In this study, the acid-alkaline transesterification of refined coconut seed oil (RCOSO) to fatty acid methyl ester was followed by the production of a trimethylolpropane-based thermosensitive biolubricant using potassium hydroxide, and its physicochemical characteristics were evaluated. The American Standard Test for Materials (ASTM) was employed to ascertain the biolubricant's pour point and index of viscosity, which were found to be -4 oC and 283.75, respectively. The opposite connection between lubricant viscosity and temperature was shown by the measured viscosities at varied transesterification to be transformed into biodiesel. Following this, a biolubricant was created by further transesterifiedtemperature. The ester group is verified by comparing the Fourier Transfer Infra-red (FTIR) spectra of the biodiesel and the biolubricant between absorption bands (1755.07-1737.21 cm-1). Gas chromatographic data shows that sweet almond oil contains 71.725 % unsaturated fatty acids for use as a biolubricant, 53.478 % more unsaturated fatty acids than saturated fatty acids, and 9.52 g iodine per 100 g of oil sample more than unsaturated glycerides. At 31.44 and 45.93 %, respectively, linoleic acid made up the majority among the fatty acids in the oil and synthetic biolubricant. In addition, palmitic, linoleic, and oleic acids were present in the biolubricant and coconut oil. The biolubricant's characterization results correlated highly with the ISO VG-32 standards, suggesting that it has the capacity to serve as light gear oil.
Gypseous soils are considered one of the most problematic soils. The skirted foundation is an alternative technology that works to improve the bearing capacity and reduce settlement. This paper investigates the use of square skirted foundations resting on gypseous soil subjected to concentric and eccentric vertical load with eccentricity values of 4, 8, and 17 mm in 16 experimental model tests. To obtain the results by using this type of foundation, a small-scale physical model was designed to obtain the load–settlement behavior of the square skirted foundation; the dimension of the square footing is 100 mm × 100 mm with 1 mm thickness, the skirt depth (
In this experimental and numerical analysis, three varieties of under-reamed piles comprising one bulb were used. The location of the bulb changes from pile to pile, as it is found at the bottom, center, and top of the pile, respectively.
Understanding the effects of fear, quadratic fixed effort harvesting, and predator-dependent refuge are essential topics in ecology. Accordingly, a modified Leslie–Gower prey–predator model incorporating these biological factors is mathematically modeled using the Beddington–DeAngelis type of functional response to describe the predation processes. The model’s qualitative features are investigated, including local equilibria stability, permanence, and global stability. Bifurcation analysis is carried out on the temporal model to identify local bifurcations such as transcritical, saddle-node, and Hopf bifurcation. A comprehensive numerical inquiry is carried out using MATLAB to verify the obtained theoretical findings and und
... Show MoreThis study experimentally investigated Free-Fall Gravity Drainage (FFGD) under combination-drive conditions in a two-dimensional Hele-Shaw model representing a water-drive reservoir. An initially high gravity potential from the oil column enabled early oil drainage before aquifer support became dominant. Three water-drive strengths were tested, demonstrating that a stronger aquifer (1.15 psig) accelerated oil recovery to approximately 75% of the original oil in place (OOIP) within 60 minutes, resulting in a final recovery of 79.5%. However, this was accompanied by rapid water breakthrough after 2.5 minutes and high-water cuts exceeding 90%. In contrast, a weaker aquifer (0.725 psig) stabilized the oil–water contact, delaying w
... Show MoreThis research aims to identify the impact of Daniel's model on the development of critical thinking. In order to achieve this objective, the following hypotheses are formulated: 1. There is no statistically significant difference at the significance level (0.05) between the average differences in the posttest scores of the experimental group taught according to Daniel's model and the control group taught according to the traditional method in the measure of critical thinking. 2. There is no statistically significant difference at the significance level (0.05) between the average differences in the preand post-tests scores of the experimental group taught according to Daniel's model in the measure of critical thinking. The current research i
... Show MoreThis experiment examined the effects of adding sodium alginate and KOJIC acid as substitutes of Conventional antibiotics to soybean lecithin extender on the characteristics of cryopreserved and frozen buffalo bull semen, as well as evaluation of their additions as antibiotics that to help lowering the microbial load. Following the collection and dilution of in the soybean lecithin extender, the experimental treatments were separated into five groups, as follows: T1: (control-) without adding any antibiotics; T2: (control+) adding the conventional antibiotics Gentamicin 0.4 IU and Tylosin 0.08 IU per 100 ml; T3: adding Kojic acid at (0.06 g/L) T4: adding sodium alginate at (0.6 mg/mL)T