Airflow Dynamics and Aluminum Coating Oxidation Behavior under Electric-Arc Spraying with Airflow Pulsations

The paper aims to investigate the airflow dynamics of electric-arc spraying (EAS) with airflow pulsation. The study is focused on the dynamic structure of the airflow with an obstacle in the form of crossed electrodes at the steady and the pulsating air supply (with a frequency up to 120 Hz). The work was fulfilled using a computer simulation, the airflow “shadow” photo visualization, and the microstructure characterization of the coatings formed. It was found that when air flows along the crossed electrodes with a gap of 2 mm, a depression zone appears in the flow with a pressure drop from 0.56 MPa to 0.01 MPa. The air pulsation resulted in a change in a flow’s dynamic structure towards an increase in the length of the depression zone, which covers most of the arc, affecting the liquid metal oxidation. It is established that the frequency of a droplet formation should match the frequency of the airflow pulsation to minimize the metal oxidation. With the air pulsating at about 65 Hz, the oxide volume fraction in the aluminum coating was reduced by 3.6 times compared to the steady airflow. EAS with airflow pulsation has the potential for technological cost reduction.

Components of Appearance in the Structure of Perception of Visual Representations of Age

The article discusses the problem of perception of age (one’s own and that of other people), which is regarded as a special case of social perception. The aim of this study was to analyze the components of another person’s appearance in the structure of perception of visual representations of age. For these purposes the authors created a special technique, “Identifying Age through Photo Visualization” (Shkurko T.A., Nikolaeva E. G.). The study enrolled 20 individuals (10 men, 10 women aged 18 to 58 years) as “models” (i.e. objects of perception) and 60 individuals (47 women and 13 men aged 18 to 77 years) as subjects of perception. The paper shows that in the structure of perception of visual representations of age the most important are stable, moderately stable and dynamic components of appearance, among which the stable parameters prevail. The face as the focus of the stable, moderately stable and dynamic components of appearance is the key element of appearance in one’s perception of other people’s age.