Preparation, characterization and manipulation of conjugates between gold nanoparticles and DNA

Here we described the preparation and characterization by atomic force microscopy of dumbbell-shaped conjugates between 450 bp double-stranded DNA polymer, poly(dG)-poly(dC), and 5 nm gold nanoparticles (GNPs). We have demonstrated that the size of the nanoparticles in the conjugates can be increased in a controlled fashion. Application of the conjugates for measuring the electrical conductivity of DNA is discussed

Creativity out of chaos

Creativity is said to be highly desired in post-modern and post-industrial organizations Creativity and anarchy on the one hand, and managerialism, on the other, can be seen as different forms of knowledge, two opposed ideals. In many organizational as well as societal reforms we currently observe it is the managerialist ideal that wins over the anarchic. In this paper, we wonder if people fear anarchy? We reflect on the possible reasons for the fear, and we also try to explain why we believe that anarchic organizing should not be avoided or feared

Structural and mechanical characterization of (TiZrNbHfTa)N/WN multilayered nitride coatings

The (TiZrNbHfTa)N/WN multicomponent coatings were deposited by vacuum arc evaporation under dif- ferent substrate bias (-90 and -280 V).X-ray photoelectron spectroscopy was used for analyzing of com- plex composition of investigated coatings by reflecting of atomic scale chemical interactions. The structural investigations showed the formation of a simple disordered solid solution in (TiZrNbHfTa)N layer, b-W2N phase in WN layer with fcc crystal structure and highly disordered bcc (110) and (220) -oriented high-entropy alloy phases, regardless of the applied bias potential. It was shown that with increasing of substrate bias from -90 to -280 V, there is a slight decrease of hardness from 34 to 31 GPa and increase of Young’s modulus from 325 to 337 GPa, which can be explained by annihilation of point defects and precipitation of relatively softer metallic phase

Structural and mechanical characterization of (TiZrNbHfTa)N/WN multilayered nitride coatings

The (TiZrNbHfTa)N/WN multicomponent coatings were deposited by vacuum arc evaporation under dif- ferent substrate bias (-90 and -280 V).X-ray photoelectron spectroscopy was used for analyzing of com- plex composition of investigated coatings by reflecting of atomic scale chemical interactions. The structural investigations showed the formation of a simple disordered solid solution in (TiZrNbHfTa)N layer, b-W2N phase in WN layer with fcc crystal structure and highly disordered bcc (110) and (220) -oriented high-entropy alloy phases, regardless of the applied bias potential. It was shown that with increasing of substrate bias from -90 to -280 V, there is a slight decrease of hardness from 34 to 31 GPa and increase of Young’s modulus from 325 to 337 GPa, which can be explained by annihilation of point defects and precipitation of relatively softer metallic phase

A new type of (TiZrNbTaHf)N/MoN nanocomposite coating: Microstructure and properties depending on energy of incident ions

A novel (TiZrNbTaHf)N/MoN nanocomposite coatings, which consist of the nitride of the high-entropy alloy and the binary nitride, were synthesized by vacuum-arc deposition at various substrate biases. The elemental composition, chemical bonding state, phase structure, microstructure and mechanical properties of the coatings were studied by high-resolution experimental methods: SIMS, GDMS, XPS, XRD, HR-TEM and nano-indentation.It was found that the chemical state of the (TiZrNbTaHf)N/MoN coatings has a complex nature, which consist of a mixture of nitrides of constituting elements. It was also shown that the coatings are based on B1 NaCl-structured γ-Mo2N-phase with a mixture of crystallographic orientations (111), (200), (220) and (311) together with the B1NaCl-structured (TiZrNbTaHf)N solid-solution phase. First-principles calculations demonstrated that the metal sub-lattice of the (TiZrNbTaHf)N solid solution can be based on Ti1-xHfyTa1-x-y, Zr1-xHfyTa1-x-y, Zr0.25Ti0.25Ta0.5 ternary alloys, which have the lowest mixing energy. The HR-TEM results showed that the nanocomposite nitride coatings have nano-scale multilayer structure with modulation periods ranged from 20nm to 25nm. The maximum hardness of approximately 29GPa demonstrated the coating deposited at a higher energy condition (−200V) with the thinnest modulation period of bilayer of 20nm (15nm of (TiZrNbTaHf)N and 5nm of Mo2N)