Crater depth prediction in granular collisions: A uniaxial compression model.

Impact crater experiments in granular media traditionally involve loosely packed sand targets. However, this study investigates granular impact craters on both loosely and more tightly packed sand targets. We report experiments that consistently adhere to power-law scaling laws for diameter as a function of impacting energy, similar to those reported by other groups for their experiments utilizing both solid and granular projectiles.

Graphene as Barrier to Prevent Volume Increment of Air Bubbles over Silicone Polymer in Aqueous Environment.

The interaction of air bubbles with surfaces immersed in water is of fundamental importance in many fields of application ranging from energy to biology. However, many aspects of this topic such as the stability of surfaces in contact with bubbles remain unexplored. For this reason, in this work, we investigate the interaction of air bubbles with different kinds of dispersive surfaces immersed in water.

Primary cortical neurons on PMCS TiO films towards bio-hybrid memristive device: A morpho-functional study.

We report a comprehensive study of the biocompatibility and neurocompatibility of titanium dioxide films (TiO) prepared by Pulsed Microplasma Cluster Source (PMCS). This technique uses supersonic pulsed beams seeded by clusters of the metal oxide synthesized in a plasma discharge. The final stoichiometry of the TiO thin films is tuned changing the gas mixture, achieving stoichiometric or oxygen overstoichiometric films.

Interaction of the Helium, Hydrogen, Air, Argon, and Nitrogen Bubbles with Graphite Surface in Water.

The interaction of the confined gas with solid surface immersed in water is a common theme of many important fields such as self-cleaning surface, gas storage, and sensing. For that reason, we investigated the gas-graphite interaction in the water medium. The graphite surface was prepared by mechanical exfoliation of highly oriented pyrolytic graphite (HOPG).

Tribological characteristics of few-layer graphene over Ni grain and interface boundaries.

The tribological properties of metal-supported few-layered graphene depend strongly on the grain topology of the metal substrate. Inhomogeneous distribution of graphene layers at such regions led to variable landscapes with distinguishable roughness. This discrepancy in morphology significantly affects the frictional and wetting characteristics of the FLG system.

PDMS/Kapton interface plasma treatment effects on the polymeric package for a wearable thermoelectric generator.

The present work highlights the progress in the field of polymeric package reliability engineering for a flexible thermoelectric generator realized by thin-film technology on a Kapton substrate. The effects of different plasma treatments on the mechanical performance at the interface of a poly(dimethylsiloxane) (PDMS)/Kapton assembly were investigated. To increase the package mechanical stability of the realized wearable power source, the Kapton surface wettability after plasma exposure was investigated by static contact-angle measurements using deionized water and PDMS as test liquids.

Mechanical characterization of thin TiO2 films by means of microelectromechanical systems-based cantilevers.

The measurement of mechanical parameters by means of microcantilever structures offers a reliable and accurate alternative to traditional methods, especially when dealing with thin films, which are extensively used in microfabrication technology and nanotechnology. In this work, microelectromechanical systems (MEMS)-based piezoresistive cantilevers were realized and used for the determination of Young's modulus and residual stress of thin titanium dioxide (TiO(2)) deposited by sputtering from a TiO(2) target using a rf plasma discharge. Films were deposited at different thicknesses, ranging from a few to a hundred nanometers.

Production and characterization of thin a-C:(H) films for gas permeation barrier functionality against He, CO(2), N(2), O(2) and H(2)O.

This work reports on (i) the gas barrier properties of a-C:H films rf-sputtered in Ar-H(2) plasmas from a graphite target on polyethylene terephthalate (PET) and (ii) the influence of the film chemical structure and defect properties on the gas permeability. The intrinsic permeabilities of the films to He, CO(2), O(2), N(2) gases and H(2)O vapour were determined and found to be orders of magnitude lower than that of the bare PET. Indirect evidence was given to a solubility-diffusion process as the more probable permeation mechanism, over a gas flow through microdefects or gas transport through nanodefects by a Knudsen diffusion mechanism.

Occurrence of cyclic AMP and related enzymes during germination of Pinus pinea seeds.

The occurrence of cAMP, adenylate cyclase and cAMP phosphodiesterase has been tested in Pinus pinea seed during germination. The study has been carried out on dormant and imbibed seeds, seedlings, endospermic residues, roots and cotyledons. cAMP has been detected by the protein binding method and its occurrence has been verified by HPLC detections.