Phase transitions in the Ising model with transverse field

We show the existence of a phase transition in the Ising model with transverse field for dimensionsv 2 provided the transverse term is sufficiently small. This is done by proving long-range order occurs using the reflection positivity of the Hamiltonian and localization of eigenvectors.     

Enhanced ethanol sensing properties of WO3 modified TiO2 nanorods

Pristine and WO₃ decorated TiO₂ nanorods (NRs) were synthesised to investigate n-n-type heterojunction gas sensing properties. TiO₂ NRs were fabricated via hydrothermal method on fluorine-doped tin oxide coated glass (FTO) substrates. Then, tungsten was sputtered on the TiO₂ NRs and thermally oxidised to obtain WO₃ nanoparticles. The heterostructure was characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectroscopy. Fabricated sensor devices were exposed to VOCs such as toluene, xylene, acetone and ethanol, and humidity at different operation temperatures. Experimental results demonstrated that the heterostructure has better sensor response toward ethanol at 200 °C. Enhanced sensing properties are attributed to the heterojunction formation by decorating TiO₂ NRs with WO₃.     

The physics of a metric space with a time variable

It is shown that the introduction of a time variable in a curved metric four-space of the Einstein type leads to an interpretation of gravity as an ether flow in a Riemannian three-space. It is assumed that the only motion that enters into physical laws is either motion relative to the ether or the relative motion of nearby points that are fixed in the ether, and this assumption is formulated analytically. A previous formulation of Newtonian fields in a metric four-space indicates that the three-space can be assumed to be Euclidean and provides field equations to determine the motion of the ether. It is also suggested that the velocity of light relative to the ether has the constant valuec in many important physical fields. Finally, the observer's coordinates of the special theory of relativity are defined in the presence of a gravitational field.     

Stress concentrations around multiple windows in a high-pressure vessel

A pressure vessel with four radial windows was designed in which to conduct equation-of-state experiments at pressures up to 1 GPa (145,000 psi). To determine the relative safety of the vessel, the stress distribution in the cylindrical sidewalls, particularly the stress concentration near the window openings, was studied. Conventional analysis was used for the initial evaluation but was found to give somewhat higher stress values than were actually present. Better determinations of the stress distribution were obtained by photoelastic analysis of a model of the pressurevessel linear and by proof tests with strain gages of the actual liner and the assembled pressure vessel. Apparently, the tapered sapphire windows, loaded in compression by the internal pressure in the vessel, modify the stress distribution sufficiently to allow operation at higher pressures than otherwise would be attainable. Design features of the pressure vessel are presented, together with a synoptic stress analysis, a photoelastic analysis, and results of the strain-gage studies.