Search

Abstract Severe pollution-induced flashovers on insulators present a pressing challenge to power system safety. The frequent failure of high-voltage insulators, particularly in the polluted environments of Pakistan, poses a critical concern. This paper investigates the impact of insulator profile on reducing pollution flashovers, testing two designs as per IEC standard 60383 and simulated using the Finite Element Method in COMSOL Multiphysics®. The test results revealed that deep under-ribs insulators exhibited a 5.008% reduction in flashover voltage, while alternating shed insulators experienced a 3.233% decrease in polluted conditions compared to clean conditions. Notably, under both clean and polluted conditions, alternating shed insulators consistently outperformed deep under-ribs insulators, with a 25.377% higher flashover voltage in clean conditions and a 27.400% superiority in polluted conditions. Computational analysis through the Finite Element Method in COMSOL Multiphysics shows a consistent pattern in potential distribution with increasing insulator count, but the presence of a pollution layer introduces spikes in the electric field distribution, validating experimental results. These findings highlight the superior performance of alternating shed insulators, especially in polluted environments.

Abstract The transformer mineral oil is generally hydrocarbon-based and is not environmentally friendly, so it holds a significant share in environmental pollution. As an alternative to conventional transformer oil, plant-based insulation oil has been investigated globally in the past few decades. Even though vegetable oils are considered an environmentally viable alternative to mineral oil, the extensive utilization of vegetable oils could create a threat to Indian food security. The present work focuses on using Pongamia Pinnata oil (PPO) as a significant alternative to conventional transformer oil (CTO) in distribution transformers. The effectiveness of the proposed PPO is experimentally verified using thermal studies and electrical studies through a low-level distribution transformer of 1 kVA. A comparative analysis was carried out between the proposed and conventional oil regarding physical, chemical, and thermal properties. Also, scanning electron microscopy (SEM) and Energy Dispersive X-ray spectroscopy analysis have been carried out for fibreglass cloth insulation material with PPO and CTO to ensure the intrinsic structural strength of the insulation material. The structural strength ensures the bonding and life span of the insulation in the transformer. The cost–benefit analysis is also favourable for the proposed oil as a better green liquid dielectric for transformers.

Abstract QSPR mathematically links physicochemical properties with the structure of a molecule. The physicochemical properties of chemical molecules can be predicted using topological indices. It is an effective method for eliminating costly and time-consuming laboratory tests. We established a QSPR between mev-degree and mve-degree-based indices and the physical properties of benzenoid hydrocarbons. To compute these indices, we designed a program using Maple software and the correlation between indices and physical properties was developed using the SPSS software. Our study reveals that the mve-degree-based sum-connectivity $$(\chi ^{mve})$$ ( χ mve ) and atom bond connectivity ( $$ABC^{mve}$$ A B C mve ) index, mev-degree-based Randić ( $$R^{mev}$$ R mev ) and Zagreb ( $$M^{mev}$$ M mev ) index are the three most significant parameters and have good prediction ability for the physicochemical properties. We examined that $$R^{mev}$$ R mev predicts the molar refractivity and boiling point, $${\chi }^{mve}$$ χ mve predicts the LogP and enthalpy, $$ABC^{mve}$$ A B C mve predicts the molecular weight, $$M^{mev}$$ M mev predicts the Gibb’s energy, Pie-electron energy and Henry’s law. Moreover, we computed the indices for the linear [n]-phenylen.

Abstract The present power generation government companies focus on Renewable Power Sources (RPS) because their features are zero carbon footprint, unlimited power source, fewer greenhouse pollutants, fewer output wastages, plus creatinga very healthy atmosphere. In this work, the sunlight source is utilized for the Photovoltaic (PV) standalone network. The merits of sunlight sources are very optimal human resources needed, unlimited natural sources, plus easy operation. However, the solar power resource is nonlinear fashion. As a result, the operating point of the sunlight network fluctuates concerning sunlight intensity. So, in this article, the Modified Grey Wolf Methodology with Adaptive Fuzzy Logic Controller (MGWM-AFLC) is introduced to maintain the operating point of the sunlight system at the global power point position of the PV array. This controller traces the MPP with very low fluctuations in the PV-produced voltage. The advantages of this proposed method arefewer sensing devices required, less difficulty in development, more useful for rapid changes inthe sunlight temperatures, simpler to realize operation, greater economic growth, plus highly useful for household applications. The sunlight set-up generation voltage is lowwhich is improved by introducing the new Wide Power Rating High Voltage DC-DC Boost Converter (WPRHVBC). The features of this WPRHV converter are low voltage strain on semiconductor devices, few passive elements are enough to develop the circuit, plus easy understanding.

Abstract The research aim is to clarify the effect of courtyard placement, the ratio between length and width, and courtyard orientation on energy consumption in residential buildings in hot and dry climates, to seek planning and designing alternatives for new cities and new residential complexes that are consistent with the environment and climate and save the consumption of energy used in the buildings. The research method was conducted through Design Builder software for simulation purposes. The reference model with the 157.25 m2 which accommodates a central square courtyard measuring 5 m × 5 m, on a residential building model in the New Valley Governorate of Kharga City, Egypt. The courtyard simulation is aimed to determine Less energy consumption inside the different case studies, in 9 courtyard placements The studied alternatives for Courtyard Placement, are (the center of the building, sub facades, and main facades). The different ratios are (1:1, 1.25:1, 1.5:1–1.75:1, 2:1, 2.25:1, 2.5–1). The longitudinal axis of the Courtyard has been oriented to the east–west direction for all placements, and north–south direction for all placements. Also, (orientation angle is Zero), it offered the percentages of better and worst cases in each position of the courtyard. The research findings suggest that the best Placement of the Courtyard that achieved the highest rate of saving of energy consumed inside the used building model was at the southwestern façade, with a saving rate of 18.73%. Then, the Placement of the Courtyard at the northwestern and southeastern facades with a saving rate of 17.91%, with a length-to-width ratio (2.5:1) if the longitudinal axis of the Courtyard is oriented in the north–south direction, Through the study, we conclude that the placement and orientation of the courtyard and its regular formation have contributed to rationalizing energy consumption in residential buildings, the study reached some important standards that could represent a methodological framework for designing contemporary residential buildings with an energy-efficient inner courtyard.

Abstract Based on the benefits of different ensemble methods, such as bagging and boosting, which have been studied and adopted extensively in research and practice, where bagging and boosting focus more on reducing variance and bias, this paper presented an optimization ensemble learning-based model for a large pipe failure dataset of water pipe leakage forecasting, something that was not previously considered by others. It is known that tuning the hyperparameters of each base learned inside the ensemble weight optimization process can produce better-performing ensembles, so it effectively improves the accuracy of water pipe leakage forecasting based on the pipeline failure rate. To evaluate the proposed model, the results are compared with the results of the bagging ensemble and boosting ensemble models using the root-mean-square error (RMSE), the mean square error (MSE), the mean absolute error (MAE), and the coefficient of determination (R2) of the bagging ensemble technique, the boosting ensemble technique and optimizable ensemble technique are higher than other models. The experimental result shows that the optimizable ensemble model has better prediction accuracy. The optimizable ensemble model has achieved the best prediction of water pipe failure rate at the 14th iteration, with the least RMSE = 0.00231 and MAE = 0.00071513 when building the model that predicts water pipe leakage forecasting via pipeline failure rate.

Abstract Traditionally, isolated and non-isolated boost converters are used for solar photovoltaic systems (SPV). These converters have limitations such as low voltage gain, less voltage ripples, temperature dependence, high voltage stress across the switches, and being bulky in size. Besides, the solar PV system also has non-linear characteristics between I–V and P–V, and the energy yield potential is affected by partial shading phenomena. Therefore, maximum power point tracking (MPPT) is being added to the SPV system to get the maximum output power under steady and dynamic climate conditions. Although the conventional MPPT has drawbacks such as less accuracy in predicting the MPP under partial shading conditions, low tracking speed, and more ripples, Hence, the research proposes a stackable single switch boost converter (SSBC) with a Cuckoo search MPPT controller for the SPV system. The efficiency of the proposed circuit topology has been compared with conventional boost converters with various MPPTs. Subsequently, the accuracy of tracking true MPPT by CSO is compared with that of PSO and FPNA. The results show, that the CMPPT with CBC has produced more ripples, whereas the BMPPT with SSBC produces ripple-free power under steady conditions. It is also observed that SSBC with BMPPT produces more power than SSBC with TMPPT. The efficiency of SSBC with BMPPT is better than other combinations. Finally, a prototype model has been developed and verified.

Abstract This paper presents a comprehensive approach for optimal charge scheduling and on-board vehicular control of electrified fleets based on synthetic driving cycles. The proposed approach is conducted within a real case-study in Cairo, Egypt, whereto a representative distance-based driving cycle has been synthesized using K-means clustering over a sliding horizon of gathered data-sets. Two multi-objective problems defining optimal charge scheduling and vehicular control have been formulated to achieve minimal energy consumption and operating cost of the fleet . Non-dominant genetic algorithm (NSGA-II) has been implemented to solve the optimization problems jointly considering fluctuating electricity cost of the grid. The comparative evaluation of results reveals an improvement of 19% and 28% in energy consumption and retention of on-board energy accordingly, with less than 2% mitigation of driveability. Moreover, a reduction of 40.8%, 20%, and 21.9% in fleet size, required charging stations, and annual recharging cost respectively has been realized. The main innovation of this work can be put forward as the ability to address the above-mentioned quadrilateral objectives of electrified fleets in a single comprehensive approach, considering synthetic driving cycles and electricity prices to yield a customized-optimal solution.

Abstract This work presents an energy management scheme (EMS) based on a rule-based grasshopper optimization algorithm (RB-GOA) for a solar-powered battery-ultracapacitor hybrid system. The main objective is to efficiently meet pulsed load (PL) demands and extract maximum energy from the photovoltaic (PV) array. The proposed approach establishes a simple IF-THEN set of rules to define the search space, including PV, battery bank (BB), and ultracapacitor (UC) constraints. GOA then dynamically allocates power shares among PV, BB, and UC to meet PL demand based on these rules and search space. A comprehensive study is conducted to evaluate and compare the performance of the proposed technique with other well-known swarm intelligence techniques (SITs) such as the cuckoo search algorithm (CSA), gray wolf optimization (GWO), and salp swarm algorithm (SSA). Evaluation is carried out for various cases, including PV alone without any energy storage device, variable PV with a constant load, variable PV with PL cases, and PV with maximum power point tracking (MPPT). Comparative analysis shows that the proposed technique outperforms the other SITs in terms of reducing power surges caused by PV power or load transition, oscillation mitigation, and MPP tracking. Specifically, for the variable PV with constant load case, it reduces the power surge by 26%, 22%, and 8% compared to CSA, GWO, and SSA, respectively. It also mitigates oscillations twice as fast as CSA and GWO and more than three times as fast as SSA. Moreover, it reduces the power surge by 9 times compared to CSA and GWO and by 6 times compared to SSA in variable PV with the PL case. Furthermore, its MPP tracking speed is approximately 29% to 61% faster than its counterparts, regardless of weather conditions. The results demonstrate that the proposed EMS is superior to other SITs in keeping a stable output across PL demand, reducing power surges, and minimizing oscillations while maximizing the usage of PV energy.

Abstract Secondary metabolites (SMs) are the primary source of therapeutics and lead chemicals in medicine. They have been especially important in the creation of effective cures for conditions such as cancer, malaria, bacterial and fungal infections, neurological and cardiovascular problems, and autoimmune illnesses. In the present study, Aspergillus pseudodeflectus AUMC 15761 was demonstrated to use wheat bran in solid state fermentation (SSF) at optimum conditions (pH 7.0 at 30 °C after 10 days of incubation and using sodium nitrate as a nitrogen source) to produce methyl ferulate and oleic acid with significant antioxidant and antibacterial properties. Gas chromatography-mass spectrometry (GC–MS) analysis of the crude methanol extract revealed eleven peaks that indicated the most common chemical components. Purification of methyl ferulate and oleic acid was carried out by column chromatography, and both compounds were identified by in-depth spectroscopic analysis, including 1D and 2D NMR and HR-ESI–MS. DPPH activity increased as the sample concentration increased. IC50 values of both compounds obtained were 73.213 ± 11.20 and 104.178 ± 9.53 µM, respectively. Also, the MIC value for methyl ferulate against Bacillus subtilis and Staphylococcus aureus was 0.31 mg/mL, while the corresponding MIC values for oleic acid were 1.25 mg/mL and 0.62 mg/mL for both bacterial strains, respectively. Molecular modeling calculations were carried out to reveal the binding mode of methyl ferulate and oleic acid within the binding site of the crucial proteins of Staphylococcus aureus. The docking results were found to be well correlated with the experimental data.

Abstract Refactoring tools have advanced greatly and are being used in many large projects. As a result, a great deal of information is now available about past refactoring and its effects on the source code. However, when multiple refactoring is performed at once, it becomes more difficult to analyze their impact. Refactoring visualization can help developers create more maintainable code that is easier to understand and modify over time. Although there is an increasing interest in visualizing code changes in software engineering research, there has been relatively little research on visualizing the process of refactoring. In this paper, we propose a Radar Chart Refactoring Visualization (RcRV) approach to visualize software refactoring of source code across multiple software releases. Radar charts are a form of 2D visualization that can show multiple variables on a single chart. The RcRv receives input from developers or through refactoring identification tools, such as Ref-Finder, to generate charts. The generated charts can show the changes made during the refactoring process, highlighting areas of the trend of refactoring over evolution for multiple refactoring, multiple methods, and multiple classes. The evaluation study conducted to assess the usefulness of the RcRV tool has shown that the proposed tool is useful to developers, appealing, and easy to use. The proposed method of visualization can be beneficial for developers and maintainers to detect design violations and potential bugs in the code, thus saving time and effort during the development and maintenance process. Therefore, this research presents a significant contribution to the software engineering field by providing developers with an efficient tool to enhance code quality and maintainability.

Abstract Globally, tuberculosis (TB) and anemia are public health problems related with high morbidity and mortality. Furthermore, anemia is frequently manifested among people with TB in Africa, prevalence ranging from 25 to 99%. The presence of anemia is associated with an increase in individuals’ susceptibility to TB and poor treatment outcomes. Studies have reported heterogeneous estimate of prevalence of anemia among people with TB in Africa. This review aimed to estimate the prevalence of anemia among newly diagnosed people with TB n Africa. We searched studies in Medline/PubMed, Cochrane library, ScienceDirect, JBI database, the Web of Science, Google Scholar, WorldCat, Open Grey, Scopus, Agency for Healthcare Research and Quality, ProQuest, and African Journals Online that reported the prevalence of anemia at TB diagnosis. Two reviewers performed data extraction with pre-defined inclusion criteria. A random-effects logistic regression model was used to pool the prevalence of anemia and levels of anemia with a 95% confidence interval (CI) in STATA version 14. Heterogeneity and publication biases were explored. A total of 1408 studies were initially identified, and seventeen studies with 4555 people with TB were included in the analysis. The prevalence of anemia among people with TB in Africa was 69% (95% CI 60.57–77.51). The pooled prevalence of anemia of chronic disease was 48% (95% CI 13.31–82.75) and normocytic normochromic anemia was 32% (95% CI 13.74–50.94) while mild anemia was 34% (95% CI 20.44–46.86). Females were more anemic than males at TB diagnosis in Africa (74% vs. 66%). The finding indicates that anemia is a common co-morbidity present among people with TB, especially among females. Mild anemia and normocytic normochromic anemia were more common at TB diagnosis. The finding indicates that anemia is a common co-morbidity present among people with TB in Africa region. Hence, it is recommended to instigate a routine anemia screening at TB diagnosis to improve treatment outcomes.

Abstract This meta-analysis aims to compare Apert syndrome (AS) patients with non-AS populations (not clinically or genetically diagnosed) on craniofacial cephalometric characteristics (CCC) to combine publicly available scientific information while also improving the validity of primary study findings. A comprehensive search was performed in the following databases: PubMed, Google Scholar, Scopus, Medline, and Web of Science, an article published between 1st January 2000 to October 17th, 2021. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed to carry out this systematic review. We used the PECO system to classify people with AS based on whether or not they had distinctive CCC compared to the non-AS population. Following are some examples of how PECO has been used: People with AS are labeled P; clinical or genetic diagnosis of AS is labeled E; individuals without AS are labeled C; CCC of AS are labeled O. Using the Newcastle–Ottawa Quality-Assessment-Scale, independent reviewers assessed the articles' methodological quality and extracted data. 13 studies were included in the systematic review. 8 out of 13 studies were score 7–8 in NOS scale, which indicated that most of the studies were medium to high qualities. Six case–control studies were analyzed for meta-analysis. Due to the wide range of variability in CCC, we were only able to include data from at least three previous studies. There was a statistically significant difference in N-S-PP (I 2: 76.56%; P = 0.014; CI 1.27 to − 0.28) and Greater wing angle (I 2: 79.07%; P = 0.008; CI 3.07–1.17) between AS and control subjects. Cleft palate, anterior open bite, crowding in the upper jaw, and hypodontia occurred more frequently among AS patients. Significant shortening of the mandibular width, height and length is the most reported feature in AS patients. CT scans can help patients with AS decide whether to pursue orthodontic treatment alone or to have their mouth surgically expanded. The role of well-informed orthodontic and maxillofacial practitioners is critical in preventing and rehabilitating oral health issues.

Abstract This paper presents an ultra-low-profile copper indium gallium selenide (CIGS) based solar cell integrated antenna with a high form factor. A tiny slot was etched from the solar cell to develop an ultra-low-profile solar-cell-integrated antenna. This tiny slot increases the form factor due to the small clearance area from the solar cell. A ground-radiation antenna design method was applied in which lumped elements were employed inside the tiny slot for antenna operation. Another substrate was used under the solar cell for designing the feeding structure with lumped elements connected to the tiny slot using via holes. A prototype was fabricated and measured to verify the operation of a built-in solar-cell antenna and validate the simulated results. The measured results demonstrate that the solar-cell-integrated antenna covers the entire frequency range of the Industrial Scientific Medical band, from 2.4 to 2.5 GHz, with a maximum gain of 2.79 dBi and radiation efficiency higher than 80% within the impedance bandwidth range. Moreover, the proposed design has an ultra-low-profile structure of only 0.0046 λo, where λo represents the free space wavelength at 2.45 GHz, and a high form factor of 99.1% with no optical blockage. The antenna and solar cell were designed to avoid affecting the performance of each other using the radio-frequency decoupler.