X-ray powder diffraction of red kangaroo (Macropus rufus) dental enamel, with a relative density greater than 2.60, showed a longer a-axis length of the apatite unit cell, a = 9.462 A, a shorter c-axis length, c = 6.877 A, and a smaller crystallite size, ca. 185 A, than those of human dental enamel. The a-axis of red kangaroo dental enamel was one of the longest among the values reported previo...

In general, the influence of pore size is not considered when determining the Young's modulus of nanoporous materials. Here, we demonstrate that the pore size needs to be taken into account to properly assess the mechanical properties of these materials. Molecular dynamics simulations of spherical indentation experiments on single crystalline nanoporous Cu have been undertaken in systems with: ...

Origami is the art of folding two-dimensional (2D) materials, such as a flat sheet of paper, into complex and elaborate three-dimensional (3D) objects. This study reports origami-based metamaterials whose electromagnetic responses are dynamically controllable via switching the folding state of Miura-ori split-ring resonators. The deformation of the Miura-ori unit along the third dimension induc...

The distribution and relative density of smooth-coated otters Lutra perspicillata Geoffroy were studied along a 425 km stretch of Chambal river within the National Chambal Sanctuary, Central India, between 1988 and 1992. Sample sites of l km were surveyed every 5 km. The study revealed that the distribution of otters along the river is patchy and largely restricted to the upper reaches. During ...

A revised water model intended for use in condensed phase simulations in the framework of the self consistent polarizable ion tight binding theory is constructed. The model is applied to water monomer, dimer, hexamers, ice, and liquid, where it demonstrates good agreement with theoretical results obtained by more accurate methods, such as DFT and CCSD(T), and with experiment. In particular, the...

The paper describes an investigation of the effect of structural damping in the torsion mode on wing flutter with the object of finding circumstances in which damping reduces the flutter speed. The drop in flutter speed can be considerable (25 per cent) and extend to very large values of structural damping. The effect is most apparent when the relative density (wing to air) is high, and when th...

OBJECTIVES To evaluate the effect of Fe₂O₃on the optical properties of yttria-stabilised tetragonal zirconia (Y-TZP) dental ceramic when added, and to determine the correct content required to mimic the natural dentin. METHODS Disc-shaped Y-TZP specimens (0.50 ± 0.01 mm in thickness) containing various contents of Fe₂O₃were fabricated by cold isostatic pressing and pressureless sintering, and...

To enhance the performance of thermoelectric materials and enable access to their widespread applications, it is beneficial yet challenging to synthesize hollow nanostructures in large quantities, with high porosity, low thermal conductivity (κ) and excellent figure of merit (z T). Herein we report a scalable (ca. 11.0 g per batch) and low-temperature colloidal processing route for Bi2 Te2.5 Se...

Abstract: The celebrated Green-Tao theorem states that there are arbitrarily long arithmetic progressions in the primes. The proof has two parts. The first part is a relative Szemerédi theorem which says that any subset of a pseudorandom set of integers of positive relative density contains long arithmetic progressions, where a set is pseudorandom if it satisfies two conditions, the linear form...

Ag/Bi-2223 tapes were fabricated using the Powder-In-Tube method, involyH1~ intermediate deformation techniques of sandwich rolling (SR), pressing (P) and nQl1l1~~ rolling (NR). Magnetic field B depen:lence of Jc was measured. Depending 6rt:~~' relationship between )c and B, the irreversible magnetic field Birr was determineli)lIl..W: pinning force density F was calculated. The experimental res...