Effect of Scraper Geometry on Scraping HAP/ZrO2 Slurry in Digital Light Processing

Digital light processing (DLP) can be used to form HAP/ZrO2 mixed ceramic slurry. In the printing technology, the scraper geometry has an important effect on the scraping process; thus, it is necessary to conduct analysis. A modified lattice Boltzmann method (LBM) is proposed to conduct the numerical simulations according to the non-Newtonian behavior of the slurry. The Cross behavior of the slurry is viewed as a special external force; then, the traditional LBM including the true external force can be utilized effectively. The triangle, rectangle, trapezium, and rounded rectangle are the main considered section geometries of the scraper. When the flow velocity is set to 0.1 m/s, the results show that the maximum velocity occurs near the bottom surface of the scraper. In four situations, the velocity peak of the triangle case is 0.6270 m/s, which is the maximum, and much larger than the flow velocity of 0.1 m/s. The velocity peak of the rectangle case is 0.0466 m/s, which is the minimum. Although the velocity peak of the rounded rectangle case is 0.0556 m/s, the second velocity peak is 0.0465 m/s; the difference is smaller than that of the rectangle case. In addition, the streamlines figures show that the sharp corner leads to the obvious velocity change. In summary, the rounded rectangle is considered to be more suitable for scraping the HAP/ZrO2 mixed slurry.

An investigation into the effect of thermal variables on the 3D printed shape memory polymer structures with different geometries

In this paper, the effects of thermal parameters including the deformation temperature, shape recovery temperature, and heating rate on the shape recovery of a specific rounded rectangle structure were investigated using the design of experiments. Three-point bending thermo-mechanical tests were subsequently carried out where water was used for controlling the temperature. It was found that the deformation temperature and heating rate have the most and the least effect on the shape recovery of polylactic acid (PLA) SMPs, respectively. The mathematical modeling results showed that the optimum condition of the highest shape recovery is obtained at the deformation temperature of 53.31°C, recovery temperature of 59.94°C, and heating rate of 8.05°C/min. It was also observed that the shape recovery of the specified rounded rectangle structure manufactured by the 3D printing method was enhanced from 93.03% to 98.14% by optimizing the thermal parameters. Besides, the optimum condition was applied to structures with different cell geometries and it was shown that the obtained condition was also enhanced the shape recovery of structures with diamond and honeycomb. More specifically, the shape recovery of noted structures was significantly enhanced to 98.00% and 97.71 % from 82.86% and 78.89%, respectively.

The Influence of Brand Logo Frame on Brand Character and Consumer’s Brand Evaluation

This paper proposes that the different border shapes of brand logos (rectangle and rounded rectangle) cause the differences in the evaluation of brand personality by consumers, which further affects the evaluation of brand by consumers. At the same time, this process is regulated by product category. If product category and brand personality are in the same direction, the border shape of brand logo will generate positive brand evaluation. In this paper, two experiments were designed to verify the hypothesis respectively and to guess the results of data analysis. However, due to the time problem, complete data has not been collected for analysis. This paper provides marketing inspiration for brand identification and deepens the related research on brand identification and brand evaluation.

Friction Reduction of Oil-Impregnated Sintered Bearings by Surface Texturing

In this study, to reduce the friction of oil-impregnated sintered bearings, rounded-rectangle dimples are processed on the bearing surface and the bearing properties are examined. The dimpled bearings achieved lower friction than the flat bearings without dimple processing. To investigate the mechanism of friction reduction of the dimpled bearings, the friction coefficient, the eccentricity ratio, and the attitude angle of the bearings were measured. As a result, the dimpled bearings showed a larger eccentricity ratio and a smaller attitude angle than the flat bearings. In addition, the attitude angles of the dimpled bearings were negative in some cases. The reason for the reduced friction of the dimpled bearings is presumed to be that the extent of the lubricating oil in the bearing clearance was narrower, while the dimple enabled a sufficient amount of lubricating oil to be supplied to the plateau region.

Evaluation of linear losses in ventilation ducts with a rounded rectangle cross-section

The paper presents a new ventilation system characterized by the cross-section of the channels in the shape of a rounded rectangle. The basic research problem was the determination of local losses in the system components. To achieve this goal, it is necessary to know the linear losses in the ducts. The principle of determining both types of losses was presented. The friction coefficients of linear pressure losses referred to the unit of the straight length of the duct section ζl[m−1] as well as generalized dimensionless friction coefficient of linear pressure losses λ [-] is presented. The main achievement of the paper is the statement that the lambda coefficient λ can replace the coefficients ζl examined duct cross-sections.