Advanced Materials Research Vol. 1181

Abstract: The present research focuses on the hot forging of 38MnSiVS5 micro-alloyed steel, examining the impact of key process variables, such as working temperature, deformation percentage and rate of cooling on mechanical properties, notably the ultimate tensile strength and impact energy. To optimize the process, Taguchi's parametric design, utilizing an orthogonal array in combination with grey relational analysis and fuzzy logic analysis, has been implemented. By applying grey-fuzzy logic analysis, the optimization of complex multiple responses is streamlined into a single grey-fuzzy reasoning grade. The study employs the Grey fuzzy logic method to concurrently optimize both responses. The grey-fuzzy reasoning grade serves as a performance index, aiding in the determination of the optimal process parameter settings for both the ultimate tensile strength and impact energy responses simultaneously.

Abstract: Because of their extraordinary qualities, titanium alloys are very sought-after materials that can be applied to a wide range of sectors. Excellent mechanical and chemical qualities, including a high strength-to-weight ratio and resistance to corrosion, are present in it. The special properties of these alloys make machining them extremely difficult. As frequent tool wear occurs throughout the machining process, Computer Numerical Control (CNC) milling has become a potential method for machining titanium alloys due to its precision and versatility. This review article provides a comprehensive overview of the development of titanium alloy CNC milling, with an emphasis on the effects of cutting tool geometries and materials on machining efficiency. The process examines several aspects of cutting circumstances, including depth of cut, speed, feed rate, and lubrication techniques, and optimizes machining parameters and procedures to achieve the best results. Surface integrity and quality, surface roughness, residual stresses, and microstructural changes brought about by CNC milling are the main points of evaluation.

Abstract: The usage of adhesively bonded lap joints in industrial applications has been growing in recent years because of the numerous advantages compared to other joining processes such as fastening, welding, and riveting. For effective design of the adhesively bonded engineering lap joints, it is essential to govern the failure potential of a particular adhesive joint under a certain load causing some stress and strain. In this work, study has been carried out by the application of multiple adhesives along the bondline region of lap joint. The objective of this paper is to experimentally examine the results of applications of single and multi-adhesives material with very different mechanical behavior along the bondline region in the single lap adhesive joint. Experimental investigations have been carried out for extracting load displacement data using tensile testing machine, Tensometer, having a capacity of 2 tonne. Multi Adhesive joint can minimize the stress concentration and improve joint strength by using different adhesive stiffness along the bondline region of lap joint and the outcome shows computable increase in the strength of the multiple adhesive bonded lap joints associated with those in which single adhesives were used over the full length of the bondline region.

Abstract: The leaf extract from Tithonia diversifolia is recognized for its ability to deter feeding in various Lepidoptera insect pests, including the larvae of Crocidolomia pavonana. Presently, transformation efforts from conventional formulations into nano-based formulations for biopesticides exhibit enhanced effectiveness and efficiency. Utilizing a low-energy process, an inversion emulsion facilitates the dispersion of the extract suspension in an organic solvent into a water-immiscible solvent using a suitable surfactant. The forming nano-size droplets in water (t1, t2, t3, t4) are influenced by the ratio of surfactant and organic suspension (Water: Tween 80: Organic suspension). The emulsification method successfully formulated T. diversifolia leaf extract, into dispersed nano-size and submicron suspensions in water. The t3 formula exhibits the smallest nano-size dispersed in water (D=23.6 ± 39.6 nm; polydispersity index IP=0.702) and enhanced wettability, evident in the lower contact angle of the droplet on the cabbage leaf surface (49.4°) compare with the control group. The Phytochemicals confirmed by IR-spectra analysis identified the phenols, alkaloids, and steroids constituents of leaf extract, which are known to have antifeedant properties. The enhanced antifeedant properties of T. diversifolia nanosuspension against C. pavonana third-instar larvae demonstrated by the antifeedant test results showing that t3 is the most successful deterrent larvae feeding activity compared to the control (P<0.05), due to the highest total antifeedant coefficient (74.27%) in a category medium antifeedant activity, while the non-emulsification displayed the lowest antifeedant coefficient (25.36%) in a category as low antifeedant activity. T. diversifolia leaf extract with a nano-based formula succeeded resulting in dispersed nano-size and submicron suspension in aqueous media, thereby reducing surface tension and enhancing wettability on the leaf surface during application. The improved dispersion of antifeedant nanosuspension on the leaf surface results in more effective delivery to target insects.

Abstract: Pangasius catfish, also known as striped catfish, is a high-fat fish compared to other freshwater fish like snakehead fish and carp. The oil extracted from this fish contains unsaturated and polyunsaturated fatty acids that are beneficial for health. The quality of the oil is affected by the extraction method, especially the preliminary heating temperature for the extraction. Pangasius catfish oil contains omega-3 fatty acids (EPA and DHA) that have the potential to inhibit inflammation, hyperpigmentation, accelerate skin healing for topical applications, and act as a skin permeation enhancer and oil base for nanoemulsion due to its high oleic acid content. In this research, an experimental design was conducted on pangasius catfish oil extraction using the pressing method to optimize predetermined parameters using Response Surface Methodology (RSM). The factors considered for optimization included the quantity of water and extraction temperatures, with water content ranging from 50% to 150% (w/v) and extraction temperatures ranging from 25°C to 55°C. These ranges were intended to yield results and characterization values of oxidation parameters are tested according to the International Fish Oil Standard (IFOS) through tests including Acid Value (AV), Peroxide Value (PV), Anisidine Value (p-AnV), and Total Oxidation (TOTOX). Subsequently, the optimal conditions were confirmed to obtain the best fish oil results, which were achieved at 1.5 times the amount of pre-treatment water and a pre-treatment temperature of 55°C. The pangasius catfish oil obtained from the confirmation of optimal conditions is used as a raw material for producing nanoemulsions. The D-Optimal Mixture Design of Design Expert approach is utilized to formulate the nanoemulsion. The nanoemulsion formula containing 0.5% pangasius catfish oil was determined as the optimal formula according to the range of physical characteristics of the referenced nanoemulsion preparations with a desirability value of 0.974. This study has demonstrated the potential utility of pangasius catfish oil as a prominent base oil in nanoemulsion products.

Abstract: Coconut shell (CS) activated carbon is widely used for water purification, but its adsorption capacity is inferior compare to graphene oxide (GO). GO has oxygen functional groups so it can effectively bind pollutants like methylene blue (MB). In this study we synthesized graphene-like material from CS charcoal using the modified Hummers method by varying its oxidation times. The XRD decomposition results for H-CS3.2 show a structural composition similar to GO material. The diffraction peak at 10.7° (3.04%) falls within GO's characteristic range of 8°-11°, supported by a Raman I_D/I_G ratio of 0.95. In contrast, H-CS3.1 material does not exhibit GO's structural composition, with a diffraction peak at 13.9° (1.09%). An increasing of oxidation time, enhanced adsorption capacity in the equilibrium state of H-CS3.2 (22.368 mg/g) surpassing H-CS3.1 (17.079 mg/g). The heightened adsorption was linked to an increased O/C ratio or higher % of atomic oxygen (0.04 for H-CS3.1 and 0.17 for H-CS3.2). The pseudo second-order Ho (PSO) adsorption kinetic model demonstrated the adsorption mechanism, with active sites (oxygen functional groups) such as carbonyl (C = O) and epoxy (C – O) at basal plane carbon. Steric hindrance caused by hydroxyl functional groups (C – OH) led to a reduction in π-π interactions and decreased adsorption ability of the H-CS3.1 material. Desorption of H-CS3.1 material was influenced by MB detachment through interface diffusion.

Abstract: A study to find the effectiveness of chitosan concentration as a natural preservative on Kenyan fish (Sarda orientalis) has been conducted. The chitosan powder used is extracted from tiger prawn (Penaeus monodon) shells, and it is used in the form of a solution with a concentration of 1%, 1.5%, 2%, and 2.5%. Fresh kenyar fish of 500 g were soaked in those chitosan solutions and named A1, A2, A3, and A4, respectively. Two sample groups were prepared as a comparison; they weren’t treated with any chitosan solution; they were A02, 500 g of kenyar fish soaked in 2% acetic acid, and A01, 500 g of kenyar fish without any treatment. The soaking times were varied as 20, 40, and 60 minutes. Storage is carried out at room temperature. The activity of chitosan as a fish preservative was analyzed using various methods, including pH, organoleptic, and antimicrobial tests. The measurements of pH and organoleptic test were made at 0, 24, 48, and 72 hours. The antimicrobial tests were carried out after 24 hours of storage. The study concluded that the effective concentration of chitosan as a preservative agent of fresh kenyar fish is 2.5% (A4) with 40 minutes of soaking time, with the quality parameters are pH 5, an organoleptic score of 9, and the total number of microbes is 1.2 x 10⁵ CFU/g.

Abstract: The moving bed biofilm reactor (MBBR) has been identified as a promising method for reducing water pollution. Biocarriers are important in MBBR treatment processes because they provide surface area for biofilm attachment and improve treatment efficiency. These biocarriers use decomposing microorganisms attached to their surface and have been developed in a variety of shapes, materials, and procedures. This study aims to create a biocarrier using an additive manufacturing process and a PETG (Polyethylene Terephthalate Glycol) filament as its material. The biocarrier's pore size plays a crucial role in determining its effectiveness for biofilm attachment and treatment efficiency. By modifying the net diameter of the biocarrier's design, we aimed to investigate the impact of different pore sizes on these factors. We experimented with fabricating three different sizes of the biocarrier's pore by modifying three different sizes of the net diameter of the biocarrier's design: type 1 is 1.8 ± 0.22 mm, type 2 is 1.0 ± 0.29 mm, and type 3 is 0.8 ± 0.27 mm. This research provides insights for the next step: evaluating biofilms' attachment efficiency on each type of biocarrier and comparing their performance.