Advanced Materials Research Vol. 1189

Abstract: Additive Manufacturing (AM) is growing much faster because of its capability to produce complex geometries accurately without material wastage, using a CAD 3D model. It has immense scope in sectors such as aerospace, healthcare, filtration, mechanical, and electrical industries. Out of the many AM technologies available, Stereolithography (SLA) is one process that can build prototypes and end-use products using resins. SLA is particularly known for producing smooth surfaces with tight dimensional tolerances. Several SLA process parameters play a crucial role in producing dimensionally accurate parts. This study focuses on the impact of layer thickness, exposure time, print orientation, and curing time on the dimensional accuracy of SLA-printed parts. A Taguchi-based array was used to design and conduct the experimental work, and the analysis was carried out using Analysis of Means (AOM) plots and regression equations. The optimal settings improved precision, with a 0° orientation yielding the best results for the inside diameter, and 45° and 90° orientations performing best for outside dimensions. Proper curing time was also found to prevent dimensional errors. A validated prediction model showed minimal errors, thereby enhancing the accuracy of SLA-printed parts. These findings show that by optimizing layer thickness, exposure time, print orientation, and curing time, SLA printing can consistently achieve high dimensional accuracy. Such improvements make SLA more viable for industrial applications requiring precision, such as aerospace components, custom medical devices, and high-performance mechanical parts

Abstract: Fused Deposition Modeling (FDM) is used primarily to fabricate parts with complex geometries, but dimensional inaccuracies can often result in inefficiencies and limits to its use in high-precision applications. This problem increases in metal–polymer composites, such as this PLA–copper study, because of the combination due to the incorrect dimensional reactions of the heterogeneous materials. Thus, enhancing dimensional accuracy is critical in this application, not only to disprove the need for post-processing but also to support industrial applications. This investigation evaluates the impact of layer thickness, print speed, infill density, and wall thickness on the dimensional accuracy of PLA–copper parts. The experimental design using Taguchi’s L9 orthogonal array created 9 unique parts to evaluate and measure deviations in geometrical properties. Analysis of the results indicated that wall thickness exhibited the greatest influence on length accuracy, while layer thickness predominated breadth accuracy. For square side length and diameter accuracy, layer thickness and infill density appeared to have the most influence, respectively.

Abstract: Underutilized legumes velvet beans (Mucuna pruriens) and lima beans (Phaseolus lunatus) were assessed for nutritional composition and the effects of traditional processing treatments involving 24-hour soaking and 60-minute cooking, using proximate analysis and Gas Chromatography-Mass Spectrometry (GC-MS). Raw velvet beans contained significantly higher crude protein than lima beans, comparable to cowpeas. Processing reduced protein content from 9-29 % across legumes but led to increases in carbohydrate concentration. The analysis through GC-MS showed that L-DOPA (in velvet beans) neurotoxin decreased by 66.42% and the complete elimination of juglone, a protease inhibitor in lima beans. Although conventional processing methods worked well to lower anti-nutritional factors, they also lowered protein retention, showing an important tradeoff between detoxification and nutrient retention. This study highlights the value of using underutilized legumes like velvet beans which have a protein content similar to cowpeas, to diversify sources of protein in areas of food insecurity. By advocating for optimized processing strategies that prioritize both safety and nutritional quality, these findings contribute to sustainable dietary solutions aligned with global goals to combat malnutrition and promote resilient food systems.

Abstract: Rice (Oryza sativa) is the most important source of food which provide diet to more than 50% of Nigerias population. A principal objective in modern agriculture is to enhance productivity while adhering to ecological principles, creating a demand for sustainable pest management strategies like biocontrol agents (BCAs). The fungus Trichoderma, a prominent BCA, employs a multi-enzymatic system to exert its biocontrol effects. Its efficacy is largely attributed to enzymes that degrade pathogen cell walls, improve resilience against biotic and abiotic stressors, and support robust hyphal development. Trichoderma viride was isolated and identified using morphological and molecular techniques, with ITS sequencing and subsequent BLAST analysis on the NCBI database. The experiment consists of four treatments (FAR044; treated with Trichoderma viride and control; SIPPIRICE; treated with Trichoderma viride) laid out in a completely randomized design (CRD). The result demonstrated statistically significant enhancements in plant growth parameters due to Trichoderma viride treatment, with P-value of (p = 0.001) for treatment type, (p = 0.001) for time (week), and (p = 0.002) for the treatment-time interaction. By Week 5, Trichoderma viride-treated Far044 plants exhibited a mean height of 10.0 ± 0.8 cm, leaf blade length of 6.0 ± 0.5 cm, and 8.0 ± 0.6 shoots per plant, surpassing untreated controls by 34.5%, 32.1%, and 53.8%, respectively. Cohen's d effect sizes for these parameters were substantial: 1.5 (plant height), 1.4 (leaf size), and 1.7 (shoot number), all indicative of large treatment effects. Sippirice plants displayed analogous trends but with reduced increments: 7.2 cm height gain (vs. 10.0 cm in Far044), 4.3 cm leaf expansion (vs. 6.0 cm), and 6.5 shoots (vs. 8.0), reflecting varietal differences in growth responsiveness. These findings position Trichoderma viride as a sustainable alternative to chemical fungicides, particularly for resource-constrained regions like Nigeria and promote the Growth of plant and ultimately increased the grain yield significantly compared to control without any hazardous effect on the environment.

Abstract: The corrosion inhibition on mild steel by eco-friendly paint produced from Mangifera indica leaves extract was carried out using the weight loss and potentiodynamic polarization methods. Central Composite Design (CCD) in Response Surface Methodology (RSM) was used for the design of experiment for the determination of corrosion inhibition efficiency, corrosion rate, and statistical analysis of the experimental results. Corrosion protection paint was formulated, and its efficacy was tested in a hydrochloric acid medium. The surface morphology of the mild steel sample was studied using the scanning electron microscopy (SEM). The corrosion inhibition efficiency of the paint for weight loss and potentiodynamic polarization methods is 83.68 and 99.49 %, respectively. The activation energy for corrosion process with coated mild steel is 26.47 J/mol K, which is higher than the value of 16.89 J/mol K obtained for uncoated mild steel, indicating that the adsorption process is physisorption. The enthalpy change is 23.96 kJ/mol. The positive value indicates that heat is absorbed from the environment. The entropy change is-180 J/mol K, implying that the activation energy complex is the rate determining step representing association rather than dissociation. Langmuir adsorption isotherm was found to be the best fit model. It was concluded from the study that the formulated paint has a high potential for commercialisation and industrial applications.

Abstract: SS316L material exhibits superior corrosion resistance. The two grade compositions, comprising nickel and molybdenum, enable the alloy to resist acids and chlorides without degradation. Due to its exceptional corrosion resistance, both metals are among the few classified as "marine grade stainless steels." Gas Tungsten Arc Welding (GTAW) is executed to guarantee sufficient corrosion resistance during installation. This study analyzes the outcomes of welding ER316LSi as a filler material with SS316L base metal, focusing on microstructure, EDAX analysis, and corrosion rate. This study did not perform hardness testing. This study will indicate welding variables for future research on specific applications, utilizing various weld blades and current parameters. Corrosion testing, encompassing Tafel and Electrochemical Impedance Spectroscopy, indicates that the SS316LSi weld metal will yield a higher degree of ferrite development in the weld region. The welding temperature significantly influences the ferrite structures. The corrosion rates for each electrolyte solution are as follows: for the seawater electrolyte solution, a current of 110A yields a rate of 8.39857 x 10^-6 mpy, 120A results in 7.09315 x 10^-6 mpy, and 130A produces a rate of 7.85427 x 10^-6 mpy. The MgCl₂ electrolyte solution exhibits a concentration of 110A = 7.2195 × 10^-6 mpy, a current of 120A = 7.2156 × 10^-6 mpy, and a current of 130A = 7.1406 × 10^-6 mpy. The corrosion resistance at a current of 120 amperes is greater in seawater conditions than at a current of 130 amperes in MgCl2 solutions. The corrosion rate and reductions in Fe, Mo, Cr, and Mn following 14 days of immersion testing in sewage and MgCl2 are the reasons that low-heat-input or solid-phase bonding techniques can significantly enhance pitting resistance compromised by welding.

Abstract: This work relates initially to the application of various chemical formulations on leather surfaces to function as water repellents. Efforts have been made to search for a nonfluorinated formulation because of the damaging health effects of fluorinated water repellents. The metal complex stearato chromic chloride, which was prepared in the laboratory, is the most suitable. A complete synthesis protocol is developed first. Characterization tests (ATR-FTIR, XRD) of the chemical were performed to confirm that the intended product was properly synthesized. Microscopic examination of the leather revealed that it was not damaged by the application of the formulation and retained its softness and ability to feel. The methods of application to leather are then described. Finally, the necessary tests of performance are completed. For the different types of leathers that are evaluated, stearato chromic chloride can be easily applied and used as a compatible, durable and permanent water repellent. When synthesized according to a given protocol, minimal repellent chemicals are present in the exhaust solution, thus safeguarding the environment against chromium toxicity.

Abstract: Li-ion batteries generate significant heat during operation, which leads to an increase in temperature and, consequently, a reduction in the battery's efficiency and lifespan. In this study, different cooling methods are simulated for the thermal management of the battery. The cooling using air and liquids is investigated with laminar flow at varying velocities. Results indicated that the use of water/glycol is more effective than air and mineral oil.

Abstract: Antimicrobial resistance (AMR) is a global health crisis that undermines the effectiveness of antibiotics in treating infections, posing a threat to humans and animals. Antibiotics are not fully metabolized by humans or animals, leading to their dispersion within sewage streams. The dissemination of antibiotic-resistant bacteria in aquatic environments poses a significant public health risk, particularly through the release of treated wastewater into natural water bodies. This study investigated the presence of Antibiotic Resistance Genes (ARGs) in Klebsiella sp. isolates collected from four sampling points along the Wupa River and its wastewater treatment plant (WWTP): Upstream (P1), Influent (P2), Effluent (P3), and Downstream (P4). Physicochemical analyses of water samples showed that most parameters, including temperature, pH, total dissolved solids, dissolved oxygen, and nitrates, stayed within WHO-recommended limits. However, phosphates, total suspended solids, and ammoniacal nitrogen consistently exceeded these limits at all sites. The highest levels of biochemical oxygen demand (BOD), soluble chemical oxygen demand (COD), and total COD were found at the influent. The Total Viable Count carried out for bacterial colonies and Klebsiella colonies to assess microbial load showed the highest value at the 10^ (- 2) dilution factor and the lowest at the 10^ (- 5) dilution factor. Isolation and identification of Klebsiella spp. were performed using biochemical tests, including Voges-Proskauer (+), Indole (-), Citrate (+), Urease (+), Methyl red (-), Triple Sugar Agar (+), and Gram staining, revealing Gram-negative rods. Molecular analysis detected amplification of key resistance genes sul2, tetB, blaTEM, and blaCTX. Amplification of tetB gene in both influent and effluent samples indicates incomplete removal of tetracycline resistance genes during wastewater treatment. The blaTEM and blaCTX genes were detected across all sampling points, suggesting widespread environmental dissemination and potential contamination sources beyond the WWTP. These findings highlight the persistence and spread of multidrug-resistant Klebsiella in riverine and wastewater environments, underscoring the critical need for improved wastewater treatment strategies and continuous monitoring to mitigate the public health impact of antibiotic resistance in aquatic ecosystems.