background and aims. the aim of this study was to compare shear bond strength (sbs) of metal and ceramic brackets bonded to enamel using acid versus er:yag laser etching. materials and methods. eighty premolars were divided into 4 groups: am (acid etching/ metal brackets), ac (acid etching/ ceramic brackets), lm (laser etching/ metal brackets) and lc (laser etching/ ceramic brackets). enamel co...

Zheng Cui Rutherford Appleton Laboratory Chilton, Didcot Oxon OX11 0QX United Kingdom Abstract. A new photolithographic technique that combines the advantages of a programmable digital liquid crystal display (LCD) system and projection photolithography system to fabricate arbitrarily shaped microstructures using LCD panels as real-time masks is reported. Its principle and design method are expl...

In this treatment method laser radiation, which is guided from a co-axially expanding liquid jet-stream, locally initiates on a metal surface a thermochemical etching reaction, which leads to selective material removal. Time-resolved measurements of the electrical potential were correlated with the specific processing parameters to identify conditions for stable and enhanced chemical etching re...

In fabricating Bi2Sr2CaCu2O8+δ intrinsic Josephson junctions in 4-terminal mesa structures, we modify the conventional fabrication process by markedly reducing the etching rates of argon ion milling. As a result, the junction number in a stack can be controlled quite satisfactorily as long as we carefully adjust those factors such as the etching time and the thickness of the evaporated layers. ...

The current laboratory study is evaluating the effect of hydrofluoric acid etching duration on the surface characteristics of five silica-based glass ceramics. Changes in the pore pattern, crystal structure, roughness, and wettability were compared and evaluated. Seventy-five rectangularly shaped specimens were cut from each material (IPS e-max™, Dentsply Celtra™, Vita Suprinity™, Vita mark II™...

Background: The Poly-Allyl Diglycol Carbonate (PADC) detector is of particular interest for development of a fast neutron dosimeter. Fast neutrons interact with the constituents of the CR-39 detector and produce H, C and O recoils, as well as (n, α) reaction. These neutron- induced charged particles contribute towards the response of CR-39 detectors. Material and Methods: Electrochemical...

– We combine ab initio and Monte Carlo simulations in multiscale modelling of anisotropic wet chemical etching of silicon. The anisotropy of the macroscopic etching patterns observed in the experiments is explained by two mechanisms at an atomistic scale: the weakening of backbonds following OH termination of surface sites and the existence of significant interaction between the surface-termina...

We describe a method to control the shape of nanoholes in GaAs (001) which combines the technique of local droplet etching using Ga droplets with long-time thermal annealing. The cone-like shape of inverted nanoholes formed by droplet etching is transformed during long-time annealing into widened holes with flat bottoms and reduced depth. This is qualitatively understood using a simplified mode...