Effect of pretreatment by shotblasting prior to lubrication for cold forging

Effect of pretreatment by shotblasting to workpieces before lubricating of a non-chemical conversion lubricant in cold forging was examined by making several surfaces with different topographies, using wet shotblasting. Backward-cup extrusion test estimated the performance of the pretreatment. This test provides extremely large surface expansion to bring severe tribological conditions. After the tests, the insides of the cup-like workpieces were observed with scanning electron microscope and surface-analyzed energy dispersive X-ray spectroscopy to measure the distributive amount of the lubricant on the workpiece. The pretreated surface resulting large aspect ratio (Ra / RSm) raised the potential of lubrication performance. Especially, the surface treated with angular shaped media indicated higher potential to improve anti-galling performance

Morphological changes in functional tricuspid regurgitation on contrast-enhanced computed tomography correlates to tricuspid regurgitation grade

PURPOSE: To examine the relationship between each severity of functional tricuspid regurgitation (FTR) and morphological evaluation on contrast-enhanced computed tomography (CT). METHODS: Forty-five patients underwent contrast-enhanced CT. Tricuspid annulus area (TAA), tricuspid annulus circumference (TAC), right ventricular volume (RVV), and the distances between the tips and bases of the papillary muscles were measured on contrast-enhanced CT in diastole and systole. The patients were classified organized into 4 groups by TR grade measured by transthoracic echocardiography (none+trivial: 26, mild: 6, moderate: 6, severe: 7), and the data were compared among the groups. RESULTS: In parameters measured on contrast-enhanced CT images, TAA, TAC, and the distances between the tips of the anterior and posterior papillary muscles in both diastole and systole and RVV in diastole were significantly different among the groups (p0.40). The septal papillary muscle could not be identified in about 1/3 (35.6%) of cases. CONCLUSIONS: TAA, TAC, RVV, and the distance between the tips of the anterior and posterior papillary muscles measured on contrast-enhanced CT images had relatively positive correlations with TR grade