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A novel modified whale optimization algorithm (MWOA) is presented in this study to minimize transmission losses. The proposed method is used to determine the best control variables, such as reactive power generation, transformer tap settings, and reactive power sources. First, the power flow analysis method is used to determine where the flexible AC transmission system (FACTS) devices should be placed. To achieve the intended objectives, the suggested MWOA approach is applied on multiple IEEE standard test bus systems (IEEE-30, -57, and-118) at different active and reactive loading conditions. The shunt compensation was handled by a Static VAR compensator (SVC) while the series compensation was handled by a thyristor-controlled series compensator (TCSC). The results of applying the MWOA approach are shown and contrasted with those of other promising optimization techniques, including the sine cosine algorithm (SCA), whale optimization algorithm (WOA), moth flame optimization (MFO), grey wolf optimization (GWO), and particle swarm optimization (PSO). The proposed method significantly reduces the active power loss, i.e., 11.11 % in IEEE 30, 50.32 % in IEEE 57 and 15.17% in IEEE 118 bus system at base loading. Ultimately, a comprehensive study of the statistical data was conducted to validate the precision and robustness of the suggested methodology.

Abstract Modern electrical networks, particularly microgrids, have seen a sharp rise in acquiring non‐conventional sources. The inertia of the microgrid decreases drastically because RESs have been used in place of traditional synchronous generators. The reduced inertia negatively impacts the dynamics and performance of the microgrid with RESs, which decreases the microgrid's stability, especially in operation on an island. The primary purpose of this research study is to enhance the dynamic security of an island microgrid by merging an electric vehicle with a frequency control technique based on virtual inertia control. A Proportional Integral Derivative Filter Constant (PIDFN) controller optimally created using the Modified Differential Evolution (MDE) method served as the foundation for control in the virtual inertia control loop. The effectiveness of the MDE‐based PIDFN controller was examined considering the diverse operational scenarios are compared and contrasted with those of traditional methods Differential Evolution (DE) and Teaching Learning Based Optimization (TLBO)‐based PIDFN controllers. Real‐time wind and solar power statistics and random load fluctuations were incorporated to provide realistic simulation settings. The outcomes demonstrate that the MDE‐based PIDFN controller performs better in reference frequency tracking and reducing frequency disturbances than the other optimization strategies.

Abstract This paper proposes an improved sine–cosine algorithm (ISCA) based 2-DOF-PID controller for load frequency control. A three-area test system is built for study, while some physical constraints (nonlinearities) are considered for the investigation of a realistic power system. The proposed method is used as the parameter optimizer of the LFC controller in different scenarios. The 2-DOF-PID controllers are used because of their capability of fast disturbance rejection without significant increase of overshoot in set-point tracking. The 2-DOF-PID controllers’ efficacy is observed by examining the responses with the outcomes obtained with PID and FOPID controllers. The simulation results with the suggested scheme are correlated with some of the existing algorithms, such as SCA, SSA, ALO, and PSO in three different scenarios, i.e., a disturbance in two areas, in three areas, and in the presence of physical constraints. In addition, the study is extended to a four-area power system. Statistical analysis is performed using the Wilcoxon Sign Rank Test (WSRT) on 20 independent runs. This confirms the supremacy of the proposed method.

In modern power systems, there is a greater penetration of renewable sources, resulting in the expansion of microgrid. By implementing RES instead of conventional synchronous machines, the system’s overall inertia is significantly reduced. Modern and future power systems must reduce system inertia and keep the frequency at its nominal value since frequency oscillation impacts on the functionality, stability, and resilience of the system. Therefore, creating a stable, scalable, and reliable virtual inertia control system is crucial to effectively minimize the deviations during significant contingencies. Consequently, taking into account the probable issues, the foremost objective of this research work is to improve the dynamic security of an island microgrid through the implementation of a frequency control concept based on virtual inertia control. In the research study, the proposed microgrid system comprises of photovoltaics, wind-generating units, thermal power units, storage units, electric vehicles (EVs), and loads. A cascaded PIDFN controller is optimally designed using a novel metaheuristic modified differential evolution (MDE) algorithm that regulates the frequency based on virtual inertia control. In the MATLAB®/SIMULINK environment, various operating situations such as load variations, RES, and EVs disconnection are investigated, and the performance of the VIC-based MDE controller was compared to that of other controllers based on evolutionary optimization algorithms such as DE and TLBO. The results validate that the recommended virtual inertia control strategy enhances the reliability of the system.

In this article, a simplified sine cosine algorithm (SSCA) is applied to solve the optimal reactive power dispatch (ORPD) issues by estimating the control variables. This algorithm uses sine cosine functions and generates number of random solutions to obtain the best solution by fluctuating inwards or outwards. The SSCA is implemented in the ORPD problem to find the best control variables to achieve minimum power loss and maximum net savings. Furthermore, the efficacy of SSCA is validated with other recently used algorithms considering three case studies, i.e., IEEE-30, -57, and -118 bus test system. The results show that the SSCA approach finds more precise and superior ORPD solutions. A comparison among SSCA and other methods proves the robustness of SSCA to attain the solution with faster convergence. The statistical analysis is performed to justify the effectiveness of SSCA by yielding minimum operating cost and maximum net savings as compared to other techniques considered in this study.

This study proposes a novel modified grey-wolf optimization algorithm (MGWOA) to enhance power system stability. The power system stabilizer and static synchronous series compensator (SSSC) are used as damping controllers. Additionally, fractional-order PID (FOPID) controller is used to handle the system nonlinearities and thus achieve better performance. The control parameters are tuned using the proposed MGWOA method which has been verified on unimodal and multimodal functions. Single-machine infinite bus (SMIB) and multimachine power system (MMPS) are taken as case studies to analyze the efficacy of the proposed controller. Minimization of rotor speed deviation is considered an objective function. The results obtained from the MGWOA-tuned FOPID-based damping controllers are compared with those obtained using recently developed efficient and competitive heuristic algorithms. It was observed that the MGWOA method is well-suited for damping low-frequency oscillations. Furthermore, statistical analysis is performed on the obtained results to justify the superiority of the MGWOA method. The simulation results suggest that the MGWOA exhibits superior performance characteristics when applied to a real power system.

Chronic periodontitis is a ubiquitous inflammatory disease in dental healthcare that is challenging to treat due to its impact on bone and tooth loss. Conventional mechanical debridement has been challenging in eliminating complex subgingival biofilms. Hence, adjunctive approaches like low-level laser antimicrobial photodynamic therapy (A-PDT) utilising methylene blue (MB) have been emerging approaches in recent times. This review evaluates the latest research on the use of MB-mediated A-PDT to decrease microbial count and enhance clinical results in chronic periodontitis. Studies have shown the interaction between laser light and MB generates a phototoxic effect thereby, eliminating pathogenic bacteria within periodontal pockets. Moreover, numerous clinical trials have shown that A-PDT using MB can reduce probing depths, improve clinical attachment levels, and decrease bleeding during probing in comparison to traditional treatment approaches. Notably, A-PDT shows superior antibiotic resistance compared to conventional antibiotic treatments. In conclusion, the A-PDT using MB shows promise as an adjunctive treatment for chronic periodontitis. Additional research is required to standardize treatment protocols and assess long-term outcomes of A-PDT with MB in the treatment of periodontitis.

Abstract Background Thoracic epidural placement (TEP) using the conventional anatomic landmark-based technique is technically challenging, may require multiple attempts, and is associated with a high failure rate (12–40%). We hypothesized that real-time ultrasound guidance would be superior in the “first-pass” success rate of TEP, when compared with the conventional technique. Methods This prospective, randomized, superiority trial was conducted in a University hospital, and recruited 96 patients undergoing elective major abdominal or thoracic surgery and scheduled to receive a TEP for postoperative analgesia. Patients were randomly allocated to receive TEP using either the conventional technique (Gp-Conv, n = 48) or real-time ultrasound guidance (Gp-Usg, n = 48). The success of TEP was defined as eliciting loss of resistance technique and being able to insert the epidural catheter. The primary outcome variable was the “first-pass success rate” meaning the successful TEP at the first needle insertion without redirection or readvancement of the Tuohy needle. The secondary outcomes included the number of skin punctures, number of attempts, the overall success rate, TEP time, and total procedure time. Results The first-pass success rate of TEP was significantly higher (p = 0.002) in Gp-Usg (33/48 (68.8%); 95%CI 55.6 to 81.9) than in Gp-Conv (17/48 (35.4%); 95%CI 21.9 to 49.0). There was no statistically significant difference (p = 0.12) in the overall success rate of TEP between the 2 study groups (Gp-Usg; 48/48 (100%) vs. Gp-Conv; 44/48 (91.7%); 95%CI 83.9 to 99.5). Ultrasound guidance reduced the median number of skin punctures (Gp-Usg; 1 [1, 1] vs Gp-Conv; 2 [1, 2.2], p

Abstract Coagulation is an essential and easy process to treat water and wastewater and also to adopt for point of use solutions. Coagulants have played a significant role in providing safe and potable water. Nevertheless, the ill effects of chemical coagulants, such as health effects and substantial sludge quantities, cannot be ignored. Under given conditions, the search for alternative coagulants has been the need of the hour, and researchers have presented those natural coagulants are promising alternatives. The exploration and evaluation of plant-based coagulants have shown that these are fit to substitute chemical coagulants sustainably. Previous studies have presented the efficacy of various coagulants but could not fill in the gap existing in terms of a cumulative database of natural coagulants. In these lines, the focus of the current review is to present the history of natural coagulants, the science involved and studies carried out to evaluate them at different levels. Furthermore, a cumulative database of 57 natural coagulants with their efficacy in removing impurities from raw water is presented.

Abstract Quality of water, along Mandal headquarters of a coastal district of Andhra Pradesh, India, was assessed prior to and past rainfall season to determine water's acceptability for consumption using water quality index (WQI). The present work involved collecting groundwater samples from Mandal headquarters' locations present in the entire district. All the samples were analysed in a comprehensive way for ten physicochemical parameters, including pH, magnesium, calcium, chloride, sulphate, nitrates, total dissolved solids, fluoride, potassium, and sodium. The geographical information system was used for mapping sampling sites. The coordinates of sample collection areas were recorded employing GPS. Correlation matrices for cation–anion were illustrated and from the qualitative results of the samples. Results indicate that WQI prior and past-rainfall seasons ranged from 37.53 to 312.46; 42.04 to 211.89 in 2016, while for 2017, these were in the range of 25.01 to 137.06; 30.06 to 228.83. The present study's WQI values indicate that the water samples possess poor quality, and no fluoride contaminations were observed. The analysis suggests appropriate treatment of sub-surface water from the study site before consumption.

Abstract Dependency on sea food has increased owing to its nutrition as well as being complete food. As the production of seafood is enhanced through aquaculture, wastewater release has also improved. The composition of wastewater from aquaculture production has been a concern as it has oil and grease, organic content, etc., which makes its treatment challenging. The present study aims at treating aquaculture wastewater using two natural coagulants—chitin and seeds of Moringa oleifera. The efficiency of the natural coagulants was compared against inorganic chemical coagulant ferric chloride. A blended coagulant with two natural coagulants seeds of Moringa oleifera and chitin was also tested. Jar test apparatus was used in the current experiments, and four coagulant doses were tested against 3 pH ranges, from 6 to 8. The study results showed that the coagulants showed a 30–50% reduction in various physicochemical parameters. Further, the most promising result was obtained with the blended coagulants (di-blend) with 70–81% removal of total nitrogen and total phosphorus and the highest reduction of chloride with 95%. The Fourier-transform infrared spectroscopy showed functionalized groups responsible for coagulation, and X-ray powder diffraction analysis of the blended coagulant indicated the crystallinity and amorphous nature of the compounds. Scanning electron microscope analysis presented a firm and dense structure indicating adsorption of impurities onto the coagulant. Thus, it is evident that natural coagulants can be the solution for the challenges of aquaculture wastewater and specifically the di-blend used in the present is ascertained to be a promising solution.

Globalization and industrialization lead to the corresponding increase of effluents discharged into the nearest water bodies. The persistence of pollution in the ecological system has led to uncertainty about living habitats; drinking water safety has become a societal issue attached to great importance. As we increasingly become aware of environmental problems and their impacts on human life, we realize that current problem-solving using contemporary water treatment techniques cannot provide adequate solutions owing to their advantages and disadvantages. Nature-based solutions are required as they are the best alternative for treating polluted water. Conventional coagulation is not a new technique that has been utilized in ancient times and works as a sustainable solution for water treatment and reduces the costs associated with the other treatment methods. Even though these techniques have been practised since ancient times, there is still a need to explore more plants to identify coagulating properties. The current study aims to do the phytochemical and physicochemical screening of the plant-based materials to identify them as coagulants and compare their efficiencies with the conventional inorganic and animal-based coagulants; out of 18 plant-based materials, Moringa oleifera, Manihot esculenta and Pisum Sativum removed turbidity up to 100% are subjected to the FTIR, XRD, and SEM to analyze the functionalized groups responsible for the polymer formation and identify the interaction between the coagulator's and suspended particles. The results showed that plant-based materials could be promising solutions for water quality challenges.

Water demand for consumption has been increasing continuously due to the expanding population worldwide. The current accessible water is continually contaminated by global climate change and anthropogenic activities. Economically viable and safe treatment technologies are required for the contemporary world to meet the water demand. The coagulation process is an economically feasible method and gaining much prominence in developing countries for water treatment. During the operation, Sludge and secondary by-products are formed due to the overdosage of the coagulant and improper mixing speeds. Optimizing process parameters is essential to reduce the costs associated with further treatment. Thus, the current study aimed to optimize the process parameters by using Alum, Chitin and Sago coagulants with three pH variations, i.e., 6, 7, and 8, with a mixing speed of 100–30 and 80–20 rpm. The results revealed that Sago performed better than other coagulants and removed the turbidity up to 99.42 %. In addition, Sludge was reduced to 90 % with a dosage of 0.4 g/L, a minor dosage compared to the literature with an optimal pH of 7. Further, the coagulants were characterized to identify the functionalized groups by FTIR, the nature of the coagulant by XRD and Surface morphology by SEM. From the current study, it can be concluded that a coagulant dose ranging from 0.1 to 0.4 g/L with a mixing speed of 100 rpm for 2 min and 30 rpm for 30 min might be the best solution for obtaining greater coagulation efficiency.

Abstract Owing to the advantages of the natural coagulants under study, the present objective is to study the efficiency of blended coagulants: alum and chitin; alum and sago; and alum + chitin + sago. In this attempt, we have reduced the quantity of alum dose and added increasing quantities of the natural coagulants. The surface water samples collected from nearby sources were analyzed for the following parameters pre- and post-treatment with the coagulants. Coagulation and flocculation experiments were carried out using conventional jar test apparatus. Turbidity removal was observed to be nearly 99.29% at all pH ranges and doses. Removal of conductivity, solids and hardness was 58.83%, 32.03% and 33.33%, respectively. From the results obtained, it can be observed that the efficiency of blended coagulants in removal of various physicochemical parameters from the waters was better when compared to individual coagulants. The floc size in blend coagulants was larger than that of single coagulants. The data obtained in this study indicated the coagulation efficiency could be enhanced by using the blend coagulant.