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Authors = Muhammad Majeed

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19 pages, 3848 KiB  
Article
Assessment of Exploited Stock and Management Implications of Tiger Tooth Croaker (Otolithes ruber) in Coastal Waters of Makran, Pakistan
by Samroz Majeed, S M Nurul Amin, Asad Ullah Ali Muhammad and Sudheer Ahmed
Fishes 2025, 10(5), 238; https://doi.org/10.3390/fishes10050238 - 20 May 2025
Viewed by 1608
Abstract
Pakistan’s marine fishing industry is crucial to the country’s economy, generating employment opportunities and foreign revenue. It produces 80% of the country’s total fish production. Otolithes ruber is a commercially important fish on the Makran coast of Pakistan, contributing significantly to the region’s [...] Read more.
Pakistan’s marine fishing industry is crucial to the country’s economy, generating employment opportunities and foreign revenue. It produces 80% of the country’s total fish production. Otolithes ruber is a commercially important fish on the Makran coast of Pakistan, contributing significantly to the region’s croaker fisheries. This study is the first to apply three length-based approaches for assessing the stock status of O. ruber in the Makran coast: (1) TropFishR to estimate the mortality, growth parameters, and current exploitation status, reference points based on the yield per recruitment model, (2) the length-based Bayesian biomass method (LBB) to calculate stock biomass, and (3) the length-based spawning potential ratio (LBSPR) to estimate the spawning potential ratio. The length–weight relationship of Otolithes ruber was a positive allometric pattern (b = 3.28; R2 = 0.94). Growth parameters for Otolithes ruber were L = 55.47 cm, K = 0.50 year−1. The calculated total mortality rate (Z), natural mortality (M), and fishing mortality (F) were 2.27 year−1, 0.67 year−1, and 1.6 year−1, respectively. The exploitation rate (E) was 0.70, indicating severe overexploitation. The current length at first capture (Lc50) = 27.37 cm was lower than that at first maturity (Lm50) = 30.75 cm, indicating growth overfishing. The current spawning potential ratio (8%) was lower than the optimal value (40%), indicating recruitment overfishing. The current biomass, concerning virgin biomass B/Bo, was also 8%, resulting in a 92% stock decline. We recommend reducing the exploitation pressure by limiting the commercial catch to an optimum length range of 34.5–42.2 cm and reducing fishing pressure by 40% to ensure sustainable fishery management. Full article
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18 pages, 2265 KiB  
Article
Pathogenomic Characterization of Multidrug-Resistant Escherichia coli Strains Carrying Wide Efflux-Associated and Virulence Genes from the Dairy Farm Environment in Xinjiang, China
by Muhammad Shoaib, Sehrish Gul, Sana Majeed, Zhuolin He, Baocheng Hao, Minjia Tang, Xunjing Zhang, Zhongyong Wu, Shengyi Wang and Wanxia Pu
Antibiotics 2025, 14(5), 511; https://doi.org/10.3390/antibiotics14050511 - 15 May 2025
Cited by 2 | Viewed by 733
Abstract
Background/Objectives: Livestock species, particularly dairy animals, can serve as important reservoirs of E. coli, carrying antibiotic resistance and virulence genes under constant selective pressure and their spread in the environment. In this study, we performed the pathogenomic analysis of seven multidrug [...] Read more.
Background/Objectives: Livestock species, particularly dairy animals, can serve as important reservoirs of E. coli, carrying antibiotic resistance and virulence genes under constant selective pressure and their spread in the environment. In this study, we performed the pathogenomic analysis of seven multidrug resistant (MDR) E. coli strains carrying efflux-associated and virulence genes from the dairy farm environment in Xinjiang Province, China. Methods: First, we processed the samples using standard microbiological techniques followed by species identification with MALDI-TOF MS. Then, we performed whole genome sequencing (WGS) on the Illumina NovaSeq PE150 platform and conducted pathogenomic analysis using multiple bioinformatics tools. Results: WGS analysis revealed that the E. coli strains harbored diverse antibiotic efflux-associated genes, including conferring resistance to fluoroquinolones, aminoglycosides, aminocoumarins, macrolides, peptides, phosphonic acid, nitroimidazole, tetracyclines, disinfectants/antiseptics, and multidrug resistance. The phylogenetic analysis classified seven E. coli strains into B1 (n = 4), C (n = 2), and F (n = 1) phylogroups. PathogenFinder predicted all E. coli strains as potential human pathogens belonging to distinct serotypes and carrying broad virulence genes (ranging from 12 to 27), including the Shiga toxin-producing gene (stx1, n = 1). However, we found that a few of the virulence genes were associated with prophages and genomic islands in the E. coli strains. Moreover, all E. coli strains carried a diverse bacterial secretion systems and biofilm-associated genes. Conclusions: The present study highlights the need for large-scale genomic surveillance of antibiotic-resistant bacteria in dairy farm environments to identify AMR reservoir spillover and pathogenic risks to humans and design targeted interventions to further stop their spread under a One Health framework. Full article
(This article belongs to the Special Issue Antibiotic Resistance: A One-Health Approach, 2nd Edition)
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20 pages, 3501 KiB  
Article
Climate Change: A Major Factor in the Spread of Aedes aegypti (Diptera: Culicidae) and Its Associated Dengue Virus
by Shahid Majeed, Waseem Akram, Muhammad Sufyan, Asim Abbasi, Sidra Riaz, Shahla Faisal, Muhammad Binyameen, Muhammad I. Bashir, Shahzad Hassan, Saba Zafar, Oksana Kucher, Elena A. Piven and Olga D. Kucher
Insects 2025, 16(5), 513; https://doi.org/10.3390/insects16050513 - 11 May 2025
Viewed by 1330
Abstract
Climate change is thought to be responsible for the spread of various vector-borne diseases. The current study was conducted to evaluate the impact of different temperature and relative humidity regimes on the developmental stages of the yellow fever mosquito, Aedes aegypti (Diptera: Culicidae). [...] Read more.
Climate change is thought to be responsible for the spread of various vector-borne diseases. The current study was conducted to evaluate the impact of different temperature and relative humidity regimes on the developmental stages of the yellow fever mosquito, Aedes aegypti (Diptera: Culicidae). The study also evaluated the impact of larval density on the survival of Ae. aegypti. In addition, the association between vector larval abundance, dengue incidence, and climatic factors were elucidated during 2016–2019 in three populated districts of Punjab, Pakistan, i.e., Lahore, Rawalpindi, and Multan. The results of the study revealed that at 10 °C and 35 °C, egg hatching and adult emergence were significantly reduced, regardless of the relative humidity. In contrast, at 20 °C and 30 °C, the rates of egg and adult survival increased with higher relative humidity. In addition, a density-dependent response was observed regarding larval survival of Ae. aegypti. Moreover, larval incidence was positively correlated with the number of dengue patients, Tmax, RH, and precipitation at Lahore (0.55, 0.23, 0.29, and 0.13), Rawalpindi (0.90, 0.30, 0.21, and 0.14), and Multan (0.05, 0.27, and 0.13) respectively, except in Multan, where a negative correlation (−0.09) with precipitation was observed. The inflow of patients had a positive correlation with the occurrence of a larval population, relative humidity, and precipitation at Lahore, Rawalpindi, and Multan districts, with the scale values of 0.55, 0.25, and 0.16; 0.90, 0.22, and 0.03; and 0.05, 0.06, and 0.03, respectively. In addition, a forecast model, ARIMA, predicted that there was a higher rate of larval occurrence in Rawalpindi, followed by Lahore. This study concluded that the role of precipitation > 200 mm prior to a 1–2-month lag, a 20–30 °C temperature range, and an RH exceeding 60% lead to the occurrence of larvae and dengue case spikes. This study will help to reinforce dengue surveillance and control strategies in Pakistan and to establish early management strategies based on changing climatic factors. Full article
(This article belongs to the Special Issue Insect Dynamics: Modeling in Insect Pest Management)
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12 pages, 9413 KiB  
Article
Design of a Miniaturized and Polarization-Independent Frequency-Selective Surface for Targeted EMI Shielding
by Muhammad Idrees, Yejun He, Youquan Wen and Abdul Majeed
Appl. Sci. 2025, 15(8), 4534; https://doi.org/10.3390/app15084534 - 20 Apr 2025
Cited by 1 | Viewed by 675
Abstract
In this article, a miniaturized frequency-selective surface (FSS)-based electromagnetic shield is investigated for EMI mitigation in the X-band. The FSS comprises a convoluted conducting loop designed over an FR-4 substrate. It operates at 10 GHz X-band frequency and offers an effective shielding of [...] Read more.
In this article, a miniaturized frequency-selective surface (FSS)-based electromagnetic shield is investigated for EMI mitigation in the X-band. The FSS comprises a convoluted conducting loop designed over an FR-4 substrate. It operates at 10 GHz X-band frequency and offers an effective shielding of at least 33 dB. It reveals rejection bandwidths of 26% for the TE and TM wave modes at normal incidence. Moreover, it accomplishes polarization-insensitive and angularly stable spectral responses owing to its structural symmetry and compact size. In addition, an equivalent circuit model (ECM) and a finite prototype of the shield are developed to verify EM simulations. A comparison of the results indicates that the FSS offers wide angular stability and excellent shielding performance, which makes it a suitable candidate for applications requiring targeted EMI mitigation. Full article
(This article belongs to the Special Issue Recent Advances in Magnetic Shielding)
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21 pages, 1379 KiB  
Article
Generalization of Ramsey Number for Cycle with Pendant Edges
by Jagjeet Jakhar, Monu Moun, Youngsoo Seol, Majeed Ahmad Yousif, Muhammad Amer Latif and Pshtiwan Othman Mohammed
Mathematics 2025, 13(7), 1196; https://doi.org/10.3390/math13071196 - 4 Apr 2025
Viewed by 655
Abstract
This paper explores various Ramsey numbers associated with cycles with pendant edges, including the classical Ramsey number, the star-critical Ramsey number, the Gallai–Ramsey number, and the star-critical Gallai–Ramsey number. These Ramsey numbers play a crucial role in combinatorial mathematics, determining the minimum number [...] Read more.
This paper explores various Ramsey numbers associated with cycles with pendant edges, including the classical Ramsey number, the star-critical Ramsey number, the Gallai–Ramsey number, and the star-critical Gallai–Ramsey number. These Ramsey numbers play a crucial role in combinatorial mathematics, determining the minimum number of vertices required to guarantee specific monochromatic substructures. We establish upper and lower bounds for each of these numbers, providing new insights into their behavior for cycles with pendant edges—graphs formed by attaching additional edges to one or more vertices of a cycle. The results presented contribute to the broader understanding of Ramsey theory and serve as a foundation for future research on generalized Ramsey numbers in complex graph structures. Full article
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40 pages, 12138 KiB  
Article
Non-Similar Analysis of Boundary Layer Flow and Heat Transfer in Non-Newtonian Hybrid Nanofluid over a Cylinder with Viscous Dissipation Effects
by Ahmed Zeeshan, Majeed Ahmad Yousif, Muhammad Imran Khan, Muhammad Amer Latif, Syed Shahzad Ali and Pshtiwan Othman Mohammed
Energies 2025, 18(7), 1660; https://doi.org/10.3390/en18071660 - 26 Mar 2025
Cited by 2 | Viewed by 780
Abstract
Highlighting the importance of artificial intelligence and machine learning approaches in engineering and fluid mechanics problems, especially in heat transfer applications is main goal of the presented article. With the advancement in Artificial Intelligence (AI) and Machine Learning (ML) techniques, the computational efficiency [...] Read more.
Highlighting the importance of artificial intelligence and machine learning approaches in engineering and fluid mechanics problems, especially in heat transfer applications is main goal of the presented article. With the advancement in Artificial Intelligence (AI) and Machine Learning (ML) techniques, the computational efficiency and accuracy of numerical results are enhanced. The theme of the study is to use machine learning techniques to examine the thermal analysis of MHD boundary layer flow of Eyring-Powell Hybrid Nanofluid (EPHNFs) passing a horizontal cylinder embedded in a porous medium with heat source/sink and viscous dissipation effects. The considered base fluid is water (H2O) and hybrid nanoparticles titanium oxide (TiO2) and Copper oxide (CuO). The governing flow equations are nonlinear PDEs. Non-similar system of PDEs are obtained with efficient conversion variables. The dimensionless PDEs are truncated using a local non-similarity approach up to third level and numerical solution is evaluated using MATLAB built-in-function bvp4c. Artificial Neural Networks (ANNs) simulation approach is used to trained the networks to predict the solution behavior. Thermal boundary layer improves with the enhancement in the value of Rd. The accuracy and reliability of ANNs predicted solution is addressed with computation of correlation index and residual analysis. The RMSE is evaluated [0.04892, 0.0007597, 0.0007596, 0.01546, 0.008871, 0.01686] for various scenarios. It is observed that when concentration of hybrid nanoparticles increases then thermal characteristics of the Eyring-Powell Hybrid Nanofluid (EPHNFs) passing a horizontal cylinder. Full article
(This article belongs to the Section J1: Heat and Mass Transfer)
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17 pages, 429 KiB  
Article
Corporate Social Responsibility’s Influence on Brand Image in the Automotive Sector: The Corporate Reputation and Product Quality Role
by Mohsen Brahmi, Zahid Hussain, Muhammad Ussama Majeed, Arman Khan, Muhammad Asif Qureshi and Rohit Bansal
Adm. Sci. 2025, 15(4), 121; https://doi.org/10.3390/admsci15040121 - 25 Mar 2025
Cited by 1 | Viewed by 2102
Abstract
This study investigates the impact of perceived corporate social responsibility (CSR) on brand image within the automotive industry. It also examines how company reputation (CR) and product quality (PQ) mediate the relationship between CSR and brand image (BI). Utilizing a sample of 243 [...] Read more.
This study investigates the impact of perceived corporate social responsibility (CSR) on brand image within the automotive industry. It also examines how company reputation (CR) and product quality (PQ) mediate the relationship between CSR and brand image (BI). Utilizing a sample of 243 clients from the Pakistani automotive sector, data were collected through a survey and analyzed using structural equation modeling (SEM) with AMOS version 24.0. The results indicate that perceived CSR positively influences brand image, with both company reputation and product quality acting as significant mediators. This underscores the importance of CSR initiatives for enhancing brand image. The findings have significant implications for auto manufacturers, highlighting the need to integrate CSR into their strategic brand management to improve company reputation, product quality, and, ultimately, brand image. This study expands the conventional understanding of CSR’s impact on consumer perceptions and addresses a critical gap in the literature. Full article
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2 pages, 639 KiB  
Correction
Correction: Zeng et al. Hedgehog Signaling: Linking Embryonic Lung Development and Asthmatic Airway Remodeling. Cells 2022, 11, 1774
by Ling-Hui Zeng, Muhammad Qasim Barkat, Shahzada Khurram Syed, Shahid Shah, Ghulam Abbas, Chengyun Xu, Amina Mahdy, Nadia Hussain, Liaqat Hussain, Abdul Majeed, Kashif-ur-Rehman Khan, Ximei Wu and Musaddique Hussain
Cells 2025, 14(5), 356; https://doi.org/10.3390/cells14050356 - 28 Feb 2025
Viewed by 422
Abstract
In the original publication [...] Full article
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19 pages, 2520 KiB  
Article
Super Broad Non-Hermitian Line Shape from Out-of-Phase and In-Phase Photon-Phonon Dressing in Eu3+: NaYF4 and Eu3+: BiPO4
by Muhammad Kashif Majeed, Muhammad Usman, Iqbal Hussain, Usman Javed, Muhammad Qasim Khan, Faisal Nadeem, Faisal Munir, Huanrong Fan, Yin Cai and Yanpeng Zhang
Photonics 2024, 11(12), 1169; https://doi.org/10.3390/photonics11121169 - 12 Dec 2024
Viewed by 798
Abstract
We report super broad non-Hermitian line shape from out-of-phase and in-phase photon-phonon dressing (quantization) in Eu3+: NaYF4 and Eu3+: BiPO4 nanocrystals. The line shape is controlled by changing time gate position, time gate width, power, temperature, sample, [...] Read more.
We report super broad non-Hermitian line shape from out-of-phase and in-phase photon-phonon dressing (quantization) in Eu3+: NaYF4 and Eu3+: BiPO4 nanocrystals. The line shape is controlled by changing time gate position, time gate width, power, temperature, sample, photomultiplier tubes, and laser. We observed that the fluorescence (FL) line-shape contrasts are 69.23% for Eu3+: BiPO4 and 43.75% for Eu3+: NaYF4, owing to the stronger out-of-phase photon-phonon dressing (destructive quantization). Moreover, we observed that the spontaneous four-wave mixing (SFWM) line shape was approximately three times wider at 300 K than at 77 K for the [(12:1)-phase] Eu3+: NaYF4 due to more high-frequency in-phase phonon dressing (strong constructive quantization). Furthermore, we showed that the noise line-shape width remains unchanged for Eu3+: BiPO4 (16 nm) and Eu3+: NaYF4 (12 nm) due to out-of-phase and in-phase photon-phonon dressing balance. Such results have potential applications in multi-channel band stop filter. Full article
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22 pages, 3992 KiB  
Article
Optimizing Tomato (Lycopersicon esculentum) Yield Under Salt Stress: The Physiological and Biochemical Effects of Foliar Thiourea Application
by Jawaria Abdul Majeed, Safura Bibi, Athar Mahmood, Liaqat Ali, Muhammad Ehsan Safdar, Mahmoud F. Seleiman, Zain Ul Abidin, Bushra A. Alhammad and Muhammad Ahsan Asghar
Plants 2024, 13(23), 3318; https://doi.org/10.3390/plants13233318 - 26 Nov 2024
Cited by 1 | Viewed by 1702
Abstract
A pot experiment was conducted to investigate the role of thiourea exogenous application (0 mg/L and 100 mg/L) on the morphological, physiological, and yield traits of two varieties of tomato (Naqeeb and Nadir) under different salt stress treatments (0, 60, and 120 mM) [...] Read more.
A pot experiment was conducted to investigate the role of thiourea exogenous application (0 mg/L and 100 mg/L) on the morphological, physiological, and yield traits of two varieties of tomato (Naqeeb and Nadir) under different salt stress treatments (0, 60, and 120 mM) in completely randomized design (CRD). The imposition of salinity by rooting medium showed that salt stress reduced plant height by 20%, fresh shoot weight by 50%, dry shoot weight by 78%, fresh root weight by 43%, dry root weight by 84%, root length by 34%, shoot length by 32%, shoot K+ by 47%, Ca2+ by 70%, chlorophyll a by 30%, chlorophyll b by 67%, and the number of seeds per berry by 53%, while shoot Na+ ions were increased by 90% in comparison to those grown with control treatment. However, the exogenous application of thiourea significantly enhanced dry root weight by 25% and the number of seeds per berry by 20% in comparison to untreated plants with thiourea when grown under salt stress. Salt stress resulted in a reduction in the number of berries, weight per berry, number of seeds per berry, and seed weight in both varieties, while thiourea foliar application increased these yield parameters. On the other hand, the Nadir variety surpassed Naqeeb in plant height (+13%), root length (+31%) and shoot length (+11%), fresh shoot weight (+42%) and dry shoot weight (+11%), fresh root weight (+29%), dry root weight (+25%), area of leaf (+26%), chlorophyll a (+32%), and chlorophyll b (+24%). In conclusion, the exogenous application of thiourea can be used to mitigate salt stress in tomato plants since it can improve the growth, physiological, and yield traits of this strategic crop. Full article
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26 pages, 1111 KiB  
Article
Buffer Occupancy-Based Congestion Control Protocol for Wireless Multimedia Sensor Networks
by Uzma Majeed, Aqdas Naveed Malik, Nasim Abbas, Ahmed S. Alfakeeh, Muhammad Awais Javed and Waseem Abbass
Electronics 2024, 13(22), 4454; https://doi.org/10.3390/electronics13224454 - 13 Nov 2024
Viewed by 1234
Abstract
Wireless multimedia sensor networks (WMSNs) have stringent constraints and need to deliver data packets to the sink node within a predefined limited time. However, due to congestion, buffer overflow occurs and leads to the degradation of the quality-of-service (QoS) parameters of event information. [...] Read more.
Wireless multimedia sensor networks (WMSNs) have stringent constraints and need to deliver data packets to the sink node within a predefined limited time. However, due to congestion, buffer overflow occurs and leads to the degradation of the quality-of-service (QoS) parameters of event information. Congestion in WMSNs results in exhausted node energy, degraded network performance, increased transmission delays, and high packet loss. Congestion occurs when the volume of data trying to pass through a network exceeds its capacity. First, the BOCC protocol uses two congestion indicators to detect congestion. One is the buffer occupancy and other is the buffer occupancy change rate. Second, a rate controller is proposed to protect high-priority I-frame packets during congestion. BOCC sends a congestion notification to the source node to reduce congestion in the network. The source node adjusts its data transmission rate after receiving the congestion notification message. In the proposed algorithm, the rate adjustment is made by discarding low-priority P-frame packets from the source nodes. Third, to further improve the performance of the BOCC protocol, the problem is formulated as a constrained optimization problem and solved using convex optimization and sequential quadratic programming (SQP) methods. Experimental results based on Raspberry Pi sensor nodes show that the BOCC protocol achieves up to 16% reduction in packet loss and up to 23% reduction in average end-to-end delay compared to state-of-the-art congestion control algorithms. Full article
(This article belongs to the Special Issue Recent Advances in Wireless Ad Hoc and Sensor Networks)
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24 pages, 6631 KiB  
Article
Preparation and Characterization of Cumin Essential Oil Nanoemulsion (CEONE) as an Antibacterial Agent and Growth Promoter in Broilers: A Study on Efficacy, Safety, and Health Impact
by Muhammad Jabbar, Irfan Baboo, Hamid Majeed, Zahid Farooq, Valiollah Palangi and Maximilian Lackner
Animals 2024, 14(19), 2860; https://doi.org/10.3390/ani14192860 - 4 Oct 2024
Cited by 5 | Viewed by 1607
Abstract
This research characterized and explored the effect of cumin essential oil nanoemulsion (CEONE) on broiler growth performance, serum biochemistry, hematological parameters, and cecal microbial count. Day-old (n = 96) broilers (Ross 308) were randomly assigned to six treatments with five replicates of [...] Read more.
This research characterized and explored the effect of cumin essential oil nanoemulsion (CEONE) on broiler growth performance, serum biochemistry, hematological parameters, and cecal microbial count. Day-old (n = 96) broilers (Ross 308) were randomly assigned to six treatments with five replicates of three broilers each. The dietary treatments consisted of negative control (only basal diet), positive control (basal diet + 200 µL of enrofloxacin), 25 µL (basal diet + 25 µL of CEONE), 50 µL (basal diet + 50 µL of CEONE), 75 µL (basal diet + 75 µL of CEONE), and 100 µL (basal diet + 100 µL of CEONE). The broiler’s body weight gain (BWG) after 42 days of treatment exhibited increased weight in the CEONE group (976.47 ± 11.82–1116.22 ± 29.04). The gain in weight was further evidenced by the beneficial microbe load (107 log) compared to the pathogenic strain. All the biochemical parameters were observed in the normal range, except for a higher level of HDL and a lower LDL value. This safety has been validated by pKCSM toxicity analysis showing a safe and highly tolerable dose of cuminaldehyde. In conclusion, this research observed the potential of CEONE as a multifunctional agent. It is a valuable candidate for further application in combating bacterial infections and enhancing animal health and growth. Full article
(This article belongs to the Special Issue Feed Additives in Broiler Nutrition)
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16 pages, 15905 KiB  
Article
Decentralized Stochastic Recursive Gradient Method for Fully Decentralized OPF in Multi-Area Power Systems
by Umair Hussan, Huaizhi Wang, Muhammad Ahsan Ayub, Hamna Rasheed, Muhammad Asghar Majeed, Jianchun Peng and Hui Jiang
Mathematics 2024, 12(19), 3064; https://doi.org/10.3390/math12193064 - 30 Sep 2024
Cited by 14 | Viewed by 1492
Abstract
This paper addresses the critical challenge of optimizing power flow in multi-area power systems while maintaining information privacy and decentralized control. The main objective is to develop a novel decentralized stochastic recursive gradient (DSRG) method for solving the optimal power flow (OPF) problem [...] Read more.
This paper addresses the critical challenge of optimizing power flow in multi-area power systems while maintaining information privacy and decentralized control. The main objective is to develop a novel decentralized stochastic recursive gradient (DSRG) method for solving the optimal power flow (OPF) problem in a fully decentralized manner. Unlike traditional centralized approaches, which require extensive data sharing and centralized control, the DSRG method ensures that each area within the power system can make independent decisions based on local information while still achieving global optimization. Numerical simulations are conducted using MATLAB (Version 24.1.0.2603908) to evaluate the performance of the DSRG method on a 3-area, 9-bus test system. The results demonstrate that the DSRG method converges significantly faster than other decentralized OPF methods, reducing the overall computation time while maintaining cost efficiency and system stability. These findings highlight the DSRG method’s potential to significantly enhance the efficiency and scalability of decentralized OPF in modern power systems. Full article
(This article belongs to the Special Issue Artificial Intelligence and Game Theory)
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46 pages, 10095 KiB  
Article
Spectral Efficiency Maximization for Mixed-Structure Cognitive Radio Hybrid Wideband Millimeter-Wave Transceivers in Relay-Assisted Multi-User Multiple-Input Multiple-Output Systems
by Hafiz Muhammad Tahir Mustafa, Jung-In Baik, Hyoung-Kyu Song, Muhammad Adnan and Waqar Majeed Awan
Sensors 2024, 24(12), 3713; https://doi.org/10.3390/s24123713 - 7 Jun 2024
Cited by 2 | Viewed by 1200
Abstract
This paper proposes a cognitive radio network (CRN)-based hybrid wideband precoding for maximizing spectral efficiency in millimeter-wave relay-assisted multi-user (MU) multiple-input multiple-output (MIMO) systems. The underlying problem is NP-hard and non-convex due to the joint optimization of hybrid processing components and the constant [...] Read more.
This paper proposes a cognitive radio network (CRN)-based hybrid wideband precoding for maximizing spectral efficiency in millimeter-wave relay-assisted multi-user (MU) multiple-input multiple-output (MIMO) systems. The underlying problem is NP-hard and non-convex due to the joint optimization of hybrid processing components and the constant amplitude constraint imposed by the analog beamformer in the radio frequency (RF) domain. Furthermore, the analog beamforming solution common to all sub-carriers adds another layer of design complexity. Two hybrid beamforming architectures, i.e., mixed and fully connected ones, are taken into account to tackle this problem, considering the decode-and-forward (DF) relay node. To reduce the complexity of the original optimization problem, an attempt is made to decompose it into sub-problems. Leveraging this, each sub-problem is addressed by following a decoupled design methodology. The phase-only beamforming solution is derived to maximize the sum of spectral efficiency, while digital baseband processing components are designed to keep interference within a predefined limit. Computer simulations are conducted by changing system parameters under different accuracy levels of channel-state information (CSI), and the obtained results demonstrate the effectiveness of the proposed technique. Additionally, the mixed structure shows better energy efficiency performance compared to its counterparts and outperforms benchmarks. Full article
(This article belongs to the Section Communications)
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21 pages, 9524 KiB  
Article
Evaluation of Efficiency Enhancement in Photovoltaic Panels via Integrated Thermoelectric Cooling and Power Generation
by Muhammad Faheem, Muhammad Abu Bakr, Muntazir Ali, Muhammad Awais Majeed, Zunaib Maqsood Haider and Muhammad Omer Khan
Energies 2024, 17(11), 2590; https://doi.org/10.3390/en17112590 - 27 May 2024
Cited by 9 | Viewed by 2518
Abstract
Among renewable resources, solar energy is abundant and cost effective. However, the efficiency and performance of photovoltaic panels (PVs) are adversely affected by the rise in the surface temperature of solar cells. This paper analyzes the idea of utilizing thermoelectric modules (TEMs) to [...] Read more.
Among renewable resources, solar energy is abundant and cost effective. However, the efficiency and performance of photovoltaic panels (PVs) are adversely affected by the rise in the surface temperature of solar cells. This paper analyzes the idea of utilizing thermoelectric modules (TEMs) to enhance the efficiency and performance of PV panels. The proposed hybrid solar thermoelectric generation (HSTEG) system employs TEMs as thermoelectric coolers (TECs) to enhance panel efficiency and as thermoelectric generators (TEGs) to convert excess heat into additional electricity. This study includes an extensive evaluation of the proposed idea using MATLAB Simulink and experimental validation in indoor as well as outdoor environments. The use of TECs for the active cooling of the PV system leads to an increase in its efficiency by 9.54%. Similarly, the passive cooling by TECs along with the additional power generated by the TEGs from the excessive heat led to an increase in the efficiency of the PV system of 15.50%. The results demonstrate the HSTEG system’s potential to significantly improve PV panel efficiency and energy generation, offering a promising avenue for advancing solar energy technology. Full article
(This article belongs to the Section A1: Smart Grids and Microgrids)
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