In chameleon theories where the field couples to matter much more strongly than gravity does, the fifth force between two bodies with thin-shell is independent of their coupling to the field. As a consequence present days bounds on these models can be exponentially relaxed.

A cold-shock technique was used to determine radula production rates for the chitons Acanthopleura hirtosa and Plaxiphora albida, and for the limpet Patelloida alticostata, which replaced their radular teeth at rates of 0.40, 0.36 and 0.51 rows d−1, respectively. These rates are far slower than those determined previously for non-iron-mineralizing molluscs, suggesting that the improved working life of the teeth afforded by iron-mineralization acts to significantly reduce replacement rates. In addition, inductively coupled plasma-atomic emission spectroscopy has been used to determine the quantity of iron and other elements comprising the radula of each species. These data, used in conjunction with the radula production rates, reveal that A. hirtosa, Plaxiphora albida and Patelloida alticostata have daily radula mineralization requirements for iron of 3.06, 4.12 and 0.55 μg, respectively. Such information is vital for continuing studies related to the cellular delivery of ions and subsequent biomineralization of the tooth cusps in chitons and limpets.

In this paper, we investigate the correlation of electrical properties and structure of 1-4 nm thick SiO2 grown on H-passivated Si(100) for ultra-thin gate applications. Ordered (1×1) Si(100) stable in ambient air is obtained at room temperature by wet chemical cleaning. Ion Beam Analysis using a combination of ion channeling and 16O(α,α)16O nuclear resonance yields Si areal densities lower than that of a bulk-terminated Si crystal as calculated by Monte-Carlo simulations. This result indicates shadowing of Si substrate atoms by Si atoms in the thermally grown oxide. Detection of order by ion channeling is supported by Reflection High Energy Electron Diffraction (RHEED). C-V and I-V measurements are generally inconclusive for ultra-thin (1-2 nm) oxides because of leakage and breakdown. Surface charge analysis enables a comparison between ordered oxides and conventional oxides. The results are promising.