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A Green Approach to the Corrosion Inhibition Effect of Waste Extract on Copper in an Alkaline Environment
No full textWaste extract was examined to inhibit copper corrosion in 0.5 M KOH (alkaline) solutions. The inhibitory action of the waste extract was investigated using potentiodynamic polarization and gravimetric methods. The result indicated that the extract prevented the copper corrosion in the tested environment, achieving 90.68% effectiveness. The polarization test indicates that the extract is a mixed-type corrosion inhibitor, capable of inhibiting both cathodic and anodic processes in the Cu/KOH system. The inhibitory effect was due to the waste extract sticking to the copper surface, which formed a barrier that prevented harmful ions from reaching the metal. The molecules extracted adsorb on the surface of the metal following Langmuir adsorption model, denoting the extract forms a monolayer protective film on the copper surface. Consequently, the waste extract can effectively prevent copper from corroding in an alkaline environment
Evaluation of flank wear of a self-propelled rotary tool during turning using nanofluid under MQL
No full textInconel 718, a heat-resistant nickel alloy, is employed in aerospace, marine, and defence applications due to its unique properties. However, these alloys are difficult to cut due to their low heat conductivity and proclivity for work-hardening. With a focus on sustainability, ongoing efforts are underway to enhance the manufacturability of these alloys. This study assesses the flank wear progression of a self-propelled rotary tool (SPRT) while turning Inconel 718 using a hybrid nanofluid under minimum quantity lubrication (NFMQL) conditions. To create a hybrid nanofluid, multi-walled carbon nanotubes (MWCNTs) and aluminium oxide (Al2O3) nanoparticles were mixed with 0.25% in a commercially available palm oil. Experiments were carried out by changing the process parameters. Flank wear was monitored and analysed with digital and electron microscopes. Experimental-based models were created to analyse and compare the influence of cutting conditions and machining time on SPRT flank wear under NFMQL conditions. Additionally, an ANN model is created to predict how flank wear will change over time. To provide precise forecasts, the ANN model makes use of past tool wear rate data. Lastly, the processes of tool wear for SPRTs under NFMQL are investigated
Biological effectiveness of using fungicides and IFO PZN suspension in combination with fungicides against yellow rust and powdery mildew diseases of winter wheat
No full textIn this study, effective protection methods were applied against fungal diseases commonly found in soft winter-sown wheat grown in the foothill regions of the Kashkadarya region, using fungicides and suspensions. The research identified the impact of these treatments on plant health and the progression of disease development. During the 2019–2020 growing season, in untreated control plots, the average number of wheat plants per 1 m² was 410, with the initial incidence of yellow rust (Puccinia striiformis) affecting 230 plants (infection rate: 56.1%). During the disease’s peak and decline phases, infection rates increased to 73.41% and 76.1%, respectively, with 301 and 312 infected plants. Between 2020 and 2022, disease severity increased significantly. For instance, during the epidemic stage of 2020–2022 and 2021–2022, infection levels rose by 2.43% to 5.72% compared to 2019–2020, and by 1.65% to 4.24% in the final stage, with yields reduced by 1.5 to 3.2 c/ha. In field trials, the biological effectiveness of combining fungicides (Duazol 40% EC at 0.25 l/ha (reference), Bi- Kanazol 400 g/l at 0.3 l/ha, AZOTE 320 SC 32% SC at 0.3 l/ha, Rauma 490 EC at 1.25 l/ha, Alta Super 40% at 0.3 l/ha, Altus Duo 32.5% at 0.3 l/ha) with IFO PZN suspension (3.0 l/ha) was tested against yellow rust and powdery mildew (Erysiphe graminis). Results showed that disease incidence in untreated control plots ranged from 74.2% to 54.4%, while combining AZOTE 320 SC and Rauma 490 EC with IFO PZN reduced disease levels to 0.8% and 0.5%, respectively. Biological effectiveness reached 98.6– 99.1% against yellow rust and 99.0% against powdery mildew. Thus, using a combination of IFO PZN suspension with AZOTE 320 SC or Rauma 490 EC fungicides is recommended for chemical control of these diseases in winter wheat. The combined application enhances chlorophyll content and improves biochemical composition in plant tissues, increasing resistance to both diseases and environmental stress. These methods contribute to high- quality yields and effective disease prevention in wheat production
Mechanical Characterization of AA6061/Groundnut Shell Powder Matrix Composite
No full textThe paper presents a study on the possibility of reinforcing aluminium alloy 6061 with groundnut shell powder (GSP), to generate an eco-friendly and economical metal matrix composite (MMC) with a superior mechanical and corrosion resistant properties. The mixing of composites was done through stir casting technique at different weight percentages of GSP of 2%, 4% 6%, and 8%. The samples were taken through a form of testing comprising hardness, impact, tensile, flexural, fracture toughness, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The findings show that the mechanical properties like hardness, tensile strength, and flexural strength increased with the increase in GSP content till 6 percent and then started to decrease with the increase in the content because of the agglomeration of particles and porosity. The best performance was registered in the 6% GSP sample where the higher hardness (65.97 BHN), tensile strength (357.44 MPa), and flexural stress (2890.35 MPa) are realized. With SEM analysis, it was found that the grain was refined and dispersed well through to 6 % GSP whereas the XRD showed formation of a reinforcing phase such as MgO within the matrix. The study shows that GSP could be used as reinforcement of aluminium alloys with enhanced mechanical and structural properties
Acoustic characterization and hydration number analysis of nicotinamide (Vitamin B
No full textThe ultrasonic velocity (u) and density (π) of aqueous nicotinamide (Vitamin B3) solutions were determined using an Anton Paar DSA 5000 M densimeter–sound velocity analyser at 0.1 MPa. Measurements were carried out over a molal concentration range from 0 to 1.11177 mol.kg-1 and at temperatures between 298.15 K and 323.15 K. From these experimental data, hydration number (nH), acoustic properties like apparent molar isentropic compressibility (KΦ), limiting apparent molar isentropic compressibility (KΦ0) and a semi-empirical interaction factor (SK) were evaluated. The analysis of these parameters provides insight into solute–solvent interactions, revealing whether nicotinamide acts as a structure-maker or structure-breaker in water. The results also explain the hydration phenomena, acoustic behavior, and structural modifications occurring within these binary mixtures
Investigation on corrosion behaviour of butt welded En-8 steel
No full textStructural components fabricated from carbon steels such as EN- 8 are widely employed in engineering applications where they are frequently exposed to corrosive environments. The present investigation focuses on evaluating the corrosion behaviour of butt-welded EN-8 steel joints when subjected to different corrosive media. Three representative environments were selected for this study: 1 M hydrochloric acid (HCl) simulating an industrial acidic condition, synthetic seawater representing marine exposure, and distilled water serving as a neutral environment. Arc welding was employed to fabricate butt joints using E7018 electrodes under controlled parameters. The specimens were exposed to the respective corrosive environments for predetermined time intervals, and the corrosion rates were determined using the weight loss method. Microstructural characterization was performed to analyse the corrosion morphology across the weld zone, heat-affected zone (HAZ), and base metal, while microhardness testing was carried out to assess the degradation in mechanical properties. Results revealed that the corrosion rate was highest in 1 M HCl, moderate in seawater, and negligible in distilled water. The HAZ exhibited the most pronounced corrosion attack owing to its heterogeneous microstructure and residual stresses developed during welding. A gradual stabilization of corrosion rate over time was observed, which may be attributed to the formation of a protective oxide film. Overall, the study highlights that acidic environments significantly accelerate the corrosion of welded EN-8 joints, and careful consideration of operating environment is essential for prolonging the service life of welded components. These findings provide valuable insights for the design and maintenance of welded steel structures in industrial and marine conditions
Micro structural and mechanical characterization of SS32750 welded using GTAW and CO
No full textStainless steel 32750 (SS32750) is a duplex stainless steel renowned for its exceptional corrosion resistance and mechanical properties, making it ideal for demanding applications, particularly in harsh environments such as offshore and marine industries. This study examines the microstructure and mechanical properties of SS32750 weldments produced using two distinct welding techniques: Gas Tungsten Arc Welding (GTAW) and Laser Welding. The investigation focuses on the effect of various welding parameters, including heat input, welding speed, and shielding gas composition, on the resulting microstructure. Mechanical properties such as tensile strength, surface roughness, distortion, and weld integrity were evaluated using methods like tensile load testing, X-ray radiography, and wire-cut EDM. The study provides critical insights into the relationship between welding techniques, process parameters, and the resulting performance of SS32750 weldments
Investigation on the performance of reversible polymer electrolyte membrane fuel cell during the electrolysis phase
No full textDue to its sustainable and zero-carbon potential, electrolysis of water is considered a suitable alternative for the production of green hydrogen. The electrolysis accounts for 2 to 5% of hydrogen production worldwide. The primary objective of this study is to simulate the performance of the RPEMFCs in producing green hydrogen. The investigation was more specifically carried out on the reversible polymer electrolyte membrane fuel cell (RPEMFC) unit with Nafion-115 membrane with different anode and cathode catalyst loadings at the current density of 1 A/cm2. This study acknowledges the significance of the ramp-up phase in the investigation of the steady state electrolysis process at fixed current density. Also, it is observed that cell voltage tends to increase with an increase in current density from 0.1A/cm2 to 1A/cm2. The operating voltage was reported as 1.89 V at the current density of 1A/cm2. Furthermore, the voltage efficiency of the reversible polymer electrolyte membrane fuel cell (RPEMFC) electrolysis was 65% under the given conditions
Integral dielectric kernel implementation to model RF heating in toroidal plasmas
No full textAs discussed in Ref. [1], recent theoretical and numerical treatments [2, 3] have sought to express the plasma radiofrequency (RF) response as a nonlocal integral operator formulated in configuration space. Analytical expressions of the integral kernels are available for Maxwellian particle species. This approach enables (i) direct use of the finite element method (FEM) to model wave propagation and absorption in hot inhomogeneous fusion plasmas, (ii) local mesh-refinement, (iii) provides RF field representations suited to address tokamak geometry, and (iv) allows straightforward connection between plasma and antenna models. The present contribution focuses on the concrete application of this method, in an incremental way, developing codes and exploiting finite element codes/libraries
Full-wave modeling of RF waves in fusion plasmas with finite element method: Progress in past decades and its future role
No full textThis paper reviews the progress in computing radio frequency (RF) wave fields in fusion plasmas, specifically focusing on simulations utilizing the finite element method (FEM) over the past few decades. Computing RF wave fields in fusion plasmas presents unique challenges due to large simulation domains, complex antenna structures, non-local dielectric properties, and wide ranges of spatial scales. It highlights key developments and outlines future directions, primarily addressing waves in the ion cyclotron (IC) to lower hybrid (LH) frequency range. We begin with briefly revisiting earlier developments before the widespread availability of modern computer-aided engineering (CAE) software based on FEM. This historical perspective illuminates early progress and the physics difficulties that motivated ongoing work within the community. Modern wave simulations for RF antennas based on FEM are characterized by the use of detailed 3D antenna model geometry generated from engineering CAD software and localized wave dielectric model. Significant advancements have also been made in improving physics models to include phenomena such as RF sheath rectification and wave scattering. FEM-based RF simulations have also been applied to compute wave propagation in the core region, where the inclusion of non-local dielectric response is crucial. This is a challenging goal, and several promising approaches have been proposed in this area. Additionally, RF simulation development initiatives based on open-source libraries have gained popularity, demonstrating scalability and flexibility in extending physics models. This paper will discuss the advantages and disadvantages of using such a publicly available FEM library