This paper proposes a new machine vision method to test the quality of a semi-transparent automotive illuminant component. Difference images of Frangi filtered surface images are used to enhance ...defect-like image structures. In order to distinguish allowed structures from defective structures, morphological features are extracted and used for a nearest-neighbor-based anomaly score. In this way, it could be demonstrated that a segmentation of occurring defects is possible on transparent illuminant parts. The method turned out to be fast and accurate and is therefore also suited for in-production testing.
Micro-compression tests were performed on pre-strained nickel (Ni) single crystals in order to investigate the influence of the initial dislocation arrangement on the size dependence of small-scale ...metal structures. A bulk Ni sample was grown using the Czochralski method and sectioned into four compression samples, which were then pre-strained to nominal strains of 5, 10, 15 and 20%. Bulk samples were then characterized using transmission electron microscopy (TEM), micro-Laue diffraction, and electron backscatter diffraction. TEM results show that a dislocation cell structure was present for all deformed samples, and Laue diffraction demonstrated that the internal strain increased with increased amount of pre-straining. Small-scale pillars with diameters from 200nm to 5μm were focused ion beam (FIB) machined from each of the four deformed bulk samples and further compressed via a nanoindenter equipped with a flat diamond punch. Results demonstrate that bulk pre-straining inhibits the sample size effect. For heavily pre-strained bulk samples, the deformation history does not affect the stress–strain behavior, as the pillars demonstrated elevated strength and rather low strain hardening over the whole investigated size range. In situ TEM and micro-Laue diffraction measurements of pillars confirmed little change in dislocation density during pillar compression. Thus, the dislocation cell walls created by heavy bulk pre-straining become the relevant internal material structure controlling the mechanical properties, dominating the sample size effect observed in the low dislocation density regime.
The touch-feel sensation of product surfaces arouses growing interest in various industry branches. To entangle the underlying physical and material parameters responsible for a specific touch-feel ...sensation, a new measurement system has been developed. This system aims to record the prime physical interaction parameters at a time, which is considered a necessary prerequisite for a successful physical description of the haptic sensation. The measurement setup enables one to measure the dynamic coefficient of friction, the macroscopic contact area of smooth and rough surfaces, the angle enclosed between the human finger and the soft-touch surfaces and the vibrations induced in the human finger during relative motion at a time. To validate the measurement stand, a test series has been conducted on two soft-touch surfaces of different roughness. While the individual results agree well with the literature, their combination revealed new insights. Finally, the investigation of the haptics of polymer coatings with the presented measuring system should facilitate the design of surfaces with tailor-made touch-feel properties.
A large number of allergenic proteins have now their complete cDNA sequences determined and in some cases also the 3D structures. It turned out that most allergens could be grouped into a small ...number of structural protein families, regardless of their biological source. Structural similarity among proteins from diverse sources is the molecular basis of allergic cross‐reactivity. The clinical relevance of immunoglobulin E (IgE) cross‐reactivity seems to be influenced by a number of factors including the immune response against the allergen, exposure and the allergen. As individuals are exposed to a variable number of allergenic sources bearing homologous molecules, the exact nature of the antigenic structure inducing the primary IgE immune response cannot be easily defined. In general, the ‘cross‐reactivity’ term should be limited to defined clinical manifestations showing reactivity to a source without previous exposure. ‘Co‐recognition’, including by definition ‘cross‐reactivity’, could be used to describe the large majority of the IgE reactivity where co‐exposure to a number of sources bearing homologous molecules do not allow unequivocal identification of the sensitizing molecule. The analysis of reactivity clusters in diagnosis allows the interpretation of the patient's reactivity profile as a result of the sensitization process, which often begins with exposure to a single allergenic molecule.
Abstract Background The Resuscitation Council (UK) Immediate Life Support (ILS) course provides training in the prevention and management of cardiac arrest. This course was introduced at our ...institution and we subsequently undertook an analysis to determine its impact on the incidence and outcome of in-hospital cardiac arrest. Methods A 6-year prospective audit of 3126 in-hospital emergency alert calls within a multi-site 1200 bedded London teaching hospital following the organisation-wide adoption of the ILS course. Key measures used to detect improvement were the incidence of emergency alert calls, in particular the proportion of calls which were pre-arrest versus cardiac arrest calls, episodes of resuscitations without return of spontaneous circulation, survival to hospital discharge; the proportion of clinical staff who were ILS trained was an important organisational measure. Results The total number of emergency alert calls showed no significant change. We observed a reduction in the proportion of calls for cardiac arrests ( p < 0.0001; from 85% in 2002 to 45% in 2007), a corresponding increase in the proportion of ‘pre-arrest’ calls ( p < 0.0001; from 15% in 2002 to 55% in 2007), a reduction in deaths at cardiac arrest ( p = 0.0002) and an increased survival to hospital discharge following an emergency call from 28% in 2004 to 39% in 2007. There was a temporal relationship between the proportion of staff who were ILS trained and outcome. Conclusion The introduction of a simple and widespread educational programme was associated with a reduction in both the number of in-hospital cardiac arrests and unsuccessful cardiopulmonary resuscitation attempts.
Various fracture tests have been performed to determine the fracture toughness of sintered and rolled tungsten rods. The polycrystalline rods experienced a degree of deformation of about 65% after ...sintering and exhibited a pronounced fiber texture. Specimens with three different kinds of crack orientation were extracted and tested in the temperature range between −
150
°C and 950
C. The results confirm the strong influence of the anisotropic microstructure on the fracture behavior and on the brittle-to-ductile transition. To gain insight into the failure mechanisms, a close analysis of the microstructure was done by scanning electron microscopy and electron backscatter diffraction. Furthermore, in situ experiments were conducted at elevated temperatures in the transition regime to study crack initiation and fracture. Auger spectroscopy showed segregations of phosphorus and fluorine at intergranular fracture surfaces.
Some general observations relating to tyre shear forces and road surfaces are followed by more specific considerations from circuit racing. The discussion then focuses on the mechanics of rubber ...friction. The classical experiments of Grosch are outlined and the interpretations that can be put on them are discussed. The interpretations involve rubber viscoelasticity, so that the vibration properties of rubber need to be considered. Adhesion and deformation mechanisms for energy dissipation at the interface between rubber and road and in the rubber itself are highlighted. The enquiry is concentrated on energy loss by deformation or hysteresis subsequently. Persson's deformation theory is outlined and the material properties necessary to apply the theory to Grosch's experiments are discussed. Predictions of the friction coefficient relating to one particular rubber compound and a rough surface are made using the theory and these are compared with the appropriate results from Grosch. Predictions from Persson's theory of the influence of nominal contact pressure on the friction coefficient are also examined. The extent of the agreement between theory and experiment is discussed. It is concluded that there is value in the theory but that it is far from complete. There is considerable scope for further research on the mechanics of rubber friction.
Dynamic perception includes amodal and modal completion, along with apparent movement. It fills temporal gaps for single objects. In 2 experiments, using 6 stimulus presentation conditions involving ...3 sensory modalities, participants experienced 8–10 sequential stimuli (200 ms each) with interstimulus intervals (ISIs) of 0.25–7.0 s. Experiments focused on spatiotemporal completion (walking), featural completion (object changing), auditory completion (falling bomb), and haptic changes (insect crawling). After each trial, participants judged whether they experienced the process of “happening” or whether they simply knew that the process must have occurred. The phenomenon was frequency independent, being reported at short ISIs but not at long ISIs. The phenomenon involves dynamic modal completion and possibly also conceptual processes.
PDF
