Enhancing the Tribological Behavior of Lubricating Oil by Adding TiO2, Graphene,and TiO2/Graphene Nanoparticles

This article investigates the tribological behavior of nanoparticles (NPs) of titanium dioxide anatase TiO₂ (A), graphene, and TiO₂ (A) + graphene added to the pure base oil group ΙΙ (PBO-GΙΙ). The morphology of these two nanostructures of TiO₂ (A) and graphene was characterized by transmission electron microscopy (TEM). Oleic acid (OA) was blended as a surfactant into the formulation to help stabilize the NPs in the lubricant oil. A four-ball test rig was used to determine the tribological performance of six different samples, and an image acquisition system was used to examine and measure the wear scar diameter of the stationary balls. Field emission–scanning electron microscopy (FE-SEM) was used to examine the wear morphology. Energy-dispersive X-ray spectroscopy (EDX), element mapping, and Raman spectroscopy were employed to confirm the presence of (TiO₂ (A) + graphene) and the formation of a tribolayer/film on the mating surfaces. Moreover, a 3D optical surface texture analyzer was utilized to investigate the scar topography and tribological performance. The experiments proved that adding (0.4?wt% TiO₂ (A) + 0.2?wt% graphene) to the PBO-GΙΙ optimized its tribological behavior. These excellent results can be attributed to the dual additive effect and the formation of a tribofilm of NPs during sliding motion. Furthermore, the average reductions in the coefficient of friction (COF), wear scar diameter (WSD), and specific wear rate (SWR) were 38.83, 36.78, and 15.78%, respectively, for (0.4?wt% TiO₂ (A) + 0.2?wt% graphene) nanolubricant compared to plain PBO-GΙΙ lubricant.     

The microstructure of buccal cavity and alimentary canal of Siganus rivulatus: Scanning electron microscope study

The microstructure of the oral cavity and alimentary canal of herbivorous fish Siganus rivulatus collected from the Red Sea were investigated by using scanning electron microscope (SEM). The results showed that S. rivulatus has three types of teeth, tri‐cusped, bi‐cusped, and papilliform. A taste bud (Type I) was recorded in the oropharyngeal cavity. Characteristic styles of microridges on the cell's surface inside the buccal cavity were recorded. Also, the distribution of the mucous cells in the lining of the mouth cavity, alimentary canal was observed. Mucosal folds along the distinct parts of alimentary canal, showed characteristic pattern which was complex in the intestinal mucosa. The results concluded that there are characteristic microstructures according to feeding habitat compared with other bony fishes.     

Improvement in Ultrasound Liquid Machining by Activating Cavitational Clusters

Russian Engineering Research - In the erosion-free zone that appears during high-amplitude ultrasound treatment, the useful work is mainly performed by cavitational clusters. In the absence of...     

Electromechanical Converters in Guaranteed Power-Supply Systems for Drives of Machine Tools and Manufacturing Equipment

Russian Engineering Research - The electromagnetic calculation of electromechanical converters in guaranteed power-supply systems for drives of machine tools and manufacturing equipment is outlined.     

Drives in Systems Based on a Composite Electrical Machine with a Circular Field in the Air Gap

Russian Engineering Research - Principles are outlined for mathematical modeling of the drives of machine tools and manufacturing equipment based on a composite electrical machine with a circular...     

3D Printing of Components for the Gas-Discharge Chamber of Electric Rocket Engines

Russian Engineering Research - A technology is developed for 3D printing of the large-diameter gas-discharge chambers of electric rocket engines. The material employed is a ceramic composite based...     

Manufacture of the Transceiver Housing for an Active Phased Array Antenna with Built-In Cooling Channels by Selective Laser Melting

Russian Engineering Research - A cooled transceiver housing of an active phased array antenna is produced by 3D printing from aluminum, on the basis of selective laser melting (SLM). The housing...     

Selection of Working Frequencies in Complex Plane Motion of Saws within a Woodcutting System

Russian Engineering Research - Abstract—A woodcutting system based on complex plane motion (translation + rotation) of the saw blades is promising in principle but proves unstable in...     

Influence of Alternating Stress on the Life of Metal-Cutting Tools

Russian Engineering Research - Abstract—The failure of cutting tools is investigated. A generalized approach to describing failure is proposed, on the basis of the theory of random point...     

Electrocaloric effect and pyroelectric energy harvesting in diffuse ferroelectric Ba(Ti 1-x Ce x )O 3 ceramics

In the present work Ba(Ti1-xCex)O3 ceramics are prepared through a standard solid-state sintering process. Crystal structures, dielectric properties, ferroelectric properties and electrocaloric...