A method for extracting the substrate-independent stress–strain curves of thin films was developed using spherical nanoindentation to investigate the yield behavior of diamond-like carbon (DLC) thin films with Young’s moduli of ∼73 GPa and ∼76 GPa. The resulting stress–strain curves showed that these films commence yielding at ∼13 GPa and ∼14 GPa, respectively. These yield strength values agree with the critical pressure necessary to initiate the transformation of sp 2-bonded carbon into significantly harder sp 3-bonded carbon, indicating that the yielding of the materials is associated with the sp 2-to-sp 3 phase transition. The ability of a DLC film to accommodate a progressively increasing contact stress with strain beyond the yield point while dissipating part of the accumulated strain energy, as evidenced in this work, implies a unique mechanism of the brittle material for passively mitigating contact deformation and fracture in tribological applications.

Drug delivery systems (DDSs) have been developed to target tumor cells by releasing active biomolecules at the specific site of infection, thus eliminating the side effects of anticancer drugs. However, DDSs are generally limited by high drug dosage, biobarriers, poor target recognition, etc. To address these deficiencies, we propose a new noninvasive method consisting of exposing the cancer cells to a combination of low-intensity pulsed ultrasound (LIPUS) and static magnetic field (SMF). This combined treatment found to negatively regulate colon cancer cell (HCT116) activities in vitro by altering their cell membrane potential and permeability thus increased the DDS efficacy by 40%. The treated cancer cell membrane became hyperpolarized leading to cancer cell death. The combination treatment (LIPUS + SMF) restricted the cancer cell proliferation to 16 and 5% in the presence of bare anticancer drug and DDS, respectively, in 72 h, which is almost 40% higher than that observed without the treatment. The acceleration of cancer cellular inhibition was confirmed by the significant increase in the apoptosis of the cell exposed to the LIPUS + SMF treatment. The observed improvement is believed to be due to changes in the cell membrane stability/permeability as a result of mechanical (20–22 kPa) and electrical (19–23 µV/cm) stimuli generated during the LIPUS + SMF treatment.

The self-learning kinetic Monte Carlo method has been shown to be suitable for examining the temporal and spatial evolution of adatom islands on the (111) surface of several fcc metals, unbiased by diffusion processes chosen a priori. A pattern-recognition scheme and a diffusion path finder scheme enable collection of a large database of diffusion processes and their energetics. A variety of mechanisms involving single and multiple atoms, and concerted island motion are uncovered in long-time simulations. In this contribution, after reviewing the methodology, we present results comparing the diffusion kinetics of two sets of homo-epitaxial and hetero-epitaxial systems: small (2–8 atom) Pd and Ag islands on the respective (111) surfaces and small Cu islands on Ni(111) and Ni islands on Cu(111). We trace the dominance of concerted motion in Pd/Pd(111) and Ni/Cu(111) and competition among concerted, multiatom and single-atom processes in Ag/Ag(111) and Cu/Ni(111) to the strength of the lateral interaction among adatoms in these systems.

Titania nanoparticles (anatase or anatase + rutile) with enhanced photocatalytic activity were successfully produced by treating titanyl sulfate with various peroxo compounds (hydrogen peroxide, ammonium persulfate, and urea hydrogen peroxide) with further annealing. Transformation of titanyl sulfate to titanium dioxide was investigated by X-ray diffraction, electron microscopy, X-ray microanalysis, IR, Raman, X-ray photoelectron, and UV/vis spectroscopy. The peroxo compound and annealing temperature play an important role in phase composition and properties of the samples. Correlations between phase composition, oxygen content, band gaps, and constant rates for methyl orange (MO) discoloration were found. The [TiOx(O2)2−x(H2O)m] phase, which forms on the first stage of the reaction, contains nanoparticles with small crystallites (1–2 nm) and promotes formation of titanium dioxide with the anatase structure. Thermal decomposition of the peroxo-containing phase results in formation of titanium dioxide. Oxygen excess prevents transformation of anatase to rutile, decreases band gap, and increases activity of titanium dioxide (anatase or anatase + rutile) in the model reaction of MO destruction.