OBJECTIVES The aim of this study was to determine the apical surface characteristics and presence of dental cracks in single-rooted premolars, resected 3.0 mm from the root apex, using the Er: YAG laser, tungsten carbide bur, and diamond-coated tip, by scanning electron microscopy (SEM). EXPERIMENTAL DESIGN Thirty single-rooted premolar teeth were collected. The instrumented and obturated tee...

Spatial patterns of tungsten and cobalt are described for surface dust of Fallon, Nevada, where a cluster of childhood leukemia has been ongoing since 1997. In earlier research, airborne tungsten and cobalt was shown to be elevated in total suspended particulates in Fallon. To fine-tune the spatial patterns of tungsten and cobalt deposition in Fallon, surface dust was collected in a grid patter...

We investigated the photocbromic (PC) and electrocbromic (EC) behavior of sputtered tungsten oxide (W03_1) films with different oxygen deficiency y. It was found that both the PC and EC coloration efficiency increase with increasing oxygen deficiency in tungsten oxide. For PC efficiency, this behavior is consistent with the model of photocbromism developed recently. A recently developed model b...

Recently reported results on the behaviour of the tungsten under conditions expected in the Neutrino Factory target have strengthened the case for a solid target option for the Neutrino Factory. This paper gives a description of the measurements of the surface motion of tungsten wires, stressed by a pulsed current, using a Laser Doppler Vibrometer in order to measure tungsten properties at high...

Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding process that uses a nonconsumable tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by a shielding gas (usually an inert gas such as argon), and a filler metal is normally used, though some welds, known as autogenous welds, do not require it. A const...

Atomically sharp tungsten tips made from single crystal tungsten wire are superior to those made from cold-drawn polycrystalline wire but are rarely used due to their high price. We have devised a method of obtaining highly crystalline tungsten wire by recrystallizing cold-drawn wire. The effect of various heat treatments on the wire microstructure was observed using scanning electron microscop...

Recently reported results of the high strain rates, high temperature measurements of the yield stress of tungsten and tantalum have been analyzed. The highest temperature reached in the experiment, based on heating and stressing a thin wire by a fast, high current pulse, was 2250 C and 2450 C, for tantalum and tungsten, respectively. The strain-rates in both the tungsten and tantalum tests were...

A two-stage sintering practice was applied to W­3.99Ni­1.71Fe (mass%) to control its microstructural evolution and, accordingly, mechanical properties under high strain rates. Unlike the traditional one-stage liquid phase sintering, the alloy was first solid-state-sintered to close to full densification, and then liquid-phase-sintered by induction heating where the cooling rate was fast. With t...

The ITER reference materials have been tested separately in tokamaks, plasma simulators, ion beams and high heat flux test beds. In order to perform a fully integrated material test JET has launched the ITER-like Wall Project with the aim of installing a full metal wall during the next major shutdown. As a result of R&D projects in 2005–2006, bulk tungsten tiles are foreseen at the outer horizo...

An ionization source designed to efficiently utilize sub-milligram quantities of electrically non-conducting compounds (i.e. oxides) for prolonged periods of mass spectrometric analysis is described. The source is coupled to a quadrupole ion trap mass spectrometer in this report, but could readily be modified for alternative types of mass spectrometers. The coaxial-design glow discharge ion sou...