multiple analyses of bond strengths, except the strong binding from transition metal, the centered Li atom is verified to possess greater influence than corner Li atom, which makes a viable regulation of hydrogen properties by substituting centered alkali metal atom in future. As concluded in this study, LiTi3LiH8 has a high storage capacity of 4.83 wt% along with a desorption temperature of 305.5 K, which is considered as a promising hydrogen storage material.

«ОПТИКА» БӨЛІМІ БОЙЫНША ЭЛЕКТРОНДЫҚ ОҚУЛЫҚТАРДЫҢ ЗАМАНУИ БІЛІМ БЕРУ ҚҰРАЛЫ РЕТІНДЕ РӨЛІ

The article examines the effectiveness and role of the use of electronic textbooks in the education system. And, including in the section «Optics», optical phenomena and patterns are taken as a basis. The creation of electronic textbooks is one of the most pressing problems of the educational process today. The expansion of the use of modern information technologies has led to the need to develop electronic learning tools that increase the effectiveness of self-learning and the quality of learning for students. The use of electronic means in the learning process is effective for both the teacher and the student. The use of electronic learning tools in the educational process does not contradict the traditional teaching method, but rather complements the use of its achievements. Comparison parameters are also considered: page and rotation; reader's movement through the book; plane and depth; book block; personal appearance of the book; text; illustration; tactile sensations; reliability of information storage and accessible information update; one can say about the pros and cons of this and other types of books. The advantages of an electronic textbook in terms of printing are accompanied only by sound effects associated with its large information capacity and ease of use. With all the convenience of the e-book format, the reader may want to see it directly on the site if he does not want to download it, or, as in a bookstore, first view the publication and then decide whether to download it or not. The main disadvantages of the electronic textbook are due to its loss of personal artistic appearance. Currently, there are many tools for creating electronic textbooks. For example, the possibilities of the program SunRav BookEditor, SunRav BookReader, TurboSite, Flipsnack, EdApp, Canva, etc. are considered. In the article, we will define the role of analyzing the digital literacy of students using an electronic textbook. Examples of electronic forms of a physics textbook for grades 7-9 can be given.

A deep reinforcement learning approach towards distributed Function as a Service (FaaS) based edge application orchestration in cloud-edge continuum

Serverless computing has emerged as a new cloud computing model which in contrast to IoT offers unlimited and scalable access to resources. This paradigm improves resource utilization, cost, scalability and resource management specifically in terms of irregular incoming traffic. While cloud computing has been known as a reliable computing and storage solution to host IoT applications, it is not suitable for bandwidth limited, real time and secure applications. Therefore, shifting the resources of the cloud-edge continuum towards the edge can mitigate these limitations. In serverless architecture, applications implemented as Function as a Service (FaaS), include a set of chained event-driven microservices which have to be assigned to available instances. IoT microservices orchestration is still a challenging issue in serverless computing architecture due to IoT dynamic, heterogeneous and large-scale environment with limited resources. The integration of FaaS and distributed Deep Reinforcement Learning (DRL) can transform serverless computing by improving microservice execution effectiveness and optimizing real-time application orchestration. This combination improves scalability and adaptability across the edge-cloud continuum. In this paper, we present a novel Deep Reinforcement Learning (DRL) based microservice orchestration approach for the serverless edge-cloud continuum to minimize resource utilization and delay. This approach, unlike existing methods, is distributed and requires a minimum subset of realistic data in each interval to find optimal compositions in the proposed edge serverless architecture and is thus suitable for IoT environment. Experiments conducted using a number of real-world scenarios demonstrate improvement of the number of successfully composed applications by 18%, respectively, compared to state-of-the art methods including Load Balance, Shortest Path algorithms.

Preparation and investigation of structural, optical, and dielectric properties of PVA/PVP blend films boosted by MWCNTs/AuNPs for dielectric capacitor applications

With the rising global energy demands, there is a pressing need for the invention of efficient and reliable energy storage systems. This research centers on the creation and analysis of flexible dielectric capacitors composed of polymer nanocomposites (PNCs), incorporating a blend of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) as the base polymer, with multi-walled carbon nanotubes (MWCNTs) and gold nanoparticles (AuNPs) serving as nanofillers. The AuNPs were produced through an environmentally friendly synthesis method. Films made from PVA/PVP blended with MWCNTs and AuNPs were fabricated using the casting approach. Various characterization methods, including TEM, XRD, FTIR, and UV–Vis spectroscopy, were utilized to evaluate the samples. A detailed analysis of their electrical/dielectric characteristics was conducted. XRD analysis revealed a significant decrease in crystallinity from 55% for the pure PVA/PVP blend to 37% for the 1.6 wt% nanofiller composite, indicating increased amorphous content, which facilitates better ion mobility. FTIR confirmed strong interactions between the polymer matrix and nanofillers, with intensified vibrational peaks pointing to enhanced molecular dynamics. UV–Vis spectroscopy demonstrated a red shift in the absorption edge, and Tauc plot analysis showed a reduction in the indirect/direct optical band gap from 4.84 eV/5.68 eV for the pure blend to 4.26/5.35 eV for the nanocomposite with 1.6 wt% nanofillers. The addition of nanofillers resulted in improvements in their dielectric features, which exhibited a significant performance improvement, with the dielectric constant (ε′) reaching approximately 1100 at low frequency for the 1.6 wt% nanofiller sample, compared to 9 for the pure blend. Additionally, the dielectric loss (ε'') and tangent loss (tan δ) were reduced, with tan δ showing a decrease from 15 for the pure blend to 2 for the 1.6 wt% nanofiller composite at low frequency, indicating enhanced dielectric efficiency and reduced energy dissipation. The capacitors' functionality was assessed through capacitance-frequency and conductance-frequency analyses. The capacitors exhibited stable high capacitance across a broad frequency spectrum, making them alternatives for energy storage solutions.

Virtual energy dispatching method for hybrid microgrid demand response based on Lyapunov optimization

Abstract The hybrid microgrid (HMG) possesses power generation, storage, and distribution capabilities, serving as an integrated foundational structure for advanced localized distribution networks. However, due to significant discrepancies in load demands and energy consumption among different users, the photovoltaic (PV) generation output and end-user load requirements exhibit unpredictability, resulting in relatively low self-sufficiency ratio (SSR) and self-consumption ratio (SCR) of the HMG PV system. To address this issue, this study proposes a virtual energy dispatching method for hybrid microgrid demand response based on Lyapunov optimization. Initially, a bidirectional virtual energy dispatching system model based on energy provider/buyer classification is constructed, optimizing load demands and energy management of both the load side and the main utility grid (MUG) while considering demand response. Subsequently, a Lyapunov optimization-based bidirectional virtual energy dispatching algorithm (LOBVED) is introduced, optimizing queueing systems in stochastic networks based on drift-plus-penalty technique to resolve the dynamic interactions among stability, performance, and energy self-sufficiency in the HMG environment, aiming to maximize the PV SSR and SCR of the HMG while ensuring the reliability of battery energy storage (BES) energy queues. Finally, the effectiveness of the proposed method is validated through MATLAB simulations.