Significance of residual stress in PVD-coated carbide cutting tools

The performance of PVD-coated carbide cutting tools is influenced by their residual stress state, where coating and substrate subsurface have to be considered. The substrate stress is the result of different impacts caused by pre-coating processes and the PVD-coating itself. This presentation demonstrates the significance of residual stress in coating and substrate as well as the influence of each step of a conventional commercial process chain on the respective residual stress state for the manufacture of PVD-coated carbide cutting tools. Alterations of the process chain for tool micro geometry preparation by laser beam removal are considered.     

Results and consequences of high heat flux testing as quality assessment of the Wendelstein 7-X divertor

The series manufacturing of the first 282 Wendelstein 7-X divertor elements was concluded in 2011. The divertor is designed to remove a steady-state heat load of 10 MW/m². 940 target elements of five different types made of CuCrZr heat sinks and covered with 16,000 CFC NB31 flat-tiles have to be produced. Additional to quality assessment during the manufacturing process, a final assessment of the delivered elements with operational heat load is indispensable to ensure a constant high thermal performance of the installed divertor.Based on the results of the pre-series testing a statistical quality assessment method has been developed for the series production. The application of this method to the series elements ensures their thermal performance with reasonable high heat flux test effort.     

Dietary fatty acid intervention of lactating cows simultaneously affects lipid profiles of meat and milk

BACKGROUND: The present study investigated tissue‐specific responses of muscle and mammary gland to a 10 week intervention of German Holstein cows (n = 18) with three different dietary fat supplements (saturated fat; linseed oil or sunflower oil plus docosahexaenoic acid‐rich algae) by analysing fatty acid profiles and quality parameters of meat and milk. RESULTS: Plant oil/algae intervention affected neither fat content nor quality parameters of meat but decreased fat content and saturated fatty acid amounts of milk. Linseed oil/algae intervention caused significantly higher concentrations of C18:3n‐3 (meat, 1.0 g per 100 g; milk, 1.2 g per 100 g) and C22:6n‐3 (meat, 0.3 g per 100 g; milk, 0.14 g per 100 g). Sunflower oil/algae intervention increased n‐6 fatty acid contents in milk (4.0 g per 100 g) but not in meat. Elevated amounts of C18:1trans isomers and C18:1trans‐11 were found in meat and especially in milk of plant oil/algae‐fed cows. C18:1cis‐9 amounts were found to be increased in milk but decreased in meat after plant oil/algae intervention. CONCLUSION: The present study demonstrated that dietary fatty acid manipulation substantially shifted the fatty acid profiles of milk and to a lesser extent of meat, whereas meat quality traits were not affected. Indications of tissue‐specific responses of mammary gland and muscle were identified. Copyright © 2012 Society of Chemical Industry     

Prior shape level set segmentation on multistep generated probability maps of MR datasets for fully automatic kidney parenchyma volumetry

Fully automatic 3-D segmentation techniques for clinical applications or epidemiological studies have proven to be a very challenging task in the domain of medical image analysis. 3-D organ segmentation on magnetic resonance (MR) datasets requires a well-designed segmentation strategy due to imaging artifacts, partial volume effects, and similar tissue properties of adjacent tissues. We developed a 3-D segmentation framework for fully automatic kidney parenchyma volumetry that uses Bayesian concepts for probability map generation. The probability map quality is improved in a multistep refinement approach. An extended prior shape level set segmentation method is then applied on the refined probability maps. The segmentation quality is improved by incorporating an exterior cortex edge alignment technique using cortex probability maps. In contrast to previous approaches, we combine several relevant kidney parenchyma features in a sequence of segmentation techniques for successful parenchyma delineation on native MR datasets. Furthermore, the proposed method is able to recognize and exclude parenchymal cysts from the parenchymal volume. We analyzed four different quality measures showing better results for right parenchymal tissue than for left parenchymal tissue due to an incorporated liver part removal in the segmentation framework. The results show that the outer cortex edge alignment approach successfully improves the quality measures.     

Robust mobile video streaming in a peer-to-peer system

In a peer-to-peer (P2P) video streaming system, peers not only consume video, but also route it to other peers in the system, where ordinary peers are assumed to have sufficient downlink speed and media capability. This assumption often fails when the P2P system consists of peers that are heterogeneous in their computing power, hardware, and media capability.In this paper, we address a problem of streaming video to mobile devices, which are less capable than ordinary peers. In order to stream video to mobile devices, transcoding is often required to render video suitable for their small display, limited downlink speed, and limited video decoding capability. However, performing transcoding at a single peer is vulnerable to peer churn, which leads to video disruption. We propose interleaved distributed transcoding (IDT), a robust video encoding scheme that allows peers more capable than mobile devices to perform transcoding in a collaborative fashion. IDT is designed in such a way that transcoded substreams are assembled into a single video stream, which can be decoded by any H.264/AVC baseline profile compliant decoder. Extensive simulations and its implementation in a real P2P system demonstrate that the proposed scheme not only reduces computational load at a peer, but also achieves robust streaming in the case of peer failure or packet loss due to adverse wireless channel conditions. We confirm this finding by analyzing the effect of distributed transcoding under peer failure.     

Survival of Brucella spp. in mineral water, milk and yogurt

Knowledge of the number of organisms in a food product at the time of consumption is crucial to assess the risk from a deliberate contamination of food samples with Brucella. To date, very little data on the survival times of Brucella in different food matrices is available.This study was conducted to assess the survival times of Brucella spp. in water, milk and yogurt. These food products were inoculated with bacteria, serial dilutions of the food samples plated and the number of surviving bacteria counted.Under normal storage conditions Brucella survived in UHT milk for 87 days, for 60 days in water and less than a week in yogurt. Also, when milk was inoculated with low bacterial numbers, Brucella multiplied by five log units within three weeks.Further we could not confirm that a high fat content in food has a protective effect on Brucella survival. Brucella survived in 3.5% and 10.0% fat yogurt for four and two days, respectively.These results show that appropriate methods for the rapid detection of this pathogen from food matrices are required.