Hasil untuk "Plasma engineering. Applied plasma dynamics"

Mustafa Faisal Ghlaim, Asmaa Miran Hussein, Mustafa Fakhir Hussein

The unrelenting effort to mitigate carbon emissions has gained crucial momentum in establishing a secure and sustainable environment. Significant emphasis is being placed on achieving environmental sustainability and enhancing carbon capture. This study highlights the critical importance of solar photovoltaic (PV) energy systems in addressing environmental concerns and strengthening energy sectors. It specifically focuses on the emergence of connected photovoltaic systems and their potential to supply the energy sector while reducing carbon dioxide emissions. Through the design of a connected photovoltaic system with a maximum operating power of 584 kW under conditions of 1000 W/m² and 50°C, consisting of 1,095 modules covering an area of 2,994 m², the study demonstrated the system’s ability to save between 13,636 and 23,117 tons of carbon dioxide. These results indicate that photovoltaic systems are a sustainable and transformative solution capable of maintaining the energy sector’s balance by 2050. Furthermore, they serve as a pivotal link in promoting environmental enhancement through renewable, inexhaustible energy sources.

Devika G, Asha Gowda Karegowda

Due to their wide variety of diseases, oral lesions present a substantial diagnostic problem. This research uses deep learning techniques, particularly the EfficientNetB7 model, to present an automated categorisation analysis of oral lesions. The study divides lesions into benign and malignant categories using the Oral Lesions: Cancer Detection Dataset, comprising 2270 high-resolution pictures. Known for its effectiveness in processing large-scale image collections, the EfficientNetB7 architecture is employed in this work. The model successfully distinguishes between benign and malignant tumors with an exceptional accuracy rate of 99.12%. The study highlights the diagnostic dependability of the model by analyzing its performance, including metrics for sensitivity, specificity, and accuracy. Moreover, the study investigates how interpretable the model’s predictions are, emphasizing essential aspects that support its decision-making process.

Umair Asghar, Muhammad Imran Asjad, Yasser Salah Hamed et al.

Abstract This paper comprehensively analyzes exact solutions for the nonlinear long-short wave interaction system within the optical field. Consider two general techniques in this field, the Sardar sub-equation method, and a new auxiliary-equation technique. These methods are applied to derive a wide range of soliton solutions for nonlinear partial differential equations. By transforming the original partial differential equation into an ordinary differential equation using an appropriate transformation, various types of solitary wave solutions are obtained. The novelty of this work lies in the application of two powerful analytical methods. The study significantly broadens the scope of these techniques and their applications, providing a diverse set of exact solutions. To enhance comprehension, the obtained solutions are visualized through 3D, 2D, contour, and density plots, offering clear insights into the dynamics of solitary waves. Long-short-wave interaction model has many applications in different kinds of areas such as in optical fiber communication, to understand the interaction between different wave components that can influence the transmission of signals. This model is used to study the interaction between ion-acoustic waves and electron plasma waves. This helps in understanding energy transfer and wave stability in plasma, which is essential for applications like fusion energy research and space plasma. This is important in coastal engineering for predicting wave behaviors that affect coastal structures, sediment transport, and tsunami dynamics.

Alfa Unekwiu Dickson, Umonye Eunice Elachi

Drinking water is essential for life worldwide and is used daily. However, the quality of this drinking water varies from one source to another. In this research, analysis of five heavy metals: Pb, Zn, Cu, Mn, and Cd was carried out using the AAS technique in four water samples꞉: upper river water (L1), middle river water (L2), lower river water (L3), and Bottled water. The results of the study showed that Pb was found in the range of 0.411±0.001 mg/L to 0.852±0.021 mg/L in all the water samples analysed which is above the permissible limits of USEPA (0.015 mg/L), WHO (0.01 mg/L), SON (0.01 mg/L), and NAFDAC (0.01 mg/L) indicating health risk. Report from the four samples indicated the concentrations of Zn to be in the range 0.140±0,003 mg/L to 0.171±0.003 mg/L, which is below the permissible limits of USEPA (5.0 mg/L), WHO (5 mg/L), NAFDAC (5 mg/L), and SON (3.0 mg/L), and hence, no possible health risk. The results of the findings showed that the concentration of Cu is within the range of 0.212±0.027 mg/L to 0.761±0.012 mg/L and is found to be lower when compared to WHO (2.0 mg/L), NAFDAC (1.5 mg/L), USEPA (1.3 mg/L), and SON (1.0 mg/L). Mn ranged from 0.140±0.002 mg/L to 0.162±0.002 mg/L, below the standard that all the regulatory agencies set. Cd was found in the range of 0.200±0.001 mg/L to 0.231±0.231 mg/L and was found to be above all the regulatory agencies. Therefore, there is a need to take proactive action following the results of this research, which showed that concentrations of Pb and Cd in all the water samples analysed were detected above the permissible limits of the regulatory bodies, which is a potential health risk, either short-term or long-term, to the human body. The study further reviewed the fact that the bottled water analysed is of no significant quality compared to the river water.

Tianyu Gao, Xuehua Sun, Hongmei Chai

Given the environmental hazards of 2,4,6-trinitrophenol (TNP) and the limitations of existing detection methods, sodium-doped fluorescent carbon dots (Na-CDs) were successfully synthesized via a one-step hydrothermal method using citric acid and ascorbic acid as carbon sources. Compared with undoped carbon quantum dots, Na-CDs exhibited nearly identical surface functional groups but significantly enhanced fluorescence stability and markedly improved selective responsiveness toward TNP. Accordingly, a Na-CD-based fluorescent probe was developed for the highly selective detection of TNP. Results demonstrated a good linear relationship between the relative fluorescence intensity change (<i>F</i>₀ − <i>F</i>)/<i>F</i>₀ and TNP concentration ranging from 7 × 10⁻⁷ to 2 × 10⁻⁵ mol/L, with a detection limit of 3.5 × 10⁻⁸ mol/L. When applied to detect TNP in local river water samples, the method achieved recoveries of 95.40–104.0%, confirming its reliability for real-world environmental sample analysis. This study develops a novel, sensitive, and highly selective approach for monitoring TNP in environmental systems.

Okebule Toyin, Oguntimilehin Abiodun, Abiola O.B

Hypertension, also known as high blood pressure, is a major risk factor for cardiovascular diseases and stroke, and it often progresses silently until severe complications arise. Early detection is therefore essential for timely management and prevention. Traditional screening methods, however, do not always integrate multiple risk factors for accurate and early identification. This study develops a hypertension prediction system using deep learning and ensemble machine-learning techniques based on a dataset containing demographic, clinical, and lifestyle features. A Multi-Layer Perceptron (MLP), Random Forest, and XGBoost were trained and evaluated, with the Random Forest achieving an accuracy of 87.13%, XGBoost 84.50%, and the MLP 76.28%. An ensemble of the three models achieved 94% accuracy, indicating improved stability and predictive capability. While the system performs well, limitations such as possible overfitting and population-specific bias are noted. The study contributes to AI-driven healthcare by demonstrating a practical approach for early hypertension risk prediction. Future work may involve expanding the dataset, incorporating additional clinical indicators, and improving model robustness across diverse populations.

Thakrar Pooja Tulshibhai, N. D. Zala

This study explores the key factors influencing consumer behavior in the organic food market of Rajkot City. Empirical research reveals that price is the most significant determinant across demographic groups, strongly influenced by age, education, occupation, and monthly income. Age and income moderately affect brand perception, suggesting its relevance for specific consumer segments. Taste plays a crucial role, particularly among different genders, and is slightly influenced by education, highlighting the importance of sensory appeal in purchase decisions. While health benefits, environmental concerns, and organic certifications show limited demographic influence, they remain universal motivators for organic food consumption. The study also identifies key barriers: gender influences perceptions of limited availability, while age and education significantly affect awareness levels. Additionally, education impacts perceptions of availability, and occupation plays a role in consumer awareness. Notably, monthly income does not significantly affect any of the identified barriers. These insights contribute to a better understanding of consumer preferences and challenges in the organic food sector, offering valuable implications for marketers, policymakers, and businesses aiming to promote sustainable and organic consumption in Rajkot City.

Mahmood A. Mohammed, Mohammed Z. Hasan, Mohammed Salam Taha

In this research, the fatigue resistance of low alloy steel was improved by using surface hardening by gas nitridation at different temperatures, 475 to 610°C, and in a medium containing 70% nitrogen and 30% hydrogen. The results obtained showed a significant improvement in the fatigue resistance of the samples used after the nitridation process, where the highest fatigue resistance was obtained (580 MPa) at the temperature range 475 to 510°C. At the same time, there was a decrease in the fatigue resistance when using high temperatures in the gas nitridation process, which decreased to 400 MPa at 610 °C. In comparison, the value of the fatigue resistance before nitridation was 325 MPa. Through the results of the micro hardness and tensile test, it was found that there was an increase in the hardness tensile strength values on the surface and in general for all groups of samples treated by nitriding, It was also observed that the hardness gradually decreased smoothly as we moved away from the surface towards the depth, as the metal retains good hardness up to a depth of 300 microns. It helps to avoid the sudden and non-gradual transition from a rigid surface to a soft center. Thus, a structure of sufficient thickness is formed from the nitriding layer, coherent with the core. The results of the X-ray diffraction examination also showed the formation of nitrides of various alloying elements, Fe3N, Fe4N, Cr2N, Fe2Al5, Al2N, which have a significant role in increasing the hardness and improving the fatigue resistance.

Hira Ashaq, Sheikh Zain Majid, Muhammad Bilal Riaz et al.

The current study explores the (2+1)-dimensional Chaffee-Infante equation, which holds significant importance in theoretical physics renowned reaction-diffusion equation with widespread applications across multiple disciplines, for example, ion-acoustic waves in optical fibres, fluid dynamics, electromagnetic wave fields, high-energy physics, coastal engineering, fluid mechanics, plasma physics, and various other fields. Furthermore, the Chaffee-Infante equation serves as a model that elucidates the physical processes of mass transport and particle diffusion. We employ an innovative new extended direct algebraic method to enhance the accuracy of the derived exact travelling wave solutions. The obtained soliton solutions span a wide range of travelling waves like bright-bell shape, combined bright-dark, multiple bright-dark, bright, flat-kink, periodic, and singular. These solutions offer valuable insights into wave behaviour in nonlinear media and find applications in diverse fields such as optical fibres, fluid dynamics, electromagnetic wave fields, high-energy physics, coastal engineering, fluid mechanics, and plasma physics. Soliton solutions are visually present by manipulating parameters using Wolfram Mathematica software, graphical representations allow us to study solitary waves as parameters change. Observing the dynamics of the model, this study presents sensitivity in a nonlinear dynamical system. The applied mathematical approaches demonstrate its ability to identify reliable and efficient travelling wave solitary solutions for various nonlinear evolution equations.

Gopichand Gatti, Rahul Kumar Singh, V Pavan Kumar

Concrete, as a fundamental construction material, is constantly evolving to enhance its performance and sustainability. This study explores the effects of incorporating natural zeolite powder and glass powder as partial replacements for cement in M50 grade concrete. The experimental investigation evaluates the compressive, split tensile, and flexural strengths of concrete specimens at 7, 14, and 28 days. Concrete mixtures containing various proportions of zeolite powder (10%, 20%, 30%) and glass powder (10%, 20%, 30%), both individually and in combination, were prepared and tested. Results indicate that the inclusion of zeolite and glass powders positively influences the strength properties of concrete, with certain mixes outperforming conventional concrete. The analysis of experimental data provides insights into the strength enhancement mechanisms and underscores the potential of these supplementary materials to improve the durability and sustainability of concrete structures. These findings contribute to the development of eco-friendly and high-performance concrete, advancing the field of construction materials engineering.

Mohd Aqib Aslam

Carbon capture and storage (CCS) has become a vital technological advancement in the fight against climate change by lowering greenhouse gas emissions from energy generation and industrial operations. However, the development and application of CCS technologies confront formidable legal and policy obstacles despite their potential to help achieve global carbon reduction goals. This study examines the legislative and policy tools required to support the implementation of CCS as a sustainable energy choice. To solve these issues, it evaluates national, regional, and international legal methods and the regulatory gaps that prevent CCS projects from being widely implemented. The analysis focuses on identifying the factors that hinder and facilitate the deployment of CCS, including environmental regulations, intellectual property rights, liability concerns, and public participation. The research also examines how current international climate agreements, like the Paris Agreement, impact CCS’s regulatory environment. This paper identifies optimal methods for establishing a favorable legal environment by evaluating case studies from nations with advanced CCS efforts. Lastly, suggestions are made for coordinating legislative and regulatory frameworks so that CCS can significantly contribute to realizing sustainable energy transitions.

J. Shi, Bingchen Li, Lei Li et al.

Tungsten (W) is regarded as a viable choice for plasma-facing materials in nuclear fusion reactors. However, its mechanical properties are significantly degraded by hydrogen (H) atoms during irradiation, of which the mechanism is still elusive. In this study, we conduct molecular dynamics (MD) simulations to study the impact of H atoms on the propagation of a crack in single crystal W. The results show that the propagation rate of the crack slows down with increasing temperature. This is due to the enhanced plastic deformation, leading to blunting of the crack tip. A pre-existing crack in W is then considered at various temperatures and uniaxial applied tensile strain conditions. The propagation rate of the crack decreases with the increase of the applied tensile strain rate. This phenomenon occurs due to the relaxation of the stress around the crack tip following the emission of the dislocation at high strain rates. After introducing H atoms, it can be observed that at low temperatures, H impedes the propagation of the crack, while at high temperatures, H promotes it. This is primarily due to the formation of voids at the slip traces of dislocations and the reduction in surface energy. Additionally, the crack tip becomes blunted and its propagation rate decreases with increasing strain rate. These results indicate that providing sufficient time for H atoms to migrate is a key factor affecting the mechanical properties of W. The current results provide valuable insights into understanding the interaction mechanism of a crack and H atoms in W.

Ajay Kumar, Raj Shekhar Prasad

In this paper, we study a nonlinear fractional Damped Burger and Sharma–Tasso–Olver equation using a new novel technique, called homotopy perturbation transform method (FHPTM). There are three examples used to demonstrate and validate the proposed algorithm’s efficiency. This nonlinear model depicts nonlinear wave processes in fluid dynamics, ecology, solid-state physics, shallow-water wave propagation, optical fibers, fluid mechanics, plasma physics, and other applied science, engineering, and mathematical physics disciplines, as well as other phenomena. Numerous algebraic properties of the fractional derivative Caputo–Fabrizio operator are illustrated concerning the Laplace transformation to demonstrate their utility. Different graphs and tables compare the results obtained by R. Nawaz et al. [Alex. Eng. J. 60, 3205 (2021)] and M. S. Rawashdeh [Appl. Math. Inform. Sci. 9, 1239 (2015)]. The proposed scheme accelerates the convergence of the series solution and guarantees the convergence associated with the homotopy parameter. Furthermore, the physical nature of various fractional orders has been captured in plots. The obtained results demonstrate that the employed solution procedure is dependable and methodical in investigating the behaviors of nonlinear models of both integer and fractional orders.

Rongchang Fu, Wang Kun, Wu Hui

BACKGROUND: Sand therapy is a non-pharmacological physiotherapy method that uses the natural environment and resources of Xinjiang to treat through the heat transfer and magnetic effects of sand. OBJECTIVE: Employing the two-phase flow-Casson blood flow model, we investigate the mechanism of atherosclerosis prevention via sand therapy, offering a biomechanical theoretical rationale for the prevention of atherosclerosis through sand therapy via the prism of computational fluid dynamics (CFD). METHODS: Sand therapy experiments were conducted to obtain popliteal artery blood flow velocity, and blood was considered as a two-phase flow composed of plasma and red blood cells, and CFD method was applied to analyze the hemodynamic effects of Casson’s blood viscosity model before and after sand therapy. RESULTS: (1) The blood flow velocity increased by 0.24 m/s and 0.04 m/s at peak systolic and diastolic phases, respectively, after sand therapy; the axial velocity of blood vessels increased by 28.56% after sand therapy. (2) The average red blood cell viscosity decreased by 0.00014 Pa ⋅ s after sand therapy. (3) The low wall shear stress increased by 1.09 Pa and the high wall shear stress reached 41.47 Pa after sand therapy. (4) The time-averaged wall shear stress, shear oscillation index and relative retention time were reduced after sand therapy. CONCLUSION: The increase of blood flow velocity after sand therapy can reduce the excessive deposition of cholesterol and other substances, the decrease of erythrocyte viscosity is beneficial to the migration of erythrocytes to the vascular center, the increase of low wall shear stress has a positive effect on the prevention of atherosclerosis, and the decrease of time-averaged wall shear stress, shear oscillation index and relative retention time can reduce the occurrence of thrombosis.

M. M. Shanmugapriya

Global economic activity is driven by business. The significant transformation in how firms across industries, inside and outside the digital economy, develop, produce, and market their goods and services is a result of the expanding use of digital technology. The major goal of this article is to identify the various digital platforms used in business development in Chennai and to assess the challenges experienced by businesspeople in implementing these platforms. Numerous businesses in Chennai cater to both locals and tourists, including clothing stores, digital marketing agencies, IT service providers, and others. 200 businesspeople from those five firms are chosen as the sample unit and size of this study utilizing a practical random method. The entire focus of this study work is description. Primary data is gathered via a well-designed questionnaire that is divided into three sections: demographics of the respondents, use of digital platforms, and issues experienced by businesspeople in Chennai City with digital platforms. Annual reports, journals, periodicals, books, and newspapers are used to gather secondary data. The gathered data were analyzed using percentage analysis, the weighted average method, and the Kruskal-Wallis test. The study’s conclusions showed a strong correlation between businesspeople’s investments and the extent to which they use digital platforms for their operations.

Andrey Sarikov

High-temperature anneals of nonstoichiometric Si oxide (SiO_x, <i>x</i> < 2) films induce phase separation in them, with the formation of composite structures containing amorphous or crystalline Si nanoinclusions embedded in the Si oxide matrix. In this paper, a thermodynamic theory of the phase separation process in SiO_x films is proposed. The theory is based on the thermodynamic models addressing various aspects of this process which we previously developed. A review of these models is provided, including: (i) the derivation of the expressions for the Gibbs free energy of Si oxides and Si/Si oxide systems, (ii) the identification of the phase separation driving forces and counteracting mechanisms, and (iii) the crystallization behavior of amorphous Si nanoinclusions in the Si oxide matrix. A general description of the phase separation process is presented. A number of characteristic features of the nano-Si/Si oxide composites formed by SiO_x decomposition, such as the local separation of Si nanoinclusions surrounded by the Si oxide matrix; the dependence of the amount of separated Si and the equilibrium matrix composition on the initial Si oxide stoichiometry and annealing temperature; and the correlation of the presence of amorphous and crystalline Si nanoinclusions with the presence of SiO_x (<i>x</i> < 2) and SiO₂ phase, respectively, in the Si oxide matrix, are explained.

Cesar A. Barbero

Different methods which could be used to produce colloidal dispersions of polyaniline (PANI) nano-objects without templates are described. While the methods are non-deterministic, different nano-objects (nanospheres, nanofibers, nanobelts, nanorice, nanotubes, nanorods, nanodisks, etc.) can be produced. Those most used are: (i) solution polymerization with steric stabilizers (SPS) to produce nanospheres, (ii) interfacial polymerization (IP) to produce nanofibers and (iii) solution polymerization in the presence of additives (SPA) to produce nanotubes. Oxidation of aniline in aqueous solution could produce nanotubes, nanofibers and other shapes by controlling mass transport/concentration of reactants, pH, and the presence of oligomers/additives. The different models proposed to explain the formation of various nano-objects are discussed. Mechanochemical polymerization (MCP) could produce nanofibers or nanospheres by controlling the aniline/oxidant ratio. PANI nanospheres of tunable sizes can also be produced by nanoprecipitation (NPT) of preformed PANI from its solutions using an antisolvent. The geometrical constraints to the small nano-objects made of high-molecular-weight rigid polymers are described. The conditions to produce nanostructures also affect the intrinsic properties of PANI (conductivity, crystallinity, and electroactivity). Selected technological applications of PANI nano-objects manufactured as colloidal dispersions without templates are discussed. Based on the reviewed work and models, future lines of work are proposed.

Ayesha Kausar, Ishaq Ahmad, Tingkai Zhao et al.

This article fundamentally reviews progress in the design and manufacturing of three-dimensional (3D) graphene-based nanocomposites for technical applications. The 3D graphene nanostructures have been manufactured using techniques like the template method, chemical vapor deposition, sol-gel, freeze-drying, hydrothermal technique, and other approaches. The nanofoam has been reinforced in polymers to achieve superior structural, morphological, and physical characteristics of the ensuing polymer/graphene nanofoam nanocomposites. The polymer/graphene nanofoam nanocomposites have been manufactured using the approaches like direct template method, in situ technique, infiltration process, and other methods. The 3D nanofoam- and polymer-based nanostructures have shown high specific surface area, suppleness, electron transport, thermal conduction, mechanical resilience, and other physical properties. The technical applications of hierarchical graphene nanofoams have been observed in the fields of radiation shielding, solar cells, supercapacitors, fuel cells, and other applications.

Aslan Mussin, Ali A. AlJulaih, Neli Mintcheva et al.

This article reports on polymer (PLLA, poly(L-lactic acid)) nanosheets incorporated with Fe-ion nanoparticles, aiming at using the latter nanoparticles as a source to release Fe ions. Such Fe ions should facilitate burn wound healing when such nanosheets are applied as a biomedical tissue on skin. Laser ablation in liquid phase was used to produce Fe-containing nanoparticles that, after incorporation into PLLA nanosheets, would release Fe ions upon immersion in water. Unlike most iron-oxide nanostructures, which are poorly soluble, such nanoparticles prepared in chloroform were found to have water solubility, as they were shown by XPS to be based on iron chloride and oxide phases. After incorporation into PLLA nanosheets, the ion-release test demonstrated that Fe ions could be released successfully into water at pH 7.4. Incorporation with two different metal ions (Fe and Zn) was also found to be efficient, as both types of ions were demonstrated to be released simultaneously and with comparable release rates. The results imply that such polymer nanosheets show promise for biomedical applications as potential patches for healing of burns.

Ashraful Hossain Howlader, Ashraf Uddin

Chloride–iodide perovskites have received substantial interest due to their better photovoltaic performance compared to pure iodide ones. The superior properties of chloride–iodide perovskites boost photovoltaic performance. However, quantifying the Cl composition in perovskite films remains challenging. Hence, it is not easy to correlate the Cl quantity with the improved photovoltaic performance. Considering this critical issue, it is still necessary to determine the correlation between the Cl quantity and the improved photovoltaic performance to solve this puzzle. Here, a critical review is presented showcasing the significant impacts of the Cl quantity on chloride–iodide perovskites and related solar cell devices. This review provides an up-to-date picture of different strategic methods to overcome the challenges of Cl incorporation in I-based perovskites, aiming to improve photovoltaic performance. Finally, some valuable remedies are prescribed for potential future research strategies to study the photovoltaic performance of chloride–iodide perovskite solar cells. Hopefully, this review will be a noteworthy scientific contribution to the advancement of the continuous progress of perovskite solar cells.