Alumina ceramics in a wear test reacts with air humidity to form a film layer of aluminum hydroxide which acts as a lubricant. Increasing sliding test load and/or speed affects the tribofilm and changes the wear regim...
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Alumina ceramics in a wear test reacts with air humidity to form a film layer of aluminum hydroxide which acts as a lubricant. Increasing sliding test load and/or speed affects the tribofilm and changes the wear regime from mild to severe. The purpose of this work was to determine critical values of load and sliding speed for the wear regime transition under controlled atmosphere humidity, in a pin-on-disc test. The wear rate and the worn surface SEM image and roughness allowed to distinguish the mild and severe wear regime for different speed/load combinations so that the boundaries of mild wear region was determined. The boundaries were characterized by a narrow transition zone. The image analyses have shown distinct wear mechanisms as function of sliding speed and load.
Efficient phosphors based on YNbO4 and doped by Eu3+, Ga3+, Al3+ were synthesized and investigated under UV, and X-ray excitation in luminescence and Raman spectroscopy. Monoclinic fergusonite crystal structure and ex...
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Single walled carbon nanotubes (SWNT) have shown tremendous promise as agents for diagnostic and therapeutic intervention in vivo. We demonstrate how Dextran sulfate (DS) can render SWNT transparent to macrophages, a ...
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The aspartic protease cathepsin E has been shown to induce apoptosis in cancer cells under physiological conditions. Therefore, cathepsin E-activity-enhancing peptides functioning in the physiological pH range are val...
Photonic crystal cavities with tunable surface area via multiple-hole defects were investigated for increased resonance wavelength shifts upon exposure to variable-index analytes. Sensitivity was improved by 10% compa...
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Photonic crystal cavities with tunable surface area via multiple-hole defects were investigated for increased resonance wavelength shins upon exposure to variable-index analytes. Sensitivity was improved by 10% compar...
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The reconstruction and evaporation at graphene nanoribbon (GNR) edges are investigated by tight-binding molecular-dynamics simulations and ab initio calculations. It is observed that reconstruction through the formati...
The reconstruction and evaporation at graphene nanoribbon (GNR) edges are investigated by tight-binding molecular-dynamics simulations and ab initio calculations. It is observed that reconstruction through the formation of pentagon-heptagon pairs can take place quickly along the zigzag edge and it is energetically favorable. At very high temperatures, the armchair edge is found to change into a zigzag edge structure, which further accelerates the evaporation of carbon atoms and leads to the formation of carbon linear chains. The evaporation of carbon atoms from both the zigzag and armchair edges is preceded by the formation of heptagon rings, which serve as a gateway for carbon atoms to escape. In the simulation for a GNR armchair-zigzag-armchair junction, carbon atoms are evaporated row by row from the outermost row of the zigzag edge while the armchair edge remains nearly intact. These results can be applied to nanoelectronic devices fabrication through the temperature-controlled edge structure of GNR.
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