Efficient Protection System Research Articles

Context-Aware Adaptive Encryption: Integrating Sensitive Data Detection and Network intrusion detection for Dynamic Data Security and Encryption

In today's digital landscape, ensuring the security of sensitive data and protecting against network intrusions are critical challenges. This research project develops and evaluates a novel context-aware adaptive encryption system that integrates sensitive data detection, network intrusion detection, and dynamic encryption techniques to enhance data security. The proposed system employs deep learning models to identify sensitive information and machine learning algorithms to monitor network activity for potential intrusions. Upon detecting sensitive data or a security threat, the system automatically applies encryption with adjustable strength based on the context, increasing protection in high-risk situations. This approach minimizes unnecessary overhead in low-risk scenarios while maintaining robust security measures. Through simulations using real-world data, the system's effectiveness in accurately detecting sensitive information and network intrusions, as well as its capability to adapt encryption dynamically, is evaluated. The results demonstrate the potential of combining machine learning with adaptive security measures to create a responsive and efficient data protection system.

Distribution System Survey and Analysis: A Case Study of Kathmandu University

Load flow analysis helps to understand a power system's voltage profile and power flow distribution, enabling the identification of potential issues such as overloading and under-voltage conditions. Fault analysis ensures reliability and safety by understanding and mitigating abnormal conditions in electrical distribution systems. Together, they contribute to efficient operation, equipment protection, and overall system reliability. This paper presents the Kathmandu University distribution system's load flow and fault analysis. Starting from the careful study of the power usage of the Kathmandu University distribution system then followed by the load flow analysis employed in the Dig Silent Power factory software, critical insights into the system’s performance were unveiled. Additionally, fault analysis within the simulated distribution system provides valuable data to enhance the understanding of the different patterns of currents for the various types of faults that occur at different locations of the Kathmandu University distribution system. This study provides a comprehensive understanding of the Kathmandu University distribution system. It identifies potential issues that can help to make the Kathmandu University power system more reliable and efficient in the future.

Efficient self-powered cathodic corrosion protection system based on multi-layer grid synergistic triboelectric nanogenerator and power management circuits

The last few years have seen a boom in the use of triboelectric nanogenerators (TENGs) for capturing wave energy in the ocean. This work reports a multi-layer grid synergistic triboelectric nanogenerator (MLGS-TENG). In this work, the independent layer triboelectric nanogenerator in the grid format is skillfully employed, and the design of the multi-layer parallel structure can effectively increase the capture rate of blue energy in the ocean. The shell of the triboelectric nanogenerator adopts a gyroscopic structure, which, when combined with its internal architecture, operates effectively on the surface of ocean waves. Moreover, it can be very effective in harvesting low-frequency wave energy in the ocean and converting it into mechanical energy, and then converting it into electrical energy through the friction of the internal self-assembly layer. In low-frequency mechanical tests, when the frequency is about 1 Hz and the load impedance is 400 MΩ, the peak power output of the generator in a single layer can reach 77 mW/m2. Given the excellent energy harvesting performance of MLGS-TENG, it is applied to build a high-efficiency cathodic corrosion protection system in conjunction with a buck rectifier circuit. This work is of great significance for the wide application of triboelectric nanogenerators in the marine environment and provides a feasible way to ensure the long-term stability of offshore platforms.

Dual-function fault current limiter for electric vehicles protections

ABSTRACT Electric vehicles (EVs) are becoming increasingly popular and the development of reliable and efficient protection systems for their DC systems has become a pressing issue. In response to this need, this paper proposes a novel Dual-Function Fault Current Limiter (DF-FCL) to protect EVs against fault currents. The DF-FCL is comprised of a DC reactor with a superconductive resistor that acts as a short circuit in normal and dynamic operational modes, and as a fault current limiter in fault operational mode. The unique advantage of this structure over existing protection systems is its low weight and negligible impedance in normal operational mode, combined with its ability to provide high impedance during a short circuit occurrence time using a simple superconductive resistor. In order to demonstrate the effectiveness of the proposed DF-FCL, MATLAB/Simulink software is used to model its performance, and a prototype is built to verify the simulation results. Overall, the proposed DF-FCL offers a promising solution for protecting EVs against fault currents.

Improving thermal insulation and fire resistance of ceramifiable EVA/ceramic hybrid composites via low temperature sintering and foaming strategy

Energy efficient buildings, propulsion components and thermal protection systems require materials with high thermal protective properties. Traditional polymer composites or ceramic materials have limited comprehensive applications because of their poor thermal protective properties or poor processability. Herein, a novel fire resistant and thermally insulating polymer/ceramic hybrid ceramifiable composite was developed based on low temperature sintering principle and foaming on fire strategy. Specifically, the influences of raw materials of low temperature ceramics, such as glass frit, phosphate, etc, on the properties of ceramifiable ethylene-vinyl acetate (EVA) composites were investigated. Its fire resistance and thermal insulation properties were evaluated by simulating different sintering environments. The results show that the ceramifiable composite exhibits the highest improvement in fire resistance because a crystalline phase was formed at high temperatures. Gas evolution from the thermal decomposition of ammonium polyphosphate (APP) and EVA contributes to the formation of the porous structure in ceramic residues. The optimal system can resist above 1000 °C flame for 30 min without disintegration, and the temperature of the unfired side was maintained around 200 °C. The reliability of the strategy was verified by the effective medium theory model.

Characteristics of wind-sand transportation along railways in the eastern fringe of the Taklimakan Desert and sand control system

Abstract This paper focuses on the Korla-Ruoqiang desert railway line, utilizing ERA5 (ERA5 is the fifth generation of ECMWF (European Centre for Medium-Range Weather Forecasts) atmospheric reanalysis global climate data) wind data to conduct a comprehensive analysis of the wind energy environment along the line in all aspects, reveals the characteristics of wind-sand transport, and puts forward the countermeasures to prevent and control wind-sand disasters. The results of the study indicate that: (1) the wind-sand along the line mainly occurs in the spring and summer seasons, and the dominant sand-moving directions are easterly (ENE, E and NNE) and northeasterly (NE). (2) The average annual sand-moving wind speed ranges from 5.80 m/s to 7.25 m/s, and the annual frequency of sand-moving ranges from 11.99% to 37.26%. (3) The annual sand drift potential (DP) along the line ranges from 69.20 VU to 607.24 VU, with three types of wind energy environments: low, medium and high. The resultant drift potential (RDP) ranges from 45.52 VU to 547.49 VU, and the wind variability index (RDP/DP) is between 0.54 and 0.90. (4) The average sand transport quantity along the line ranges from 2.92 m³/m/a to 9.09 m³/m/a. Based on these results, we optimize the sand blocking, sand fixing and wind erosion prevention measures for different types of wind-sand environments, establish a scientific and efficient wind-sand protection and control system to solve the wind-sand problems and provide a scientific foundation for the prevention and control of wind-sand disasters along the line.

An efficient ionic gelation based nano-delivery system to improve the stability and controlled release of saffron extracts

Saffron bioactive compounds possess exceptional nutritional and health properties. However, their industrial utilization has been limited due to challenges such as low solubility, poor bioavailability, untargeted release, and instability during processing and preparation. This study aimed to improve the delivery and stability of nano-sized saffron extracts as a rich antioxidant and anticancer agent via an ionic gelation-based approach. Efficient alcoholic and aqueous extracts of saffron loaded in chitosan-alginate nanoparticles (CANPs) were developed. Size and zeta potential of produced CANPs recorded in the range of 218–251 nm and 27.5–53.6 mV, respectively. The spherical CANPs showed high encapsulation efficiency. Also, AFM analysis depicted the distinct shape and uniform size distribution of prepared CANPs. The CANPs swelled in neutral solution, while in acidic conditions, it tended to shrink. The release profiles revealed that non-Fickian diffusion of encapsulants would be controlled by adjusting the pH. The encapsulation of saffron extracts within the CANPs significantly enhanced the storage stability. Both refrigerator and room temperatures in dark condition were detected suitable for the storage of saffron extracts loaded CANPs. Cytotoxicity test against MCF-7 cells demonstrated higher anticancer activity of the aqueous extract compared to the alcoholic extract loaded CANPs. Deionized water demonstrated more efficient performance for saffron extract preparation and biological functions in comparison to ethanolic extract. In brief, the CANPs could be introduced as an efficient protective delivery system for the rich bioactive compounds source, namely saffron extracts in functional food and pharmaceutical industries.

Investigation of Induced Overvoltages on DC Cables of PV System Subjected to Lightning Strikes Using FDTD Method

Due to installation of photovoltaic (PV) panels in outdoor areas, they are subjected to lightning strikes which may cause degradation or complete damage, resulting in service interruption and added cost. Hence, it is crucial to provide an efficient and effective lightning protection system which requires some considerations to increase its efficiency and reduce its cost. Any damage to the PV system inverter causes service interruption, so it is important to analyze the transient voltages induced on the dc cables connected to the inverter during lightning strikes. In this article, the induced voltages on dc cables are calculated using the finite difference time domain (FDTD) method, which introduces high accuracy in transient studies. Important factors affecting the transient voltages on dc cables are studied, including the effect of lightning strike polarity and changing the separation distance between the PV panel and the isolated protection system. Moreover, the effect of modifying dc cable arrangement is studied, in addition to the impact of concrete foundation presence in the grounding system. Then, some recommendations are proposed which succeeded in reducing transient voltages on dc cables. In addition, the induced voltages calculated by FDTD are compared with those obtained by partial element equivalent circuit method.

Ice Accretion: Image Post-Processing Measurement Techniques for 2D Ice Shapes

Ice accretion poses substantial safety hazards for the manned and unmanned aviation industries. Its study is essential for icing events risk assessment and for the development of efficient ice protection systems. The existing ice accretion measurement techniques—casting, molding, and laser-scanning—are time-consuming, sometimes cumbersome to use, and highly expensive, while hand tracing is inexpensive, but has lower accuracy and time-consuming post-processing. This work presents two low-cost, fast, and easy-to-use measurement techniques for 2D ice accretion profiles. Both employ algorithms of automatic ice shape detection, one based on unmediated image-processing, another based on the processing of manual ice tracings. The techniques are applied to ice accretion experiments conducted in an icing wind tunnel at low Reynolds numbers, and their results are validated against ice thickness caliper measurements. A comparison of the results shows that both techniques accurately measure the leading-edge ice thickness and the 2D shape of the ice accretion profiles. One technique is faster, with higher measurement accuracy, but produces interrupted-line 2D ice profiles and requires good lighting conditions, while the other generates continuous-line 2D profiles and has no application restriction, but it is slower, with lower accuracy. A discussion is conducted, aiming to help one determine the best applications for each ice accretion measurement technique presented.

Experimental design and characterization of Eu-doped tellurite matrix glassy composite for medical and ionizing-radiation sensing applications

This study experimentally presents the synthesis and characterisation of a new transparent Eu-doped tellurite matrix glassy composite with the view of predicting its UV and radiation sensing applications. This glassy composite, described by 50TeO2–15Na2O – 15ZnO – (20-x)PbO – xEu2O3 for x = 0 (TPEu-0), 1 (TPEu-1), 2 (TPEu-2), and 3 (TPEu-3) mol%, was prepared by the well-known melting-and- quenching technique. The glassy nature of the prepared samples was verified by the X-ray diffraction (XED) technique, and the density of the glasses was measured by the Archimedes method. The glasses’ optical features were determined from optical transmission and absorption spectra. In addition, the gamma radiation sensing and shielding prowess of the TPEu-X samples was determined from Monte Carlo simulation data using FLUKA code and direct calculations from the NISTXCOM database. The response of the glasses under UV-excitation was also analysed. The melting point and density of the glasses increased as the glasses was enriched with Eu2O3. The density of TPEu-X increased from 5.51 to 5.58 while the melting point grew from 750 °C to 1100 °C Eu2O3 concentration grew from 0 to 3 mol%. The increase in the concentration of Eu2O3 activated crystallization in the glass system. TPEu-1 has the highest optical bandgap energy (3.0 eV) and the lowest refractive index (2.39) among the TPEu-X glasses. The Eu2O3 content of the glasses affected their responses and appearance under UV light. Generally, the glass with the lowest Eu2O3 content possessed the least capacity to shield gamma radiation. The prepared TPEu-3 glass displayed the ability to displace many conventional and non-traditional shields in design of efficient radiation protection systems.

Coloured concrete produced from low-carbon cements: Mechanical properties, chromatic stability and sustainability

The global construction industry is responsible for 39% of CO2 emissions and for more than 50% of the extracted natural resources. Dematerialization and the use of low-carbon materials would be mitigating actions in the current scenario. In developing countries, where the housing deficit is high, a short-term and novel solution could come from the construction of social housing using multipurpose coloured concrete casings, which have no rendering of mortars and paints and are produced from low-carbon cements. In the Amazon, the wide availability of light and kaolinite-rich waste would enable the production of low-carbon cements (LCC) from ternary mixtures of clinker, calcined kaolin waste and limestone. The objective was evaluated the performance of coloured concretes from LCC against the weathering of the rainy equatorial climate of the Amazon, environment which favours the formation of biofilm films, impairing the aesthetic quality of the facades. The LCC provided coloured concretes with good pigmentation capacity and a significant reduction in CO2 emissions. On the other hand, its use compromised the surface quality of concrete due to the low chromatic stability. The climate conditions of the Amazon and low alkalinity of the LCC favoured the growth of microorganisms, leading the concrete surfaces to become prematurely blackened, decreasing their albedo and, consequently, raising the surface temperature of the substrate, which compromises the thermos-energetic performance of the building. Nevertheless, the results are promising and justify the continuity of research using new compositions of limestone calcined clay cement associated with the use of more efficient surface protection systems.

National health systems strengthening as the primary strategy to achieve Universal Health Coverage in African countries

Africa is the second largest continent and has its socioeconomic and health peculiarities. Countries are faced with varying challenges towards its Universal Health Coverage (UHC) achievement and hence the region requires health system reforms to drive equitable and balanced medical services to its populace. The main objectives of the paper were to explore the complexities of the African health systems, subsequently highlighting major challenges to UHC and to provide a framework for strategic approaches to health system strengthening to ensure realization of UHC. Information presented in this paper was collected from published literature and reports on Rwanda, Kenya, Nigeria, Tanzania, Ghana, Tunisia, Democratic Republic of Congo, Zambia, Egypt and South Africa, amidst other African countries. The published literature points to the presence of a somewhat slow progress towards UHC or at least an existent knowledge of it. However, common challenges faced can be grouped into 1) Financial constraints which include low levels of government expenditure on health and increased out-of-pocket percentages, (2) Lack of coverage of key services which includes majorly immunization rates and existence of health insurance for citizens, (3) Input constraints ranging from drug availability to skilled healthcare workforce, information and research and (4) Lack of political support and commitment towards universal health coverage. To overcome the above-stated constraints, two broad groups of interventions were identified; General interventions largely focusing on reprioritization of health budget, quality and improved services, equipped facilities and efficient social protection systems; and Specific interventions which emphasizes the importance of eliminating shortage of health workers, ensuring availability of essential medicines/ products, embracing decentralization at supply chain management, validating data/ information system and advocacy for impactful health education/promotion. Although there will be strength and weakness for whatever reforms adopted, implementation is totally contextual and contingent upon countries' specific health system bottlenecks. Sources of Funding None Conflicts of Interest The authors declare no conflict of interest Acknowledgement We would like to thank Dr. AugustinoTing Mayai for assistance and mentorship

Актуальные вопросы обеспечения работоспособности электрооборудования систем противопожарной защиты объектов

In Russia, at energy enterprises, in large industrial buildings, as well as at some other industrial facilities, the number of fire protection systems operate to protect people from fire hazards. Their reliability and efficiency are largely determined by the performance (fire resistance) of electrical wiring during a fire. Requirements for fire resistance of electrical wiring are determined by clause 2 of Art. 82 of the Federal Law of July 22, 2008 № 123-FZ «Technical Regulations on Fire Safety Requirements». It is established that cable lines and electrical wiring of fire protection systems of the protected objects must remain operational under fire conditions for the entire time required to perform their functions and evacuate people to a safe area. Based on the studies performed, the article substantiates the requirements included in the updated regulatory documents: GOST R 53316—2021 and SP 6.13130.2021. It is shown that these documents, together with those in force in Russia and harmonized with the standards of IEC GOST 50571.5.56—2013, constitute a single regulatory framework regulating the requirements and testing methods of electrical equipment for fire protection systems of the objects. Efficiency of the proposed norms is reflected in their scientific and technical substantiation carried out by All-Russian Research Institute for Fire Protection during many years of research work on requests of the EMERCOM of Russia. Based on the results of the conducted research, it was concluded that the application of these norms ensures compliance with the established requirements of the law. This helps to increase the efficiency and reliability of the certification assessment of such electrical installations, and, as a result, guarantees their reliability during operation at the object. It is proposed to pay special attention to the issues of scientifically based choice and subsequent implementation of highly efficient fire protection systems at the energy facilities.

Pore scale visualization of thermal-fluid-structural evolution in the ablation of carbon/carbon composites

Understanding the complex thermal and physicochemical mechanisms of an ablated structure is fundamental for the accurate design of highly efficient thermal protection systems. This study proposed a pore-scale comprehensive model combining the lattice Boltzmann and volume fraction methods to couple the heat and mass transfer, flow, carbon interphase and ablation reaction in the ablation of carbon/carbon (C/C) composites. The influences of aerodynamic heat, pressure gradient, and kinematic viscosity on the thermal-fluid-structural evolution in the ablation of C/C composite structure were investigated. The results revealed that the velocity and structure morphology evolution rate in the C/C composite structure increased with an increase in aerodynamic heat. Further, the competitive relationship between the aerodynamic heat and convective heat transfer caused by the structural morphology evolution was identified. Moreover, the velocity and structural morphology evolution rate in the C/C composite structure decreased with an increase in the pressure gradient and kinematic viscosity. The findings of this study can be used as a guide for the design of C/C composite thermal protection systems.

Propeller-integrated airfoil heater system for small multirotor drones in icing environments: Anti-icing feasibility study

Atmospheric icing is one of the most common and hazardous environmental challenges for aircraft operations. So far, only large passenger aircraft, a few general aviation aircraft, and specialized rotorcraft are equipped with ice protection systems because of their additional energy consumption and weight. The emerging markets of small electric aircraft like Urban Air Mobility and Unmanned Aerial Vehicles for transportation, logistics, search and rescue, and other specialized operations will require efficient, lightweight and all-electric ice protection systems in order to allow operations in ice and snow conditions. In this work, an electrothermal ice protection system with an average heat power density of 1Wcm−2 was designed and developed for use on small multirotor drones. Commercially available propeller blades with diameters of 33cm were retrofitted with lightweight multilayer heating foils independently powered by super-capacitors. The heated propellers were tested in close-to-real icing conditions in a small-scale icing wind tunnel. Thrust, rotational speed, and power consumption of a non-heated reference propeller and a heated propeller were compared. In glaze ice conditions at air temperatures > −5°C the thrust of the non-heated propeller fluctuated between 60 and 90% with frequent cycles of ice accretion and shedding for the entire duration of the test. The heated propeller maintained a thrust of >95% in the same icing conditions. In rime ice conditions at air temperatures < −8°C the heating was not sufficient and the thrust of the non-heated and heated propellers similarly decreased over time. Heat flux calculations along the span of the propeller were made for different icing conditions and compared to the heat power density distribution of the tested ice protection system.

Investigation of energy accommodation coefficient at gas-solid interface of a hypersonic flying vehicle

An effective thermal protection system is crucial for hypersonic flying vehicles performing multiple cycles of flight under high aerodynamic heating loads. Accurate calculation of heat transfer between a flying vehicle and its front shock waves is not possible due to complex gas-solid interactions. In this study, it was observed that the energy accommodation coefficient (EAC) at the interface between the shock wave formed by monoatomic gas and the flying vehicle exhibited a decrease-increase trend, which is attributed to that the averaged lasting time for each gas atom interacting with the solid decreases exponentially while the interacting depth increases logarithmically with the increase of the flight velocity. A one-dimensional collision model disclosed that the minimum EACs at different spring-mass systems occurred at the same Deborah number, indicating that the incident velocity of gas atoms corresponding to the minimum EAC is proportional to the natural frequency of the spring-mass system. Our research results suggest that the EAC strongly depends on the vehicle flying velocity and provide a rule for the optimal design of an efficient thermal protection system.

Secure and efficient privacy protection system for medical records

The healthcare sector has witnessed robust growth in the realm of medical information and its application during the last two decades. Consequently, the universal availability of patient records using web-based technology has acquired great significance in providing quality healthcare services on a global scale. With paramount aspects such as medical records confidentiality, it is an important consideration of modern times to secure medical information like CT-scan, X-Ray, and MRI when transmitted across public networks. Combining watermarking and BioHashing in medical image protection provides the means to safely transmit data over the internet and enhance authentication. In this context, we present a BioHashing and watermarking-based technique capable of providing integrity, authenticity, and confidentiality to different medical images. At the sender side, first, the BioHashing method is used to generate the watermark which is then embedded in weber local descriptor excitation component images using discrete cosine transform. The proposed technique meets all the requirements of robustness and imperceptibility. The experimental and comparison results demonstrate that the proposed method is superior to existing methods.

Experimental and Numerical Analysis of Transient Overvoltages of PV Systems When Struck by Lightning

PV systems are considered one of the most important and popular forms of renewable energy sources worldwide. Due to the installation of PV modules on rooftops and outdoor areas, they are frequently subjected to lightning strikes, leading to a deterioration in PV systems. To provide an efficient lightning protection system, the accurate modeling of PV systems during lightning strikes is required. The main objective of this paper is to assess the transient behavior of PV systems when struck by lightning, where the PV system is modeled using the partial element equivalent circuit (PEEC) and finite difference time-domain (FDTD) methods. The PEEC method is one of the accurate methods used to represent the PV system by its equivalent RLC circuit to study lightning transients. Moreover, the FDTD method provides high accuracy when studying lightning transients by analyzing the electric and magnetic fields inside the PV system. The PEEC and FDTD methods are used to calculate the transient overvoltages at different points of the PV system. Then, a small-scale PV system is tested in the laboratory using an impulse generator representing the lightning strike to verify the correctness of the results obtained by simulation. Most of the existing research works introduce low accuracy in PV system modeling during lightning transients by neglecting the effect of the mounting system, metal frame, and mutual coupling, which are considered in this work. Moreover, the high-frequency nature of lightning current is considered when modeling the elements of the grounding system. Verifying the results by laboratory experiments can guarantee the application of the simulation model on large-scale PV systems.

Fault Analysis &amp; Efficient Protection System for Transmission Network Around Base Load Power Plant to Improve Stability

Fault Analysis &amp; Efficient Protection System for Transmission Network Around Base Load Power Plant to Improve Stability

Highly Fast Innovative Overcurrent Protection Scheme for Microgrid Using Metaheuristic Optimization Algorithms and Nonstandard Tripping Characteristics

The incorporation of renewable energy microgrids brings along several new protection coordination challenges due to the new and stochastic behaviour of power flow and fault currents distribution. An optimal coordination scheme is a potential solution to develop an efficient protection system to handle the microgrid protection challenges. In this paper, new optimal Over Current (OC) relays coordination schemes have been developed using nonstandard tripping characteristics for a power network connected to renewable energy resources. The International Electrotechnical Commission (IEC) microgrid and IEEE-9 bus systems have been used as benchmark networks to test and evaluate the coordination schemes. The proposed OC relays coordination approach delivers a fast and more reliable performance under different OC faults scenarios compared to traditional approaches. In addition, to improve and evaluate the performance of the proposed coordination approach, four modern and novel metaheuristic optimization algorithms are developed and employed to solve the OC relay coordination problem, namely: Modified Particle Swarm Optimization (MPSO), Teaching Learning (TL), Grey Wolf Optimizer (GWO) and Moth-Flame Optimization Algorithm (MFO). In this paper, the modern metaheuristic algorithms have been employed to handle the impact of renewable energy on the grid, and enhance the sensitivity and selectivity of the protection system. The test cases, consider the impact of integrating the different levels of renewable energy resources (with a capacity increment of 25% and 50%) in the microgrid on the OC relays protection performance by using nonstandard and standard tripping characteristics. In addition, a comparison analysis for the modern metaheuristic algorithms with Particle Swarm Optimization (PSO) algorithm as a common and standard technique in solving coordination problems under different fault scenarios considering also the higher impedance faults are introduced. The results in all cases showed that the proposed optimal nonstandard approach successfully reduced the overall tripping time and improve the performance of the protection system in terms of sensitivity and selectivity.