Hasil untuk "Plasma engineering. Applied plasma dynamics"

Venkata Lakshmi Keerthi K, Vijayalakshmi P, Rajendran V

Side-scan sonar images present significant challenges for object detection due to high noise levels, limited spatial resolution, and complex seabed structures. These factors, along with speckle noise and acoustic shadowing effects, further complicate reliable target detection. Nonetheless, object detection is extremely important in many areas, including marine archaeology, underwater search and rescue, mine countermeasures operations, and the inspection of critical national infrastructure, to improve safety and operational efficiency. In this work, a hybrid convolutional neural network (CNN) is presented for object detection in challenging side-scan sonar imagery. The proposed model combines the complementary feature-extraction capabilities of VGG-16 and ResNet-50 via feature fusion to improve target discrimination in sonar images. Transfer learning from ImageNet-pretrained backbones is employed to address data sparsity and improve model generalization on sonar datasets. Experimental evaluation demonstrates that the proposed model achieves an overall classification accuracy of 84.2% and a mean Average Precision (mAP) of 88.35%, outperforming several existing methods. The results pave the way to enhance the efficacy and accuracy of underwater surveys, search-and-rescue missions, and seabed mapping.

Chenyang Liu, Xiong He, Yunli Xu et al.

In recent years, antiferromagnetic kagome materials have attracted considerable attention in condensed matter physics owing to their distinctive lattice geometry. In this work, high-quality single crystals of D019-structured Mn_2.16Ga were grown using the flux method, and their magnetotransport properties were systematically studied. Measurements of magnetization versus field (M–H), temperature-dependent magnetization (M–T), and the anomalous Hall effect confirm that the crystal undergoes a magnetic-structural transition driven by both temperature and the magnetic field. Remarkably, a coexistence of positive and negative longitudinal magnetoresistance (MR) is observed in Mn_2.16Ga. The MR shows a field-induced sign change from negative to positive. The negative MR is attributed to field-modified magnetic ordering, whereas the positive MR originates mainly from interlayer electron conduction in the kagome lattice and distortion of the in-plane triangular arrangement of Mn magnetic moments. These results offer valuable insights into the electronic and magnetic transport behavior of Mn-based antiferromagnetic single crystals.

D. Chou, S. A. Baloch, Imran Siddique et al.

The nonlinear Fisher equation, which can be applied to crystallization, fluid dynamics, fiber optics, plasma, and biological population models, is of particular importance. We build bilinear equations using Hirota’s derivatives, and then we compute several kinds of solitons. We use the Hirota Bilinear Method (HBM) and the ansatz approach to develop Lump Solution (LS), Multi-Waves (MWs), Ma-Breathers (MBs), Kuznetsov-Ma-Breathers (KMBs), and Rogue Waves solutions (RWs) for the proposed model. In the domains of science and engineering, the developed wave solutions are highly significant. We also investigated the stability analysis of the proposed model by using the linear stability approach. Solutions for breathers could be applied to increase the effectiveness of solitons in plasma waves and optical communication systems. Lump wave solutions can be used to manipulate and control laser beams for material manufacturing or laser surgery, whereas rogue wave solutions can help ensure the safety of ships and oil rigs. Under certain constraints, we additionally investigate one, two, and other soliton interactions for suggested model. To anticipate the wave dynamics, specific 2D, 3D, and contour portraits are also examined with the help of computing software Mathematica. To regulate fusion as a potential energy source in the future, these interactions may be applied to plasma stability and containment. This work presents a novel contribution to the field by exploring soliton solutions of the nonlinear Fisher equation. To the best of our knowledge, this research has not been previously addressed in the literature. The suggested method provides a more powerful computational framework for examining Non Linear Evolution Equations (NLEEs) in engineering and mathematical sciences and yields a wide variety of solutions.

Cesar A. Barbero, Petr Slobodian, Robert Olejnik et al.

A simple method is developed to produce free-standing films of polypyrrole (PPy) in one step. It consists of the interfacial polymerization (without surfactants) of pyrrole (dissolved in chloroform) with an oxidant (ammonium persulfate, dissolved in water). It is observed that the area of the formed film only depends on the size of the interface, achieving the manufacture of PPy films of up to 300 cm², with a thickness of 200 microns. Transmission electron microscopy (TEM) images show the presence of superimposed nanoplatelets of ca. 100 nm main axis. These nanoparticles seem to aggregate in two dimensions to form the free-standing film. Scanning electron microscopy (SEM) shows a compact surface with nanowires decorating the surface. PPy films show an electrical conductivity of 63 (±3) S cm⁻¹. PPy conductive films are then applied in the construction of an antenna that shows a response in two bands: at 1.52 GHz (−13.85 dB) and at 3.50 GHz (−33.55 dB). The values are comparable to those of other antennas built with different PPy films. The simple synthesis of large-area PPy films in a single step would allow the fabrication of large quantities of electronic elements (e.g., sensors) with uniform properties in a short time.

Sevastia Gkiouzel, Vasileios Ioannou, Christina Gioti et al.

MgO–C refractory materials were developed by incorporating different ratios of alumina/titania nano-additives which were synthesized chemically. Their physical and mechanical properties, oxidation resistance, slag wettability, bulk density, apparent porosity, cold crushing strength, oxidation index, and closed porosity were tested, evaluated, and compared using conventional techniques as well as X-ray micro-computed tomography (µCT). This investigation indicated a slight degradation of physical properties and mechanical strengthening which was stronger for samples with increased alumina content. Oxidation and corrosion extent were tested both with X-ray tomography and conventional methods. The first method allowed for the calculation of the oxidation index, the detection of closed porosity, and an improved analysis of the internal corrosion, avoiding the sectioning of the materials. This result confirms the supremacy of the first technique. On the contrary, although conventional methods such as the Archimedes procedure cannot detect close porosity, they provide more accurate measurements of the physical properties of refractories. This study shows that conventional methods exhibit superiority in investigations of the pore structures of refractories for pore sizes in the range 1–2 μm, while the use of the μCT system is limited for pore sizes equal to or larger than 20 μm.

Jogen Sharma

This paper examines the state and challenges of public libraries in India amid the ongoing digital transformation. With over 75,000 rural and nearly 5,000 urban libraries, India’s public library network plays a crucial role in democratizing information access but faces significant issues, including funding disparities, staffing shortages, uneven ICT adoption, and limited digital resources, particularly in rural and underserved areas. The study examines staffing patterns, budgeting, collection development, ICT integration, and national policy frameworks, utilizing government reports and relevant literature. Findings highlight critical gaps in infrastructure, professional capacity, and policy implementation that hinder efforts to modernize. The paper recommends targeted investments in digital infrastructure, professional training, stable funding mechanisms, policy reform, and the development of multilingual resources to bridge the digital divide and enhance library services for inclusive lifelong learning.

Lucas Diniz Araujo, Bianca Sartori, Matheus Damião Machado Torres et al.

Metal-oxide heterostructures represent an effective strategy to overcome the limitations of pristine TiO₂, including its ultraviolet-only light absorption and rapid electron–hole recombination, which hinder its performance in solar-driven applications. Among various configurations, coupling TiO₂ with tungsten oxide (WO_x) forms a favorable type-II band alignment that enhances charge separation. However, a comprehensive understanding of how WO_x overlayer thickness affects the optical and photoelectrochemical (PEC) behavior of device-grade thin films remains limited. In this study, bilayer TiO₂/WO_x heterostructures were fabricated via reactive DC magnetron sputtering, with controlled variation in WO_x thickness to systematically investigate its influence on the structural, optical, and PEC properties. Adjusting the WO_x deposition time enabled precise tuning of light absorption, interfacial charge transfer, and donor density, resulting in markedly distinct PEC responses. The heterostructure obtained with 30 min of WO_x deposition demonstrated a significant enhancement in photocurrent density under AM 1.5G illumination, along with reduced charge-transfer resistance and improved capacitive behavior, indicating efficient charge separation and enhanced charge storage at the electrode–electrolyte interface. These findings underscore the potential of sputtered TiO₂/WO_x bilayers as advanced photoanodes for solar-driven hydrogen generation and light-assisted energy storage applications.

Alfa Unekwu Dickson, Umonye Eunice Elachi

Food insecurity remains a pressing global issue, particularly in rapidly growing communities such as Odugbo, which may face challenges in sustaining food supply due to increasing population pressure. To mitigate this, the adoption of off-season irrigation farming becomes essential. In this study, water samples were collected during the dry season from three points along a river in the Odugbo area: the upper course (P1), middle course (P2), and lower course (P3). Physical parameters, heavy metal concentrations using Atomic Absorption Spectrophotometry (AAS), and anion levels via titration methods were analyzed. The results showed: Temperature 28.2 ± 0.05 – 28.60 ± 0.05 °C, pH 6.12 ± 0.063 – 6.79 ± 0.05, TDS 1022 ± 2.00 – 1026 ± 2.00 mg/L, DO 5.75 ± 0.11 – 7.19 ± 0.09 mg/L, BOD 0.13 ± 0.01 – 0.57 ± 0.05 mg/L, Electrical Conductivity 825 ± 3.00 – 875 ± 4.00 µS/cm, Turbidity 1.7 ± 0.00 – 2.1 ± 0.00 NTU, Pb 0.521 ± 0.852 mg/L, Zn 0.140 ± 0.003 – 0.158 mg/L, Cu 0.212 ± 0.027 – 0.751 ± 0.023 mg/L, Mn 0.141 ± 0.003 – 0.162 ± 0.002 mg/L, Cd 0.221 ± 0.002 – 0.231 ± 0.003 mg/L, Cl⁻ 80.61 ± 0.010 – 110.58 ± 0.022 mg/L, NO₃⁻ 25.81 ± 0.01 – 45.33 ± 0.01 mg/L, PO₄³⁻ 0.023 ± 0.0007 – 0.190 ± 0.01 mg/L, and SO₄²⁻ 78.53 ± 0.001 – 115.22 ± 0.02 mg/L. The findings suggest that the river water is generally suitable for irrigation farming, as most of the tested parameters fall within the FAO-recommended limits for irrigation water quality.

Spyridoula G. Farmaki, Panagiota T. Dalla, Dimitrios A. Exarchos et al.

This study explores the influence of various nano-inclusions on the electrical and thermal properties of cement-based materials. Specifically, it investigates the incorporation of Multi-Walled Carbon Nanotubes (MWCNTs) and Graphene Nanoplatelets (GNPs) as reinforcement materials in cement composites. These advanced nanomaterials enhance the mechanical strength, durability, and functional properties of cementitious matrices. A series of experimental tests was conducted to evaluate the thermal and electrical behavior of nano-reinforced concrete, employing nondestructive evaluation techniques, such as Infrared Thermography (IRT) and Electrical Resistivity measurements. The results indicate that increasing the concentration of nanomaterials significantly improves both the thermal and electrical conductivity of the composites. Optimum performance was observed at a CNT dosage of 0.6% and a GNP dosage of 1.2% by weight of cement in cement paste, while in concrete, both nanomaterials showed a significant decrease in resistivity beginning at 1.0%, with optimal performance at 1.2%. The study also emphasizes the critical role of proper dispersion techniques, such as ultrasonication, in achieving a homogeneous distribution of nanomaterials within the cement matrix. These findings highlight the potential of carbon nanotubes (CNTs) and GNPs to enhance the multifunctional properties of cement-based materials, paving the way for their application in smart and energy-efficient construction applications.

Saniul Haque Mahi, Md. Sabbir Ahmed, Mehedi Hasan et al.

The significance of concrete in the construction sector may include strength and durability, but because of the low tensile strength and the cracking tendencies, its applicability is severely limited on many occasions. Fibers are also finding their way into concrete to counter such problems by enhancing their tensile strength, crack-bridging capacity, and general durability. This paper reflects on the effects of jute fiber reinforcement on the mechanical properties of concrete, in this case, compressive strength, split tensile strength, and workability. M20-grade concrete was mixed with jute fibers at 0.1%, 0.2%, and 0.4% volume fractions and treated with three different methods: alkali (6% NaOH), acidic (2% HCl), and hot water (80–100°C). Workability of the concrete was determined by carrying out a slump test, and the mechanical behavior of the concrete by the compressive and split tensile strength tests. It was found that by the addition of the jute fibers, there was a decrease in the workability of the mixture, such that an increase in fiber content resulted in a decrease in the slump. The alkali treatment enhanced workability and fiber dispersion, whereas the acidic treatment had the greatest impact on the reduction of workability since the fibers are degraded in the acidic treatment. As far as strength is concerned, alkali-treated jute fibers resulted in the best improvements on compressive and split tensile strength, especially for low fiber contents. Untreated and acidic-treated fibers, on the other hand, were weaker, especially at higher contents, because fibers did not disperse well and were weakly bonded to the matrix. It can be concluded that alkali treatment on jute fiber reinforced concrete improves strength and durability to a significant extent.

D. Hamm, C. Theiler, M. Simeoni et al.

Plasma diagnostics often employ computerized tomography to estimate emissivity profiles from a finite, and often limited, number of line-integrated measurements. Decades of algorithmic refinement have brought considerable improvements, and led to a variety of employed solutions. These often feature an underlying, common structure that is rarely acknowledged or investigated. In this paper, we present a unifying perspective on sparse-view tomographic reconstructions for plasma imaging, highlighting how many inversion approaches reported in the literature can be naturally understood within a Bayesian framework. In this setting, statistical modelling of acquired data leads to a likelihood term, while the assumed properties of the profile to be reconstructed are encoded within a prior term. Together, these terms yield the posterior distribution, which models all the available information on the profile to be reconstructed. We show how credible reconstructions, uncertainty quantification and further statistical quantities of interest can be efficiently obtained from noisy tomographic data by means of a stochastic gradient flow algorithm targeting the posterior. This is demonstrated by application to soft x-ray imaging at the TCV tokamak. We validate the proposed imaging pipeline on a large dataset of generated model phantoms, showing how posterior-based inference can be leveraged to perform principled statistical analysis of quantities of interest. Finally, we address some of the inherent, and thus remaining, limitations of sparse-view tomography. All the computational routines used in this work are made available as open access code.

S. Tuomivaara, Chin Fen Teo, Y. Jan et al.

To facilitate our understanding of proteome dynamics during signaling events, robust workflows affording fast time resolution without confounding factors are essential. We present Surface-exposed protein Labeling using PeroxidaSe, H2O2, and Tyramide-derivative (SLAPSHOT) to label extracellularly exposed proteins in a rapid, specific, and sensitive manner. Simple and flexible SLAPSHOT utilizes recombinant soluble APEX2 protein applied to cells, thus circumventing the engineering of tools and cells, biological perturbations, and labeling biases. We applied SLAPSHOT and quantitative proteomics to examine the TMEM16F-dependent plasma membrane remodeling in WT and TMEM16F KO cells. Time-course data ranging from 1 to 30 min of calcium stimulation revealed co-regulation of known protein families, including the integrin and ICAM families, and identified proteins known to reside in intracellular organelles as occupants of the freshly deposited extracellularly exposed membrane. Our data provide the first accounts of the immediate consequences of calcium signaling on the extracellularly exposed proteome. Surface-exposed protein Labeling using PeroxidaSe, H2O2, and Tyramide-derivative (SLAPSHOT) coupled with mass spectrometry reveals the dynamics in the extracellularly exposed protein landscape in short time scales.

Johanna Rimböck, Patrick Schuster, Lisa Vsetecka et al.

In this work, three different coating techniques are compared and their applicability for ultraviolet nanoimprint lithography (UV-NIL) is investigated. As UV-NIL is considered a suitable volume manufacturing production solution for various emerging applications, it is mandatory to consider environmental aspects such as operational energy use and material consumption as well as waste management. In this paper, spin coating, spray coating, and inkjet coating are used to coat both a high refractive index resin (n = 1.9) and a filler-free resin (n = 1.5), respectively. Variable Angle Spectroscopy Ellipsometry (VASE) was used to analyze the influence of different process parameters on the resin thickness as well as to compare the refractive index achieved from each coating technology. Finally, the applicability of the different coating methods for UV-NIL was investigated by imprinting the resin layers with different test structures. For the final imprints, the resolution, the surface roughness, and the pattern fidelity over 25 imprints was assessed using AFM. Finally, a comparison of the resin consumption and the process time was performed for each coating method.

Seelam Rajesh, K. Sai Anitha, Ch. Sivanarayana

This study investigates the use of ceramic insulator waste (CIW) as a partial replacement for coarse aggregate in concrete, along with the effects of curing conditions on the mechanical properties of the resulting concrete mixtures. Concrete specimens with varying percentages of CIW replacement (0%, 2%, 4%, 6%, 8%, and 10%) were subjected to compressive strength, flexural strength, and tensile strength tests at 7 days, 14 days, and 28 days. Additionally, the specimens were cured under both traditional water curing and acidic curing conditions to assess the impact of different curing environments on concrete performance. The results indicate a consistent increase in compressive strength, flexural strength, and tensile strength of concrete with increasing CIW replacement by up to 4%, regardless of the curing method. However, beyond the 4% replacement threshold, there is a slight decline in mechanical properties. Furthermore, the study highlights the necessity of optimizing mix proportions and implementing quality control measures to mitigate the negative effects of higher CIW replacement ratios. These steps are essential to ensure the durability and structural integrity of concrete structures. This research contributes to the growing body of knowledge on sustainable construction materials and provides valuable insights for engineers and researchers aiming to develop environmentally friendly and structurally sound concrete mixtures.

Yuyan Liu, Xavier Ferrer-Florensa, Claus Sternberg et al.

Initial studies indicate that structured polymer surfaces can support the attachment and biofilm formation of bacteria and thereby provide enhanced positive effects of beneficial bacteria, for instance in biocontrol in aquacultures. In this study, we demonstrate a test platform to further explore the surface topography for bacterial attachment and biofilm growth. It is based on a cyclic olefin copolymer (COC) materials platform, and nanoimprint technology was used for the replication of microstructures. The use of nanoimprint technology ensures precise micropattern transfer, enabling easy prototyping. Further, the process parameters of the mold preparation and nanoimprinting are discussed, with the purpose of optimizing the polymer pattern profile. This study has the potential to identify promising surfaces for biofilm growth of beneficial bacteria.

A. Radhika, K. Satyamurthy

Food plays a vital role in maintaining the body, enhancing mental capacity, boosting immunity, and extending longevity. This paper explores the multidimensional significance of food in yogic practice, drawing from classical texts such as the Upanishads, Bhagavad-Gita, and Hatha Yoga Pradipika. These texts emphasize the classification of food into sattvic, rajasik, and tamasik, highlighting their effects on physical, mental, and spiritual well-being. The discussion extends to the functional value of food in yoga, focusing on its role in achieving harmony across physical, astral, and magnetic planes. Food is presented as a bridge between terrestrial needs and spiritual aspirations, fostering a balance between physiological, psychological, and transcendental dimensions. The paper also examines how food supports yoga practice through its therapeutic qualities, aligning with seasonal and geographical factors, and enabling holistic wellness. By integrating ancient wisdom with modern perspectives, the paper underscores the transformative power of yogic food, not only as nourishment but also as a tool for achieving self-realization and spiritual harmony.

Zhixin Lu, Guo Meng, Eric Sonnendrücker et al.

This paper presents a novel approach for simulating plasma instabilities in tokamak plasmas using the piecewise field-aligned finite element method in combination with the particle-in-cell method. Our method traditionally aligns the computational grid but defines the basis functions in piecewise field-aligned coordinates to avoid grid deformation while naturally representing the field-aligned mode structures. This scheme is formulated and implemented numerically. It also applied to the unstructured triangular meshes in principle. We have conducted linear benchmark tests, which agree well with previous results and traditional schemes. Furthermore, multiple-$n$ simulations are also carried out as a proof of principle, demonstrating the efficiency of this scheme in nonlinear turbulence simulations within the framework of the finite element method.

S. Tuomivaara, C. Teo, Y. Jan et al.

To facilitate our understanding of the often rapid and nuanced dynamics of extracellularly exposed proteomes during signaling events, it is important to devise robust workflows affording fast time resolution without biases and confounding factors. Here, we present Surface-exposed protein Labeling using PeroxidaSe, H2O2, and Tyramide-derivative (SLAPSHOT), to label extracellularly exposed proteins in a rapid, sensitive, and specific manner, while preserving cellular integrity. This experimentally simple and flexible method utilizes recombinant soluble APEX2 peroxidase that is applied to cells, thus circumventing biological perturbations, tedious engineering of tools and cells, and labeling biases. APEX2 neither requires metal cations for activity nor contains disulfide bonds, conferring versatility for a wide spectrum of experimental setups. We applied SLAPSHOT followed by quantitative mass spectrometry-based proteomics analysis to examine the immediate and extensive cell surface expansion and ensuing restorative membrane shedding upon the activation of Scott syndrome-linked TMEM16F, a ubiquitously expressed calcium-dependent phospholipid scramblase and ion channel. Time-course data ranging from one to thirty minutes of calcium stimulation using wild-type and TMEM16F deficient cells revealed intricate co-regulation of known protein families, including those in the integrin and ICAM families. Crucially, we identified proteins that are known to reside in intracellular organelles, including ER, as occupants of the freshly deposited membrane, and mitovesicles as an abundant component and contributor to the extracellularly exposed proteome. Our study not only provides the first accounts of the immediate consequences of calcium signaling on the extracellularly exposed proteome, but also presents a blueprint for the application of SLAPSHOT as a general approach for monitoring extracellularly exposed protein dynamics. Highlights An enzyme-driven method to tag extracellularly exposed proteins in an unbiased manner with a superior combination of temporal resolution, spatial specificity, and sensitivity A general approach applicable to primary and scarce cells without involving cellular engineering Short time scale proteome dynamics of Jurkat cells with and without TMEM16F revealed by SLAPSHOT coupled with quantitative mass spectrometry provide insights into phospholipid scrambling-mediated plasma membrane remodeling

Katuri Sravani, S.V. Padmavathi Devi

Images captured underwater usually suffer from color distortion, detail blurring, low contrast, and a bluish or greenish tone due to light scattering and absorption in the underwater medium, which in turn affects the visibility adversely. Underwater image processing schemes are broadly categorized into two groups, restoration methods and enhancement methods. The approach of restoration methods is to assume the effects of underwater environment as degradation but in enhancement, this environment is assumed to be natural and tries to enhance the visual information to next extent. Restoration schemes are proved to give better performance than enhancement schemes. These restoration schemes are further classified as optical imaging methods, polarization methods and prior knowledge methods. The key problems faced by these schemes are excessive optimization parameters, difficulty of recognizing artificial lighting, adapting to multi-scatter scenario, red artifacts and over exposure. A large number of schemes are proposed in the literature under these categories and most of them suffer from one or more of the above-mentioned issues. In this paper, a rapid and effective scene depth estimation model will be proposed based on underwater light attenuation prior for underwater images and train the model coefficients with learning-based supervised linear regression. With the correct depth map, the background light and transmission maps for R-G-B light are easily estimated to recover the true scene radiance under the water.

Erik Díaz-Cervantes, Alejandra Monjaraz-Rodríguez, Faustino Aguilera-Granja

We studied two main bioactive molecules of oregano, carvacrol and thymol, in the present work. These bioactive conformers are linked to single wall carbon nanotubes (SWCNT) and so-called functionalized SWCNT (f-SWCNT) to find their application as anti-inflammatory drugs. We use the multiscale methods and the density functional theory (DFT) of formalism to achieve this aim. We have proposed two nanocarriers based on a finite size model of a metallic single wall carbon nanotube linked to carvacrol and thymol (with a size around 2.74 nm): the main bioactives present in oregano. The results show that the proposed molecules, Carva-SWCNT-Gluc and Thymol-SWCNT-Gluc, can be synthesized with the exposed condensation reaction; with an exergonic and spontaneous behavior, Gibbs free energies of the reaction are −1.75 eV and −1.81 eV, respectively. The studied molecules are subjected to an electronic characterization, considering the global descriptors based on the conceptual DFT formalism. Moreover, the results show that the studied molecules can present a possible biocompatibility due to the higher polarization of the molecule and the increase in apparent solubility. Finally, the interaction between the studied nanodevices (Carva-SWCNT-Gluc and Thymol-SWCNT-Gluc) with cancer and anti-inflammatory targets shows that the hydrogen bond and electrostatic interactions play a crucial role in the ligand–target interaction. The proposed f-SWCNT presents higher potentiality as a carrier vector nanodevice since it can deliver the oregano bioactives on the studied targets, promoting the putative apoptosis of neoplastic cells and simultaneously regulating the inflammatory process.