Cutting performance and wear characteristics of PVD coated and uncoated carbide tools in face milling Inconel 718 aerospace alloy

In this paper, cutting performance and failure characteristics of two PVD TiN coated and an uncoated tungsten carbide grades with identical geometry are presented. Face-milling tests of Inconel 718 superalloy were performed to investigate the effect of cutting speed and feed rate on tools performance under wet conditions. Tools were thoroughly examined under SEM at two stages in order to reveal the failure modes and wear mechanisms. These stages were after cutting for 5 s and when the tool failed. It was noted that the coating resulted in a marginal improvement, as it was delaminated by adhering workpiece material at the beginning of the cut, impeding the performance of the tool for the rest of the experiment. A combination of progressive chipping and flank wear was the general mode of tool failure, former being dominant at high speeds and the latter at the low speed region. Results showed that uncoated tool performed better than coated tools at low cutting speeds while coated tools gave slightly better performance as the speed was raised

Evaluation of the Minimum Effective Concentration of Foam Sclerosant in an Ex-vivo Study

AbstractBackgroundFoam sclerosants are widely used in sclerotherapy and have been accepted as more effective than the liquid form; however, there is no consensus about the most applicable and effective concentration.ObjectiveThe aim of this study was to investigate the histopathological changes caused by various widely used concentrations of foam sclerosant.MethodsFifty-six varicose vein segments of 5–10 mm diameter were gently resected and exposed to various concentrations of foam sclerosant (0.5%, 1%, 2%, 3%) for 5 min, and were then prepared for routine histopathological examination. A total damage scoring system, including the presence of endothelial swelling, intimal thickening, cellular vacuolization in the muscle layer, edema in the tunica media and extent of necrosis, was established.ResultsThe total damage score of the foam sclerosant groups was significantly higher than that of the control group (median 2.75 vs 1, p = 0.007). The highest damage score was achieved by 1% and 2% foam sclerosants (3.5 and 2.5). No significant difference was found among the different concentrations of sclerosant, although the 1% group caused more severe damage at a near significant level (p = 0.074).ConclusionSignificant pathological damage can be caused by even the lowest doses of foam sclerosant. The most injurious concentrations were found to be 1% and 2%, morphologically. A working concentration of 1% could thus be preferable to 0.5%, especially in larger veins. Further in-vivo studies are needed in order to validate these findings

Effect of Annotation Errors on Drone Detection with YOLOv3

Following the recent advances in deep networks, object detection and tracking algorithms with deep learning backbones have been improved significantly; however, this rapid development resulted in the necessity of large amounts of annotated labels. Even if the details of such semi-automatic annotation processes for most of these datasets are not known precisely, especially for the video annotations, some automated labeling processes are usually employed. Unfortunately, such approaches might result with erroneous annotations. In this work, different types of annotation errors for object detection problem are simulated and the performance of a popular state-of-the-art object detector, YOLOv3, with erroneous annotations during training and testing stages is examined. Moreover, some inevitable annotation errors in CVPR-2020 Anti-UAV Challenge dataset is also examined in this manner, while proposing a solution to correct such annotation errors of this valuable data set.Comment: Best Paper Award at The 1st Anti-UAV Workshop & Challenge - CVPR Workshops, 202