56 research outputs found
Grouping in the shine-through effect
How the elements of a visual scene are grouped into objects is one of the most fundamental but still poorly understood questions in visual neuroscience. Most investigations of perceptual grouping focus on static stimuli, neglecting temporal aspects. Using a masking paradigm, we show that the neural mechanisms underlying grouping seem to be both fast and complex. For example, a vernier target was followed by, first, a briefly presented grating and, then, a long-lasting, extended grating. Under these conditions, the briefly presented grating is hardly visible. Still, vernier discrimination strongly changed with the number of elements of the briefly displayed grating being worst for small gratings. In accordance with a neural network model of masking, we propose that the edges of the briefly presented grating and the vernier interfere in spite of the short presentation time. We suggest that this fast edge processing is a first step for unconscious grouping processe
Grouping in the shine-through effect
How the elements of a visual scene are grouped into objects is one of the most fundamental but still poorly understood questions in visual neuroscience. Most investigations of perceptual grouping focus on static stimuli, neglecting temporal aspects. Using a masking paradigm, we show that the neural mechanisms underlying grouping seem to be both fast and complex. For example, a vernier target was followed by, first, a briefly presented grating and, then, a long-lasting, extended grating. Under these conditions, the briefly presented grating is hardly visible. Still, vernier discrimination strongly changed with the number of elements of the briefly displayed grating being worst for small gratings. In accordance with a neural network model of masking, we propose that the edges of the briefly presented grating and the vernier interfere in spite of the short presentation time. We suggest that this fast edge processing is a first step for unconscious grouping processes
Cryogenic analysis of frozen hydrated biological tissue at the Hard X-ray Micro-Probe Beamline at PETRA III
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Cryogenic synchrotron radiation X-ray fluorescence analysis of biological model organisms using a state-of-the-art cryochamber at P06, PETRA III
A cryogenic sample environment for the analysis of frozen hydrated biological tissue at the hard X-ray micro/nano-probe Beamline P06 at PETRA III
Schnelle, bildgebende RFA mit Sub-Mikrometer Auflösung: Der Maia Detektor an der Strahlführung P06 des Deutschen Elektronen-Synchrotrons
2D and 3D Imaging of Li-Ion Battery Materials Using Synchrotron Radiation Sources
Characterization of microstructural properties in electrodes for Li-Ion batteries can be regarded a key factor to understand functionality and aging process in the cells. X-ray microscopy has proven extremely powerful to capture a number of morphological parameters such as porosity, tortuosity or particle size distribution but also chemical information regarding phase distribution, state of charge or elemental migration over a large range of length scales. With their high penetration power utilizing various contrast methods X-rays offer deep insight into the battery materials and microstructural characteristics
X-ray Fluorescence Tomography of Aged Fluid-Catalytic-Cracking Catalyst Particles Reveals Insight into Metal Deposition Processes
Microprobe X-ray fluorescence tomography was used to investigate metal poison deposition in individual, intact and industrially deactivated fluid catalytic cracking (FCC) particles at two differing catalytic life-stages. 3 D multi-element imaging, at submicron resolution was achieved by using a large-array Maia fluorescence detector. Our results show that Fe, Ni and Ca have significant concentration at the exterior of the FCC catalyst particle and are highly co-localized. As concentrations increase as a function of catalytic life-stage, the deposition profiles of Fe, Ni, and Ca do not change significantly. V has been shown to penetrate deeper into the particle with increasing catalytic age. Although it has been previously suggested that V is responsible for damaging the zeolite components of FCC particles, no spatial correlation was found for V and La, which was used as a marker for the embedded zeolite domains. This suggests that although V is known to be detrimental to zeolites in FCC particles, a preferential interaction does not exist between the two
X-ray Fluorescence Tomography of Aged Fluid-Catalytic-Cracking Catalyst Particles Reveals Insight into Metal Deposition Processes
Microprobe X-ray fluorescence tomography was used to investigate metal poison deposition in individual, intact and industrially deactivated fluid catalytic cracking (FCC) particles at two differing catalytic life-stages. 3D multi-element imaging, at submicron resolution was achieved by using a large-array Maia fluorescence detector. Our results show that Fe, Ni and Ca have significant concentration at the exterior of the FCC catalyst particle and are highly co-localized. As concentrations increase as a function of catalytic life-stage, the deposition profiles of Fe, Ni, and Ca do not change significantly. V has been shown to penetrate deeper into the particle with increasing catalytic age. Although it has been previously suggested that V is responsible for damaging the zeolite components of FCC particles, no spatial correlation was found for V and La, which was used as a marker for the embedded zeolite domains. This suggests that although V is known to be detrimental to zeolites in FCC particles, a preferential interaction does not exist between the two
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