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Preparation and characterization of activated charcoal from a plant mixture and its use in the adsorption of methyl orange dye from aqueous solutions, a chemical and thermodynamic study
No full textWater pollution from industrial effluents, particularly those containing synthetic dyes, poses a serious environmental and health threat due to their toxicity, persistence, and resistance to conventional treatment methods. Developing sustainable and cost-effective adsorbents is therefore of great importance. In this work, nano-activated carbon was synthesized from a mixture of wormwood and acacia seed pods and evaluated for the removal of orange dye from aqueous solutions. The adsorbent showed high efficiency, achieving 95% removal within 40 minutes. The effects of contact time, temperature, and adsorbent dosage were systematically investigated. Kinetic analysis indicated that the adsorption process followed the pseudo- second-order model, while thermodynamic results confirmed that the process was endothermic and spontaneous at all studied temperatures, as shown by negative Gibbs free energy values. Positive entropy changes suggested increased randomness at the solid–solution interface, and equilibrium data fitted well to the Freundlich model, indicating heterogeneous multilayer adsorption. Overall, the findings demonstrate that the adsorption mechanism is mainly physical in nature and highlight the potential of this green-synthesized nano-activated carbon as an efficient and eco-friendly material for treating dye-contaminated wastewater
Synthesis and characterization of nanocomposites using cyclic maleimides and low-cost graphene sheets prepared by ball milling of hydrated coal
No full textThis study included the preparation of cyclic maleimides by the process of water withdrawal using water-extracting agents and ring-closing of amino acids prepared by a previous step of reacting aromatic amines containing two amino groups with maleic anhydride. The synthesized organic compounds were evaluated using melting point analysis, infrared (IR) spectroscopy, proton nuclear magnetic resonance (1H NMR), and carbon nuclear magnetic resonance (13C NMR). Inexpensive graphene nanosheets of partly reduced graphene oxide (p.rGO) were synthesized using the ball milling of coal, which was dampened with deionized water droplets. They were used to prepare five nanocomposites by chemical sublimation with the prepared cyclic maleimides in the presence of deionized water. The prepared nanocomposites were characterized by spectroscopic methods
Modeling rf sheath formation in turbulent tokamak boundary plasma
No full textDuring ICRF antenna operation, complex interactions between turbulent density profiles, nonlinear RF sheaths, and RF-induced convective transport are observed to alter plasma density in the tokamak edge [D’Ippolito
et al., Nucl. Fusion 38, 1543 (1998)]. In this work, we explore the physics of such interactions via numerical modeling, using a nonlinear EM/plasma/sheath code (VSim) and profiles obtained from a fluid plasma turbulence code (Hermes) in a 3D slab domain containing biased side-wall limiters. RF-rectified sheath formation on antenna and limiter surfaces is observed as electromagnetic waves launched by the antenna are refracted through the turbulent density profile. On transport timescales, such sheath potentials have been shown to influence both the mean species density and its RMS fluctuation spectrum [Smithe
et al., these proceedings]. On the faster RF timescales, we demonstrate that the converse is also true – regions of high plasma density near material surfaces give rise to the highest sheath potential amplitudes. When density is turbulent and spatially nonuniform, localized regions of high sheath potential (hotspots) may develop where high-density filaments intersect material surfaces. Such hotspots are of particular concern as sources of impurity sputtering, and we explore their behavior in response to changes both to the local plasma density and to antenna operating parameters and structure. Related results exploring the role of Faraday shields and/or enclosing structures in suppressing high sheath potentials for other devices (e.g. SPARC) will also be shown
Prediction of compressive strength of brick masonry using machine learning models
No full textThis paper explores predicting brick masonry strength using machine learning models, such as Linear Regression (LRM), Polynomial Regression (PRM), Exponential Regression (ERM), Support Vector Regression (SVR), Decision Trees (DTM), Random Forests (RFM), Artificial Neural Network (ANN) and Adaptive Neuro Fuzzy Inference System (ANFIS). The dataset comprises 245 data points on brick, mortar and masonry strength, split into training, validation and testing sets. Python and MATLAB were used to implement the models. DTM and RFM achieved highest determination coefficient (R2) values of 0.97 and 0.965. SVR also demonstrated high R2 value of 0.936. ANN, ANFIS and PRM achieved moderate to strong R2 values, while LRM and ERM displayed limitations. Overall, DTM, RFM and SVR emerged as the top performers, exhibiting strong predictive capability and good generalization ability. These models are suggested for practical applications in construction projects for their superior accuracy in estimating the masonry compressive strength
Improvised hand layup fabrication of alkali treated jute epoxy composites: A comparative study of positive and vacuum-assisted compaction
No full textThere lie several benefits of using fiber composites which have increased the desire for using these materials in various higher-level applications. They have been widely used in automobile sector, aerospace, sports industry, medical field, and so on. This has created a demand for better manufacturing techniques with cost-effectiveness. This work has been focused on improvising the hand layup procedure. To enhance the properties of the samples prepared by this conventional method, surface treatment was incorporated. Woven jute fiber was chemically treated with KOH under various sizing conditions. Hand layup was carried out for the samples followed by applying pressure considering two different methods; vacuum- assisted compaction and positive compaction. The jute composites prepared by the positive compaction hand layup technique were found to be better than the vacuum-assisted or negative compaction composites for the same set of sizing samples. There is a maximum increase of 32.4% in the tensile strength of treated composites prepared by positive compaction in comparison to untreated samples. On the other hand, the values of all the treated samples showed a reduction in tensile strength with a maximum decrease of 50% than the untreated sample for the negative compaction technique
Damping RF waves with low reflection in simulations of slab or curved magnetized plasma: Parametrization, verification and implementation of Bermudez Perfectly Matched Layers
No full textMost Radio-Frequency antenna simulations in magnetic fusion require emulating radiation at infinity at some boundaries of the simulation domain. To this end, the Perfectly Matched Layer (PML) technique amounts to stretching artificially the (real) spatial coordinates into the complex plane. Following reference [1], this contribution parametrizes, tests numerically and implements unbounded stretching functions, whose only numerical limitations arise from the PML discretization: refining the mesh can reduce the spurious reflections from the PML arbitrarily low, at the expense of a larger numerical cost. We tune the PML to ensure low wave reflection in a prescribed spectral range [kn,min, kn,max] in a direction n, with a minimal discretization (i.e. at a minimal computational cost). We extensively quantify the reflection coefficients using 1D Finite Element simulations. The minimal discretization for a regular mesh scales as kn,max/kn,min. We extend the PML formulation to a cylindrical geometry, where the wave eigenmodes involve Bessel functions. We implement slab radial and parallel Bermudez PMLs in realistic multi-2D RF simulations [2], to attenuate the propagative Slow Waves parasitically emitted by the ITER ICRF antenna into a tenuous scrape-off layer
Outcome of surgical treatment for metastatic bone disease of the distal femur: Observational single-center study of 47 patients
No full textIntroduction: There is a paucity of data regarding the surgical treatment of distal femoral metastatic lesions. In this retrospective study, we aim to describe the outcome of surgery in this location and further analyze the findings based on the type of surgical reconstruction. Methods: 47 patients (48 fractures) who underwent surgery due to pathological fractures of the distal third of the femur, between 2000 and 2024, were included in the analysis. There were 29 prostheses and 19 osteosyntheses (10 plates, 9 nails). Local complications, implant revision rate, functional outcome regarding pain and ambulatory capacity, and overall survival were analyzed depending on the type of surgical treatment. Results: The complication pattern was different among implants used, with severe infections seen in prostheses (3/29 implants) and tumor recurrence in osteosynthesis (2/19 implants). In cases of osteosynthesis, failures resulting in revision surgery were documented only in cases of plate reconstruction (none when nails were used), resulting in a marginally higher revision rate (p = 0.14). Surgical treatment resulted in the restoration of the ambulatory capacity in 85% of patients, and pain levels were minor or moderate in 93%, without any significant difference between the surgical methods. Prostheses were used in patients with better overall survival (p = 0.015). Discussion: The patterns of local complications and their management differed between the different reconstruction techniques. Plate osteosynthesis had the highest risk for re-operation. The overall postoperative result was satisfactory, and functional outcomes were generally comparable. Patients with a good prognosis should be considered for reconstruction with a prosthesis when the bone quality does not allow nail osteosynthesis. Level of evidence: IV, retrospective study
Retraction Notice: Automatic Non-linear Feature Selection Framework for Epileptic Seizure Detection
No full textWe take a zero tolerance to any situation where fraudulent research is published in our journals. As a result, this article has been retracted by the Publisher because it is suspected to be a nonsensical computer-generated publication with a number of tortured phrases and irrelevant references.
Additional measures have been implemented to prevent these issues from reoccurring.
EDP Sciences is extremely grateful to anonymous whistleblowers and the Problematic Paper Screene
Antioxidant Activity of Ethanolic Extract and Aqueous Fraction of Purple Sweet Potato
No full textOxidative stress, triggered by an imbalance between the production of Reactive Oxygen Species (ROS) and the body's antioxidant defence mechanisms, contributes significantly to various chronic diseases. This study aimed to compare the antioxidant activity of ethanolic extract and aqueous fraction of purple sweet potato (Ipomoea batatas L.) leaves using the DPPH method. Extraction was performed using maceration with ethanol, followed by liquid-liquid fractionation with n-hexane, ethyl acetate, and water. Phytochemical screening confirmed the presence of flavonoids in both samples. Antioxidant activity testing revealed IC50 values of 95.57 μg/mL for the ethanolic extract and 85.69 μg/mL for the aqueous fraction, indicating strong antioxidant activity for both samples. The aqueous fraction demonstrated superior antioxidant activity compared to the ethanolic extract, suggesting that the fractionation process successfully concentrated polar antioxidant compounds. The results indicate that purple sweet potato leaves, particularly the aqueous fraction, possess significant potential as a natural source of antioxidants
Modelling And Laboratory Test of An IoT-Solar Energy Based Automatic Irrigation Gate System
No full textThis study describes the modelling and laboratory testing about Internet of Things (IoT)-solar energy based automatic irrigation gate system for sustainable agricultural water management. The system designed utilizes a photovoltaic energy source combined with Maximum Power Point Tracking (MPPT) for optimizing energy generation and enables autonomous operation. In the model, the irrigation gate and electrical system is a set, represented 3D simulation that illustrates the relationship between operational states and laboratory conditions. To represent the hydraulic relationship between gate openings, flow discharge, water level changes, a mathematical model was derived and validated using scaled laboratory tests in different operational scenarios. The prototype provided good accuracy in discharge prediction (R2 > 0.9) and fast response time (<5 s) and stable water level control and low head loss (<5 cm). The MPPT implementation provided a 15-18% increase in energy efficiency compared to the conventional solar systems. Finally, brokering IoT data acquisition and control provided low communication latency (200-300 ms) and a small packet loss (< 1%), demonstrating the prototype is suitable for real-time irrigation management. The results demonstrate technological sophistication and the feasibility of scaling innovations with smart irrigation gate systems that couple renewable resources with digital technologies